sloop-daemon 0.1.0

use std::collections::{BTreeMap, HashMap, HashSet};
use std::fs::{self, OpenOptions};
use std::io::{self, BufRead, BufReader, Read, Write};
use std::os::unix::fs::PermissionsExt;
use std::os::unix::net::UnixStream as StdUnixStream;
use std::os::unix::process::CommandExt;
use std::path::{Path, PathBuf};
use std::process::{Child, Command, Stdio};
use std::sync::Arc;
use std::sync::atomic::{AtomicBool, AtomicU64, Ordering};
use std::time::{Duration, Instant};

use base64::Engine;
use base64::engine::general_purpose::URL_SAFE_NO_PAD as BASE64_TOKEN;
use fs2::FileExt;
use serde_json::json;
use tokio::io::{AsyncBufReadExt, AsyncReadExt, AsyncWriteExt, BufReader as AsyncBufReader};
use tokio::net::{UnixListener, UnixStream};
use tokio::sync::{mpsc, oneshot};

use crate::clock::{Clock, FileClock, SystemClock, format_timestamp};
use crate::config::{AgentConfig, Config, ConfigError, Project, RunningHours, expand_agent_cmd};
use crate::flow::Flow;
use crate::frontmatter::{Frontmatter, FrontmatterError};
use crate::ids::{IdError, next_id};
use crate::logging::{LogLevel, OperationalLog};
use crate::outcome::{
    MergeOutcome, RunEvidence, StageOutcome, classify_exit, derive_outcome, wants_merge,
    wants_tests,
};
use crate::protocol::{
    Capability, ErrorBody, ErrorCode, Request, RequestEnvelope, RequestId, ResponseEnvelope,
};
use crate::run_log::{OutputSource, OutputStream, RunLogWriter};
use crate::store::{
    ActivationKind, ClaimRequest, EvidenceRecord, NewActivation, QueuedActivation, RecoverableRun,
    StageRecord, Store, StoreError, TicketState,
};

const MAX_ENVELOPE_BYTES: u64 = 1024 * 1024;
const STARTUP_TIMEOUT: Duration = Duration::from_secs(5);
const CLIENT_TIMEOUT: Duration = Duration::from_secs(5);
const DISPATCH_CHANNEL_CAPACITY: usize = 64;
const DEFAULT_LEASE_MS: i64 = 10 * 60 * 1000;
pub(crate) const WORKER_BOOTSTRAP_PROMPT: &str =
    include_str!("worker-instructions.md").trim_ascii();
/// One `logs` page; chunks are ≤8KiB, so a page stays well inside the
/// envelope limit once cursor arguments arrive.
const LOGS_PAGE_LIMIT: usize = 64;

static NEXT_REQUEST_ID: AtomicU64 = AtomicU64::new(1);
static MERGE_LOCK: std::sync::Mutex<()> = std::sync::Mutex::new(());

pub struct ClientResponse {
    pub response: ResponseEnvelope,
    pub started: bool,
}

pub fn request(request: Request) -> Result<ClientResponse, DaemonError> {
    let cwd = std::env::current_dir().map_err(DaemonError::CurrentDirectory)?;
    let project = Project::discover(&cwd)?;
    Config::load(&project)?;

    if let Ok(response) = send_existing(&project, request.clone()) {
        return Ok(ClientResponse {
            response,
            started: false,
        });
    }

    spawn_daemon(&project)?;
    let deadline = Instant::now() + STARTUP_TIMEOUT;
    loop {
        match send_existing(&project, request.clone()) {
            Ok(response) => {
                return Ok(ClientResponse {
                    response,
                    started: true,
                });
            }
            Err(error) if Instant::now() >= deadline => return Err(error),
            Err(_) => std::thread::sleep(Duration::from_millis(20)),
        }
    }
}

