trusty_memory/

web.rs

//! HTTP API + embedded SPA shell for the trusty-memory admin UI.
//!
//! Why: The web admin panel is the primary GUI for non-MCP clients. Bundling
//! the Svelte build via `rust-embed` keeps deployment to "drop the binary on
//! a host"; the JSON API surface mirrors the MCP tool set so anything
//! trusty-memory can do via Claude Code can also be done via curl or browser.
//! What: All `/api/v1/*` handlers (status, palaces, drawers, recall, KG,
//! config, chat) plus an embedded-asset fallback that serves `ui/dist/`.
//! Test: `cargo test -p trusty-memory-mcp web::tests` covers the asset
//! fallback and JSON shape of every read endpoint against an in-memory
//! palace built on a `tempdir`.

use crate::attribution::{
    CreatorInfo, CreatorSource, HTTP_DEFAULT_CLIENT, X_TRUSTY_CLIENT_CWD, X_TRUSTY_CLIENT_NAME,
};
use crate::hook_emit::HookEventPayload;
use crate::{ActivityFilter, ActivitySource, AppState, DaemonEvent};
use axum::{
    body::Body,
    extract::{Path as AxumPath, Query, State},
    http::{header, HeaderMap, HeaderValue, Request, StatusCode},
    response::{IntoResponse, Response},
    routing::{delete, get, post},
    Json, Router,
};
use rust_embed::RustEmbed;
use serde::{Deserialize, Serialize};
use serde_json::{json, Value};
use trusty_common::memory_core::community::KnowledgeGap;
use trusty_common::memory_core::palace::{Palace, PalaceId, RoomType};
use trusty_common::memory_core::retrieval::recall_with_default_embedder;
use trusty_common::memory_core::store::kg::Triple;
use uuid::Uuid;

/// Dedicated palace id used by the `/health` round-trip probe (issue #185).
///
/// Why: Earlier revisions of `run_health_round_trip` picked whichever palace
/// happened to be first on disk (APFS creation order on macOS), which meant
/// the probe always wrote — and, if recall failed, *leaked* — a drawer in a
/// real user-facing palace. Routing the probe to a dedicated palace whose id
/// starts with the reserved `__` prefix means leaked drawers are confined to a
/// palace the user never sees (filtered by `MemoryService::list_palaces`) and
/// real palaces stay clean.
/// What: A constant `&str` reused by the probe and tests. The leading double
/// underscore is the project-wide convention for "system" palaces hidden from
/// user listings.
/// Test: `health_probe_palace_is_invisible`, `health_probe_cleans_up_on_success`,
/// `health_probe_cleans_up_on_recall_miss`.
pub(crate) const HEALTH_PROBE_PALACE: &str = "__health_probe__";

/// Embedded UI assets produced by `pnpm build` in `ui/`.
///
/// Why: Single-binary deploys with no separate static-file dance. `build.rs`
/// runs the Vite build before compilation so this folder is always populated.
/// What: All files under `ui/dist/` are included in the binary.
/// Test: `serves_index_html` confirms the SPA shell loads.
#[derive(RustEmbed)]
// Monorepo migration: upstream trusty-memory put the Svelte UI at the repo
// root (`ui/dist/`), so the original path was `$CARGO_MANIFEST_DIR/../../ui/dist/`.
// In the trusty-tools monorepo we keep the UI inside the crate to avoid
// polluting the workspace root with per-crate asset directories.
#[folder = "$CARGO_MANIFEST_DIR/ui/dist/"]
struct WebAssets;

/// Build the public router with API routes + SPA asset fallback.
///
/// Why: `run_http` calls this so the same router shape is used in tests.
/// What: All API routes under `/api/v1`, fallback to the SPA shell.
/// Test: `serves_index_html` and `status_endpoint_returns_payload`.
pub fn router() -> Router<AppState> {
    // axum 0.8 path syntax uses `{param}` instead of `:param`. The shared
    // `trusty_common::server::with_standard_middleware` layer brings in CORS,
    // tracing, and gzip (with SSE excluded) so we don't drift from sibling
    // trusty-* daemons.
    let router = Router::new()
        .route("/api/v1/status", get(status))
        .route("/api/v1/config", get(config))
        .route("/api/v1/palaces", get(list_palaces).post(create_palace))
        .route(
            "/api/v1/palaces/{id}",
            get(get_palace_handler)
                .delete(delete_palace_handler)
                .patch(update_palace_handler),
        )
        .route(
            "/api/v1/palaces/{id}/drawers",
            get(list_drawers).post(create_drawer),
        )
        .route(
            "/api/v1/palaces/{id}/drawers/{drawer_id}",
            delete(delete_drawer),
        )
        // Issue #70 — `/memories` is a backward-compatible alias for `/drawers`.
        // Some clients (and earlier docs) POST/GET against `…/memories`, which
        // 404'd because only `/drawers` was registered. Aliasing here keeps
        // both vocabularies working against the same handlers without breaking
        // existing `/drawers` callers.
        .route(
            "/api/v1/palaces/{id}/memories",
            get(list_drawers).post(create_drawer),
        )
        .route(
            "/api/v1/palaces/{id}/memories/{drawer_id}",
            delete(delete_drawer),
        )
        .route("/api/v1/palaces/{id}/recall", get(recall_handler))
        .route("/api/v1/recall", get(recall_all_handler))
        .route("/api/v1/palaces/{id}/kg", get(kg_query).post(kg_assert))
        .route("/api/v1/palaces/{id}/kg/subjects", get(kg_list_subjects))
        .route(
            "/api/v1/palaces/{id}/kg/subjects_with_counts",
            get(kg_list_subjects_with_counts),
        )
        .route("/api/v1/palaces/{id}/kg/all", get(kg_list_all))
        .route("/api/v1/palaces/{id}/kg/graph", get(kg_graph))
        .route("/api/v1/palaces/{id}/kg/count", get(kg_count))
        .route(
            "/api/v1/palaces/{id}/kg/triples/{triple_id}",
            delete(kg_delete_triple),
        )
        .route(
            "/api/v1/palaces/{id}/dream/status",
            get(palace_dream_status),
        )
        .route("/api/v1/dream/status", get(dream_status))
        .route("/api/v1/dream/run", post(dream_run))
        .route("/api/v1/kg/gaps", get(kg_gaps_handler))
        .route("/api/v1/kg/prompt-context", get(prompt_context_handler))
        .route("/api/v1/kg/aliases", post(add_alias_handler))
        .route(
            "/api/v1/kg/prompt-facts",
            get(list_prompt_facts_handler).delete(remove_prompt_fact_handler),
        )
        .route("/api/v1/chat", post(crate::chat::chat_handler))
        .route("/api/v1/chat/providers", get(crate::chat::list_providers))
        .route(
            "/api/v1/palaces/{id}/chat/sessions",
            get(crate::chat::list_chat_sessions).post(crate::chat::create_chat_session),
        )
        .route(
            "/api/v1/palaces/{id}/chat/sessions/{session_id}",
            get(crate::chat::get_chat_session).delete(crate::chat::delete_chat_session),
        )
        // Issue #99: inter-project messaging.
        .route(
            "/api/v1/messages",
            get(crate::chat::list_messages_handler).post(crate::chat::send_message_handler),
        )
        .route(
            "/api/v1/messages/mark_read",
            post(crate::chat::mark_message_read_handler),
        )
        .route("/health", get(health))
        .route("/api/v1/logs/tail", get(logs_tail))
        .route("/api/v1/activity", get(activity_handler))
        .route("/api/v1/activity/hook", post(hook_activity_handler))
        .route("/api/v1/admin/stop", post(admin_stop))
        // Issue: fire-and-forget memory save for callers that cannot speak
        // MCP. Sub-agents spawned via Claude Code's Agent tool inherit no
        // MCP connections, so `memory_remember` is unreachable to them.
        // This endpoint lets the agent shell out to `trusty-memory note`
        // (which in turn POSTs here) and the request returns 202 the moment
        // the body is parsed — the actual `memory_remember` dispatch runs
        // on a detached `tokio::spawn`. Failures are logged at warn but
        // never surface to the caller because the contract is one-way.
        .route("/api/v1/remember", post(remember_async))
        // Multi-transport refactor: a single JSON-RPC 2.0 endpoint that
        // accepts the same envelopes the UDS transport speaks. Lets
        // browser clients, curl, and the stdio bridge fallback hit the
        // tool surface without learning the REST routes. The REST
        // routes above remain for backwards compatibility.
        .route("/rpc", post(rpc_handler))
        .fallback(static_handler);

    trusty_common::server::with_standard_middleware(router)
}

// ---------------------------------------------------------------------------
// Health check
// ---------------------------------------------------------------------------

/// Liveness/version payload for `GET /health`.
///
/// Why: `daemon_probe` requires an HTTP 200 from `/health` to confirm that the
/// port is owned by this daemon (and not a stale or foreign process). Issue
/// #35 enriches it with process resource metrics so operators (and the admin
/// UI) can see RSS, disk footprint, CPU, and uptime in one cheap call.
/// The fd-exhaustion fix adds `open_fds` and `fd_soft_limit` so operators can
/// see "244 / 256" before EMFILE hits.
/// What: Carries a fixed `status` string, the compile-time crate version,
/// the issue-#35 resource block, and `open_fds` / `fd_soft_limit`.
/// Test: Asserted by `health_endpoint_returns_ok`,
/// `health_endpoint_includes_resource_fields`, and
/// `health_endpoint_includes_fd_gauge` in this module's tests.
#[derive(serde::Serialize)]
struct HealthResponse {
    /// `"ok"` when the round-trip smoke test succeeds (or no palace exists
    /// yet), `"degraded"` when store/recall is broken (issue #71). Owned
    /// `String` so the handler can report different statuses without
    /// requiring static lifetimes.
    status: String,
    /// Populated only when `status == "degraded"` (issue #71). Carries a
    /// short phrase identifying which round-trip stage failed so operators
    /// can triage quickly (e.g. `"store failed: ..."`).
    #[serde(skip_serializing_if = "Option::is_none")]
    detail: Option<String>,
    version: &'static str,
    /// Current process Resident Set Size in megabytes (issue #35). Sampled
    /// via the shared `SysMetrics` on each health request.
    rss_mb: u64,
    /// On-disk footprint of the daemon's `data_root` in bytes (issue #35):
    /// the sum of every palace file. Refreshed by a background task every
    /// 10 s; `0` until the first walk completes.
    disk_bytes: u64,
    /// Current process CPU usage as a percentage (issue #35), where `100.0`
    /// means one fully-saturated core. The first reading after daemon start
    /// may be `0.0` until a delta window exists.
    cpu_pct: f32,
    /// Seconds elapsed since the daemon started (issue #35).
    uptime_secs: u64,
    /// Bound `host:port` of the HTTP listener. Why: dynamic port selection
    /// (7070..=7079 + OS fallback) means clients cannot assume `7070`; this
    /// field advertises the real port without forcing them to read
    /// `~/.trusty-memory/http_addr`. `None` when the daemon was constructed
    /// without ever binding (tests that drive the router with `TestServer`).
    #[serde(skip_serializing_if = "Option::is_none")]
    addr: Option<String>,
    /// Number of file descriptors currently open by this process (fd-exhaustion
    /// gauge). `None` when the platform does not expose this cheaply (rare).
    /// Sampled on every `/health` call via [`crate::fd_metrics::count_open_fds`].
    #[serde(skip_serializing_if = "Option::is_none")]
    open_fds: Option<u64>,
    /// Soft `RLIMIT_NOFILE` ceiling for this process (fd-exhaustion gauge).
    /// `None` when `getrlimit` fails or returns `RLIM_INFINITY` (unlimited).
    /// Together with `open_fds`, lets operators see "244 / 256" before EMFILE.
    #[serde(skip_serializing_if = "Option::is_none")]
    fd_soft_limit: Option<u64>,
    /// Newer crates.io version available, if any (issue #537).
    ///
    /// Why: surfaces update availability without polling crates.io on every
    /// health call — a single background check at startup stores the result
    /// here for the health handler to read cheaply.
    /// What: `null`/absent = up to date or check not completed; `"x.y.z"` =
    /// the available newer version.
    #[serde(skip_serializing_if = "Option::is_none")]
    update_available: Option<String>,
    /// Daemon readiness state (issues #910 / #911).
    ///
    /// Why: operators and monitoring scripts need to distinguish "the daemon
    /// is alive but the embedder hasn't finished compiling yet" from "the
    /// daemon is fully operational". Before this field, a fresh daemon looked
    /// healthy to external monitors even while `memory_remember` /
    /// `memory_recall` calls were returning warming errors.
    /// What: `"warming"` until the embedder init succeeds; `"ready"` once
    /// `spawn_startup_tasks` flips `AppState::daemon_readiness`.
    daemon_state: String,
}

/// `GET /health` — unauthenticated liveness probe with store/recall smoke test.
///
/// Why: Gives `daemon_probe` and external monitors a cheap way to confirm port
/// ownership without touching palace state. Issue #35 additionally reports
/// process RSS, CPU, the `data_root` disk footprint, and uptime. Issue #71
/// upgrades the check to a full memory round-trip (store → recall → verify →
/// delete) so operators learn about store/recall regressions immediately
/// instead of after a real request fails. Issue #185 routes the round-trip
/// to a dedicated `__health_probe__` palace (hidden from user listings) so
/// the probe never leaks drawers into a real user palace even on recall
/// failures. The fd-exhaustion fix adds `open_fds` and `fd_soft_limit` so
/// operators can catch "approaching ceiling" before EMFILE hits.
/// What: Returns HTTP 200 with `{status, version, rss_mb, disk_bytes,
/// cpu_pct, uptime_secs, open_fds?, fd_soft_limit?, detail?}`. RSS + CPU are
/// sampled live; `disk_bytes` is read from the background ticker;
/// `uptime_secs` is elapsed since `state.started_at`; `open_fds` and
/// `fd_soft_limit` are sampled best-effort (absent when the platform does not
/// expose them cheaply). The handler provisions the dedicated probe palace if
/// missing and then attempts a full remember/recall/forget cycle — `status`
/// is `"ok"` on success, `"degraded"` with a `detail` string explaining the
/// failing stage otherwise. The probe never returns non-200 so monitors
/// keyed on HTTP status still see the daemon as up.
/// Test: `health_endpoint_returns_ok`,
/// `health_endpoint_includes_resource_fields`,
/// `health_endpoint_includes_fd_gauge`,
/// `health_endpoint_round_trip_on_fresh_install_is_ok`,
/// `health_endpoint_round_trip_with_palace_is_ok`,
/// `health_probe_palace_is_invisible`,
/// `health_probe_cleans_up_on_success`,
/// `health_probe_cleans_up_on_recall_miss`.
async fn health(State(state): State<AppState>) -> Json<HealthResponse> {
    let (rss_mb, cpu_pct) = {
        let mut metrics = state.sys_metrics.lock().await;
        metrics.sample()
    };
    let disk_bytes = state.disk_bytes.load(std::sync::atomic::Ordering::Relaxed);
    let uptime_secs = state.started_at.elapsed().as_secs();
    let addr = state.bound_addr.get().map(|a| a.to_string());

    // fd-exhaustion gauge: sample best-effort; failures return None (not an
    // error so we do not have to import the fd_metrics crate in every test
    // that drives this handler via in-process TestServer).
    let open_fds = crate::fd_metrics::count_open_fds();
    let fd_soft_limit = crate::fd_metrics::fd_soft_limit();

    let (status, detail) = match run_health_round_trip(&state).await {
        Ok(()) => ("ok".to_string(), None),
        Err(err) => {
            tracing::warn!("/health round-trip degraded: {err}");
            ("degraded".to_string(), Some(err.to_string()))
        }
    };

    let update_available = state.update_available.lock().ok().and_then(|g| g.clone());
    // Issues #910/#911: surface readiness so monitors and Claude Code can
    // distinguish "alive but warming" from "fully ready".
    let daemon_state = match state.readiness() {
        crate::DaemonReadiness::Warming => "warming",
        crate::DaemonReadiness::Ready => "ready",
    }
    .to_string();

    Json(HealthResponse {
        status,
        detail,
        version: env!("CARGO_PKG_VERSION"),
        rss_mb,
        disk_bytes,
        cpu_pct,
        uptime_secs,
        addr,
        open_fds,
        fd_soft_limit,
        update_available,
        daemon_state,
    })
}

/// Stages of the `/health` round-trip that can fail (issue #71).
///
/// Why: `thiserror`-derived enum gives every failure point a stable phrase the
/// handler can render into the `detail` field without printing implementation
/// detail or full backtraces. Issue #185 dropped the `NoPalaces` and
/// `ListPalaces` sentinels: the probe now provisions its dedicated
/// `__health_probe__` palace itself, so neither short-circuit can occur.
/// What: One variant per stage (open palace, ensure-probe-palace, store,
/// recall, missing-in-results, delete).
/// Test: Exercised indirectly by the `health_endpoint_round_trip_*` and
/// `health_probe_*` tests.
#[derive(Debug, thiserror::Error)]
enum HealthProbeError {
    #[error("open palace failed: {0}")]
    OpenPalace(String),
    #[error("provision health probe palace failed: {0}")]
    EnsureProbePalace(String),
    #[error("store failed: {0}")]
    Store(String),
    #[error("recall failed: {0}")]
    Recall(String),
    #[error("recall did not return the probe drawer (id={0})")]
    ProbeMissing(Uuid),
    #[error("delete probe drawer failed: {0}")]
    Delete(String),
}

/// Ensure the dedicated `__health_probe__` palace exists on disk.
///
/// Why: Issue #185 — picking whichever palace `list_palaces` returns first
/// leaked health-probe drawers into a real user palace whenever recall failed
/// or returned an empty result. Routing the probe to a dedicated palace whose
/// id starts with the reserved `__` prefix confines any leak (e.g. a daemon
/// crash mid-round-trip) to a palace the user can never see. This helper is
/// idempotent: it is safe to call on every `/health` request, even when the
/// palace already exists.
/// What: Calls `PalaceRegistry::open_palace` first (cheap cache hit when the
/// palace is already registered). If the palace metadata is missing on disk,
/// creates it via `PalaceRegistry::create_palace` with a description that
/// flags its purpose. Either path returns success when the palace is ready
/// for the round-trip; failures propagate as `HealthProbeError::EnsureProbePalace`.
/// Test: `health_probe_palace_is_invisible`, `health_probe_cleans_up_on_success`,
/// `health_probe_cleans_up_on_recall_miss`.
fn ensure_health_probe_palace(state: &AppState) -> Result<(), HealthProbeError> {
    let id = PalaceId::new(HEALTH_PROBE_PALACE);

    // Fast path: already registered in-memory, no disk hit needed.
    if state.registry.get(&id).is_some() {
        return Ok(());
    }

    // Try to open from disk first — succeeds on every request after the
    // first one once the palace has been persisted.
    if state.registry.open_palace(&state.data_root, &id).is_ok() {
        return Ok(());
    }

    // Cold path: first run on this `data_root`. Create the palace metadata
    // on disk so subsequent probes hit the open-path above.
    let palace = Palace {
        id: id.clone(),
        name: HEALTH_PROBE_PALACE.to_string(),
        description: Some(
            "Internal health-probe palace (issue #185). Hidden from listings; \
             holds short-lived round-trip drawers cleaned up on every probe."
                .to_string(),
        ),
        created_at: chrono::Utc::now(),
        data_dir: state.data_root.join(HEALTH_PROBE_PALACE),
    };
    state
        .registry
        .create_palace(&state.data_root, palace)
        .map_err(|e| HealthProbeError::EnsureProbePalace(format!("{e:#}")))?;
    Ok(())
}

/// Execute a remember/recall/forget cycle against the dedicated probe palace.
///
/// Why: `/health` used to return `status: "ok"` even when `POST /drawers` or
/// the recall path was broken — only that the process was alive. Issue #71
/// asks the probe to actually exercise the store and recall service layer
/// (no HTTP loopback) so monitors detect data-plane regressions on the next
/// poll instead of waiting for a real client to surface them. Issue #185
/// additionally requires the probe to (a) never touch user-facing palaces and
/// (b) never leak drawers even when recall fails or returns an empty result.
/// What: Provisions the dedicated `__health_probe__` palace via
/// [`ensure_health_probe_palace`], opens its handle, stores a content-unique
/// probe drawer via `PalaceHandle::remember`, runs
/// `recall_with_default_embedder` with the probe phrase, and then **always**
/// attempts `PalaceHandle::forget` *before* propagating any recall error so a
/// failing recall (Err *or* empty result) can never leave a drawer behind.
/// The probe palace is hidden from `MemoryService::list_palaces`, so any rare
/// leak (e.g. mid-call daemon crash) is confined to a palace the user can't see.
/// Test: Indirect — `health_endpoint_round_trip_with_palace_is_ok`,
/// `health_endpoint_round_trip_on_fresh_install_is_ok`, plus the three
/// `health_probe_*` cleanup tests added for issue #185.
async fn run_health_round_trip(state: &AppState) -> Result<(), HealthProbeError> {
    // Issue #185: always use the dedicated probe palace. Provision it on the
    // first request so a fresh install with zero user palaces still exercises
    // the full data plane — no more `NoPalaces` short-circuit.
    ensure_health_probe_palace(state)?;
    let probe_id = PalaceId::new(HEALTH_PROBE_PALACE);
    let handle = state
        .registry
        .open_palace(&state.data_root, &probe_id)
        .map_err(|e| HealthProbeError::OpenPalace(format!("{e:#}")))?;

    // Delegate the cleanup-ordering logic to the testable helper so unit tests
    // can substitute the recall implementation. The real handler always uses
    // the shared ONNX embedder.
    run_health_round_trip_inner(handle, |handle, query| async move {
        recall_with_default_embedder(&handle, &query, 5)
            .await
            .map_err(|e| HealthProbeError::Recall(format!("{e:#}")))
    })
    .await
}

/// Store-recall-forget core that always cleans up the probe drawer.
///
/// Why: Issue #185 — the cleanup invariant ("the probe drawer is always
/// deleted before any error returns") is the central correctness property of
/// the health round-trip. Splitting it out from `run_health_round_trip` lets
/// the tests inject a recall stub that returns `Ok(empty)` or
/// `Err(Recall(...))` and prove the invariant directly, without relying on
/// the ONNX embedder.
/// What: Stores a content-unique probe drawer via `PalaceHandle::remember`,
/// invokes `recall` with the probe phrase, and then **always** calls
/// `PalaceHandle::forget` *before* propagating any recall error. The recall
/// result is evaluated after the forget so a missing or errored recall can
/// never leave a drawer behind. Cleanup errors are reported only when recall
/// succeeded; otherwise the upstream recall error is preserved as the root
/// cause for operators.
/// Test: `health_probe_cleans_up_on_recall_miss` and
/// `health_probe_cleans_up_on_recall_error` exercise both failure modes with
/// a stubbed recall; `health_probe_cleans_up_on_success` covers the happy path.
async fn run_health_round_trip_inner<F, Fut>(
    handle: std::sync::Arc<trusty_common::memory_core::PalaceHandle>,
    recall: F,
) -> Result<(), HealthProbeError>
where
    F: FnOnce(std::sync::Arc<trusty_common::memory_core::PalaceHandle>, String) -> Fut,
    Fut: std::future::Future<
        Output = Result<Vec<trusty_common::memory_core::retrieval::RecallResult>, HealthProbeError>,
    >,
{
    // Content-unique probe phrase. `__trusty_memory_healthcheck__` makes the
    // probe identifiable in logs / drawer dumps if a forget step is ever
    // skipped (e.g. handler panic between store and delete); the UUID
    // guarantees uniqueness across concurrent probes.
    let probe_token = Uuid::new_v4();
    let probe_content = format!("__trusty_memory_healthcheck__ probe {probe_token}");

    let drawer_id = handle
        .remember(
            probe_content.clone(),
            RoomType::General,
            vec!["healthcheck".to_string()],
            0.0,
        )
        .await
        .map_err(|e| HealthProbeError::Store(format!("{e:#}")))?;

    let recall_result = recall(handle.clone(), probe_content).await;