/// Sends a request only if a daemon is already listening; `Ok(None)` means
/// no daemon. Never spawns one.
pub fn request_running(request: Request) -> Result<Option<ResponseEnvelope>, DaemonError> {
    let cwd = std::env::current_dir().map_err(DaemonError::CurrentDirectory)?;
    let project = Project::discover(&cwd)?;
    Config::load(&project)?;
    match send_existing(&project, request) {
        Ok(response) => Ok(Some(response)),
        Err(DaemonError::Connect(_)) => Ok(None),
        Err(error) => Err(error),
    }
}

pub fn serve_current_project() -> Result<(), DaemonError> {
    let cwd = std::env::current_dir().map_err(DaemonError::CurrentDirectory)?;
    let project = Project::discover(&cwd)?;
    let config = Config::load(&project)?;
    fs::create_dir_all(&project.state_dir).map_err(|source| DaemonError::Io {
        path: project.state_dir.clone(),
        source,
    })?;
    fs::set_permissions(&project.state_dir, fs::Permissions::from_mode(0o700)).map_err(
        |source| DaemonError::Io {
            path: project.state_dir.clone(),
            source,
        },
    )?;
    let runtime_root = project
        .runtime_dir
        .parent()
        .expect("repository runtime directories have a parent");
    fs::create_dir_all(runtime_root).map_err(|source| DaemonError::Io {
        path: runtime_root.to_path_buf(),
        source,
    })?;
    fs::set_permissions(runtime_root, fs::Permissions::from_mode(0o700)).map_err(|source| {
        DaemonError::Io {
            path: runtime_root.to_path_buf(),
            source,
        }
    })?;
    fs::create_dir(&project.runtime_dir)
        .or_else(|source| {
            if source.kind() == io::ErrorKind::AlreadyExists {
                Ok(())
            } else {
                Err(source)
            }
        })
        .map_err(|source| DaemonError::Io {
            path: project.runtime_dir.clone(),
            source,
        })?;
    fs::set_permissions(&project.runtime_dir, fs::Permissions::from_mode(0o700)).map_err(
        |source| DaemonError::Io {
            path: project.runtime_dir.clone(),
            source,
        },
    )?;

    let lock = OpenOptions::new()
        .create(true)
        .truncate(false)
        .read(true)
        .write(true)
        .open(&project.lock_path)
        .map_err(|source| DaemonError::Io {
            path: project.lock_path.clone(),
            source,
        })?;
    lock.try_lock_exclusive().map_err(|source| {
        if source.kind() == io::ErrorKind::WouldBlock {
            DaemonError::AlreadyRunning
        } else {
            DaemonError::Io {
                path: project.lock_path.clone(),
                source,
            }
        }
    })?;
    // Hold the pre-v7 runtime lock as well during the lock-location
    // transition, preventing an already-running older daemon in this runtime
    // root from sharing the database with the new process.
    let legacy_lock_path = project.runtime_dir.join("daemon.lock");
    let legacy_lock = OpenOptions::new()
        .create(true)
        .truncate(false)
        .read(true)
        .write(true)
        .open(&legacy_lock_path)
        .map_err(|source| DaemonError::Io {
            path: legacy_lock_path.clone(),
            source,
        })?;
    legacy_lock.try_lock_exclusive().map_err(|source| {
        if source.kind() == io::ErrorKind::WouldBlock {
            DaemonError::AlreadyRunning
        } else {
            DaemonError::Io {
                path: legacy_lock_path,
                source,
            }
        }
    })?;
    // Identity is advisory; the flock is the guard, so write errors are
    // ignored rather than fatal.
    let identity = json!({
        "pid": std::process::id(),
        "started_at_ms": process_start_time(std::process::id()),
        "socket": project.operator_socket,
    });
    let _ = lock.set_len(0);
    let _ = {
        use std::io::Write as _;
        writeln!(&lock, "{identity}")
    };

    let clock: Arc<dyn Clock> = match std::env::var_os("SLOOP_TEST_CLOCK_PATH") {
        Some(path) => Arc::new(FileClock::new(path.into())),
        None => Arc::new(SystemClock),
    };
    let store = Store::open(&project.db_path, clock.now_ms()).map_err(DaemonError::Store)?;
    if let Some(agent) = &config.agent {
        store
            .backfill_ticket_targets(&agent.default_target, clock.now_ms())
            .map_err(DaemonError::Store)?;
    }
    index_projects(
        &project.root,
        &config.project_dir,
        &store,
        clock.now_ms(),
        &config.project_prefix,
    )?;
    reconcile_tickets(
        &project.root,
        &store,
        clock.now_ms(),
        config.delete_missing_after_ms,
    )?;

    let runtime = tokio::runtime::Builder::new_multi_thread()
        .enable_all()
        .build()
        .map_err(DaemonError::Runtime)?;
    runtime.block_on(serve(project, config, store, lock, legacy_lock, clock))
}

#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub(crate) enum OrphanDisposition {
    MarkMissing,
    Delete,
    Keep,
}

/// Policy for a DB ticket whose file has disappeared: stamp first, delete
/// once the stamp outlives the grace window, and never delete a row
/// something else still references — such rows just stay stamped.
fn orphan_disposition(
    missing_since_ms: Option<i64>,
    is_referenced: bool,
    now_ms: i64,
    delete_missing_after_ms: i64,
) -> OrphanDisposition {
    match missing_since_ms {
        None => OrphanDisposition::MarkMissing,
        Some(since) if now_ms - since >= delete_missing_after_ms && !is_referenced => {
            OrphanDisposition::Delete
        }
        Some(_) => OrphanDisposition::Keep,
    }
}

/// Reconciles local ticket rows against their committed files. Runs at
/// startup; `reindex` will share it.
fn reconcile_tickets(
    root: &Path,
    store: &Store,
    now_ms: i64,
    delete_missing_after_ms: i64,
) -> Result<(), DaemonError> {
    for ticket in store.local_ticket_files().map_err(DaemonError::Store)? {
        if root.join(&ticket.file_path).is_file() {
            if ticket.missing_at_ms.is_some() {
                store
                    .clear_ticket_missing(&ticket.id, now_ms)
                    .map_err(DaemonError::Store)?;
            }
            continue;
        }
        let is_referenced = store
            .ticket_is_referenced(&ticket.id)
            .map_err(DaemonError::Store)?;
        match orphan_disposition(
            ticket.missing_at_ms,
            is_referenced,
            now_ms,
            delete_missing_after_ms,
        ) {
            OrphanDisposition::MarkMissing => {
                store
                    .mark_ticket_missing(&ticket.id, now_ms)
                    .map_err(DaemonError::Store)?;
            }
            OrphanDisposition::Delete => {
                store
                    .delete_ticket(&ticket.id)
                    .map_err(DaemonError::Store)?;
            }
            OrphanDisposition::Keep => {}
        }
    }
    Ok(())
}

/// Indexes committed project Markdown files into the store so ticket membership
/// can be validated. Runs at startup; `reindex` will share it.
fn index_projects(
    root: &Path,
    project_dir: &Path,
    store: &Store,
    now_ms: i64,
    project_prefix: &str,
) -> Result<(), DaemonError> {
    let directory = root.join(project_dir);
    let entries = match fs::read_dir(&directory) {
        Ok(entries) => entries,
        Err(error) if error.kind() == io::ErrorKind::NotFound => return Ok(()),
        Err(source) => {
            return Err(DaemonError::Io {
                path: directory,
                source,
            });
        }
    };

    let mut paths = Vec::new();
    for entry in entries {
        let path = entry
            .map_err(|source| DaemonError::Io {
                path: directory.clone(),
                source,
            })?
            .path();
        if path.extension().and_then(|extension| extension.to_str()) == Some("md") {
            paths.push(path);
        }
    }
    paths.sort();

    struct ProjectFile {
        path: PathBuf,
        content: String,
        stem: String,
        frontmatter: Frontmatter,
    }

    let mut projects = Vec::new();
    for path in paths {
        let content = fs::read_to_string(&path).map_err(|source| DaemonError::Io {
            path: path.clone(),
            source,
        })?;
        let stem = path
            .file_stem()
            .map(|stem| stem.to_string_lossy().into_owned())
            .unwrap_or_default();
        // A malformed project file must not keep the daemon from starting;
        // it is simply not indexed until fixed.
        let Ok(frontmatter) = crate::frontmatter::parse(&content) else {
            continue;
        };
        projects.push(ProjectFile {
            path,
            content,
            stem,
            frontmatter,
        });
    }