    // Issue #185: cleanup runs BEFORE we propagate any recall error so the
    // probe can never leave a drawer behind. Both the Err and the
    // empty-result failure modes used to bypass forget; this ordering closes
    // both holes. Cleanup errors are surfaced only when the recall path
    // itself succeeded; otherwise we preserve the upstream recall failure as
    // the root cause for operators.
    let delete_result = handle.forget(drawer_id).await;

    match recall_result {
        Ok(hits) => {
            if !hits.iter().any(|hit| hit.drawer.id == drawer_id) {
                return Err(HealthProbeError::ProbeMissing(drawer_id));
            }
        }
        Err(e) => return Err(e),
    }

    delete_result.map_err(|e| HealthProbeError::Delete(format!("{e:#}")))?;
    Ok(())
}

// ---------------------------------------------------------------------------
// Logs tail + admin stop (issue #35)
// ---------------------------------------------------------------------------

/// Default number of log lines returned by `GET /api/v1/logs/tail` when `n`
/// is absent. 100 lines is enough context for a glance without a huge payload.
const DEFAULT_LOGS_TAIL_N: usize = 100;

/// Hard ceiling on `GET /api/v1/logs/tail?n=` — equal to the ring-buffer
/// capacity, so a request can never ask for more lines than the buffer holds.
const MAX_LOGS_TAIL_N: usize = trusty_common::log_buffer::DEFAULT_LOG_CAPACITY;

fn default_logs_tail_n() -> usize {
    DEFAULT_LOGS_TAIL_N
}

/// Query parameters for `GET /api/v1/logs/tail`.
///
/// Why (issue #35): callers ask for a bounded number of recent log lines;
/// `n` defaults to a useful page size and is clamped server-side so a
/// misconfigured client cannot request more lines than the buffer holds.
/// What: `n` is optional; absent → [`DEFAULT_LOGS_TAIL_N`]. Clamped to
/// `[1, MAX_LOGS_TAIL_N]` in the handler.
/// Test: `logs_tail_clamps_n` exercises the clamp.
#[derive(serde::Deserialize)]
struct LogsTailParams {
    #[serde(default = "default_logs_tail_n")]
    n: usize,
}

/// `GET /api/v1/logs/tail?n=200` — return the most recent N tracing log lines.
///
/// Why (issue #35): operators debugging a running daemon want recent logs
/// over HTTP without SSHing to the box or restarting with a different
/// `RUST_LOG`. The in-memory ring buffer (fed by the `LogBufferLayer` wired
/// into the subscriber at startup) makes this near-free.
/// What: clamps `n` to `[1, MAX_LOGS_TAIL_N]`, drains the tail of
/// `state.log_buffer`, and returns `{ "lines": [...], "total": <buffered> }`
/// where `total` is the number of lines currently buffered (so callers can
/// tell whether the ring has wrapped).
/// Test: `logs_tail_returns_recent_lines` and `logs_tail_clamps_n`.
async fn logs_tail(
    State(state): State<AppState>,
    Query(params): Query<LogsTailParams>,
) -> Json<Value> {
    let n = params.n.clamp(1, MAX_LOGS_TAIL_N);
    let lines = state.log_buffer.tail(n);
    Json(serde_json::json!({
        "lines": lines,
        "total": state.log_buffer.len(),
    }))
}

/// `POST /api/v1/admin/stop` — request a graceful shutdown of the daemon.
///
/// Why (issue #35): the admin UI and operators want a one-call way to stop
/// the daemon without resolving its PID and sending a signal. The daemon is
/// localhost-only and trusts every caller, so no auth is required.
/// What: spawns a detached task that sleeps 200 ms (giving this HTTP response
/// time to flush to the client) and then calls `std::process::exit(0)`.
/// Returns `{ "ok": true, "message": "shutting down" }` immediately.
/// Test: `admin_stop_returns_ok` asserts the response shape (it does not
/// drive the real exit — that would terminate the test process).
async fn admin_stop(State(_state): State<AppState>) -> Json<Value> {
    tracing::warn!("admin_stop: shutdown requested via POST /api/v1/admin/stop");
    tokio::spawn(async {
        tokio::time::sleep(std::time::Duration::from_millis(200)).await;
        std::process::exit(0);
    });
    Json(serde_json::json!({ "ok": true, "message": "shutting down" }))
}

// ---------------------------------------------------------------------------
// Fire-and-forget memory save (`POST /api/v1/remember`)
// ---------------------------------------------------------------------------

/// Request body for `POST /api/v1/remember`.
///
/// Why: agents spawned via Claude Code's Agent tool do not inherit any MCP
/// connections, so the `memory_remember` MCP tool is unreachable to them.
/// Exposing a plain HTTP entry point lets those agents shell out via the
/// `trusty-memory note` CLI (or any `curl` call) without learning MCP.
/// What: `content` is the drawer body and is required; `palace` falls back
/// to the daemon's `--palace` default when omitted; `tags` is optional and
/// passed through verbatim to the underlying handler.
/// Test: `remember_async_*` tests in this module.
#[derive(Debug, Deserialize)]
struct RememberAsyncBody {
    /// Drawer body. Required.
    content: String,
    /// Target palace. When `None`, the daemon's `--palace` default is used;
    /// callers without a default-palace configured must pass this field or
    /// the spawned task logs a warning and drops the request.
    #[serde(default)]
    palace: Option<String>,
    /// Optional tag list to attach to the drawer.
    #[serde(default)]
    tags: Option<Vec<String>>,
}

/// Minimum word count for content accepted by `POST /api/v1/remember`.
///
/// Why (issue #466): the fire-and-forget endpoint returns `202 Accepted`
/// immediately and dispatches the write on a detached task. Any content that
/// the background worker would reject (e.g. too few tokens) caused silent data
/// loss — the caller believed the memory was stored when it wasn't. Validating
/// the minimum synchronously turns silent drops into explicit `422` rejections
/// so callers know immediately that their content was not queued.
/// What: mirrors `tools::CONTENT_GATE_MIN_WORDS` (4 words) — the same gate
/// `handle_memory_remember` applies via `content_gate` in the background task.
/// Test: `remember_async_rejects_short_content`.
const REMEMBER_MIN_WORDS: usize = 4;

/// `POST /api/v1/remember` — fire-and-forget memory save.
///
/// Why: sub-agents spawned via Claude Code's Agent tool have no MCP
/// connection (MCP servers are not inherited across sub-agent spawns), so
/// they cannot invoke `mcp__trusty-memory__memory_remember` directly. They
/// can, however, run shell commands — this endpoint plus the
/// `trusty-memory note` CLI gives them a writable handle that needs no
/// MCP plumbing. The contract is one-way: the request is parsed, validated,
/// and queued on a `tokio::spawn`, then `202 Accepted` is returned
/// immediately. Failures during the spawned dispatch (palace not found,
/// content gate skip, redb error) are logged at `warn` but never propagate
/// back to the caller because the agent has already exited by then.
/// Issue #466: synchronous validation of obvious rejections (empty content,
/// fewer than [`REMEMBER_MIN_WORDS`] whitespace-delimited words) now returns
/// `422 Unprocessable Entity` before queuing so callers receive a clear error
/// instead of a false `202`. Content that passes the synchronous checks may
/// still be dropped by the background worker's fuller filter set (blocklist,
/// dedup, MCP-level token threshold), but those are less predictable from
/// the HTTP surface.
/// What: deserialises the body, rejects empty content (400) and sub-threshold
/// word count (422), then maps `{content, palace, tags}` → `{text, palace,
/// tags}` (the field names `handle_memory_remember` expects) and dispatches
/// `memory_remember` from a detached task. Returns `202 Accepted` with
/// `{"status":"queued"}`.
/// Test: `remember_async_returns_202_and_persists` (happy path),
/// `remember_async_rejects_empty_content` (400 input validation), and
/// `remember_async_rejects_short_content` (422 for sub-word-count content).
async fn remember_async(
    State(state): State<AppState>,
    Json(body): Json<RememberAsyncBody>,
) -> Result<(StatusCode, Json<Value>), ApiError> {
    let content = body.content.trim();
    if content.is_empty() {
        return Err(ApiError::bad_request(
            "remember: 'content' must be a non-empty string",
        ));
    }
    // Issue #466: synchronous minimum-word-count guard. Content with fewer
    // than REMEMBER_MIN_WORDS whitespace-separated tokens would be silently
    // dropped by the background `content_gate`; reject it here so the caller
    // sees a 422 immediately rather than a false 202.
    let word_count = content.split_whitespace().count();
    if word_count < REMEMBER_MIN_WORDS {
        return Err(ApiError::unprocessable(format!(
            "remember: content too short ({word_count} word(s)); \
             minimum is {REMEMBER_MIN_WORDS} words. \
             Use memory_note for short curated facts."
        )));
    }

    // Build the MCP-shaped args once on the request thread so deserialisation
    // errors never end up swallowed by the spawned task. `handle_memory_remember`
    // expects `text` (not `content`), so translate the field name here.
    let mut args = serde_json::Map::new();
    args.insert("text".to_string(), Value::String(content.to_string()));
    if let Some(p) = body.palace {
        args.insert("palace".to_string(), Value::String(p));
    }
    if let Some(tags) = body.tags {
        args.insert(
            "tags".to_string(),
            Value::Array(tags.into_iter().map(Value::String).collect()),
        );
    }
    let args = Value::Object(args);

    let state_for_task = state.clone();
    tokio::spawn(async move {
        match crate::tools::dispatch_tool(&state_for_task, "memory_remember", args).await {
            Ok(v) => {
                tracing::debug!(target: "trusty_memory::remember_async", result = %v, "queued remember succeeded");
            }
            Err(e) => {
                tracing::warn!(
                    target: "trusty_memory::remember_async",
                    error = %format!("{e:#}"),
                    "queued remember failed (caller already returned 202)",
                );
            }
        }
    });

    Ok((StatusCode::ACCEPTED, Json(json!({ "status": "queued" }))))
}

// ---------------------------------------------------------------------------
// Activity log (issue #96)
// ---------------------------------------------------------------------------

/// Default page size returned by `GET /api/v1/activity` when the client
/// omits `limit`. Matches the existing 50-row dashboard window.
const ACTIVITY_DEFAULT_LIMIT: usize = 50;

/// Hard cap on a single activity-page response.
///
/// Why: bounds the per-request work the handler performs and the response
/// size on the wire. The UI never asks for more than a screen's worth at a
/// time; this leaves headroom for power users running curl.
/// What: 500 entries — large enough for ad-hoc inspection without becoming
/// a DoS lever.
/// Test: `activity_endpoint_clamps_limit`.
const ACTIVITY_MAX_LIMIT: usize = 500;

/// Query parameters accepted by `GET /api/v1/activity`.
///
/// Why: serde-driven extraction keeps the handler signature small while
/// validating shape (numeric/ISO timestamps, optional fields). All filter
/// fields are optional and combine with AND.
/// What: see [`ActivityFilter`] for the underlying filter semantics.
/// Test: `activity_endpoint_lists_recent_emits`,
/// `activity_endpoint_filters_by_source_and_palace`.
#[derive(Deserialize, Debug, Default)]
struct ActivityQuery {
    #[serde(default)]
    limit: Option<usize>,
    #[serde(default)]
    offset: Option<usize>,
    #[serde(default)]
    palace: Option<String>,
    #[serde(default)]
    source: Option<String>,
    #[serde(default)]
    since: Option<String>,
    #[serde(default)]
    until: Option<String>,
}

/// Wire shape for one row in the `GET /api/v1/activity` response.
///
/// Why: the persisted `ActivityEntry` carries a JSON-encoded `payload`
/// string so the schema is decoupled from `DaemonEvent` evolution; we
/// re-decode the payload to a `Value` here so the UI receives a structured
/// JSON object instead of a nested escaped string.
/// What: same fields as `ActivityEntry` except `payload` is the parsed
/// JSON `Value` (falls back to a string when parse fails).
/// Test: `activity_endpoint_lists_recent_emits`.
#[derive(Serialize, Debug)]
struct ActivityRow {
    id: u64,
    timestamp: chrono::DateTime<chrono::Utc>,
    source: &'static str,
    #[serde(skip_serializing_if = "Option::is_none")]
    palace_id: Option<String>,
    event_type: String,
    payload: Value,
}

/// `GET /api/v1/activity` — paginated activity history (issue #96).
///
/// Why: the dashboard activity feed (`ActivityFeed.svelte`) used to be a
/// pure live-stream — opening the UI rendered an empty pane. Returning a
/// paginated history lets the UI seed the feed on mount and load more on
/// scroll, then layer the SSE live-tail on top.
/// What: clamps `limit` to [1, [`ACTIVITY_MAX_LIMIT`]], parses optional
/// filters, and queries the persistent log. The response shape is
/// `{ entries: [...], total, limit, offset }` so the UI can decide
/// whether more rows exist.
/// Test: `activity_endpoint_lists_recent_emits`,
/// `activity_endpoint_clamps_limit`,
/// `activity_endpoint_filters_by_source_and_palace`.
async fn activity_handler(
    State(state): State<AppState>,
    Query(q): Query<ActivityQuery>,
) -> Result<Json<Value>, ApiError> {
    let limit = q
        .limit
        .unwrap_or(ACTIVITY_DEFAULT_LIMIT)
        .clamp(1, ACTIVITY_MAX_LIMIT);
    let offset = q.offset.unwrap_or(0);

    let source = match q.source.as_deref() {
        Some(s) => match ActivitySource::parse(s) {
            Some(parsed) => Some(parsed),
            None => {
                return Err(ApiError::bad_request(format!(
                    "unknown source '{s}'; expected one of http, mcp, hook",
                )))
            }
        },
        None => None,
    };

    let since = parse_iso_or_bad_request(q.since.as_deref(), "since")?;
    let until = parse_iso_or_bad_request(q.until.as_deref(), "until")?;

    let filter = ActivityFilter {
        palace_id: q.palace.filter(|s| !s.is_empty()),
        source,
        since,
        until,
    };

    let entries = state
        .activity_log
        .list(&filter, limit, offset)
        .map_err(|e| ApiError::internal(format!("activity list: {e:#}")))?;
    let total = state
        .activity_log
        .count()
        .map_err(|e| ApiError::internal(format!("activity count: {e:#}")))?;

    let rows: Vec<ActivityRow> = entries
        .into_iter()
        .map(|e| {
            let payload = serde_json::from_str::<Value>(&e.payload)
                .unwrap_or_else(|_| Value::String(e.payload.clone()));
            ActivityRow {
                id: e.id,
                timestamp: e.timestamp,
                source: e.source.as_str(),
                palace_id: e.palace_id,
                event_type: e.event_type,
                payload,
            }
        })
        .collect();

    Ok(Json(json!({
        "entries": rows,
        "total": total,
        "limit": limit,
        "offset": offset,
    })))
}

/// `POST /api/v1/activity/hook` — ingest a hook firing for the activity feed.
///
/// Why: Claude Code's hooks (`UserPromptSubmit` → `prompt-context`,
/// `SessionStart` → `inbox-check`) run as ephemeral CLI subprocesses with no
/// in-process access to `AppState`. Without an ingestion endpoint they had no
/// way to populate the activity feed, which left the TUI feed empty for any
/// session whose only daemon traffic was hooks. This endpoint accepts the
/// hook's self-reported payload and forwards it to `state.emit` so the same
/// persistence + SSE broadcast pipeline that handles `DrawerAdded`/etc. also
/// covers `HookFired`.
/// What: deserialises a [`HookEventPayload`], maps it onto a
/// `DaemonEvent::HookFired` with `source = ActivitySource::Hook`, hands it to
/// `state.emit`, and returns `204 No Content`. Errors only happen for
/// malformed JSON — handled by axum's own `Json` rejection.
/// Test: `hook_activity_endpoint_appends_to_activity_log`.
async fn hook_activity_handler(
    State(state): State<AppState>,
    Json(payload): Json<HookEventPayload>,
) -> Result<StatusCode, ApiError> {
    state.emit(DaemonEvent::HookFired {
        palace_id: payload.palace_id,
        palace_name: payload.palace_name,
        hook_type: payload.hook_type,
        injection_kind: payload.injection_kind,
        injection_length: payload.injection_length,
        trigger_prompt_excerpt: payload.trigger_prompt_excerpt,
        timestamp: chrono::Utc::now(),
        duration_ms: payload.duration_ms,
        source: ActivitySource::Hook,
    });
    Ok(StatusCode::NO_CONTENT)
}

/// `POST /rpc` — JSON-RPC 2.0 dispatch endpoint.
///
/// Why: the multi-transport refactor needs a single HTTP route that
/// accepts the same envelopes the UDS transport speaks. Browser
/// clients that want the new tool surface (or third-party scripts
/// that prefer JSON-RPC to REST) can POST a request envelope here
/// and get a response back without learning the per-tool REST
/// vocabulary. The existing `/api/v1/*` REST routes continue to work
/// unchanged — this is purely additive.
/// What: deserialises a [`JsonRpcRequest`] from the request body,
/// calls [`crate::transport::rpc::dispatch`], and returns the
/// [`JsonRpcResponse`] as JSON. Always returns HTTP 200 with the
/// envelope inside (JSON-RPC errors are carried in the `error`
/// field, not the HTTP status). Returns HTTP 400 only on JSON
/// deserialisation failure of the outer envelope.
/// Test: `http_rpc_endpoint_roundtrip` in `web::tests`.
async fn rpc_handler(
    State(state): State<AppState>,
    Json(req): Json<crate::transport::rpc::JsonRpcRequest>,
) -> Json<crate::transport::rpc::JsonRpcResponse> {
    let resp = crate::transport::rpc::dispatch(&state, req).await;
    Json(resp)
}

/// Extract a [`CreatorInfo`] for an HTTP write request.
///
/// Why: every HTTP write path (drawers, messages) must attach
/// attribution tags so operators can trace which client wrote which
/// drawer. Centralising the extraction here keeps the `X-Trusty-Client-*`
/// header contract in one place.
/// What: pulls `X-Trusty-Client-Name` (default
/// [`HTTP_DEFAULT_CLIENT`]) and the optional `X-Trusty-Client-Cwd`
/// header off the request, then builds a `CreatorInfo` with
/// `source = Http` and the current daemon crate version.
/// Test: `drawer_creator_attribution_http_default`,
/// `drawer_creator_attribution_http_header`.
pub(crate) fn creator_info_from_http(headers: &HeaderMap) -> CreatorInfo {
    let client = headers
        .get(X_TRUSTY_CLIENT_NAME)
        .and_then(|v| v.to_str().ok())
        .map(|s| s.trim())
        .filter(|s| !s.is_empty())
        .unwrap_or(HTTP_DEFAULT_CLIENT)
        .to_string();
    let cwd = headers
        .get(X_TRUSTY_CLIENT_CWD)
        .and_then(|v| v.to_str().ok())
        .map(|s| s.to_string())
        .filter(|s| !s.is_empty());
    CreatorInfo {
        client,
        version: env!("CARGO_PKG_VERSION").to_string(),
        source: CreatorSource::Http,
        cwd,
    }
}

/// Parse an optional ISO-8601 timestamp string for the activity filter.
///
/// Why: the `since` / `until` query params are user-supplied; a bad value
/// should reject the request with a clear 400 rather than be silently
/// dropped (which would return seemingly-correct but mis-filtered data).
/// What: returns `Ok(None)` when the input is `None` or empty;
/// `Ok(Some(_))` on a parseable RFC 3339 timestamp; `Err(ApiError::bad_request)`
/// otherwise.
/// Test: `activity_endpoint_lists_recent_emits` exercises the happy path
/// (no timestamps); a bad timestamp returns 400 — see manual curl.
fn parse_iso_or_bad_request(
    s: Option<&str>,
    field: &str,
) -> Result<Option<chrono::DateTime<chrono::Utc>>, ApiError> {
    match s {
        None | Some("") => Ok(None),
        Some(raw) => chrono::DateTime::parse_from_rfc3339(raw)
            .map(|dt| Some(dt.with_timezone(&chrono::Utc)))
            .map_err(|e| ApiError::bad_request(format!("invalid {field} (RFC 3339): {e}"))),
    }
}

// ---------------------------------------------------------------------------
// Static asset serving
// ---------------------------------------------------------------------------

/// Serve any embedded asset; fall back to `index.html` for SPA routes.
///
/// Why: Hash-based routing lives client-side, but `/assets/foo.js` etc. must
/// resolve to the embedded file directly.
/// What: Looks up the request path under `WebAssets`; if absent, returns
/// `index.html`. Unknown paths under `/api/` return 404.
/// Test: `serves_index_html`, `serves_static_asset`, `unknown_api_404`.
async fn static_handler(req: Request<Body>) -> Response {
    let path = req.uri().path().trim_start_matches('/').to_string();

    if path.starts_with("api/") {
        return (StatusCode::NOT_FOUND, "not found").into_response();
    }

    serve_embedded(&path).unwrap_or_else(|| {
        // SPA fallback.
        serve_embedded("index.html")
            .unwrap_or_else(|| (StatusCode::NOT_FOUND, "ui assets missing").into_response())
    })
}

fn serve_embedded(path: &str) -> Option<Response> {
    let path = if path.is_empty() { "index.html" } else { path };
    let asset = WebAssets::get(path)?;
    let mime = mime_guess::from_path(path).first_or_octet_stream();
    let body = Body::from(asset.data.into_owned());
    let mut resp = Response::new(body);
    resp.headers_mut().insert(
        header::CONTENT_TYPE,
        HeaderValue::from_str(mime.as_ref())
            .unwrap_or_else(|_| HeaderValue::from_static("application/octet-stream")),
    );
    Some(resp)
}

// ---------------------------------------------------------------------------
// /api/v1/status, /api/v1/config
// ---------------------------------------------------------------------------

pub(crate) use crate::service::StatusPayload;

async fn status(State(state): State<AppState>) -> Json<StatusPayload> {
    Json(crate::service::MemoryService::new(state).status().await)
}

#[derive(Serialize)]
struct ConfigPayload {
    openrouter_configured: bool,
    model: String,
    data_root: String,
}

async fn config(State(state): State<AppState>) -> Json<ConfigPayload> {
    let cfg = load_user_config().unwrap_or_default();
    Json(ConfigPayload {
        openrouter_configured: !cfg.openrouter_api_key.is_empty(),
        model: cfg.openrouter_model,
        data_root: state.data_root.display().to_string(),
    })
}

pub(crate) use crate::service::load_user_config;
#[allow(unused_imports)]
pub(crate) use crate::service::LoadedUserConfig;

// ---------------------------------------------------------------------------
// /api/v1/palaces
// ---------------------------------------------------------------------------

pub(crate) use crate::service::{palace_info_from, CreatePalaceBody, PalaceInfo};

async fn list_palaces(State(state): State<AppState>) -> Result<Json<Vec<PalaceInfo>>, ApiError> {
    Ok(Json(
        crate::service::MemoryService::new(state)
            .list_palaces()
            .await?,
    ))
}

async fn create_palace(
    State(state): State<AppState>,
    Json(body): Json<CreatePalaceBody>,
) -> Result<Json<Value>, ApiError> {
    let id = crate::service::MemoryService::new(state)
        .create_palace(body, ActivitySource::Http)
        .await?;
    Ok(Json(json!({ "id": id })))
}

async fn get_palace_handler(
    State(state): State<AppState>,
    AxumPath(id): AxumPath<String>,
) -> Result<Json<PalaceInfo>, ApiError> {
    Ok(Json(
        crate::service::MemoryService::new(state)
            .get_palace(&id)
            .await?,
    ))
}