    // Explicit IDs in every file establish the high-water mark before sorted
    // idless files are assigned, regardless of where those explicit files sort.
    let mut ids: Vec<String> = projects
        .iter()
        .filter_map(|project| project.frontmatter.id.clone())
        .collect();
    for project in projects {
        let id = match project.frontmatter.id {
            Some(id) => id,
            None => {
                let id = next_id(project_prefix, ids.iter().map(String::as_str))?;
                let updated =
                    crate::frontmatter::stamp_id(&project.content, &id).map_err(|error| {
                        DaemonError::Frontmatter {
                            path: project.path.clone(),
                            error,
                        }
                    })?;
                fs::write(
                    &project.path,
                    updated.expect("idless project always needs an ID stamp"),
                )
                .map_err(|source| DaemonError::Io {
                    path: project.path.clone(),
                    source,
                })?;
                ids.push(id.clone());
                id
            }
        };
        let title = project.frontmatter.title.unwrap_or(project.stem);
        let relative = project
            .path
            .strip_prefix(root)
            .unwrap_or(&project.path)
            .to_string_lossy()
            .into_owned();
        store
            .upsert_local_project(&id, &relative, &title, now_ms)
            .map_err(DaemonError::Store)?;
    }
    Ok(())
}

async fn serve(
    project: Project,
    config: Config,
    store: Store,
    _lock: fs::File,
    _legacy_lock: fs::File,
    clock: Arc<dyn Clock>,
) -> Result<(), DaemonError> {
    if project.operator_socket.exists() {
        fs::remove_file(&project.operator_socket).map_err(|source| DaemonError::Io {
            path: project.operator_socket.clone(),
            source,
        })?;
    }

    let listener =
        UnixListener::bind(&project.operator_socket).map_err(|source| DaemonError::Io {
            path: project.operator_socket.clone(),
            source,
        })?;
    fs::set_permissions(&project.operator_socket, fs::Permissions::from_mode(0o600)).map_err(
        |source| DaemonError::Io {
            path: project.operator_socket.clone(),
            source,
        },
    )?;

    let log = OperationalLog::open(&project.daemon_log).map_err(|source| DaemonError::Io {
        path: project.daemon_log.clone(),
        source,
    })?;
    log.emit(LogLevel::Info, "sloop::daemon", "daemon_started");

    let paused = store.paused().map_err(DaemonError::Store)?;
    let (dispatcher_tx, dispatcher_rx) = mpsc::channel(DISPATCH_CHANNEL_CAPACITY);
    let (events_tx, events_rx) = mpsc::channel(DISPATCH_CHANNEL_CAPACITY);
    let (shutdown_tx, mut shutdown_rx) = mpsc::channel::<()>(1);
    let shutdown_flag = Arc::new(AtomicBool::new(false));
    let mut state = DispatcherState {
        pid: std::process::id(),
        paused,
        max_agents: config.max_parallel_tasks,
        ticket_prefix: config.ticket_prefix.clone(),
        running_hours: config.running_hours.clone(),
        agent: config.agent.clone(),
        flows: config.flows.clone(),
        default_flow: config.default_flow.clone(),
        aftercare_test_cmd: config.aftercare_test_cmd.clone(),
        root: project.root.clone(),
        ticket_dir: config.ticket_dir.clone(),
        worktree_dir: project.root.join(&config.worktree_dir),
        state_dir: project.state_dir.clone(),
        runtime_dir: project.runtime_dir.clone(),
        socket: project.operator_socket.clone(),
        daemon_log: project.daemon_log.clone(),
        store,
        active: HashSet::new(),
        cancelling: HashSet::new(),
        worker_tokens: HashMap::new(),
        worker_listeners: HashMap::new(),
        worker_socket_paths: HashMap::new(),
        pending_exits: HashMap::new(),
        requests_tx: dispatcher_tx.clone(),
        log: log.clone(),
        clock,
        shutdown: shutdown_tx.clone(),
        shutdown_flag: shutdown_flag.clone(),
    };
    recover_inflight_runs(&mut state, &events_tx, &log)?;
    tokio::spawn(run_dispatcher(
        state,
        dispatcher_rx,
        events_rx,
        events_tx,
        log.clone(),
    ));