/// Query parameters for `DELETE /api/v1/palaces/{id}`.
///
/// Why: Issue #180 — `force=true` is the explicit opt-in to delete a
/// palace that still has drawers. Defaulting to `false` keeps the
/// "must be empty" guard active when callers omit the flag.
/// What: a single optional bool that the handler unwraps to `false`.
/// Test: `delete_palace_refuses_when_drawers_present`,
/// `delete_palace_force_removes_populated_palace`.
#[derive(Deserialize, Default)]
struct DeletePalaceQuery {
    #[serde(default)]
    force: Option<bool>,
}

/// `DELETE /api/v1/palaces/{id}?force=<bool>` — drop an entire palace.
///
/// Why: Issue #180 — operators need a single call to clean up a palace
/// they no longer want. The legacy drawer-by-drawer delete path is too
/// noisy and leaves the palace's KG / vector index behind.
/// What: delegates to `MemoryService::delete_palace`. Returns
/// `204 No Content` on success, `404 Not Found` when the id is unknown,
/// and `409 Conflict` when the palace still has drawers and `force` is
/// not set. Other failures bubble up as 500.
/// Test: `delete_palace_removes_dir_when_empty`,
/// `delete_palace_refuses_when_drawers_present`,
/// `delete_palace_force_removes_populated_palace`,
/// `delete_palace_returns_not_found_for_missing_id`.
async fn delete_palace_handler(
    State(state): State<AppState>,
    AxumPath(id): AxumPath<String>,
    Query(q): Query<DeletePalaceQuery>,
) -> Result<StatusCode, ApiError> {
    crate::service::MemoryService::new(state)
        .delete_palace(&id, q.force.unwrap_or(false))
        .await?;
    Ok(StatusCode::NO_CONTENT)
}

/// Request body for `PATCH /api/v1/palaces/{id}`.
///
/// Why: The only mutable palace metadata exposed today is the display name;
/// keeping the body to a single field keeps the wire contract obvious and
/// lets us extend later without breaking older clients (additive fields
/// only). Issue #180 follow-up.
/// What: a single required `name` string. Empty / whitespace-only values
/// are rejected with 400 by the handler.
/// Test: `update_palace_name_renames_palace`,
/// `update_palace_name_rejects_empty_name`.
#[derive(Deserialize)]
struct UpdatePalaceBody {
    name: String,
}

/// `PATCH /api/v1/palaces/{id}` — rename a palace's display name.
///
/// Why: Issue #180 follow-up — operators need to relabel palaces without
/// re-creating them (which would lose all stored drawers / KG / vectors).
/// Only the human-readable `name` changes; the directory name (which is the
/// palace id) is immutable.
/// What: delegates to `MemoryService::update_palace_name_typed`. Returns
/// `200 OK` with the updated palace info on success, `404 Not Found` when
/// the id is unknown, and `400 Bad Request` when the supplied name is
/// empty after trimming.
/// Test: `update_palace_name_renames_palace`,
/// `update_palace_name_rejects_empty_name`,
/// `update_palace_name_returns_not_found_for_missing_id`.
async fn update_palace_handler(
    State(state): State<AppState>,
    AxumPath(id): AxumPath<String>,
    Json(body): Json<UpdatePalaceBody>,
) -> Result<Json<Value>, ApiError> {
    let value = crate::service::MemoryService::new(state)
        .update_palace_name_typed(&id, &body.name)
        .await?;
    Ok(Json(value))
}

// ---------------------------------------------------------------------------
// Drawers
// ---------------------------------------------------------------------------

pub(crate) use crate::service::{CreateDrawerBody, ListDrawersQuery};

async fn list_drawers(
    State(state): State<AppState>,
    AxumPath(id): AxumPath<String>,
    Query(q): Query<ListDrawersQuery>,
) -> Result<Json<Value>, ApiError> {
    Ok(Json(
        crate::service::MemoryService::new(state)
            .list_drawers(&id, q)
            .await?,
    ))
}

async fn create_drawer(
    State(state): State<AppState>,
    AxumPath(id): AxumPath<String>,
    headers: HeaderMap,
    Json(body): Json<CreateDrawerBody>,
) -> Result<Json<Value>, ApiError> {
    let creator = creator_info_from_http(&headers);
    let drawer_id = crate::service::MemoryService::new(state)
        .create_drawer(&id, body, creator, ActivitySource::Http)
        .await?;
    Ok(Json(json!({ "id": drawer_id })))
}

async fn delete_drawer(
    State(state): State<AppState>,
    AxumPath((id, drawer_id)): AxumPath<(String, String)>,
) -> Result<StatusCode, ApiError> {
    crate::service::MemoryService::new(state)
        .delete_drawer(&id, &drawer_id, ActivitySource::Http)
        .await?;
    Ok(StatusCode::NO_CONTENT)
}

// Why: this shim previously bridged `tools.rs` callers into the service
//      implementation, but issue #226 moved those callers to use
//      `crate::service::MemoryService::new(...).aggregate_status_event()`
//      directly so the call site does not require the `axum-server`
//      feature. Removing the shim eliminates a dead-code warning.

// ---------------------------------------------------------------------------
// Recall
// ---------------------------------------------------------------------------

/// Query parameters shared by the per-palace and cross-palace recall endpoints.
///
/// Why: both `GET /api/v1/palaces/{id}/recall` and `GET /api/v1/recall` accept
/// the same `q` / `top_k` / `deep` triple. Keeping one struct avoids drift
/// between the two handler signatures.
/// What: `q` is required; `top_k` and `deep` are optional with handler-side
/// defaults (10 and false respectively).
/// Test: `recall_all_handler_*` tests in this module.
#[derive(Deserialize)]
struct RecallQuery {
    q: String,
    #[serde(default)]
    top_k: Option<usize>,
    #[serde(default)]
    deep: Option<bool>,
    /// Issue #465: optional palace filter on the flat `GET /api/v1/recall`
    /// endpoint. When supplied, recall is scoped to that palace instead of
    /// fanning out across all palaces. Absent → cross-palace fan-out.
    #[serde(default)]
    palace: Option<String>,
}

async fn recall_handler(
    State(state): State<AppState>,
    AxumPath(id): AxumPath<String>,
    Query(q): Query<RecallQuery>,
) -> Result<Json<Value>, ApiError> {
    Ok(Json(
        crate::service::MemoryService::new(state)
            .recall(&id, &q.q, q.top_k.unwrap_or(10), q.deep.unwrap_or(false))
            .await?,
    ))
}

#[allow(unused_imports)]
pub(crate) use crate::service::recall_entry_json;

/// `GET /api/v1/recall?q=<query>&top_k=<n>&deep=<bool>[&palace=<id>]` — recall
/// with optional palace scoping.
///
/// Why: Agents and dashboard widgets often need the most relevant memories
/// regardless of palace boundary; forcing the caller to issue one request per
/// palace and merge client-side is both slower (no fan-out) and wrong (no
/// dedup/rerank). Serving the merged top-k from the daemon collapses the
/// round-trip and reuses the shared embedder singleton.
/// Issue #465: the `palace=` query param was silently ignored — this endpoint
/// always queried the default palace regardless of the supplied filter, causing
/// callers to receive results from the wrong palace. Fix: when `palace=` is
/// present and non-empty, route the recall to that specific palace (matching
/// the behaviour of `GET /api/v1/palaces/{id}/recall`). When absent, fall back
/// to the cross-palace fan-out.
/// What: If `palace` query param is set, delegates to `MemoryService::recall`
/// for that palace. Otherwise lists all palaces, opens each (skipping any that
/// fail to open with a warning), and delegates to `execute_recall_all`. Returns
/// a JSON array of `{ palace_id, drawer, score, layer }` entries sorted by
/// score descending.
/// Test: `recall_all_handler_honors_palace_filter`,
/// `recall_all_handler_fans_out_without_palace_param`.
async fn recall_all_handler(
    State(state): State<AppState>,
    Query(q): Query<RecallQuery>,
) -> Result<Json<Value>, ApiError> {
    // Issue #465: honour the `palace=` query param when present.
    if let Some(ref palace_id) = q.palace.filter(|s| !s.is_empty()) {
        let value = crate::service::MemoryService::new(state)
            .recall(
                palace_id,
                &q.q,
                q.top_k.unwrap_or(10),
                q.deep.unwrap_or(false),
            )
            .await?;
        return Ok(Json(value));
    }
    let value = crate::service::MemoryService::new(state)
        .recall_all(&q.q, q.top_k.unwrap_or(10), q.deep.unwrap_or(false))
        .await;
    if let Some(err) = value.get("error").and_then(|v| v.as_str()) {
        return Err(ApiError::internal(err.to_string()));
    }
    Ok(Json(value))
}

// ---------------------------------------------------------------------------
// Knowledge Graph
// ---------------------------------------------------------------------------

#[derive(Deserialize)]
struct KgQueryParams {
    subject: String,
}

async fn kg_query(
    State(state): State<AppState>,
    AxumPath(id): AxumPath<String>,
    Query(q): Query<KgQueryParams>,
) -> Result<Json<Vec<Triple>>, ApiError> {
    Ok(Json(
        crate::service::MemoryService::new(state)
            .kg_query(&id, &q.subject)
            .await?,
    ))
}

pub(crate) use crate::service::KgAssertBody;

async fn kg_assert(
    State(state): State<AppState>,
    AxumPath(id): AxumPath<String>,
    Json(body): Json<KgAssertBody>,
) -> Result<StatusCode, ApiError> {
    crate::service::MemoryService::new(state)
        .kg_assert(&id, body)
        .await?;
    Ok(StatusCode::NO_CONTENT)
}

/// Default page size for KG explorer list endpoints when caller omits `limit`.
///
/// Why: 50 is large enough to feel responsive in the SPA without dumping a
/// full graph in one request; matches the default the spec calls for.
const DEFAULT_KG_LIST_LIMIT: usize = 50;

/// Hard ceiling on `limit` for KG explorer list endpoints.
///
/// Why: prevent a misconfigured client from asking the daemon to materialize
/// thousands of rows in one go; matches the spec's max=200.
const MAX_KG_LIST_LIMIT: usize = 200;

fn default_kg_list_limit() -> usize {
    DEFAULT_KG_LIST_LIMIT
}

/// Query parameters for `GET /api/v1/palaces/{id}/kg/subjects`.
///
/// Why: The KG Explorer's left panel asks for a bounded subject list; `limit`
/// is clamped server-side so the SPA cannot accidentally pull the whole graph.
/// What: `limit` defaults to [`DEFAULT_KG_LIST_LIMIT`] and is clamped to
/// `[1, MAX_KG_LIST_LIMIT]` in the handler.
/// Test: indirectly by the KG explorer UI; `kg_list_subjects_returns_distinct`
/// in the web tests below covers the happy path.
#[derive(Deserialize)]
struct KgListSubjectsParams {
    #[serde(default = "default_kg_list_limit")]
    limit: usize,
}

/// `GET /api/v1/palaces/{id}/kg/subjects?limit=N` — list distinct active
/// subjects.
///
/// Why: The KG Explorer needs to browse subjects without a prior query (the
/// existing `kg_query` endpoint requires one). Surfacing this read on the
/// daemon avoids the SPA having to know how to issue SQL.
/// What: clamps `limit` to `[1, MAX_KG_LIST_LIMIT]` and delegates to
/// `KnowledgeGraph::list_subjects`. Returns a JSON array of strings.
/// Test: `kg_list_subjects_returns_distinct` (web tests).
async fn kg_list_subjects(
    State(state): State<AppState>,
    AxumPath(id): AxumPath<String>,
    Query(q): Query<KgListSubjectsParams>,
) -> Result<Json<Vec<String>>, ApiError> {
    let limit = q.limit.clamp(1, MAX_KG_LIST_LIMIT);
    Ok(Json(
        crate::service::MemoryService::new(state)
            .kg_list_subjects(&id, limit)
            .await?,
    ))
}

/// `GET /api/v1/palaces/{id}/kg/subjects_with_counts?limit=N` — list distinct
/// active subjects with their active-triple counts.
///
/// Why: The KG Explorer's subject list shows a count badge per subject and
/// supports sort-by-count. Returning the grouped counts in a single SQL pass
/// is cheaper than issuing one query per subject from the SPA.
/// What: clamps `limit` to `[1, MAX_KG_LIST_LIMIT]` and delegates to
/// `KnowledgeGraph::list_subjects_with_counts`. Returns a JSON array of
/// `{subject, count}` objects ordered alphabetically.
/// Test: indirectly via the KG Explorer UI; the core `list_subjects_with_counts`
/// test in `kg.rs` covers the SQL grouping.
async fn kg_list_subjects_with_counts(
    State(state): State<AppState>,
    AxumPath(id): AxumPath<String>,
    Query(q): Query<KgListSubjectsParams>,
) -> Result<Json<Vec<Value>>, ApiError> {
    let limit = q.limit.clamp(1, MAX_KG_LIST_LIMIT);
    let rows = crate::service::MemoryService::new(state)
        .kg_list_subjects_with_counts(&id, limit)
        .await?;
    let out: Vec<Value> = rows
        .into_iter()
        .map(|(subject, count)| json!({ "subject": subject, "count": count }))
        .collect();
    Ok(Json(out))
}

/// Query parameters for `GET /api/v1/palaces/{id}/kg/all`.
///
/// Why: The KG Explorer's "All" mode pages through every active triple;
/// `limit`+`offset` give the SPA stable prev/next controls.
/// What: defaults match `kg_list_subjects` for limit; `offset` defaults to 0.
/// Test: `kg_list_all_returns_paginated_triples` (web tests).
#[derive(Deserialize)]
struct KgListAllParams {
    #[serde(default = "default_kg_list_limit")]
    limit: usize,
    #[serde(default)]
    offset: usize,
}

/// `GET /api/v1/palaces/{id}/kg/all?limit=N&offset=N` — list all active
/// triples ordered by `valid_from` descending.
///
/// Why: The KG Explorer's "All" mode wants a paged view across every active
/// triple regardless of subject. The existing `kg_query` requires a subject.
/// What: clamps `limit` to `[1, MAX_KG_LIST_LIMIT]` and delegates to
/// `KnowledgeGraph::list_active`. Returns a JSON array of `Triple` objects.
/// Test: `kg_list_all_returns_paginated_triples` (web tests).
async fn kg_list_all(
    State(state): State<AppState>,
    AxumPath(id): AxumPath<String>,
    Query(q): Query<KgListAllParams>,
) -> Result<Json<Vec<Triple>>, ApiError> {
    let limit = q.limit.clamp(1, MAX_KG_LIST_LIMIT);
    Ok(Json(
        crate::service::MemoryService::new(state)
            .kg_list_all(&id, limit, q.offset)
            .await?,
    ))
}

/// `GET /api/v1/palaces/{id}/kg/count` — count of currently-active triples.
///
/// Why: The KG Explorer header shows a quick "N triples" badge; computing the
/// count server-side avoids fetching every triple to count them.
/// What: returns `{ "active": N }` where N is `count_active_triples()` on the
/// palace's KG.
/// Test: indirectly via the same palace counts surfaced on `/api/v1/status`.
async fn kg_count(
    State(state): State<AppState>,
    AxumPath(id): AxumPath<String>,
) -> Result<Json<Value>, ApiError> {
    let active = crate::service::MemoryService::new(state)
        .kg_count(&id)
        .await?;
    Ok(Json(json!({ "active": active })))
}

/// Separator byte sequence used inside a URL-safe base64 triple ID.
///
/// Why: The triple primary key is `(subject, predicate)`. Encoding them as a
/// single opaque ID lets the REST path look like `/kg/triples/<id>` (a
/// resource identifier) rather than carrying both parts in the URL path, which
/// would require double-escaping arbitrary strings. A `\0` separator is safe
/// because neither subjects nor predicates ever contain null bytes.
/// What: Used by [`encode_triple_id`] and [`decode_triple_id`].
/// Test: `decode_triple_id_round_trips`.
const TRIPLE_ID_SEPARATOR: u8 = 0x00;

/// Encode a `(subject, predicate)` pair as a URL-safe base64 triple ID.
///
/// Why: Produces a single opaque string that can travel as a URL path segment
/// without percent-encoding. The null-byte separator ensures the encoding is
/// injective (no two distinct pairs can produce the same encoded string).
/// What: `base64url(subject_bytes + "\0" + predicate_bytes)`, no padding.
/// Test: `decode_triple_id_round_trips`.
// Only used in tests (for round-trip assertions); suppress the dead_code lint
// that fires in non-test builds because `pub(crate)` alone doesn't silence it.
#[allow(dead_code)]
pub(crate) fn encode_triple_id(subject: &str, predicate: &str) -> String {
    use base64::Engine as _;
    let mut buf = Vec::with_capacity(subject.len() + 1 + predicate.len());
    buf.extend_from_slice(subject.as_bytes());
    buf.push(TRIPLE_ID_SEPARATOR);
    buf.extend_from_slice(predicate.as_bytes());
    base64::engine::general_purpose::URL_SAFE_NO_PAD.encode(&buf)
}

/// Decode a URL-safe base64 triple ID back to `(subject, predicate)`.
///
/// Why: The handler for `DELETE /kg/triples/<id>` needs to recover the
/// `(subject, predicate)` pair from the opaque path segment to call the
/// service layer.
/// What: Decodes base64url, splits on the first null byte. Returns `None`
/// when the input is not valid base64url or contains no null separator.
/// Test: `decode_triple_id_round_trips`.
pub(crate) fn decode_triple_id(id: &str) -> Option<(String, String)> {
    use base64::Engine as _;
    let bytes = base64::engine::general_purpose::URL_SAFE_NO_PAD
        .decode(id)
        .ok()?;
    let sep_pos = bytes.iter().position(|&b| b == TRIPLE_ID_SEPARATOR)?;
    let subject = String::from_utf8(bytes[..sep_pos].to_vec()).ok()?;
    let predicate = String::from_utf8(bytes[sep_pos + 1..].to_vec()).ok()?;
    Some((subject, predicate))
}

/// `DELETE /api/v1/palaces/{id}/kg/triples/{triple_id}` — surgically remove
/// one active triple by its opaque base64url-encoded `(subject, predicate)` ID.
///
/// Why: Issue #278 — the existing `(subject, predicate)` retract via
/// `/kg/prompt-facts` is scope-wide (retract across all palaces). This
/// endpoint targets exactly one triple in exactly one palace, giving callers
/// a surgical way to delete a specific edge without affecting other palaces
/// or other predicates for the same subject.
/// What: Decodes `triple_id` (base64url of `subject\0predicate`) back into
/// `(subject, predicate)`, retracts the active interval via
/// `MemoryService::kg_retract_triple`, and returns:
///   - `204 No Content` on success
///   - `404 Not Found` when the triple_id is malformed or no active triple
///     matched
///
/// Test: `kg_delete_triple_returns_204_on_success` and
/// `kg_delete_triple_returns_404_for_missing`.
async fn kg_delete_triple(
    State(state): State<AppState>,
    AxumPath((id, triple_id)): AxumPath<(String, String)>,
) -> Result<StatusCode, ApiError> {
    let (subject, predicate) = decode_triple_id(&triple_id).ok_or_else(|| {
        ApiError::not_found("invalid triple id — expected base64url(subject\\0predicate)")
    })?;
    let found = crate::service::MemoryService::new(state)
        .kg_retract_triple(&id, &subject, &predicate)
        .await?;
    if found {
        Ok(StatusCode::NO_CONTENT)
    } else {
        Err(ApiError::not_found(format!(
            "no active triple with subject={subject:?} predicate={predicate:?} in palace {id:?}"
        )))
    }
}

pub(crate) use crate::service::KgGraphPayload;

async fn kg_graph(
    State(state): State<AppState>,
    AxumPath(id): AxumPath<String>,
) -> Result<Json<KgGraphPayload>, ApiError> {
    Ok(Json(
        crate::service::MemoryService::new(state)
            .kg_graph(&id)
            .await?,
    ))
}

// ---------------------------------------------------------------------------
// Dream cycle status + on-demand run
// ---------------------------------------------------------------------------

pub(crate) use crate::service::DreamStatusPayload;

async fn dream_status(State(state): State<AppState>) -> Json<DreamStatusPayload> {
    Json(
        crate::service::MemoryService::new(state)
            .dream_status_aggregate()
            .await,
    )
}

async fn palace_dream_status(
    State(state): State<AppState>,
    AxumPath(id): AxumPath<String>,
) -> Result<Json<DreamStatusPayload>, ApiError> {
    Ok(Json(
        crate::service::MemoryService::new(state)
            .dream_status_for_palace(&id)
            .await?,
    ))
}

async fn dream_run(State(state): State<AppState>) -> Result<Json<DreamStatusPayload>, ApiError> {
    Ok(Json(
        crate::service::MemoryService::new(state)
            .dream_run()
            .await?,
    ))
}

// ---------------------------------------------------------------------------
// Knowledge gaps — community detection cache (issue #53)
// ---------------------------------------------------------------------------

/// Wire shape for a single knowledge gap returned by `/api/v1/kg/gaps`.
///
/// Why: `KnowledgeGap` (in `trusty-common`) does not derive `Serialize`
/// because that would force serde into the memory-core feature surface; the
/// HTTP layer instead owns a narrow response struct mirroring its fields.
/// What: One-for-one wire representation of `KnowledgeGap` — entities, the
/// internal-density score, the cross-community bridge count, and the
/// LLM/template exploration hint.
/// Test: `kg_gaps_endpoint_returns_cached_gaps`.
#[derive(Serialize, Debug, Clone)]
pub struct KnowledgeGapResponse {
    pub entities: Vec<String>,
    pub internal_density: f32,
    pub external_bridges: usize,
    pub suggested_exploration: String,
}

impl From<KnowledgeGap> for KnowledgeGapResponse {
    fn from(g: KnowledgeGap) -> Self {
        Self {
            entities: g.entities,
            internal_density: g.internal_density,
            external_bridges: g.external_bridges,
            suggested_exploration: g.suggested_exploration,
        }
    }
}

#[derive(Deserialize)]
struct KgGapsQuery {
    #[serde(default)]
    palace: Option<String>,
}

/// `GET /api/v1/kg/gaps?palace=<name>` — return the cached knowledge gaps.
///
/// Why: Issue #53 — surfaces the community-detection output computed by the
/// dream cycle so callers (dashboard, MCP tool, external tooling) can list
/// the sparse-cluster targets the model should explore next. Reading from
/// the in-memory cache means a `/kg/gaps` request never triggers a Louvain
/// run; it just clones the latest snapshot.
/// What: Resolves the palace from the optional `palace` query arg (falling
/// back to the daemon's `default_palace`, then erroring with 400 if neither
/// is set). Returns `[]` when the cache has no entry yet — the dream cycle
/// simply hasn't populated it. Returns 404 only when the palace name is
/// unknown to the registry (handle.open failed).
/// Test: `kg_gaps_endpoint_returns_cached_gaps`,
/// `kg_gaps_endpoint_returns_empty_when_uncached`.
async fn kg_gaps_handler(
    State(state): State<AppState>,
    Query(q): Query<KgGapsQuery>,
) -> Result<Json<Vec<KnowledgeGapResponse>>, ApiError> {
    let palace_name = q
        .palace
        .clone()
        .or_else(|| state.default_palace.clone())
        .ok_or_else(|| {
            ApiError::bad_request("missing 'palace' query parameter (no default palace configured)")
        })?;

    // Validate the palace exists; we don't strictly need the handle for the
    // cache lookup but we want a 404 rather than an empty-array masking a
    // typo in the palace name.
    let _handle = open_handle(&state, &palace_name)?;

    let pid = PalaceId::new(&palace_name);
    let gaps = state.registry.get_gaps(&pid).unwrap_or_default();
    let body: Vec<KnowledgeGapResponse> =
        gaps.into_iter().map(KnowledgeGapResponse::from).collect();
    Ok(Json(body))
}

// ---------------------------------------------------------------------------
// Prompt-facts surface (issue #42)
// ---------------------------------------------------------------------------

/// Query parameters shared by the prompt-context / prompt-facts read endpoints.
///
/// Why: Both `GET /api/v1/kg/prompt-context` and `GET /api/v1/kg/prompt-facts`
/// optionally accept a `palace` filter so callers can scope reads to a single
/// project namespace. A shared struct keeps the wire shape consistent.
/// What: A single optional `palace` query parameter. When omitted, handlers
/// span every palace in the registry (matching the MCP tool behaviour).
/// Test: `prompt_context_endpoint_returns_formatted_block`,
/// `list_prompt_facts_endpoint_returns_hot_triples`.
#[derive(Deserialize)]
struct PromptFactsQuery {
    // Accepted for forward-compat with the MCP tool surface, but ignored:
    // the prompt cache is registry-wide, so reads always span every palace.
    // We keep the field rather than ignoring `?palace=...` silently so a
    // future per-palace filter is a non-breaking schema addition.
    #[serde(default)]
    #[allow(dead_code)]
    palace: Option<String>,
}

/// Wire shape for `POST /api/v1/kg/aliases`.
///
/// Why: Mirrors the `add_alias` MCP tool: a short → full mapping with an
/// optional palace target. Keeping the field names identical between the
/// HTTP and MCP surfaces makes documentation and client code reuse trivial.
/// What: Required `short` and `full`; optional `palace` (falls back to the
/// daemon default).
/// Test: `add_alias_endpoint_asserts_triple_and_refreshes_cache`.
#[derive(Deserialize)]
struct AddAliasRequest {
    short: String,
    full: String,
    #[serde(default)]
    palace: Option<String>,
}

/// Wire shape for a single hot-predicate triple in JSON responses.
///
/// Why: `list_prompt_facts` returns a structured array rather than the
/// pre-formatted Markdown so dashboards and tooling can render their own
/// views over the raw data.
/// What: subject/predicate/object string trio matching the underlying KG row.
/// Test: `list_prompt_facts_endpoint_returns_hot_triples`.
#[derive(Serialize)]
struct PromptFactRow {
    subject: String,
    predicate: String,
    object: String,
}

/// Query parameters for `DELETE /api/v1/kg/prompt-facts`.
///
/// Why: The MCP tool retracts the active interval for a `(subject, predicate)`
/// pair across every palace; the HTTP endpoint matches that contract so a
/// dashboard "Remove" button doesn't need to know which palace owns the fact.
/// What: Required `subject` and `predicate`; the issue spec mentions an
/// optional `object` filter but the underlying `KnowledgeGraph::retract` API
/// closes the entire `(subject, predicate)` interval — we accept `object`
/// for forward-compat but currently ignore it, mirroring the MCP tool.
/// Test: `remove_prompt_fact_endpoint_soft_deletes_and_refreshes_cache`.
#[derive(Deserialize)]
struct RemovePromptFactQuery {
    subject: String,
    predicate: String,
    #[serde(default)]
    #[allow(dead_code)]
    object: Option<String>,
    #[serde(default)]
    #[allow(dead_code)]
    palace: Option<String>,
}

/// `GET /api/v1/kg/prompt-context` — return the formatted prompt-context block.
///
/// Why: Lets non-MCP callers (the admin UI, curl, integration tests) fetch
/// the same Markdown block the `get_prompt_context` tool returns, without
/// needing to speak JSON-RPC. The body is a plain text response so it can
/// be piped straight into a model prompt.
/// What: Reads the in-memory `prompt_context_cache` (already kept fresh by
/// any write that touches a hot predicate), returns the formatted string,
/// or a placeholder message when nothing has been stored yet.
/// Test: `prompt_context_endpoint_returns_formatted_block`.
async fn prompt_context_handler(
    State(state): State<AppState>,
    Query(_q): Query<PromptFactsQuery>,
) -> Result<Response, ApiError> {
    let cache_snapshot = {
        let guard = state.prompt_context_cache.read().await;
        guard.clone()
    };
    let body = if cache_snapshot.formatted.is_empty() {
        "No prompt facts stored yet.".to_string()
    } else {
        cache_snapshot.formatted
    };
    let mut resp = body.into_response();
    resp.headers_mut().insert(
        header::CONTENT_TYPE,
        HeaderValue::from_static("text/plain; charset=utf-8"),
    );
    Ok(resp)
}

/// `POST /api/v1/kg/aliases` — assert a `(short, is_alias_for, full)` triple.
///
/// Why: HTTP counterpart to the `add_alias` MCP tool — lets the admin UI
/// (or an external automation) register aliases without speaking JSON-RPC.
/// What: Resolves the target palace (request body → daemon default), opens
/// the palace handle, asserts the alias triple, and rebuilds the prompt
/// cache so subsequent `GET /api/v1/kg/prompt-context` calls reflect the
/// write immediately.
/// Test: `add_alias_endpoint_asserts_triple_and_refreshes_cache`.
async fn add_alias_handler(
    State(state): State<AppState>,
    Json(req): Json<AddAliasRequest>,
) -> Result<Json<Value>, ApiError> {
    if req.short.is_empty() || req.full.is_empty() {
        return Err(ApiError::bad_request("short and full are required"));
    }
    let palace_name = req
        .palace
        .clone()
        .or_else(|| state.default_palace.clone())
        .ok_or_else(|| ApiError::bad_request("missing 'palace' (no default palace configured)"))?;
    let handle = open_handle(&state, &palace_name)?;
    let triple = Triple {
        subject: req.short.clone(),
        predicate: "is_alias_for".to_string(),
        object: req.full.clone(),
        valid_from: chrono::Utc::now(),
        valid_to: None,
        confidence: 1.0,
        provenance: Some("add_alias_http".to_string()),
    };
    handle
        .kg
        .assert(triple)
        .await
        .map_err(|e| ApiError::internal(format!("kg.assert failed: {e:#}")))?;
    if let Err(e) = crate::prompt_facts::rebuild_prompt_cache(&state).await {
        tracing::warn!("rebuild_prompt_cache after HTTP add_alias failed: {e:#}");
    }
    Ok(Json(json!({
        "subject": req.short,
        "predicate": "is_alias_for",
        "object": req.full,
        "palace": palace_name,
    })))
}

/// `GET /api/v1/kg/prompt-facts` — list every active hot-predicate triple.
///
/// Why: Mirrors the `list_prompt_facts` MCP tool. Returning the raw triples
/// (rather than the formatted block) lets dashboards group, search, and
/// edit them with their own UI.
/// What: Calls `gather_hot_triples` over the live registry and serialises
/// each row as `{subject, predicate, object}`.
/// Test: `list_prompt_facts_endpoint_returns_hot_triples`.
async fn list_prompt_facts_handler(
    State(state): State<AppState>,
    Query(_q): Query<PromptFactsQuery>,
) -> Result<Json<Vec<PromptFactRow>>, ApiError> {
    let triples = crate::prompt_facts::gather_hot_triples(&state)
        .await
        .map_err(|e| ApiError::internal(format!("gather_hot_triples: {e:#}")))?;
    let rows: Vec<PromptFactRow> = triples
        .into_iter()
        .map(|(subject, predicate, object)| PromptFactRow {
            subject,
            predicate,
            object,
        })
        .collect();
    Ok(Json(rows))
}

/// `DELETE /api/v1/kg/prompt-facts?subject=...&predicate=...` — soft-delete
/// the active triple matching the given `(subject, predicate)` pair.
///
/// Why: HTTP counterpart to the `remove_prompt_fact` MCP tool. Mirrors the
/// retract-across-palaces semantics so a single call cleans up the fact
/// regardless of which palace stored it.
/// What: Iterates every palace, calls `kg.retract(subject, predicate)`, and
/// reports the total number of intervals closed. Rebuilds the prompt cache
/// when at least one retraction occurred.
/// Test: `remove_prompt_fact_endpoint_soft_deletes_and_refreshes_cache`.
async fn remove_prompt_fact_handler(
    State(state): State<AppState>,
    Query(q): Query<RemovePromptFactQuery>,
) -> Result<Json<Value>, ApiError> {
    if q.subject.is_empty() || q.predicate.is_empty() {
        return Err(ApiError::bad_request("subject and predicate are required"));
    }
    let mut closed_total: usize = 0;
    for palace_id in state.registry.list() {
        if let Some(handle) = state.registry.get(&palace_id) {
            match handle.kg.retract(&q.subject, &q.predicate).await {
                Ok(n) => closed_total += n,
                Err(e) => tracing::warn!(
                    palace = %palace_id.as_str(),
                    "HTTP retract failed: {e:#}",
                ),
            }
        }
    }
    if closed_total > 0 {
        if let Err(e) = crate::prompt_facts::rebuild_prompt_cache(&state).await {
            tracing::warn!("rebuild_prompt_cache after HTTP remove_prompt_fact failed: {e:#}");
        }
        Ok(Json(json!({"removed": true, "closed": closed_total})))
    } else {
        Ok(Json(json!({"removed": false, "reason": "not found"})))
    }
}

#[allow(unused_imports)]
pub(crate) use crate::service::refresh_gaps_cache;

// ---------------------------------------------------------------------------
// Helpers
// ---------------------------------------------------------------------------

pub(crate) fn open_handle(
    state: &AppState,
    id: &str,
) -> Result<std::sync::Arc<trusty_common::memory_core::PalaceHandle>, ApiError> {
    state
        .registry
        .open_palace(&state.data_root, &PalaceId::new(id))
        .map_err(|e| ApiError::not_found(format!("palace not found: {id} ({e:#})")))
}

/// Lightweight error type for HTTP handlers.
pub(crate) struct ApiError {
    status: StatusCode,
    message: String,
}

impl ApiError {
    pub(crate) fn bad_request(msg: impl Into<String>) -> Self {
        Self {
            status: StatusCode::BAD_REQUEST,
            message: msg.into(),
        }
    }
    pub(crate) fn not_found(msg: impl Into<String>) -> Self {
        Self {
            status: StatusCode::NOT_FOUND,
            message: msg.into(),
        }
    }
    /// Build a 409 Conflict response.
    ///
    /// Why: `DELETE /palaces/{id}` (issue #180) returns 409 when the
    /// palace still has drawers and `force=true` is not set. A 400 would
    /// be misleading (the request is well-formed) and 404 would lie about
    /// existence.
    /// What: wraps the message with `StatusCode::CONFLICT`.
    /// Test: `delete_palace_refuses_when_drawers_present`.
    #[allow(dead_code)]
    pub(crate) fn conflict(msg: impl Into<String>) -> Self {
        Self {
            status: StatusCode::CONFLICT,
            message: msg.into(),
        }
    }
    pub(crate) fn internal(msg: impl Into<String>) -> Self {
        Self {
            status: StatusCode::INTERNAL_SERVER_ERROR,
            message: msg.into(),
        }
    }
    /// Build a 422 Unprocessable Entity response.
    ///
    /// Why (issue #466): content that is structurally valid JSON but fails
    /// semantic validation (e.g. too few words to be worth storing) should
    /// return 422 rather than 400 (which implies malformed input) or 200/202
    /// (which would imply success). 422 is the standard HTTP status for
    /// "request understood but semantically unacceptable".
    /// What: wraps the message with `StatusCode::UNPROCESSABLE_ENTITY`.
    /// Test: `remember_async_rejects_short_content`.
    pub(crate) fn unprocessable(msg: impl Into<String>) -> Self {
        Self {
            status: StatusCode::UNPROCESSABLE_ENTITY,
            message: msg.into(),
        }
    }
}

impl IntoResponse for ApiError {
    fn into_response(self) -> Response {
        (self.status, Json(json!({ "error": self.message }))).into_response()
    }
}

impl From<crate::service::ServiceError> for ApiError {
    fn from(e: crate::service::ServiceError) -> Self {
        match e {
            crate::service::ServiceError::BadRequest(m) => ApiError::bad_request(m),
            crate::service::ServiceError::NotFound(m) => ApiError::not_found(m),
            crate::service::ServiceError::Conflict(m) => ApiError::conflict(m),
            crate::service::ServiceError::Internal(m) => ApiError::internal(m),
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    // Why (issue #226): `drawer_content_preview` is now used via the
    //      axum-free `service` path; the test still validates the same
    //      helper, so we import directly to keep the assertions intact.
    use crate::service::drawer_content_preview;
    use crate::service::DRAWER_PREVIEW_MAX_CHARS;
    use axum::body::to_bytes;
    use axum::http::Request;
    use tower::util::ServiceExt;
    use trusty_common::memory_core::palace::Palace;
    use trusty_common::memory_core::retrieval::RecallResult;

    fn test_state() -> AppState {
        let tmp = tempfile::tempdir().expect("tempdir");
        let root = tmp.path().to_path_buf();
        std::mem::forget(tmp);
        // Issue #88: bypass the project-slug enforcement gate so tests can
        // create palaces with arbitrary names without having a real project
        // root on disk. The env var is harmless once set to "1" because all
        // tests in this process use the same setting.
        // SAFETY: no other thread reads/writes this var concurrently — the
        // const value "1" is idempotent and the write happens before any
        // test that creates a palace via the HTTP layer.
        unsafe {
            std::env::set_var("TRUSTY_SKIP_PALACE_ENFORCEMENT", "1");
        }
        let state = AppState::new(root);
        // Pre-existing tests exercise functional paths — flip to Ready so the
        // issue #911 warming preflight does not reject them.
        state.set_ready();
        state
    }

    #[test]
    fn drawer_preview_collapses_whitespace_and_truncates() {
        // Short single-line content is returned verbatim.
        assert_eq!(drawer_content_preview("hello world"), "hello world");

        // Multiline / tab-laden content collapses to single-spaced text.
        assert_eq!(
            drawer_content_preview("first line\n\nsecond\tline   third"),
            "first line second line third"
        );

        // Leading / trailing whitespace is stripped.
        assert_eq!(drawer_content_preview("   padded   "), "padded");

        // Empty content yields an empty preview (fallback signal for clients).
        assert_eq!(drawer_content_preview(""), "");

        // Long content is truncated to DRAWER_PREVIEW_MAX_CHARS with an ellipsis.
        let long = "x".repeat(DRAWER_PREVIEW_MAX_CHARS + 50);
        let preview = drawer_content_preview(&long);
        assert_eq!(preview.chars().count(), DRAWER_PREVIEW_MAX_CHARS);
        assert!(preview.ends_with('…'));

        // Content right at the limit is not truncated.
        let exact = "y".repeat(DRAWER_PREVIEW_MAX_CHARS);
        assert_eq!(drawer_content_preview(&exact), exact);
    }

    /// `GET /health` returns HTTP 200 with `status: "ok"` after the
    /// round-trip clears every stage against the auto-provisioned probe palace.
    ///
    /// Why: confirms the JSON contract (`status`, `version`) for monitors that
    /// poll `/health`. Marked `#[ignore]` because issue #185 routes the probe
    /// through the dedicated palace and `recall_with_default_embedder` loads
    /// ONNX — too heavy for the default CI matrix. Run with
    /// `cargo test -p trusty-memory -- --include-ignored`.
    /// What: Drives `/health` and asserts the basic JSON keys.
    /// Test: this test.
    #[tokio::test]
    #[ignore = "loads the default ONNX embedder; run with --include-ignored"]
    async fn health_endpoint_returns_ok() {
        let state = test_state();
        let app = router().with_state(state);
        let resp = app
            .oneshot(
                Request::builder()
                    .uri("/health")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        let bytes = to_bytes(resp.into_body(), 1024).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();
        assert_eq!(v["status"], "ok");
        assert_eq!(v["version"], env!("CARGO_PKG_VERSION"));
    }

    /// Issue #35 — `GET /health` carries the enriched resource block
    /// (`rss_mb`, `disk_bytes`, `cpu_pct`, `uptime_secs`).
    ///
    /// Why: external probes and the admin UI render these; the JSON contract
    /// must remain stable. `rss_mb` is sampled live so it is asserted only
    /// for a sane unit, not an exact value. Marked `#[ignore]` because
    /// issue #185 makes every `/health` request run the full round-trip and
    /// `recall_with_default_embedder` loads the ONNX embedder.
    /// What: drives `/health` through the router and asserts every new field
    /// deserialises with a plausible value.
    /// Test: this test.
    #[tokio::test]
    #[ignore = "loads the default ONNX embedder; run with --include-ignored"]
    async fn health_endpoint_includes_resource_fields() {
        let state = test_state();
        let app = router().with_state(state);
        let resp = app
            .oneshot(
                Request::builder()
                    .uri("/health")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        let bytes = to_bytes(resp.into_body(), 1024).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();
        // rss_mb must be a sane unit (megabytes, not bytes).
        let rss_mb = v["rss_mb"].as_u64().expect("rss_mb is u64");
        assert!(rss_mb < 1024 * 1024, "rss_mb unit must be MB");
        // cpu_pct is a non-negative percentage (first sample may be 0.0).
        let cpu = v["cpu_pct"].as_f64().expect("cpu_pct is a number");
        assert!(cpu >= 0.0, "cpu_pct must be non-negative");
        // disk ticker has not run in this oneshot test → 0.
        assert_eq!(v["disk_bytes"].as_u64(), Some(0));
        // uptime_secs is present and a u64.
        assert!(v["uptime_secs"].is_u64(), "uptime_secs must be present");
    }

    /// Why: the fd-exhaustion gauge must appear in the `/health` response on
    /// Unix platforms so operators can monitor fd consumption vs. the ceiling.
    /// What: drives `/health` through the router and asserts that `open_fds`
    /// and `fd_soft_limit` are present and are non-zero unsigned integers.
    /// On non-Unix platforms the fields may be absent (the helpers return None
    /// and are skipped in serialisation) — that is acceptable and tested here
    /// by not asserting presence, only asserting that when present they are sane.
    /// Test: this test.
    #[tokio::test]
    async fn health_endpoint_includes_fd_gauge() {
        let state = test_state();
        let app = router().with_state(state);
        let resp = app
            .oneshot(
                Request::builder()
                    .uri("/health")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        let bytes = to_bytes(resp.into_body(), 1024).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();

        // On Unix, both fields must be present and sane.
        #[cfg(unix)]
        {
            let open_fds = v["open_fds"]
                .as_u64()
                .expect("open_fds must be present on Unix");
            assert!(
                open_fds > 0,
                "open_fds must be > 0 (at least stdin/stdout/stderr)"
            );

            let limit = v["fd_soft_limit"]
                .as_u64()
                .expect("fd_soft_limit must be present on Unix");
            assert!(limit > 0, "fd_soft_limit must be > 0");

            // Sanity: open_fds should be well below the ceiling on test machines.
            assert!(
                open_fds < limit,
                "open_fds ({open_fds}) must be below fd_soft_limit ({limit}) in tests"
            );
        }
    }

    /// Issue #71 + #185 — `GET /health` reports `status: "ok"` on a fresh
    /// install by auto-provisioning the dedicated probe palace and running
    /// the full remember/recall/forget cycle against it.
    ///
    /// Why: Pre-#185 the handler short-circuited with "no palaces" on a fresh
    /// install, so a broken data plane would not surface until a real user
    /// created a palace. The dedicated `__health_probe__` palace removes that
    /// blind spot: the probe runs from boot. Marked `#[ignore]` because the
    /// round-trip now loads the ONNX embedder via `recall_with_default_embedder`,
    /// which is too heavy for the default CI matrix — run with
    /// `cargo test -p trusty-memory -- --include-ignored` for local verification.
    /// What: Drives `/health` through the router with an empty `data_root`
    /// and asserts `status == "ok"` (probe palace was auto-created and the
    /// round-trip cleared every stage) and the `detail` key is absent.
    /// Test: this test.
    #[tokio::test]
    #[ignore = "loads the default ONNX embedder; run with --include-ignored"]
    async fn health_endpoint_round_trip_on_fresh_install_is_ok() {
        let state = test_state();
        let app = router().with_state(state);
        let resp = app
            .oneshot(
                Request::builder()
                    .uri("/health")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        let bytes = to_bytes(resp.into_body(), 1024).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();
        assert_eq!(v["status"], "ok");
        assert!(
            v.get("detail").is_none() || v["detail"].is_null(),
            "fresh-install health must not carry a degraded detail (got {v:?})"
        );
    }

    /// Issue #71 — `GET /health` exercises the full store/recall/forget
    /// cycle against the first palace and reports `status: "ok"` on success.
    ///
    /// Why: The whole point of issue #71 is to catch store/recall
    /// regressions at probe time rather than via real client traffic. This
    /// test creates a real palace, hits `/health`, and asserts the
    /// round-trip path is happy. Marked `#[ignore]` because
    /// `recall_with_default_embedder` pulls in the ONNX model and is too
    /// heavy for the default CI matrix — run with
    /// `cargo test -p trusty-memory -- --include-ignored` for local
    /// verification.
    /// What: Builds an `AppState` with a tempdir `data_root`, creates a
    /// `health-probe-palace` via `registry.create_palace`, hits `/health`,
    /// and asserts both the status and the absence of any `detail` field.
    /// Test: this test.
    #[tokio::test]
    #[ignore = "loads the default ONNX embedder; run with --include-ignored"]
    async fn health_endpoint_round_trip_with_palace_is_ok() {
        let state = test_state();
        let palace = trusty_common::memory_core::Palace {
            id: PalaceId::new("health-probe-palace"),
            name: "health-probe-palace".to_string(),
            description: None,
            created_at: chrono::Utc::now(),
            data_dir: state.data_root.join("health-probe-palace"),
        };
        state
            .registry
            .create_palace(&state.data_root, palace)
            .expect("create_palace");

        let app = router().with_state(state);
        let resp = app
            .oneshot(
                Request::builder()
                    .uri("/health")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        let bytes = to_bytes(resp.into_body(), 2048).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();
        assert_eq!(
            v["status"], "ok",
            "round-trip should succeed against a fresh palace; got {v:?}"
        );
        assert!(
            v.get("detail").is_none() || v["detail"].is_null(),
            "successful round-trip must not carry a detail field (got {v:?})"
        );
    }

    /// Issue #185 — the `__health_probe__` palace is hidden from
    /// `MemoryService::list_palaces`.
    ///
    /// Why: The dedicated health-probe palace exists on disk and must keep
    /// existing across restarts, but it is an internal implementation detail
    /// of `/health` and must never confuse the user (in the admin UI, TUI,
    /// chat-tool palace roster, etc.).
    /// What: Provisions the probe palace via the same helper the handler uses,
    /// confirms the directory exists on disk, then asks
    /// `MemoryService::list_palaces` for the user-facing roster and asserts
    /// no palace with the reserved id (or any `__`-prefixed id) is returned.
    /// Test: this test.
    #[tokio::test]
    async fn health_probe_palace_is_invisible() {
        let state = test_state();
        ensure_health_probe_palace(&state).expect("ensure_health_probe_palace");

        // The probe palace was persisted under the data root.
        assert!(
            state.data_root.join(HEALTH_PROBE_PALACE).exists(),
            "probe palace directory should be persisted on disk"
        );

        let service = crate::service::MemoryService::new(state);
        let listed = service.list_palaces().await.expect("list_palaces");
        assert!(
            listed.iter().all(|p| !p.id.starts_with("__")),
            "no `__`-prefixed palace may appear in the user-facing list; got {:?}",
            listed.iter().map(|p| &p.id).collect::<Vec<_>>()
        );
        assert!(
            !listed.iter().any(|p| p.id == HEALTH_PROBE_PALACE),
            "the dedicated `__health_probe__` palace must be invisible; got {:?}",
            listed.iter().map(|p| &p.id).collect::<Vec<_>>()
        );
    }

    /// Issue #185 — after a successful round-trip, the probe palace holds
    /// zero drawers.
    ///
    /// Why: The probe must clean up after itself on every success path. If
    /// the forget step were ever skipped silently, the probe palace would
    /// grow unbounded over time (the original symptom was ~1,420 leaked
    /// drawers in `localLLM`). This test pins the post-condition without
    /// requiring the heavy ONNX recall — it exercises
    /// `run_health_round_trip_inner` with a recall stub that returns a
    /// synthetic hit matching the probe drawer id.
    /// What: Provisions the probe palace, opens its handle, runs the inner
    /// round-trip with a stubbed recall that returns the probe drawer, and
    /// asserts the handle's drawer count drops back to zero.
    /// Test: this test.
    #[tokio::test]
    async fn health_probe_cleans_up_on_success() {
        use trusty_common::memory_core::Drawer;

        let state = test_state();
        ensure_health_probe_palace(&state).expect("ensure_health_probe_palace");
        let handle = state
            .registry
            .open_palace(&state.data_root, &PalaceId::new(HEALTH_PROBE_PALACE))
            .expect("open probe palace");

        let result = run_health_round_trip_inner(handle.clone(), move |h, _query| async move {
            // Synthesize a hit that points at the most recently stored drawer
            // so the round-trip treats this as a successful recall.
            let drawers = h.drawers.read();
            let last = drawers
                .last()
                .cloned()
                .unwrap_or_else(|| Drawer::new(Uuid::new_v4(), "stub"));
            drop(drawers);
            Ok(vec![RecallResult {
                drawer: last,
                score: 1.0,
                layer: 1,
            }])
        })
        .await;
        assert!(
            result.is_ok(),
            "successful round-trip should return Ok; got {result:?}"
        );

        let drawer_count = handle.drawers.read().len();
        assert_eq!(
            drawer_count, 0,
            "probe palace must have zero drawers after a successful round-trip (got {drawer_count})"
        );
    }

    /// Issue #185 — when recall returns an empty result, the probe drawer is
    /// still deleted before the round-trip surfaces the failure.
    ///
    /// Why: This is the bug fix's central correctness property. Before #185
    /// the empty-result branch did `return Err(RecallMiss)` *before* calling
    /// `handle.forget(drawer_id)`, leaking the drawer. The new code calls
    /// forget unconditionally and then evaluates the recall outcome, so a
    /// recall miss can never leave a drawer behind.
    /// What: Drives `run_health_round_trip_inner` with a recall stub that
    /// returns an empty `Vec`, asserts the function reports
    /// `HealthProbeError::ProbeMissing`, and then asserts the probe palace
    /// is empty.
    /// Test: this test.
    #[tokio::test]
    async fn health_probe_cleans_up_on_recall_miss() {
        let state = test_state();
        ensure_health_probe_palace(&state).expect("ensure_health_probe_palace");
        let handle = state
            .registry
            .open_palace(&state.data_root, &PalaceId::new(HEALTH_PROBE_PALACE))
            .expect("open probe palace");

        let result = run_health_round_trip_inner(handle.clone(), |_h, _q| async move {
            // Empty result — pre-#185 this leaked the drawer.
            Ok(Vec::new())
        })
        .await;
        assert!(
            matches!(result, Err(HealthProbeError::ProbeMissing(_))),
            "recall miss must surface as ProbeMissing; got {result:?}"
        );

        let drawer_count = handle.drawers.read().len();
        assert_eq!(
            drawer_count, 0,
            "probe palace must be empty after a recall miss (got {drawer_count})"
        );
    }

    /// Issue #185 — when recall errors out, the probe drawer is still
    /// deleted before the round-trip surfaces the failure.
    ///
    /// Why: The second leak mode pre-#185: `recall` returning `Err(_)` made
    /// the function `return Err(Recall(e))` before reaching `forget`. The
    /// fix calls forget unconditionally; this test guards that ordering by
    /// stubbing a recall that always errors and asserting the palace ends
    /// empty.
    /// What: Drives `run_health_round_trip_inner` with a recall stub that
    /// returns `Err(Recall(...))`, asserts the function surfaces a Recall
    /// error, and then asserts the probe palace is empty.
    /// Test: this test.
    #[tokio::test]
    async fn health_probe_cleans_up_on_recall_error() {
        let state = test_state();
        ensure_health_probe_palace(&state).expect("ensure_health_probe_palace");
        let handle = state
            .registry
            .open_palace(&state.data_root, &PalaceId::new(HEALTH_PROBE_PALACE))
            .expect("open probe palace");

        let result = run_health_round_trip_inner(handle.clone(), |_h, _q| async move {
            Err(HealthProbeError::Recall("simulated failure".to_string()))
        })
        .await;
        assert!(
            matches!(result, Err(HealthProbeError::Recall(_))),
            "recall error must surface as Recall; got {result:?}"
        );

        let drawer_count = handle.drawers.read().len();
        assert_eq!(
            drawer_count, 0,
            "probe palace must be empty after a recall error (got {drawer_count})"
        );
    }

    /// Issue #69 — `recall_entry_json` hoists the drawer's fields to the top
    /// level so `content` is directly reachable.
    ///
    /// Why: The recall API previously wrapped the drawer under a `"drawer"`
    /// key, so clients scanning the top level for `content`/`tags` found
    /// nothing and recall always looked empty. This locks the flattened shape
    /// in place so the regression cannot silently return.
    /// What: Builds a `RecallResult`, runs it through `recall_entry_json`, and
    /// asserts `content`, `tags`, and `importance` are at the top level, that
    /// `score`/`layer` sit alongside them, and that the old `drawer` wrapper
    /// key is gone.
    /// Test: this test.
    #[test]
    fn recall_entry_json_hoists_drawer_fields() {
        use trusty_common::memory_core::Drawer;

        let room = Uuid::new_v4();
        let mut drawer = Drawer::new(room, "the answer is 42");
        drawer.tags = vec!["source:kuzu".to_string()];
        drawer.importance = 0.7;

        let entry = recall_entry_json(RecallResult {
            drawer,
            score: 0.699,
            layer: 1,
        });

        // Content must be reachable WITHOUT a `drawer` wrapper (issue #69).
        assert_eq!(
            entry.get("content").and_then(|v| v.as_str()),
            Some("the answer is 42"),
            "content must be at the top level, got {entry:?}"
        );
        assert!(
            entry.get("drawer").is_none(),
            "the legacy `drawer` wrapper must not be present, got {entry:?}"
        );
        // Other drawer fields are hoisted too.
        assert_eq!(
            entry["importance"].as_f64().map(|f| (f * 10.0).round()),
            Some(7.0)
        );
        assert_eq!(
            entry["tags"][0].as_str(),
            Some("source:kuzu"),
            "tags must be hoisted, got {entry:?}"
        );
        // Ranking metadata sits alongside the hoisted fields.
        assert_eq!(entry["layer"].as_u64(), Some(1));
        assert!(
            entry["score"]
                .as_f64()
                .is_some_and(|s| (s - 0.699).abs() < 1e-6),
            "score must be preserved, got {entry:?}"
        );
    }

    /// Issue #35 — `GET /api/v1/logs/tail` returns the most recent buffered
    /// lines and the total count.
    ///
    /// Why: operators inspect a running daemon via this endpoint; it must
    /// surface exactly what the shared `LogBuffer` holds.
    /// What: attaches a `LogBuffer` to the state, pushes three lines, GETs
    /// `?n=2`, and asserts the tail + `total`.
    /// Test: this test.
    #[tokio::test]
    async fn logs_tail_returns_recent_lines() {
        let buffer = trusty_common::log_buffer::LogBuffer::new(100);
        buffer.push("line one".to_string());
        buffer.push("line two".to_string());
        buffer.push("line three".to_string());
        let state = test_state().with_log_buffer(buffer);
        let app = router().with_state(state);
        let resp = app
            .oneshot(
                Request::builder()
                    .uri("/api/v1/logs/tail?n=2")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        let bytes = to_bytes(resp.into_body(), 4096).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();
        let lines = v["lines"].as_array().expect("lines array");
        assert_eq!(lines.len(), 2, "n=2 must return two lines");
        assert_eq!(lines[0].as_str(), Some("line two"));
        assert_eq!(lines[1].as_str(), Some("line three"));
        assert_eq!(v["total"].as_u64(), Some(3));
    }

    /// Issue #35 — `GET /api/v1/logs/tail?n=` is clamped to
    /// `[1, MAX_LOGS_TAIL_N]`.
    ///
    /// Why: a misconfigured client must not request more lines than the
    /// buffer holds, and `n=0` must still return at least one line.
    /// What: pushes five lines, requests `n=0` (clamps to 1) and an oversized
    /// `n` (clamps to the buffer length).
    /// Test: this test.
    #[tokio::test]
    async fn logs_tail_clamps_n() {
        let buffer = trusty_common::log_buffer::LogBuffer::new(100);
        for i in 0..5 {
            buffer.push(format!("l{i}"));
        }
        let state = test_state().with_log_buffer(buffer);
        let app = router().with_state(state);

        // n=0 clamps up to 1.
        let resp = app
            .clone()
            .oneshot(
                Request::builder()
                    .uri("/api/v1/logs/tail?n=0")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        let bytes = to_bytes(resp.into_body(), 4096).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();
        assert_eq!(v["lines"].as_array().expect("lines").len(), 1);

        // n far past MAX clamps down to the buffer length (5).
        let resp = app
            .oneshot(
                Request::builder()
                    .uri("/api/v1/logs/tail?n=999999")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        let bytes = to_bytes(resp.into_body(), 4096).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();
        assert_eq!(v["lines"].as_array().expect("lines").len(), 5);
    }

    /// Issue #35 — `POST /api/v1/admin/stop` acknowledges the shutdown
    /// request with `{ ok, message }`.
    ///
    /// Why: the response shape is the documented contract for the admin UI's
    /// stop button.
    /// What: calls `admin_stop` directly and asserts the JSON body. It does
    /// NOT await the spawned exit task — that would terminate the test
    /// process — but the 200 ms delay before `process::exit` guarantees the
    /// test returns first.
    /// Test: this test.
    #[tokio::test]
    async fn admin_stop_returns_ok() {
        let state = test_state();
        let Json(body) = admin_stop(State(state)).await;
        assert_eq!(body["ok"], Value::Bool(true));
        assert_eq!(body["message"].as_str(), Some("shutting down"));
    }

    /// `POST /api/v1/remember` returns 202 Accepted with a `queued` envelope
    /// and the spawned task actually persists a drawer in the target palace.
    ///
    /// Why: this is the central contract of the fire-and-forget endpoint —
    /// the response must come back immediately (no waiting on the redb write)
    /// and the work must still happen. Without this test the endpoint could
    /// silently regress to either "returns 202 but never writes" or "blocks
    /// the caller on the dispatch".
    /// What: provisions a palace, POSTs `{content, palace, tags}` to the
    /// endpoint, asserts 202 + `{status:"queued"}`, then polls the palace's
    /// drawer list (up to ~2 s) until the spawned task lands the write.
    /// Test: this test.
    #[tokio::test]
    async fn remember_async_returns_202_and_persists() {
        let state = test_state();
        // Pre-create the target palace so the spawned task does not race
        // against palace_create — we want to assert only the persist path.
        let palace = Palace {
            id: PalaceId::new("remember-async"),
            name: "remember-async".to_string(),
            description: None,
            created_at: chrono::Utc::now(),
            data_dir: state.data_root.join("remember-async"),
        };
        state
            .registry
            .create_palace(&state.data_root, palace)
            .expect("create_palace");

        let app = router().with_state(state.clone());
        let body = json!({
            "content": "Trusty-memory note CLI ships a fire-and-forget HTTP endpoint for sub-agents.",
            "palace": "remember-async",
            "tags": ["docs", "note-cli"],
        })
        .to_string();
        let resp = app
            .oneshot(
                Request::builder()
                    .method("POST")
                    .uri("/api/v1/remember")
                    .header("content-type", "application/json")
                    .body(Body::from(body))
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(
            resp.status(),
            StatusCode::ACCEPTED,
            "remember endpoint must respond 202 immediately"
        );
        let bytes = to_bytes(resp.into_body(), 1024).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();
        assert_eq!(v["status"], "queued");

        // Wait for the spawned task to finish. The dedup/blocklist gates run
        // on the spawn thread, so we cannot synchronously await the write;
        // poll the registry until the drawer lands or the deadline expires.
        let handle = state
            .registry
            .open_palace(&state.data_root, &PalaceId::new("remember-async"))
            .expect("open palace");
        let deadline = std::time::Instant::now() + std::time::Duration::from_secs(5);
        loop {
            let count = handle.drawers.read().len();
            if count >= 1 {
                break;
            }
            if std::time::Instant::now() >= deadline {
                panic!("spawned remember task never persisted a drawer (count={count})");
            }
            tokio::time::sleep(std::time::Duration::from_millis(50)).await;
        }
    }

    /// `POST /api/v1/remember` with empty `content` returns 400 — the only
    /// synchronous validation the endpoint performs.
    ///
    /// Why: empty content is a programming error in the caller (the spawned
    /// task would just hit the content-gate and silently drop the request),
    /// so we surface it as a 400 before queueing. Every other failure mode
    /// (palace not found, blocklist, dedup) is logged on the spawn task and
    /// still returns 202 because the agent has already exited by then.
    /// What: POST `{content: ""}` and assert 400. Also covers the trim path —
    /// whitespace-only content is treated as empty.
    /// Test: this test.
    #[tokio::test]
    async fn remember_async_rejects_empty_content() {
        let state = test_state();
        let app = router().with_state(state);
        for body in [json!({"content": ""}), json!({"content": "   \n  "})] {
            let resp = app
                .clone()
                .oneshot(
                    Request::builder()
                        .method("POST")
                        .uri("/api/v1/remember")
                        .header("content-type", "application/json")
                        .body(Body::from(body.to_string()))
                        .unwrap(),
                )
                .await
                .unwrap();
            assert_eq!(
                resp.status(),
                StatusCode::BAD_REQUEST,
                "empty content must be rejected; body={body}"
            );
        }
    }

    #[tokio::test]
    async fn status_endpoint_returns_payload() {
        let state = test_state();
        let app = router().with_state(state);
        let resp = app
            .oneshot(
                Request::builder()
                    .uri("/api/v1/status")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        let bytes = to_bytes(resp.into_body(), 1024).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();
        assert!(v["version"].is_string());
        assert_eq!(v["palace_count"], 0);
    }

    #[tokio::test]
    async fn unknown_api_returns_404() {
        let state = test_state();
        let app = router().with_state(state);
        let resp = app
            .oneshot(
                Request::builder()
                    .uri("/api/v1/does-not-exist")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::NOT_FOUND);
    }

    /// Issue #70 — `…/memories` is a working alias for `…/drawers`.
    ///
    /// Why: Clients that POST/GET against `…/memories` previously hit a 404
    /// because only `/drawers` was registered, which silently broke every
    /// store call (and pushed callers onto an OOM-prone CLI fallback). The
    /// alias must route to the same handler as `/drawers`.
    /// What: Creates a real palace via the registry, then GETs the `/memories`
    /// alias and asserts a 200 with a JSON array body (the list-drawers shape).
    /// Uses GET, not POST, so the test stays embedder-free (no ONNX load).
    /// Test: this test.
    #[tokio::test]
    async fn memories_alias_routes_to_drawers() {
        let state = test_state();
        let palace = Palace {
            id: PalaceId::new("alias-test"),
            name: "alias-test".to_string(),
            description: None,
            created_at: chrono::Utc::now(),
            data_dir: state.data_root.join("alias-test"),
        };
        state
            .registry
            .create_palace(&state.data_root, palace)
            .expect("create_palace");

        let app = router().with_state(state);
        let resp = app
            .oneshot(
                Request::builder()
                    .uri("/api/v1/palaces/alias-test/memories")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(
            resp.status(),
            StatusCode::OK,
            "the /memories alias must resolve to list_drawers, not 404"
        );
        let bytes = to_bytes(resp.into_body(), 4096).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();
        assert!(
            v.is_array(),
            "the alias must return the list-drawers array shape, got {v:?}"
        );
    }

    /// Issue #133 — `POST /api/v1/palaces/{id}/drawers` must trigger the
    /// same auto-KG extraction as the MCP `memory_remember` tool.
    ///
    /// Why: PR #106 wired auto-extract only into the MCP path; HTTP-origin
    /// writes silently skipped it, leaving every palace populated via the
    /// HTTP API with an empty KG. This regression test posts a drawer over
    /// HTTP and then queries the KG to confirm the expected `tag:`,
    /// `room:`, and `topic:` (`#hashtag`) auto-extracted triples landed.
    /// What: creates a palace via the registry, posts a drawer with tags +
    /// room + a `#hashtag` over the HTTP endpoint, reads
    /// `/api/v1/palaces/{id}/kg/graph`, and asserts the auto-extracted
    /// triples (provenance = `auto:remember`) appear.
    /// Test: this test.
    #[tokio::test]
    async fn http_create_drawer_runs_auto_kg_extraction() {
        let state = test_state();
        let palace = Palace {
            id: PalaceId::new("kgauto-http"),
            name: "kgauto-http".to_string(),
            description: None,
            created_at: chrono::Utc::now(),
            data_dir: state.data_root.join("kgauto-http"),
        };
        state
            .registry
            .create_palace(&state.data_root, palace)
            .expect("create_palace");

        let app = router().with_state(state.clone());
        // Why: tag "test" is in the KG extraction deny-list (issue #278), so we
        // use "backend" and "kg" tags to exercise the auto-extraction path
        // without triggering the deny-list skip.
        let body = json!({
            "content": "trusty-memory is a Rust crate that ships an MCP server. \
                        It tracks #mcp and #rust topics with care.",
            "room": "Backend",
            "tags": ["backend", "kg"],
            "importance": 0.5,
        })
        .to_string();
        let resp = app
            .clone()
            .oneshot(
                Request::builder()
                    .method("POST")
                    .uri("/api/v1/palaces/kgauto-http/drawers")
                    .header("content-type", "application/json")
                    .body(Body::from(body))
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(
            resp.status(),
            StatusCode::OK,
            "create_drawer must return 200 OK"
        );

        // Read the KG graph for the same palace and assert auto-extracted
        // triples landed. The exact set is exercised in
        // `tools::tests::auto_kg_extraction_hooks_into_memory_remember`; here
        // we only need to confirm the HTTP path now mirrors the MCP path.
        let resp = app
            .oneshot(
                Request::builder()
                    .uri("/api/v1/palaces/kgauto-http/kg/graph")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        let bytes = to_bytes(resp.into_body(), 64 * 1024).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();
        let triples = v["triples"].as_array().expect("triples array");
        assert!(
            !triples.is_empty(),
            "HTTP-origin drawer must populate the KG; got empty graph"
        );
        let auto: Vec<&Value> = triples
            .iter()
            .filter(|t| t["provenance"].as_str() == Some(crate::kg_extract::AUTO_PROVENANCE))
            .collect();
        assert!(
            !auto.is_empty(),
            "expected at least one auto-extracted triple in HTTP-populated KG; got: {triples:?}"
        );
        // Spot-check the tag-as-subject encoding survived (matches the MCP
        // path's behaviour and proves the extractor saw the body's tags).
        // Note: "test" is in the deny-list, so we use "backend" in the drawer
        // tags above (issue #278); assert on that tag instead.
        assert!(
            auto.iter()
                .any(|t| t["subject"].as_str() == Some("tag:backend")),
            "expected `tag:backend` auto-extracted edge, got: {auto:?}"
        );
        // Hashtag mention triples (room-aware extractor).
        assert!(
            auto.iter()
                .any(|t| t["predicate"].as_str() == Some("mentioned-in")),
            "expected at least one #hashtag mention triple, got: {auto:?}"
        );
    }

    #[tokio::test]
    async fn create_then_list_palace() {
        let state = test_state();
        let app = router().with_state(state.clone());
        let body = json!({"name": "web-test", "description": "from test"}).to_string();
        let resp = app
            .clone()
            .oneshot(
                Request::builder()
                    .method("POST")
                    .uri("/api/v1/palaces")
                    .header("content-type", "application/json")
                    .body(Body::from(body))
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);

        let resp = app
            .oneshot(
                Request::builder()
                    .uri("/api/v1/palaces")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        let bytes = to_bytes(resp.into_body(), 4096).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();
        let arr = v.as_array().expect("array");
        assert!(arr.iter().any(|p| p["id"] == "web-test"));
    }

    /// Why: Issue #180 — verify the happy path: create an empty palace,
    /// `DELETE /api/v1/palaces/{id}` returns 204, and a follow-up
    /// `GET /api/v1/palaces/{id}` returns 404 because the directory is gone.
    /// What: Drives the router through axum's `oneshot` testing layer; no
    /// query parameters are passed so `force` defaults to `false`. A freshly
    /// created palace has no drawers, so the conflict guard does not fire.
    /// Test: This test itself.
    #[tokio::test]
    async fn delete_palace_removes_dir_when_empty() {
        let state = test_state();
        let app = router().with_state(state.clone());
        let body = json!({"name": "to-delete"}).to_string();
        let resp = app
            .clone()
            .oneshot(
                Request::builder()
                    .method("POST")
                    .uri("/api/v1/palaces")
                    .header("content-type", "application/json")
                    .body(Body::from(body))
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);

        let resp = app
            .clone()
            .oneshot(
                Request::builder()
                    .method("DELETE")
                    .uri("/api/v1/palaces/to-delete")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::NO_CONTENT);

        // Confirm the palace is gone from the on-disk registry.
        let resp = app
            .oneshot(
                Request::builder()
                    .uri("/api/v1/palaces/to-delete")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::NOT_FOUND);

        // And the on-disk directory itself was removed.
        let palace_dir = state.data_root.join("to-delete");
        assert!(
            !palace_dir.exists(),
            "palace dir should be removed: {}",
            palace_dir.display()
        );
    }

    /// Why: Issue #180 — without `force=true` we must refuse to drop a
    /// palace that still has drawers, otherwise a stray DELETE could nuke
    /// hours of memory in one request.
    /// What: Create a palace, write a drawer into it, then DELETE without
    /// `force`. Expect 409 Conflict and verify the palace and drawer are
    /// still on disk.
    /// Test: This test itself.
    #[tokio::test]
    async fn delete_palace_refuses_when_drawers_present() {
        let state = test_state();
        let app = router().with_state(state.clone());
        // Create the palace.
        let resp = app
            .clone()
            .oneshot(
                Request::builder()
                    .method("POST")
                    .uri("/api/v1/palaces")
                    .header("content-type", "application/json")
                    .body(Body::from(json!({"name": "keep-me"}).to_string()))
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        // Add a drawer so the conflict guard fires.
        let resp = app
            .clone()
            .oneshot(
                Request::builder()
                    .method("POST")
                    .uri("/api/v1/palaces/keep-me/drawers")
                    .header("content-type", "application/json")
                    .body(Body::from(
                        json!({
                            "content": "Important fact that should not be deleted accidentally.",
                            "tags": [],
                        })
                        .to_string(),
                    ))
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);

        let resp = app
            .clone()
            .oneshot(
                Request::builder()
                    .method("DELETE")
                    .uri("/api/v1/palaces/keep-me")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::CONFLICT);

        // Palace still resolves.
        let resp = app
            .oneshot(
                Request::builder()
                    .uri("/api/v1/palaces/keep-me")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
    }

    /// Why: Issue #180 — `?force=true` is the explicit destructive opt-in;
    /// the conflict guard must yield and the palace must vanish even with
    /// drawers present.
    /// What: Same setup as the conflict test, but pass `?force=true` and
    /// assert the 204 + 404 follow-up shape.
    /// Test: This test itself.
    #[tokio::test]
    async fn delete_palace_force_removes_populated_palace() {
        let state = test_state();
        let app = router().with_state(state.clone());
        let resp = app
            .clone()
            .oneshot(
                Request::builder()
                    .method("POST")
                    .uri("/api/v1/palaces")
                    .header("content-type", "application/json")
                    .body(Body::from(json!({"name": "force-delete"}).to_string()))
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        let resp = app
            .clone()
            .oneshot(
                Request::builder()
                    .method("POST")
                    .uri("/api/v1/palaces/force-delete/drawers")
                    .header("content-type", "application/json")
                    .body(Body::from(
                        json!({"content": "Sacrificial drawer for the force-delete path.", "tags": []}).to_string(),
                    ))
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);

        let resp = app
            .clone()
            .oneshot(
                Request::builder()
                    .method("DELETE")
                    .uri("/api/v1/palaces/force-delete?force=true")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::NO_CONTENT);

        let resp = app
            .oneshot(
                Request::builder()
                    .uri("/api/v1/palaces/force-delete")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::NOT_FOUND);
    }

    /// Why: Issue #180 — deleting a missing palace must yield 404 so
    /// idempotent retries on the client are distinguishable from the
    /// "drawers present" precondition failure.
    /// What: DELETE against a never-created id and assert 404.
    /// Test: This test itself.
    #[tokio::test]
    async fn delete_palace_returns_not_found_for_missing_id() {
        let state = test_state();
        let app = router().with_state(state);
        let resp = app
            .oneshot(
                Request::builder()
                    .method("DELETE")
                    .uri("/api/v1/palaces/never-existed")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::NOT_FOUND);
    }

    /// Why: Issue #180 follow-up — verify the happy path of `PATCH
    /// /api/v1/palaces/{id}`: create a palace, rename it, and confirm
    /// `GET /api/v1/palaces/{id}` returns the new display name. The id
    /// (which is the on-disk directory) must stay stable.
    /// What: POST a palace named "rename-me", PATCH with a new display
    /// name, expect 200 + payload showing the rename, then GET to confirm
    /// persistence to disk.
    /// Test: This test itself.
    #[tokio::test]
    async fn update_palace_name_renames_palace() {
        let state = test_state();
        let app = router().with_state(state);
        let resp = app
            .clone()
            .oneshot(
                Request::builder()
                    .method("POST")
                    .uri("/api/v1/palaces")
                    .header("content-type", "application/json")
                    .body(Body::from(json!({"name": "rename-me"}).to_string()))
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);

        let resp = app
            .clone()
            .oneshot(
                Request::builder()
                    .method("PATCH")
                    .uri("/api/v1/palaces/rename-me")
                    .header("content-type", "application/json")
                    .body(Body::from(json!({"name": "New Display Name"}).to_string()))
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        let bytes = to_bytes(resp.into_body(), 4096).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();
        assert_eq!(v["id"].as_str(), Some("rename-me"));
        assert_eq!(v["name"].as_str(), Some("New Display Name"));

        let resp = app
            .oneshot(
                Request::builder()
                    .uri("/api/v1/palaces/rename-me")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        let bytes = to_bytes(resp.into_body(), 4096).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();
        assert_eq!(v["id"].as_str(), Some("rename-me"));
        assert_eq!(v["name"].as_str(), Some("New Display Name"));
    }

    /// Why: Issue #180 follow-up — empty / whitespace-only names would
    /// break the dashboard label. Reject with 400 so the caller knows the
    /// request was well-formed but the value is invalid.
    /// What: Create a palace, PATCH with `{"name": "   "}`, expect 400.
    /// Test: This test itself.
    #[tokio::test]
    async fn update_palace_name_rejects_empty_name() {
        let state = test_state();
        let app = router().with_state(state);
        let resp = app
            .clone()
            .oneshot(
                Request::builder()
                    .method("POST")
                    .uri("/api/v1/palaces")
                    .header("content-type", "application/json")
                    .body(Body::from(json!({"name": "keep-name"}).to_string()))
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);

        let resp = app
            .oneshot(
                Request::builder()
                    .method("PATCH")
                    .uri("/api/v1/palaces/keep-name")
                    .header("content-type", "application/json")
                    .body(Body::from(json!({"name": "   "}).to_string()))
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::BAD_REQUEST);
    }

    /// Why: Issue #180 follow-up — patching a non-existent palace must
    /// yield 404 so retries against the wrong id surface the real problem
    /// rather than silently no-op'ing.
    /// What: PATCH against a never-created id and assert 404.
    /// Test: This test itself.
    #[tokio::test]
    async fn update_palace_name_returns_not_found_for_missing_id() {
        let state = test_state();
        let app = router().with_state(state);
        let resp = app
            .oneshot(
                Request::builder()
                    .method("PATCH")
                    .uri("/api/v1/palaces/no-such-palace")
                    .header("content-type", "application/json")
                    .body(Body::from(json!({"name": "irrelevant"}).to_string()))
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::NOT_FOUND);
    }

    /// Why: The operator TUI's MEMORY tab reads `node_count`, `edge_count`,
    /// `community_count`, and `is_compacting` straight off the
    /// `/api/v1/palaces` payload. If any of those fields disappear or change
    /// type the spinner / counters break silently. Pin the shape here.
    /// What: Creates a palace, lists `/api/v1/palaces`, and asserts every new
    /// field is present and typed as expected (numbers default to 0, the
    /// compacting flag defaults to false on a freshly-opened palace).
    /// Test: This test itself.
    #[tokio::test]
    async fn palace_list_includes_graph_counts() {
        let state = test_state();
        let app = router().with_state(state.clone());
        let body = json!({"name": "graph-counts", "description": null}).to_string();
        let resp = app
            .clone()
            .oneshot(
                Request::builder()
                    .method("POST")
                    .uri("/api/v1/palaces")
                    .header("content-type", "application/json")
                    .body(Body::from(body))
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);

        let resp = app
            .oneshot(
                Request::builder()
                    .uri("/api/v1/palaces")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        let bytes = to_bytes(resp.into_body(), 4096).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();
        let arr = v.as_array().expect("array");
        let row = arr
            .iter()
            .find(|p| p["id"] == "graph-counts")
            .expect("created palace must appear in list");
        assert_eq!(row["node_count"].as_u64(), Some(0));
        assert_eq!(row["edge_count"].as_u64(), Some(0));
        assert_eq!(row["community_count"].as_u64(), Some(0));
        assert_eq!(row["is_compacting"].as_bool(), Some(false));
    }

    /// Why: The enriched status payload backs the dashboard's top-row stats;
    /// it must always include the new total_* counters, even on an empty data
    /// root, so the UI can render zeros without special-casing missing fields.
    /// What: Hit `/api/v1/status` on a fresh state and assert the new fields
    /// are present and set to 0.
    /// Test: This test itself.
    #[tokio::test]
    async fn status_includes_total_counters() {
        let state = test_state();
        let app = router().with_state(state);
        let resp = app
            .oneshot(
                Request::builder()
                    .uri("/api/v1/status")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        let bytes = to_bytes(resp.into_body(), 4096).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();
        assert_eq!(v["total_drawers"], 0);
        assert_eq!(v["total_vectors"], 0);
        assert_eq!(v["total_kg_triples"], 0);
    }

    /// Why: `/api/v1/dream/status` must return a well-shaped payload even
    /// when no palace has ever run a dream cycle (so the dashboard's first
    /// load doesn't error).
    /// What: Hit the endpoint on a fresh state and assert `last_run_at` is
    /// null and the counters are zero.
    /// Test: This test itself.
    #[tokio::test]
    async fn dream_status_empty_returns_nulls() {
        let state = test_state();
        let app = router().with_state(state);
        let resp = app
            .oneshot(
                Request::builder()
                    .uri("/api/v1/dream/status")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        let bytes = to_bytes(resp.into_body(), 4096).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();
        assert!(v["last_run_at"].is_null());
        assert_eq!(v["merged"], 0);
        assert_eq!(v["pruned"], 0);
    }

    /// Why: `/api/v1/chat/providers` must return a well-shaped payload even
    /// when no provider is available, so the SPA can render disabled states
    /// without special-casing missing fields.
    /// What: Hit the endpoint on a fresh state; assert it returns `providers`
    /// (an array of length 2) and an `active` field (possibly null).
    /// Test: This test itself.
    #[tokio::test]
    async fn providers_endpoint_returns_payload() {
        let state = test_state();
        let app = router().with_state(state);
        let resp = app
            .oneshot(
                Request::builder()
                    .uri("/api/v1/chat/providers")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        let bytes = to_bytes(resp.into_body(), 4096).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();
        let arr = v["providers"].as_array().expect("providers array");
        assert_eq!(arr.len(), 2);
        let names: Vec<&str> = arr.iter().filter_map(|p| p["name"].as_str()).collect();
        assert!(names.contains(&"ollama"));
        assert!(names.contains(&"openrouter"));
        // `active` may be null when no provider is configured/reachable.
        assert!(v.get("active").is_some());
    }

    /// Why: Chat-session CRUD must round-trip end-to-end through the HTTP
    /// surface — create returns an id, list shows it, get returns the
    /// (empty) history, delete removes it.
    /// What: Create a palace, then exercise the four session endpoints
    /// sequentially, asserting JSON shapes at each step.
    /// Test: This test itself.
    #[tokio::test]
    async fn chat_session_crud_round_trip() {
        let state = test_state();
        // Pre-create a palace dir so session store has a place to live.
        let palace = trusty_common::memory_core::Palace {
            id: PalaceId::new("sess-test"),
            name: "sess-test".to_string(),
            description: None,
            created_at: chrono::Utc::now(),
            data_dir: state.data_root.join("sess-test"),
        };
        state
            .registry
            .create_palace(&state.data_root, palace)
            .expect("create_palace");
        let app = router().with_state(state);

        // Create
        let resp = app
            .clone()
            .oneshot(
                Request::builder()
                    .method("POST")
                    .uri("/api/v1/palaces/sess-test/chat/sessions")
                    .header("content-type", "application/json")
                    .body(Body::from(json!({"title":"first chat"}).to_string()))
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        let bytes = to_bytes(resp.into_body(), 4096).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();
        let sid = v["id"].as_str().expect("session id").to_string();

        // List
        let resp = app
            .clone()
            .oneshot(
                Request::builder()
                    .uri("/api/v1/palaces/sess-test/chat/sessions")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        let bytes = to_bytes(resp.into_body(), 4096).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();
        let arr = v.as_array().expect("array");
        assert!(arr.iter().any(|s| s["id"] == sid));

        // Get
        let resp = app
            .clone()
            .oneshot(
                Request::builder()
                    .uri(format!("/api/v1/palaces/sess-test/chat/sessions/{sid}"))
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);

        // Delete
        let resp = app
            .clone()
            .oneshot(
                Request::builder()
                    .method("DELETE")
                    .uri(format!("/api/v1/palaces/sess-test/chat/sessions/{sid}"))
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::NO_CONTENT);

        // Get after delete -> 404
        let resp = app
            .oneshot(
                Request::builder()
                    .uri(format!("/api/v1/palaces/sess-test/chat/sessions/{sid}"))
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::NOT_FOUND);
    }

    /// Why: issue #99 — the HTTP surface for inter-project messaging is what
    /// `trusty-memory send-message` and `trusty-memory inbox-check` both
    /// drive. We pin the round-trip (send → list-unread → mark-read →
    /// list-empty) so a future refactor cannot accidentally break either
    /// CLI without a failing test.
    /// What: pre-creates the recipient palace, POSTs a message, asserts
    /// `unread_only=true` returns exactly one entry with the right
    /// envelope fields, POSTs to mark_read, asserts the unread inbox is
    /// now empty, and confirms the audit view (`unread_only=false`) still
    /// surfaces the read message.
    /// Test: this test itself.
    #[tokio::test]
    async fn messages_endpoint_round_trip() {
        let state = test_state();
        let palace = trusty_common::memory_core::Palace {
            id: PalaceId::new("msg-test"),
            name: "msg-test".to_string(),
            description: None,
            created_at: chrono::Utc::now(),
            data_dir: state.data_root.join("msg-test"),
        };
        state
            .registry
            .create_palace(&state.data_root, palace)
            .expect("create_palace");
        let app = router().with_state(state);

        // POST /api/v1/messages — send.
        let resp = app
            .clone()
            .oneshot(
                Request::builder()
                    .method("POST")
                    .uri("/api/v1/messages")
                    .header("content-type", "application/json")
                    .body(Body::from(
                        json!({
                            "to_palace":   "msg-test",
                            "from_palace": "sender-palace",
                            "purpose":     "task",
                            "content":     "please refresh schema"
                        })
                        .to_string(),
                    ))
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        let bytes = to_bytes(resp.into_body(), 4096).await.unwrap();
        let send_resp: Value = serde_json::from_slice(&bytes).unwrap();
        assert_eq!(send_resp["status"], "sent");
        let drawer_id = send_resp["drawer_id"]
            .as_str()
            .expect("drawer_id")
            .to_string();

        // GET unread inbox.
        let resp = app
            .clone()
            .oneshot(
                Request::builder()
                    .uri("/api/v1/messages?palace=msg-test&unread_only=true")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        let bytes = to_bytes(resp.into_body(), 8192).await.unwrap();
        let list: Vec<Value> = serde_json::from_slice(&bytes).unwrap();
        assert_eq!(list.len(), 1);
        assert_eq!(list[0]["id"], drawer_id);
        assert_eq!(list[0]["from_palace"], "sender-palace");
        assert_eq!(list[0]["to_palace"], "msg-test");
        assert_eq!(list[0]["purpose"], "task");
        assert_eq!(list[0]["content"], "please refresh schema");
        assert_eq!(list[0]["read"], false);
        assert!(list[0]["formatted"]
            .as_str()
            .unwrap()
            .contains("sender-palace"));

        // POST mark_read.
        let resp = app
            .clone()
            .oneshot(
                Request::builder()
                    .method("POST")
                    .uri("/api/v1/messages/mark_read")
                    .header("content-type", "application/json")
                    .body(Body::from(
                        json!({"palace": "msg-test", "drawer_id": drawer_id}).to_string(),
                    ))
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        let bytes = to_bytes(resp.into_body(), 1024).await.unwrap();
        let mark: Value = serde_json::from_slice(&bytes).unwrap();
        assert_eq!(mark["flipped"], true);

        // GET unread again — empty.
        let resp = app
            .clone()
            .oneshot(
                Request::builder()
                    .uri("/api/v1/messages?palace=msg-test&unread_only=true")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        let bytes = to_bytes(resp.into_body(), 4096).await.unwrap();
        let list: Vec<Value> = serde_json::from_slice(&bytes).unwrap();
        assert!(list.is_empty(), "inbox cleared after mark_read");

        // GET history (unread_only=false) — still has the message, now read.
        let resp = app
            .oneshot(
                Request::builder()
                    .uri("/api/v1/messages?palace=msg-test&unread_only=false")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        let bytes = to_bytes(resp.into_body(), 8192).await.unwrap();
        let history: Vec<Value> = serde_json::from_slice(&bytes).unwrap();
        assert_eq!(history.len(), 1);
        assert_eq!(history[0]["read"], true);
    }

    /// Why: The chat assistant's tool surface is part of the public API — any
    /// drift in tool names or required-argument lists is a breaking change for
    /// the UI and any external automation. Pin the shape here so a refactor
    /// has to acknowledge it.
    /// What: Snapshots the names + every tool's `required` array.
    /// Test: This test itself.
    #[test]
    fn all_tools_returns_expected_set() {
        let tools = crate::chat::all_tools();
        let names: Vec<&str> = tools.iter().map(|t| t.name.as_str()).collect();
        assert_eq!(
            names,
            vec![
                "list_palaces",
                "get_palace",
                "recall_memories",
                "list_drawers",
                "kg_query",
                "get_config",
                "get_status",
                "get_dream_status",
                "get_palace_dream_status",
                "create_memory",
                "kg_assert",
                "memory_recall_all",
            ]
        );
        // Every tool's `parameters` must be a JSON Schema object with a
        // `required` array (possibly empty).
        for t in &tools {
            assert_eq!(
                t.parameters["type"], "object",
                "tool {} schema type",
                t.name
            );
            assert!(
                t.parameters["required"].is_array(),
                "tool {} required not array",
                t.name
            );
        }
    }

    /// Why: `execute_tool` is the bridge between the model's tool_call
    /// arguments and the live Rust core. We exercise the happy path
    /// (`list_palaces` on an empty registry returns `[]`) and the unknown-
    /// tool path (returns `{"error": "..."}`) to lock down both branches.
    /// What: Calls execute_tool against a fresh `AppState`.
    /// Test: This test itself.
    #[tokio::test]
    async fn execute_tool_dispatches_known_tools() {
        let state = test_state();
        let result = crate::chat::execute_tool("list_palaces", "{}", &state).await;
        assert!(
            result.is_array(),
            "list_palaces should be array, got {result}"
        );
        assert_eq!(result.as_array().unwrap().len(), 0);

        let unknown = crate::chat::execute_tool("not_a_tool", "{}", &state).await;
        assert!(
            unknown["error"]
                .as_str()
                .unwrap_or("")
                .contains("unknown tool"),
            "expected unknown-tool error, got {unknown}"
        );

        let missing = crate::chat::execute_tool("get_palace", "{}", &state).await;
        assert!(
            missing["error"]
                .as_str()
                .unwrap_or("")
                .contains("palace_id"),
            "expected missing-arg error, got {missing}"
        );
    }

    /// Why: The SSE event bus is the dashboard's live-update transport;
    /// regressing it would silently break the UI. Subscribing before the
    /// emit guarantees the broadcast channel has a receiver when the
    /// handler fires, so we can deterministically observe the event.
    /// What: Subscribes to `state.events`, calls the `create_palace`
    /// handler through the router, then asserts a `PalaceCreated` event
    /// (and a follow-up status event from drawer mutation) flow through.
    /// Test: `cargo test -p trusty-memory-mcp sse_broadcast_emits_palace_created`.
    #[tokio::test]
    async fn sse_broadcast_emits_palace_created() {
        let state = test_state();
        let mut rx = state.events.subscribe();
        let app = router().with_state(state.clone());
        let body = json!({"name": "sse-test"}).to_string();
        let resp = app
            .oneshot(
                Request::builder()
                    .method("POST")
                    .uri("/api/v1/palaces")
                    .header("content-type", "application/json")
                    .body(Body::from(body))
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        // The handler should have emitted PalaceCreated before returning.
        let event = tokio::time::timeout(std::time::Duration::from_millis(500), rx.recv())
            .await
            .expect("event received within timeout")
            .expect("event channel still open");
        match event {
            DaemonEvent::PalaceCreated { id, name, source } => {
                assert_eq!(id, "sse-test");
                assert_eq!(name, "sse-test");
                assert_eq!(source, ActivitySource::Http);
            }
            other => panic!("expected PalaceCreated, got {other:?}"),
        }
    }

    /// Why: Confirm the `/sse` endpoint speaks `text/event-stream` and emits
    /// the initial `connected` frame so dashboard clients can rely on a
    /// known greeting.
    /// What: Issues a GET against `/sse`, reads the response body chunk,
    /// asserts the content-type header and the first SSE frame shape.
    /// Test: `cargo test -p trusty-memory-mcp sse_endpoint_emits_connected_frame`.
    #[tokio::test]
    async fn sse_endpoint_emits_connected_frame() {
        use axum::routing::get;
        let state = test_state();
        let app = router()
            .route("/sse", get(crate::sse_handler))
            .with_state(state);
        let resp = app
            .oneshot(Request::builder().uri("/sse").body(Body::empty()).unwrap())
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        assert_eq!(
            resp.headers()
                .get(header::CONTENT_TYPE)
                .and_then(|v| v.to_str().ok()),
            Some("text/event-stream")
        );
        // Read just the first chunk (the connected frame) — the stream stays
        // open otherwise, so we use a small read budget plus timeout.
        let body = resp.into_body();
        let bytes =
            tokio::time::timeout(std::time::Duration::from_millis(500), to_bytes(body, 4096))
                .await
                .ok()
                .and_then(|r| r.ok())
                .unwrap_or_default();
        let text = String::from_utf8_lossy(&bytes);
        assert!(
            text.contains("\"type\":\"connected\""),
            "expected connected frame, got: {text}"
        );
    }

    /// Why: `/api/v1/dream/status` must sum per-palace `dream_stats.json`
    /// counters and surface the most recent `last_run_at`. A regression that
    /// returned only the first palace's stats would silently break the
    /// "global dream activity" dashboard panel.
    /// What: Pre-seeds two palace dirs under the AppState root, writes a
    /// distinct `PersistedDreamStats` JSON file into each, hits the endpoint,
    /// and asserts the integer fields are summed and `last_run_at` equals the
    /// newer of the two timestamps.
    /// Test: This test itself.
    #[tokio::test]
    async fn dream_status_aggregates_across_palaces() {
        use trusty_common::memory_core::dream::{DreamStats, PersistedDreamStats};

        let state = test_state();
        // Two palace directories — each must contain a `palace.json` so
        // `PalaceRegistry::list_palaces` sees them, plus a `dream_stats.json`
        // with distinct counter values.
        for (id, stats, ts) in [
            (
                "palace-a",
                DreamStats {
                    merged: 1,
                    pruned: 2,
                    compacted: 3,
                    closets_updated: 4,
                    duration_ms: 100,
                    ..DreamStats::default()
                },
                chrono::Utc::now() - chrono::Duration::seconds(60),
            ),
            (
                "palace-b",
                DreamStats {
                    merged: 10,
                    pruned: 20,
                    compacted: 30,
                    closets_updated: 40,
                    duration_ms: 200,
                    ..DreamStats::default()
                },
                chrono::Utc::now(),
            ),
        ] {
            let palace = trusty_common::memory_core::Palace {
                id: PalaceId::new(id),
                name: id.to_string(),
                description: None,
                created_at: chrono::Utc::now(),
                data_dir: state.data_root.join(id),
            };
            state
                .registry
                .create_palace(&state.data_root, palace)
                .expect("create palace");
            let persisted = PersistedDreamStats {
                last_run_at: ts,
                stats,
            };
            persisted
                .save(&state.data_root.join(id))
                .expect("save dream stats");
        }

        let later = chrono::Utc::now();
        let app = router().with_state(state);
        let resp = app
            .oneshot(
                Request::builder()
                    .uri("/api/v1/dream/status")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        let bytes = to_bytes(resp.into_body(), 4096).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();

        // Aggregated counters.
        assert_eq!(v["merged"], 11);
        assert_eq!(v["pruned"], 22);
        assert_eq!(v["compacted"], 33);
        assert_eq!(v["closets_updated"], 44);
        assert_eq!(v["duration_ms"], 300);

        // `last_run_at` is the more-recent of the two timestamps.
        let last = v["last_run_at"].as_str().expect("last_run_at is string");
        let parsed: chrono::DateTime<chrono::Utc> = last
            .parse()
            .expect("last_run_at parses as RFC3339 timestamp");
        assert!(
            parsed <= later,
            "last_run_at ({parsed}) should not exceed wall clock ({later})"
        );
        // Must have picked palace-b's newer stamp, not palace-a's older one.
        let cutoff = chrono::Utc::now() - chrono::Duration::seconds(30);
        assert!(
            parsed >= cutoff,
            "expected the newer (palace-b) timestamp; got {parsed}"
        );
    }

    /// Why: `POST /api/v1/dream/run` triggers a dream cycle across every
    /// palace and must return the aggregated stats. Even when no palace
    /// has work to do (empty registry) the endpoint must round-trip 200
    /// with the well-formed payload shape so the dashboard's "Run now"
    /// button never fails the UI.
    /// What: Pre-creates one palace via the registry, posts to the endpoint,
    /// and asserts the response is 200 with all expected fields present.
    /// Deeper assertions (specific merged/pruned counts) are skipped here
    /// because running a full dream cycle requires the ONNX embedder load
    /// path and we want this test to stay fast and embedder-free.
    /// Test: This test itself.
    #[tokio::test]
    async fn dream_run_aggregates_stats() {
        let state = test_state();
        let palace = trusty_common::memory_core::Palace {
            id: PalaceId::new("dream-run-test"),
            name: "dream-run-test".to_string(),
            description: None,
            created_at: chrono::Utc::now(),
            data_dir: state.data_root.join("dream-run-test"),
        };
        state
            .registry
            .create_palace(&state.data_root, palace)
            .expect("create palace");

        let app = router().with_state(state);
        let resp = app
            .oneshot(
                Request::builder()
                    .method("POST")
                    .uri("/api/v1/dream/run")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        let bytes = to_bytes(resp.into_body(), 4096).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();

        // Shape: every aggregated counter must be present (even if zero) and
        // `last_run_at` is set by the handler to "now".
        for key in [
            "merged",
            "pruned",
            "compacted",
            "closets_updated",
            "duration_ms",
        ] {
            assert!(
                v.get(key).is_some(),
                "missing key {key} in dream_run payload: {v}"
            );
            assert!(
                v[key].is_u64() || v[key].is_i64(),
                "{key} should be integer, got {}",
                v[key]
            );
        }
        assert!(
            v["last_run_at"].is_string(),
            "last_run_at must be set by dream_run; got {v}"
        );
    }

    /// Why: Issue #53 — when the dream cycle has not yet run for a palace,
    /// `/api/v1/kg/gaps` must return an empty array (200 OK), not 404 or
    /// 500. The cache miss is a meaningful, non-error state.
    /// What: Creates a palace, queries `/api/v1/kg/gaps?palace=...`, asserts
    /// the response is `200` with body `[]`.
    /// Test: this test itself.
    #[tokio::test]
    async fn kg_gaps_endpoint_returns_empty_when_uncached() {
        let state = test_state();
        let palace = trusty_common::memory_core::Palace {
            id: PalaceId::new("gaps-empty"),
            name: "gaps-empty".to_string(),
            description: None,
            created_at: chrono::Utc::now(),
            data_dir: state.data_root.join("gaps-empty"),
        };
        state
            .registry
            .create_palace(&state.data_root, palace)
            .expect("create palace");

        let app = router().with_state(state);
        let resp = app
            .oneshot(
                Request::builder()
                    .uri("/api/v1/kg/gaps?palace=gaps-empty")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        let bytes = to_bytes(resp.into_body(), 4096).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();
        assert_eq!(v.as_array().expect("array").len(), 0);
    }

    /// Why: Issue #53 — when the cache *has* been populated (by the dream
    /// cycle in production, or by direct seeding here), the endpoint must
    /// return each gap with the four wire fields.
    /// What: Seeds the registry cache via `set_gaps` directly, then GETs
    /// `/api/v1/kg/gaps?palace=...` and asserts the JSON shape.
    /// Test: this test itself.
    #[tokio::test]
    async fn kg_gaps_endpoint_returns_cached_gaps() {
        use trusty_common::memory_core::community::KnowledgeGap;

        let state = test_state();
        let palace = trusty_common::memory_core::Palace {
            id: PalaceId::new("gaps-seed"),
            name: "gaps-seed".to_string(),
            description: None,
            created_at: chrono::Utc::now(),
            data_dir: state.data_root.join("gaps-seed"),
        };
        state
            .registry
            .create_palace(&state.data_root, palace)
            .expect("create palace");

        state.registry.set_gaps(
            PalaceId::new("gaps-seed"),
            vec![KnowledgeGap {
                entities: vec!["foo".to_string(), "bar".to_string(), "baz".to_string()],
                internal_density: 0.15,
                external_bridges: 2,
                suggested_exploration: "Explore connections between foo and related concepts"
                    .to_string(),
            }],
        );

        let app = router().with_state(state);
        let resp = app
            .oneshot(
                Request::builder()
                    .uri("/api/v1/kg/gaps?palace=gaps-seed")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        let bytes = to_bytes(resp.into_body(), 4096).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();
        let arr = v.as_array().expect("array");
        assert_eq!(arr.len(), 1);
        assert_eq!(arr[0]["entities"].as_array().unwrap().len(), 3);
        assert_eq!(arr[0]["external_bridges"], 2);
        assert!(arr[0]["suggested_exploration"]
            .as_str()
            .unwrap()
            .contains("foo"));
    }

    /// Why: The KG Explorer UI calls `/api/v1/palaces/{id}/kg/subjects` to
    /// populate the left panel; the endpoint must return distinct active
    /// subjects as a JSON string array.
    /// What: Creates a palace, asserts two triples via the existing kg endpoint,
    /// then GETs the subjects route and asserts the shape.
    /// Test: this test itself.
    #[tokio::test]
    async fn kg_list_subjects_returns_distinct() {
        let state = test_state();
        let app = router().with_state(state.clone());

        // Create palace.
        let resp = app
            .clone()
            .oneshot(
                Request::builder()
                    .method("POST")
                    .uri("/api/v1/palaces")
                    .header("content-type", "application/json")
                    .body(Body::from(json!({"name": "kg-list"}).to_string()))
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);

        // Assert two triples on distinct subjects.
        for subj in ["alpha", "beta"] {
            let body = json!({
                "subject": subj,
                "predicate": "is",
                "object": "thing",
            })
            .to_string();
            let r = app
                .clone()
                .oneshot(
                    Request::builder()
                        .method("POST")
                        .uri("/api/v1/palaces/kg-list/kg")
                        .header("content-type", "application/json")
                        .body(Body::from(body))
                        .unwrap(),
                )
                .await
                .unwrap();
            assert_eq!(r.status(), StatusCode::NO_CONTENT);
        }

        let resp = app
            .oneshot(
                Request::builder()
                    .uri("/api/v1/palaces/kg-list/kg/subjects?limit=10")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        let bytes = to_bytes(resp.into_body(), 4096).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();
        let arr = v.as_array().expect("subjects must be array");
        let subjects: Vec<String> = arr
            .iter()
            .filter_map(|x| x.as_str().map(String::from))
            .collect();
        assert_eq!(subjects, vec!["alpha".to_string(), "beta".to_string()]);
    }

    /// Why: KG Explorer's "All" mode pages through every active triple via
    /// `/api/v1/palaces/{id}/kg/all`; the endpoint must return a JSON array of
    /// `Triple` rows ordered by `valid_from` DESC.
    /// What: Creates a palace, asserts a triple, then GETs the all route and
    /// asserts the response is an array with the expected shape.
    /// Test: this test itself.
    #[tokio::test]
    async fn kg_list_all_returns_paginated_triples() {
        let state = test_state();
        let app = router().with_state(state.clone());

        let resp = app
            .clone()
            .oneshot(
                Request::builder()
                    .method("POST")
                    .uri("/api/v1/palaces")
                    .header("content-type", "application/json")
                    .body(Body::from(json!({"name": "kg-all"}).to_string()))
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);

        let body = json!({
            "subject": "alpha",
            "predicate": "is",
            "object": "thing",
        })
        .to_string();
        let r = app
            .clone()
            .oneshot(
                Request::builder()
                    .method("POST")
                    .uri("/api/v1/palaces/kg-all/kg")
                    .header("content-type", "application/json")
                    .body(Body::from(body))
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(r.status(), StatusCode::NO_CONTENT);

        let resp = app
            .oneshot(
                Request::builder()
                    .uri("/api/v1/palaces/kg-all/kg/all?limit=10&offset=0")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        let bytes = to_bytes(resp.into_body(), 4096).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();
        let arr = v.as_array().expect("triples must be array");
        assert_eq!(arr.len(), 1);
        assert_eq!(arr[0]["subject"], "alpha");
        assert_eq!(arr[0]["predicate"], "is");
        assert_eq!(arr[0]["object"], "thing");
    }

    /// Why (issue #97): The visual graph view fetches the entire active
    /// triple set in one call so d3-force can lay it out without paging.
    /// The endpoint must return the triple list plus the node/edge/
    /// community counts that drive the legend.
    /// What: Creates a palace, asserts a single triple, and confirms `GET
    /// /api/v1/palaces/{id}/kg/graph` returns `{ triples, node_count,
    /// edge_count, community_count }` with the right shape.
    /// Test: This test.
    #[tokio::test]
    async fn kg_graph_returns_active_triples() {
        let state = test_state();
        let app = router().with_state(state.clone());

        let resp = app
            .clone()
            .oneshot(
                Request::builder()
                    .method("POST")
                    .uri("/api/v1/palaces")
                    .header("content-type", "application/json")
                    .body(Body::from(json!({"name": "kg-graph"}).to_string()))
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);

        let body = json!({
            "subject": "alpha",
            "predicate": "is",
            "object": "thing",
        })
        .to_string();
        let r = app
            .clone()
            .oneshot(
                Request::builder()
                    .method("POST")
                    .uri("/api/v1/palaces/kg-graph/kg")
                    .header("content-type", "application/json")
                    .body(Body::from(body))
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(r.status(), StatusCode::NO_CONTENT);

        let resp = app
            .oneshot(
                Request::builder()
                    .uri("/api/v1/palaces/kg-graph/kg/graph")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        let bytes = to_bytes(resp.into_body(), 16_384).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();
        let triples = v["triples"].as_array().expect("triples array");
        assert!(triples
            .iter()
            .any(|t| t["subject"] == "alpha" && t["predicate"] == "is" && t["object"] == "thing"));
        assert!(v["node_count"].as_u64().is_some());
        assert!(v["edge_count"].as_u64().is_some());
        assert!(v["community_count"].as_u64().is_some());
    }

    /// Why (issue #97): The visual graph view's stated perf budget is
    /// "<1s for palaces with <500 triples". Seed 500 triples, time one
    /// `/kg/graph` round-trip, and assert the result stays well under that
    /// budget. The assertion uses a generous 10x ceiling so flaky CI
    /// hardware doesn't false-positive while still catching catastrophic
    /// regressions.
    /// What: Creates a palace, asserts 500 triples directly through the
    /// `KnowledgeGraph` handle (skipping the HTTP overhead of 500 separate
    /// `POST /kg` calls), then runs one `GET /kg/graph` and prints the
    /// elapsed time to stderr.
    /// Test: This test.
    #[tokio::test]
    async fn kg_graph_meets_perf_budget_for_500_triples() {
        let state = test_state();
        let app = router().with_state(state.clone());

        let resp = app
            .clone()
            .oneshot(
                Request::builder()
                    .method("POST")
                    .uri("/api/v1/palaces")
                    .header("content-type", "application/json")
                    .body(Body::from(json!({"name": "kg-perf"}).to_string()))
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);

        let pid = trusty_common::memory_core::palace::PalaceId::new("kg-perf");
        let handle = state
            .registry
            .open_palace(&state.data_root, &pid)
            .expect("open palace");
        let now = chrono::Utc::now();
        for s in 0..10 {
            for o in 0..50 {
                handle
                    .kg
                    .assert(Triple {
                        subject: format!("s{s}"),
                        predicate: format!("p{o}"),
                        object: format!("o{o}"),
                        valid_from: now,
                        valid_to: None,
                        confidence: 1.0,
                        provenance: Some("perf-test".to_string()),
                    })
                    .await
                    .expect("kg.assert");
            }
        }

        let started = std::time::Instant::now();
        let resp = app
            .oneshot(
                Request::builder()
                    .uri("/api/v1/palaces/kg-perf/kg/graph")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        let elapsed = started.elapsed();
        assert_eq!(resp.status(), StatusCode::OK);
        let bytes = to_bytes(resp.into_body(), 1_000_000).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();
        let n = v["triples"].as_array().map(|a| a.len()).unwrap_or(0);
        assert_eq!(n, 500, "expected 500 triples in payload");
        assert!(
            elapsed.as_secs_f64() < 10.0,
            "graph endpoint should serve 500 triples in well under 10s; took {elapsed:?}"
        );
        eprintln!(
            "[perf] kg_graph endpoint served 500 triples in {:.3}ms",
            elapsed.as_secs_f64() * 1000.0
        );
    }

    /// Why (issue #42): `GET /api/v1/kg/prompt-context` must serve the
    /// formatted Markdown block from the in-memory cache (or a placeholder
    /// when empty). Mirrors the MCP `get_prompt_context` tool but over HTTP.
    #[tokio::test]
    async fn prompt_context_endpoint_returns_formatted_block() {
        let state = test_state();

        // Empty cache returns the placeholder text.
        let app = router().with_state(state.clone());
        let resp = app
            .oneshot(
                Request::builder()
                    .uri("/api/v1/kg/prompt-context")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        let bytes = to_bytes(resp.into_body(), 4096).await.unwrap();
        let text = String::from_utf8(bytes.to_vec()).unwrap();
        assert_eq!(text, "No prompt facts stored yet.");

        // Populate the cache and re-fetch.
        {
            let mut guard = state.prompt_context_cache.write().await;
            let triples = vec![(
                "tga".to_string(),
                "is_alias_for".to_string(),
                "trusty-git-analytics".to_string(),
            )];
            let formatted = crate::prompt_facts::build_prompt_context(&triples);
            *guard = crate::prompt_facts::PromptFactsCache { triples, formatted };
        }
        let app = router().with_state(state);
        let resp = app
            .oneshot(
                Request::builder()
                    .uri("/api/v1/kg/prompt-context")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        let bytes = to_bytes(resp.into_body(), 4096).await.unwrap();
        let text = String::from_utf8(bytes.to_vec()).unwrap();
        assert!(text.contains("tga → trusty-git-analytics"), "got: {text}");
    }

    /// Why (issue #42): `POST /api/v1/kg/aliases` must assert the alias as
    /// an `is_alias_for` triple AND refresh the prompt cache so subsequent
    /// reads see the new alias.
    #[tokio::test]
    async fn add_alias_endpoint_asserts_triple_and_refreshes_cache() {
        let tmp = tempfile::tempdir().expect("tempdir");
        let root = tmp.path().to_path_buf();
        std::mem::forget(tmp);
        let state = AppState::new(root).with_default_palace(Some("aliases".to_string()));
        let palace = trusty_common::memory_core::Palace {
            id: PalaceId::new("aliases"),
            name: "aliases".to_string(),
            description: None,
            created_at: chrono::Utc::now(),
            data_dir: state.data_root.join("aliases"),
        };
        state
            .registry
            .create_palace(&state.data_root, palace)
            .expect("create palace");

        let body = json!({"short": "tm", "full": "trusty-memory"});
        let app = router().with_state(state.clone());
        let resp = app
            .oneshot(
                Request::builder()
                    .method("POST")
                    .uri("/api/v1/kg/aliases")
                    .header("content-type", "application/json")
                    .body(Body::from(serde_json::to_vec(&body).unwrap()))
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        let bytes = to_bytes(resp.into_body(), 4096).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();
        assert_eq!(v["subject"], "tm");
        assert_eq!(v["object"], "trusty-memory");

        // The prompt cache must reflect the new alias.
        let guard = state.prompt_context_cache.read().await;
        assert!(
            guard.formatted.contains("tm → trusty-memory"),
            "cache missing alias; got: {}",
            guard.formatted
        );
    }

    /// Why (issue #42): `GET /api/v1/kg/prompt-facts` returns the structured
    /// JSON array of every hot-predicate triple across the registry (so a
    /// dashboard can render its own table).
    #[tokio::test]
    async fn list_prompt_facts_endpoint_returns_hot_triples() {
        let tmp = tempfile::tempdir().expect("tempdir");
        let root = tmp.path().to_path_buf();
        std::mem::forget(tmp);
        let state = AppState::new(root).with_default_palace(Some("listfacts".to_string()));
        let palace = trusty_common::memory_core::Palace {
            id: PalaceId::new("listfacts"),
            name: "listfacts".to_string(),
            description: None,
            created_at: chrono::Utc::now(),
            data_dir: state.data_root.join("listfacts"),
        };
        let handle = state
            .registry
            .create_palace(&state.data_root, palace)
            .expect("create palace");

        // Insert one hot triple and one non-hot triple; only the hot one
        // should surface.
        handle
            .kg
            .assert(Triple {
                subject: "ts".to_string(),
                predicate: "is_alias_for".to_string(),
                object: "trusty-search".to_string(),
                valid_from: chrono::Utc::now(),
                valid_to: None,
                confidence: 1.0,
                provenance: None,
            })
            .await
            .expect("assert alias");
        handle
            .kg
            .assert(Triple {
                subject: "alice".to_string(),
                predicate: "works_at".to_string(),
                object: "Acme".to_string(),
                valid_from: chrono::Utc::now(),
                valid_to: None,
                confidence: 1.0,
                provenance: None,
            })
            .await
            .expect("assert works_at");

        let app = router().with_state(state);
        let resp = app
            .oneshot(
                Request::builder()
                    .uri("/api/v1/kg/prompt-facts")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        let bytes = to_bytes(resp.into_body(), 4096).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();
        let arr = v.as_array().expect("array");
        assert!(
            arr.iter().any(|r| r["subject"] == "ts"
                && r["predicate"] == "is_alias_for"
                && r["object"] == "trusty-search"),
            "missing ts alias; got {arr:?}"
        );
        // The non-hot `works_at` triple must not be present.
        assert!(
            !arr.iter().any(|r| r["predicate"] == "works_at"),
            "non-hot triple leaked into prompt facts: {arr:?}"
        );
    }

    /// Why (issue #42): `DELETE /api/v1/kg/prompt-facts` must retract the
    /// interval and refresh the cache; the next list call must omit it.
    #[tokio::test]
    async fn remove_prompt_fact_endpoint_soft_deletes_and_refreshes_cache() {
        let tmp = tempfile::tempdir().expect("tempdir");
        let root = tmp.path().to_path_buf();
        std::mem::forget(tmp);
        let state = AppState::new(root).with_default_palace(Some("rmfacts".to_string()));
        let palace = trusty_common::memory_core::Palace {
            id: PalaceId::new("rmfacts"),
            name: "rmfacts".to_string(),
            description: None,
            created_at: chrono::Utc::now(),
            data_dir: state.data_root.join("rmfacts"),
        };
        let handle = state
            .registry
            .create_palace(&state.data_root, palace)
            .expect("create palace");

        handle
            .kg
            .assert(Triple {
                subject: "ta".to_string(),
                predicate: "is_alias_for".to_string(),
                object: "trusty-analyze".to_string(),
                valid_from: chrono::Utc::now(),
                valid_to: None,
                confidence: 1.0,
                provenance: None,
            })
            .await
            .expect("assert alias");
        // Prime the cache so we can observe the removal effect.
        crate::prompt_facts::rebuild_prompt_cache(&state)
            .await
            .expect("rebuild prompt cache");

        let app = router().with_state(state.clone());
        let resp = app
            .oneshot(
                Request::builder()
                    .method("DELETE")
                    .uri("/api/v1/kg/prompt-facts?subject=ta&predicate=is_alias_for")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        let bytes = to_bytes(resp.into_body(), 4096).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();
        assert_eq!(v["removed"], true);
        assert!(v["closed"].as_u64().unwrap_or(0) >= 1);

        // Cache must no longer contain the alias.
        {
            let guard = state.prompt_context_cache.read().await;
            assert!(
                !guard.formatted.contains("ta → trusty-analyze"),
                "alias still in cache after delete: {}",
                guard.formatted
            );
        }

        // Removing a non-existent fact returns removed=false.
        let app = router().with_state(state);
        let resp = app
            .oneshot(
                Request::builder()
                    .method("DELETE")
                    .uri("/api/v1/kg/prompt-facts?subject=nope&predicate=is_alias_for")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        let bytes = to_bytes(resp.into_body(), 4096).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();
        assert_eq!(v["removed"], false);
    }

    #[tokio::test]
    async fn serves_index_html_fallback() {
        let state = test_state();
        let app = router().with_state(state);
        let resp = app
            .oneshot(Request::builder().uri("/").body(Body::empty()).unwrap())
            .await
            .unwrap();
        // Either OK with embedded HTML, or NOT_FOUND if assets not built.
        assert!(
            resp.status() == StatusCode::OK || resp.status() == StatusCode::NOT_FOUND,
            "got {}",
            resp.status()
        );
    }

    /// Why (issue #96): `GET /api/v1/activity` must return the entries
    /// captured by the persistent log so the dashboard feed has history on
    /// page load. This drives the endpoint with a sequence of emits that
    /// model both HTTP- and MCP-origin writes, then asserts the response
    /// shape, ordering, total count, and that the source labels make it
    /// onto the wire.
    /// What: emits four `DaemonEvent`s with mixed sources, fetches
    /// `/api/v1/activity?limit=10`, and checks the structure of the
    /// returned JSON.
    /// Test: this test.
    #[tokio::test]
    async fn activity_endpoint_lists_recent_emits() {
        let state = test_state();
        // Three drawer_added (one MCP, two HTTP) and one palace_created.
        state.emit(DaemonEvent::PalaceCreated {
            id: "alpha".into(),
            name: "alpha".into(),
            source: ActivitySource::Http,
        });
        state.emit(DaemonEvent::DrawerAdded {
            palace_id: "alpha".into(),
            palace_name: "alpha".into(),
            drawer_count: 1,
            timestamp: chrono::Utc::now(),
            content_preview: "hello".into(),
            source: ActivitySource::Mcp,
        });
        state.emit(DaemonEvent::DrawerAdded {
            palace_id: "beta".into(),
            palace_name: "beta".into(),
            drawer_count: 1,
            timestamp: chrono::Utc::now(),
            content_preview: "hi there".into(),
            source: ActivitySource::Http,
        });
        state.emit(DaemonEvent::DrawerDeleted {
            palace_id: "alpha".into(),
            drawer_count: 0,
            source: ActivitySource::Http,
        });
        // Issue #232: emits now fire-and-forget the redb write on the
        // blocking pool; wait for the writes to settle before querying the
        // activity endpoint.
        state.flush_activity_writes().await;

        let app = router().with_state(state);
        let resp = app
            .oneshot(
                Request::builder()
                    .uri("/api/v1/activity?limit=10")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        let bytes = to_bytes(resp.into_body(), 8192).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();
        assert_eq!(v["limit"], 10);
        assert_eq!(v["offset"], 0);
        assert_eq!(v["total"], 4);
        let entries = v["entries"].as_array().expect("entries array");
        assert_eq!(entries.len(), 4);
        // Newest-first: drawer_deleted is the last event we pushed.
        assert_eq!(entries[0]["event_type"], "drawer_deleted");
        assert_eq!(entries[3]["event_type"], "palace_created");
        // Sources made it onto the wire as lowercase strings.
        let sources: Vec<&str> = entries
            .iter()
            .filter_map(|e| e["source"].as_str())
            .collect();
        assert!(sources.contains(&"http"));
        assert!(sources.contains(&"mcp"));
        // Payload is structured JSON, not an escaped string.
        assert!(entries[0]["payload"].is_object());
    }

    /// Why: the handler must enforce a sane upper bound on `limit` so a
    /// curl with `?limit=1000000` cannot force a huge scan + response.
    /// What: asks for `limit=10000`, asserts the response advertises the
    /// clamped value.
    /// Test: this test.
    #[tokio::test]
    async fn activity_endpoint_clamps_limit() {
        let state = test_state();
        let app = router().with_state(state);
        let resp = app
            .oneshot(
                Request::builder()
                    .uri("/api/v1/activity?limit=10000")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        let bytes = to_bytes(resp.into_body(), 4096).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();
        assert_eq!(v["limit"], ACTIVITY_MAX_LIMIT);
    }

    /// Why: filters are how the dashboard scopes the feed to a single
    /// palace or to one origin (MCP vs HTTP). Confirm AND-semantics on
    /// `?palace=` and `?source=`.
    /// What: emits 3 events, queries with `?palace=alpha&source=mcp`, and
    /// asserts only the matching row is returned.
    /// Test: this test.
    #[tokio::test]
    async fn activity_endpoint_filters_by_source_and_palace() {
        let state = test_state();
        state.emit(DaemonEvent::DrawerAdded {
            palace_id: "alpha".into(),
            palace_name: "alpha".into(),
            drawer_count: 1,
            timestamp: chrono::Utc::now(),
            content_preview: "".into(),
            source: ActivitySource::Mcp,
        });
        state.emit(DaemonEvent::DrawerAdded {
            palace_id: "alpha".into(),
            palace_name: "alpha".into(),
            drawer_count: 2,
            timestamp: chrono::Utc::now(),
            content_preview: "".into(),
            source: ActivitySource::Http,
        });
        state.emit(DaemonEvent::DrawerAdded {
            palace_id: "beta".into(),
            palace_name: "beta".into(),
            drawer_count: 1,
            timestamp: chrono::Utc::now(),
            content_preview: "".into(),
            source: ActivitySource::Mcp,
        });
        // Issue #232: drain the spawn_blocking writes before querying.
        state.flush_activity_writes().await;

        let app = router().with_state(state);
        let resp = app
            .oneshot(
                Request::builder()
                    .uri("/api/v1/activity?palace=alpha&source=mcp&limit=50")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        let bytes = to_bytes(resp.into_body(), 4096).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();
        let entries = v["entries"].as_array().unwrap();
        assert_eq!(entries.len(), 1, "filter should leave one row, got {v}");
        assert_eq!(entries[0]["palace_id"], "alpha");
        assert_eq!(entries[0]["source"], "mcp");
    }

    /// Why: unknown source values must produce a 400 so the caller sees the
    /// typo instead of silently getting "no rows".
    #[tokio::test]
    async fn activity_endpoint_rejects_unknown_source() {
        let state = test_state();
        let app = router().with_state(state);
        let resp = app
            .oneshot(
                Request::builder()
                    .uri("/api/v1/activity?source=nope")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::BAD_REQUEST);
    }

    /// Why (issue #96): MCP-side `memory_remember` must now emit a
    /// `DrawerAdded` event with `source = Mcp`. Confirm by driving the MCP
    /// dispatcher directly and reading the broadcast channel.
    /// What: pre-creates a palace, calls `dispatch_tool("memory_remember",
    /// ...)`, subscribes to the events channel before the call, and
    /// asserts the next event tag is `drawer_added` with the MCP source.
    /// Test: this test.
    #[tokio::test]
    async fn mcp_memory_remember_emits_drawer_added_with_mcp_source() {
        use crate::tools::dispatch_tool;
        let state = test_state();
        let mut rx = state.events.subscribe();
        // Create palace via the MCP tool so the activity log captures both
        // the palace_created and drawer_added events.
        let _ = dispatch_tool(&state, "palace_create", json!({"name": "p1"}))
            .await
            .expect("palace_create");
        // Drain the palace_created event.
        let first = tokio::time::timeout(std::time::Duration::from_millis(500), rx.recv())
            .await
            .expect("first event")
            .expect("channel open");
        assert!(
            matches!(first, DaemonEvent::PalaceCreated { ref source, .. } if *source == ActivitySource::Mcp)
        );

        let _ = dispatch_tool(
            &state,
            "memory_remember",
            json!({
                "palace": "p1",
                "text": "the quick brown fox jumps over the lazy dog and more"
            }),
        )
        .await
        .expect("memory_remember");

        // The next event from the channel should be DrawerAdded(Mcp).
        let next = tokio::time::timeout(std::time::Duration::from_millis(500), rx.recv())
            .await
            .expect("drawer_added event")
            .expect("channel open");
        match next {
            DaemonEvent::DrawerAdded {
                source, palace_id, ..
            } => {
                assert_eq!(source, ActivitySource::Mcp);
                assert_eq!(palace_id, "p1");
            }
            other => panic!("expected DrawerAdded, got {other:?}"),
        }

        // The activity log should now hold ≥ 2 entries (palace_created +
        // drawer_added). Also confirm the HTTP endpoint surfaces them with
        // `mcp` sources.
        // Issue #232: drain fire-and-forget activity-log writes first.
        state.flush_activity_writes().await;
        let app = router().with_state(state);
        let resp = app
            .oneshot(
                Request::builder()
                    .uri("/api/v1/activity?source=mcp&limit=10")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        let bytes = to_bytes(resp.into_body(), 4096).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();
        let entries = v["entries"].as_array().unwrap();
        let event_types: std::collections::HashSet<&str> = entries
            .iter()
            .filter_map(|e| e["event_type"].as_str())
            .collect();
        assert!(event_types.contains("drawer_added"));
        assert!(event_types.contains("palace_created"));
    }

    // -----------------------------------------------------------------
    // Submission-logging tests (Part A: hook activity, Part B: drawer
    // attribution).
    // -----------------------------------------------------------------

    /// Why (submission-logging Part A): every hook firing must produce an
    /// activity-feed entry tagged `source=hook` so a normal Claude Code
    /// session that only triggers hooks no longer leaves the TUI feed
    /// empty. The simplest direct check is to POST to the hook ingestion
    /// endpoint and confirm the new entry shows up in `GET /api/v1/activity`.
    /// What: posts a `HookEventPayload` to `/api/v1/activity/hook`, then
    /// queries `/api/v1/activity?source=hook&limit=1` and asserts a row
    /// exists with the matching event_type and source.
    /// Test: itself.
    #[tokio::test]
    async fn hook_fired_activity_emit_smoke() {
        let state = test_state();
        let app = router().with_state(state.clone());

        let payload = serde_json::json!({
            "palace_id": "alpha",
            "palace_name": "alpha",
            "hook_type": "UserPromptSubmit",
            "injection_kind": "prompt-context",
            "injection_length": 256,
            "trigger_prompt_excerpt": "test prompt",
            "duration_ms": 12,
        });
        let resp = app
            .oneshot(
                Request::builder()
                    .method("POST")
                    .uri("/api/v1/activity/hook")
                    .header("content-type", "application/json")
                    .body(Body::from(payload.to_string()))
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::NO_CONTENT);
        // Issue #232: the hook handler emits via the fire-and-forget
        // `spawn_blocking` path; wait for the write to settle before
        // reading the activity history endpoint.
        state.flush_activity_writes().await;

        // Read it back through the activity history endpoint.
        let app = router().with_state(state);
        let resp = app
            .oneshot(
                Request::builder()
                    .uri("/api/v1/activity?source=hook&limit=10")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        let bytes = to_bytes(resp.into_body(), 4096).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();
        let entries = v["entries"].as_array().expect("entries array");
        assert!(
            !entries.is_empty(),
            "expected at least one hook activity row, got {entries:?}"
        );
        let first = &entries[0];
        assert_eq!(first["source"], "hook");
        assert_eq!(first["event_type"], "hook_fired");
        assert_eq!(first["palace_id"], "alpha");
        let body = &first["payload"];
        assert_eq!(body["hook_type"], "UserPromptSubmit");
        assert_eq!(body["injection_kind"], "prompt-context");
    }

    /// Why (submission-logging Part B): an HTTP drawer write with no
    /// client-identifying header must still produce a drawer carrying a
    /// `creator:client=unknown-http-client` tag so operators can recognise
    /// "writer didn't self-identify" as distinct from "writer is known".
    /// What: creates a palace via the registry, POSTs a drawer with no
    /// `X-Trusty-Client-Name` header, lists the palace drawers, asserts
    /// the new drawer carries the four creator tags with the default
    /// client name and `source=http`.
    /// Test: itself.
    #[tokio::test]
    async fn drawer_creator_attribution_http_default() {
        let tmp = tempfile::tempdir().expect("tempdir");
        let root = tmp.path().to_path_buf();
        std::mem::forget(tmp);
        let state = AppState::new(root);
        let palace = trusty_common::memory_core::Palace {
            id: PalaceId::new("cred-default"),
            name: "cred-default".to_string(),
            description: None,
            created_at: chrono::Utc::now(),
            data_dir: state.data_root.join("cred-default"),
        };
        state
            .registry
            .create_palace(&state.data_root, palace)
            .expect("create palace");

        let app = router().with_state(state.clone());
        let body = serde_json::json!({
            "content": "hello world from anonymous client",
            "tags": ["user-tag"],
        });
        let resp = app
            .oneshot(
                Request::builder()
                    .method("POST")
                    .uri("/api/v1/palaces/cred-default/drawers")
                    .header("content-type", "application/json")
                    .body(Body::from(body.to_string()))
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);

        // Inspect the persisted drawer's tags.
        let app = router().with_state(state);
        let resp = app
            .oneshot(
                Request::builder()
                    .uri("/api/v1/palaces/cred-default/drawers?limit=10")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
        let bytes = to_bytes(resp.into_body(), 8192).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();
        let drawers = v.as_array().expect("drawers array");
        assert_eq!(drawers.len(), 1, "expected one drawer, got {drawers:?}");
        let tags: Vec<&str> = drawers[0]["tags"]
            .as_array()
            .expect("tags array")
            .iter()
            .filter_map(|t| t.as_str())
            .collect();
        assert!(
            tags.contains(&"user-tag"),
            "user-supplied tag must survive; got {tags:?}"
        );
        assert!(
            tags.contains(&"creator:client=unknown-http-client"),
            "expected default client tag; got {tags:?}"
        );
        assert!(
            tags.contains(&"creator:source=http"),
            "expected http source tag; got {tags:?}"
        );
        assert!(
            tags.iter().any(|t| t.starts_with("creator:version=")),
            "expected creator:version tag; got {tags:?}"
        );
    }

    /// Why (submission-logging Part B): when an HTTP client *does* set
    /// `X-Trusty-Client-Name`, the drawer must carry that exact name in
    /// its `creator:client=` tag so operators can trace which client wrote
    /// which drawer.
    /// What: POST with `X-Trusty-Client-Name: qa-curl` and assert the
    /// rendered tag matches.
    /// Test: itself.
    #[tokio::test]
    async fn drawer_creator_attribution_http_header() {
        let tmp = tempfile::tempdir().expect("tempdir");
        let root = tmp.path().to_path_buf();
        std::mem::forget(tmp);
        let state = AppState::new(root);
        let palace = trusty_common::memory_core::Palace {
            id: PalaceId::new("cred-header"),
            name: "cred-header".to_string(),
            description: None,
            created_at: chrono::Utc::now(),
            data_dir: state.data_root.join("cred-header"),
        };
        state
            .registry
            .create_palace(&state.data_root, palace)
            .expect("create palace");

        let app = router().with_state(state.clone());
        let body = serde_json::json!({
            "content": "this is enough content to pass the signal/noise filter applied by remember",
            "tags": [],
        });
        let resp = app
            .oneshot(
                Request::builder()
                    .method("POST")
                    .uri("/api/v1/palaces/cred-header/drawers")
                    .header("content-type", "application/json")
                    .header("x-trusty-client-name", "qa-curl")
                    .header("x-trusty-client-cwd", "/tmp/qa")
                    .body(Body::from(body.to_string()))
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(resp.status(), StatusCode::OK);

        let app = router().with_state(state);
        let resp = app
            .oneshot(
                Request::builder()
                    .uri("/api/v1/palaces/cred-header/drawers?limit=10")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        let bytes = to_bytes(resp.into_body(), 8192).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();
        let tags: Vec<&str> = v[0]["tags"]
            .as_array()
            .expect("tags")
            .iter()
            .filter_map(|t| t.as_str())
            .collect();
        assert!(
            tags.contains(&"creator:client=qa-curl"),
            "expected custom client tag; got {tags:?}"
        );
        assert!(
            tags.contains(&"creator:cwd=/tmp/qa"),
            "expected cwd tag from header; got {tags:?}"
        );
    }

    /// Why (submission-logging Part B): drawers written through the MCP
    /// tool surface (`memory_remember`) must carry
    /// `creator:client=trusty-memory-mcp` and `creator:source=mcp` so
    /// operators can tell MCP-origin drawers apart from HTTP / CLI writes.
    /// What: dispatches `memory_remember` directly against an in-process
    /// `AppState` (no HTTP), then lists the palace drawers and asserts
    /// the MCP attribution tags landed.
    /// Test: itself.
    #[tokio::test]
    async fn drawer_creator_attribution_mcp_default() {
        let tmp = tempfile::tempdir().expect("tempdir");
        let root = tmp.path().to_path_buf();
        std::mem::forget(tmp);
        let state = AppState::new(root);
        // Flip to Ready so the issue #911 warming preflight allows dispatch_tool
        // to proceed (the call below goes through the MCP handler path).
        state.set_ready();
        let palace = trusty_common::memory_core::Palace {
            id: PalaceId::new("cred-mcp"),
            name: "cred-mcp".to_string(),
            description: None,
            created_at: chrono::Utc::now(),
            data_dir: state.data_root.join("cred-mcp"),
        };
        state
            .registry
            .create_palace(&state.data_root, palace)
            .expect("create palace");

        let _ = crate::tools::dispatch_tool(
            &state,
            "memory_remember",
            json!({
                "palace": "cred-mcp",
                "text": "remember a sentence with enough tokens to pass filters please",
                "room": "General",
                "tags": ["from-test"],
            }),
        )
        .await
        .expect("memory_remember dispatch");

        let app = router().with_state(state);
        let resp = app
            .oneshot(
                Request::builder()
                    .uri("/api/v1/palaces/cred-mcp/drawers?limit=10")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        let bytes = to_bytes(resp.into_body(), 8192).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();
        let drawers = v.as_array().expect("drawers array");
        assert!(!drawers.is_empty(), "expected at least one drawer");
        let tags: Vec<&str> = drawers[0]["tags"]
            .as_array()
            .expect("tags array")
            .iter()
            .filter_map(|t| t.as_str())
            .collect();
        assert!(
            tags.contains(&"creator:client=trusty-memory-mcp"),
            "expected MCP client tag; got {tags:?}"
        );
        assert!(
            tags.contains(&"creator:source=mcp"),
            "expected MCP source tag; got {tags:?}"
        );
    }

    /// Why (submission-logging Part A, failure isolation): if the daemon
    /// is unreachable when the hook fires, the hook command MUST still
    /// return `Ok(())` so the user's prompt is not blocked. The activity
    /// emit failure is surfaced via a stderr warn-log only.
    /// What: pins a tempdir as the data dir (so `read_daemon_addr`
    /// returns `Ok(None)` — no http_addr file), runs `handle_prompt_context`,
    /// and asserts it returns `Ok(())`. Separately verifies the emit
    /// helper does not panic — covered by `post_hook_event_no_daemon_is_noop`
    /// in `hook_emit::tests`.
    /// Test: itself.
    #[tokio::test]
    async fn hook_emit_failure_isolated() {
        let _guard = crate::commands::env_test_lock().lock().await;
        let tmp = tempfile::tempdir().expect("tempdir");
        // SAFETY: test serialised via env_test_lock.
        unsafe {
            std::env::set_var(trusty_common::DATA_DIR_OVERRIDE_ENV, tmp.path());
        }
        let res = crate::commands::prompt_context::handle_prompt_context().await;
        unsafe {
            std::env::remove_var(trusty_common::DATA_DIR_OVERRIDE_ENV);
        }
        assert!(
            res.is_ok(),
            "hook must complete even when daemon emit fails; got {res:?}"
        );
    }

    /// Why: The base64url triple-ID round-trip is the core invariant for
    /// `DELETE /kg/triples/<id>` — if encode/decode aren't inverses, the
    /// handler will always 404 on valid IDs.
    /// What: Encodes a (subject, predicate) pair, decodes the result, and
    /// asserts exact equality with the originals. Also tests the null-byte
    /// separator and URL-safety.
    /// Test: This test.
    #[test]
    fn decode_triple_id_round_trips() {
        let cases = [
            ("drawer:some-uuid", "has_tag"),
            ("entity:alice", "works_at"),
            ("entity:project/foo", "depends_on"),
            // edge: empty predicate
            ("subject", ""),
            // edge: subject with slashes + predicate with colons
            ("path/to/node", "rel:type:sub"),
        ];
        for (subject, predicate) in cases {
            let encoded = encode_triple_id(subject, predicate);
            // Must be URL-safe: no +, /, or = characters.
            assert!(
                !encoded.contains('+') && !encoded.contains('/') && !encoded.contains('='),
                "encoded triple id {encoded:?} is not URL-safe"
            );
            let (s, p) = decode_triple_id(&encoded)
                .unwrap_or_else(|| panic!("decode_triple_id failed for {encoded:?}"));
            assert_eq!(s, subject, "subject mismatch for ({subject}, {predicate})");
            assert_eq!(
                p, predicate,
                "predicate mismatch for ({subject}, {predicate})"
            );
        }
    }

    /// Why: `decode_triple_id` must return `None` on garbage input (not panic).
    /// What: Passes invalid base64 and base64 without a null separator; asserts None.
    /// Test: This test.
    #[test]
    fn decode_triple_id_returns_none_for_invalid_input() {
        assert!(decode_triple_id("not!!valid%%base64").is_none());
        // Valid base64url but no null separator → no split possible.
        use base64::Engine as _;
        let no_sep = base64::engine::general_purpose::URL_SAFE_NO_PAD.encode(b"no-separator");
        assert!(decode_triple_id(&no_sep).is_none());
    }

    // -------------------------------------------------------------------------
    // Issue #465 — GET /api/v1/recall?palace= must honour the palace filter
    // -------------------------------------------------------------------------

    /// Why (issue #465): `GET /api/v1/recall?palace=<id>&q=...` was silently
    /// ignoring the `palace=` parameter and always fanning out across all
    /// palaces, returning results from the wrong palace. This test proves the
    /// route now scopes the recall to the requested palace.
    /// What: creates two palaces with distinct drawers, requests recall with
    /// `palace=` set to one of them, and asserts the response is a JSON array
    /// (the per-palace shape), not the cross-palace object shape.
    /// Test: this test.
    #[tokio::test]
    async fn recall_all_handler_honors_palace_filter() {
        let state = test_state();
        // Pre-create a palace so the handler can open it.
        let palace = Palace {
            id: PalaceId::new("filter-target"),
            name: "filter-target".to_string(),
            description: None,
            created_at: chrono::Utc::now(),
            data_dir: state.data_root.join("filter-target"),
        };
        state
            .registry
            .create_palace(&state.data_root, palace)
            .expect("create_palace");

        let app = router().with_state(state);
        // With palace= set, the handler should delegate to the per-palace path.
        // Even with no drawers, a valid palace returns a JSON array (possibly
        // empty), NOT a 404 or a cross-palace object shape.
        let resp = app
            .oneshot(
                Request::builder()
                    .uri("/api/v1/recall?q=anything&palace=filter-target")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(
            resp.status(),
            StatusCode::OK,
            "recall with valid palace= must return 200"
        );
        let bytes = to_bytes(resp.into_body(), 4096).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();
        assert!(
            v.is_array(),
            "recall with palace= must return a JSON array (per-palace shape); got {v}"
        );
    }

    /// Why (issue #465): when `palace=` refers to a non-existent palace, the
    /// handler must return a 404 — not silently fall back to cross-palace recall.
    /// What: requests recall with a `palace=` that was never created and asserts
    /// the response is 404.
    /// Test: this test.
    #[tokio::test]
    async fn recall_all_handler_palace_filter_missing_palace_returns_404() {
        let state = test_state();
        let app = router().with_state(state);
        let resp = app
            .oneshot(
                Request::builder()
                    .uri("/api/v1/recall?q=anything&palace=nonexistent-palace")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(
            resp.status(),
            StatusCode::NOT_FOUND,
            "recall with palace= pointing to missing palace must return 404"
        );
    }

    /// Why (issue #465): when `palace=` is absent, the endpoint must continue
    /// to fan out across all palaces (original cross-palace behaviour).
    /// What: with no palace= param and no palaces created, the cross-palace
    /// fan-out returns an empty JSON array (no palaces → nothing to search).
    /// Test: this test.
    #[tokio::test]
    async fn recall_all_handler_fans_out_without_palace_param() {
        let state = test_state();
        let app = router().with_state(state);
        let resp = app
            .oneshot(
                Request::builder()
                    .uri("/api/v1/recall?q=anything")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(
            resp.status(),
            StatusCode::OK,
            "cross-palace recall with no palace= must return 200"
        );
        let bytes = to_bytes(resp.into_body(), 4096).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();
        // No palaces → empty array.
        assert!(
            v.is_array(),
            "cross-palace recall must return a JSON array; got {v}"
        );
    }

    // -------------------------------------------------------------------------
    // Issue #466 — POST /api/v1/remember must reject short content synchronously
    // -------------------------------------------------------------------------

    /// Why (issue #466): content that is too short was silently dropped by the
    /// background worker while the HTTP response claimed `202 Accepted`.
    /// Callers believed the memory was stored when it wasn't — silent data loss.
    /// The fix: validate the minimum word count synchronously and return 422
    /// before queueing so the caller gets an actionable error immediately.
    /// What: POSTs content with fewer than REMEMBER_MIN_WORDS words and asserts
    /// the response is 422, not 202.
    /// Test: this test.
    #[tokio::test]
    async fn remember_async_rejects_short_content() {
        let state = test_state();
        let app = router().with_state(state);
        // "hi" is 1 word — well below REMEMBER_MIN_WORDS (4).
        for body in [
            json!({"content": "hi"}),
            json!({"content": "two words"}),
            json!({"content": "three word content"}),
        ] {
            let resp = app
                .clone()
                .oneshot(
                    Request::builder()
                        .method("POST")
                        .uri("/api/v1/remember")
                        .header("content-type", "application/json")
                        .body(Body::from(body.to_string()))
                        .unwrap(),
                )
                .await
                .unwrap();
            assert_eq!(
                resp.status(),
                StatusCode::UNPROCESSABLE_ENTITY,
                "short content must return 422; body={body}"
            );
        }
    }

    /// Why (issue #466): content that meets the minimum word count must still
    /// return 202, proving the synchronous gate does not over-reject.
    /// What: POSTs exactly REMEMBER_MIN_WORDS words and asserts 202.
    /// Test: this test (companion to `remember_async_rejects_short_content`).
    #[tokio::test]
    async fn remember_async_accepts_content_at_min_words() {
        let state = test_state();
        // Pre-create a palace so the spawned task can find it.
        let palace = Palace {
            id: PalaceId::new("min-words-test"),
            name: "min-words-test".to_string(),
            description: None,
            created_at: chrono::Utc::now(),
            data_dir: state.data_root.join("min-words-test"),
        };
        state
            .registry
            .create_palace(&state.data_root, palace)
            .expect("create_palace");

        let app = router().with_state(state);
        // Exactly 4 words — the minimum.
        let body = json!({
            "content": "four words exactly here",
            "palace": "min-words-test",
        });
        let resp = app
            .oneshot(
                Request::builder()
                    .method("POST")
                    .uri("/api/v1/remember")
                    .header("content-type", "application/json")
                    .body(Body::from(body.to_string()))
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(
            resp.status(),
            StatusCode::ACCEPTED,
            "content at minimum word count must return 202"
        );
        let bytes = to_bytes(resp.into_body(), 512).await.unwrap();
        let v: Value = serde_json::from_slice(&bytes).unwrap();
        assert_eq!(
            v["status"], "queued",
            "accepted body must carry status=queued"
        );
    }
}