    loop {
        tokio::select! {
            accepted = listener.accept() => {
                let (stream, _) = accepted.map_err(|source| DaemonError::Io {
                    path: project.operator_socket.clone(),
                    source,
                })?;
                let dispatcher_tx = dispatcher_tx.clone();
                let log = log.clone();
                let shutdown = shutdown_tx.clone();
                tokio::spawn(async move {
                    if let Err(error) = handle_connection(stream, dispatcher_tx, shutdown).await {
                        log.emit_with_fields(
                            LogLevel::Error,
                            "sloop::socket",
                            "connection_failed",
                            json!({"error": error.to_string()}),
                        );
                    }
                });
            }
            _ = shutdown_rx.recv() => {
                shutdown_flag.store(true, Ordering::Release);
                log.emit(LogLevel::Info, "sloop::daemon", "daemon_stopped");
                let _ = fs::remove_file(&project.operator_socket);
                return Ok(());
            }
        }
    }
}

async fn handle_connection(
    stream: UnixStream,
    dispatcher: mpsc::Sender<DispatcherMessage>,
    shutdown: mpsc::Sender<()>,
) -> io::Result<()> {
    let reader = AsyncBufReader::new(stream);
    let mut limited = reader.take(MAX_ENVELOPE_BYTES + 1);
    let mut bytes = Vec::new();
    let read = limited.read_until(b'\n', &mut bytes).await?;
    if read == 0 {
        return Ok(());
    }

    let mut stream = limited.into_inner().into_inner();
    let envelope = if bytes.len() as u64 > MAX_ENVELOPE_BYTES {
        Err(protocol_error("request envelope is too large"))
    } else {
        std::str::from_utf8(&bytes)
            .map_err(|_| protocol_error("request envelope must be UTF-8"))
            .and_then(|line| RequestEnvelope::decode(line.trim_end()).map_err(|error| error.body))
    };

    let is_stop = matches!(
        &envelope,
        Ok(envelope) if matches!(envelope.request, Request::Stop(_))
    );
    let response = match envelope {
        Ok(envelope) if envelope.token.is_some() => ResponseEnvelope::failure(
            Some(envelope.id),
            unauthorized("operator socket does not accept worker tokens"),
        ),
        Ok(envelope)
            if !matches!(
                envelope.request.capability(),
                Capability::Operator | Capability::Both
            ) =>
        {
            ResponseEnvelope::failure(
                Some(envelope.id),
                unauthorized("worker verbs are not available on the operator socket"),
            )
        }
        Ok(envelope) => dispatch_envelope(envelope, RequestOrigin::Operator, &dispatcher).await,
        Err(error) => ResponseEnvelope::failure(None, error),
    };

    // The reply must be flushed before the daemon exits, so the connection
    // handler owns the shutdown signal for an accepted stop.
    let stopping = is_stop && response.ok;
    let encoded = serde_json::to_vec(&response).map_err(io::Error::other)?;
    stream.write_all(&encoded).await?;
    stream.write_all(b"\n").await?;
    stream.shutdown().await?;
    if stopping {
        let _ = shutdown.send(()).await;
    }
    Ok(())
}

/// Reads one request line from a per-run worker socket, enforces the verb
/// split at the boundary, and funnels the request through the dispatcher
/// with the presented token for validation against the run's issued one.
async fn handle_worker_connection(
    stream: UnixStream,
    run_id: String,
    dispatcher: mpsc::Sender<DispatcherMessage>,
) -> io::Result<()> {
    let reader = AsyncBufReader::new(stream);
    let mut limited = reader.take(MAX_ENVELOPE_BYTES + 1);
    let mut bytes = Vec::new();
    let read = limited.read_until(b'\n', &mut bytes).await?;
    if read == 0 {
        return Ok(());
    }

    let mut stream = limited.into_inner().into_inner();
    let envelope = if bytes.len() as u64 > MAX_ENVELOPE_BYTES {
        Err(protocol_error("request envelope is too large"))
    } else {
        std::str::from_utf8(&bytes)
            .map_err(|_| protocol_error("request envelope must be UTF-8"))
            .and_then(|line| RequestEnvelope::decode(line.trim_end()).map_err(|error| error.body))
    };

    let response = match envelope {
        Ok(envelope)
            if !matches!(
                envelope.request.capability(),
                Capability::Worker | Capability::Both
            ) =>
        {
            ResponseEnvelope::failure(
                Some(envelope.id),
                unauthorized("operator verbs are not available on a worker socket"),
            )
        }
        Ok(envelope) => {
            let token = envelope.token.clone();
            dispatch_envelope(
                envelope,
                RequestOrigin::Worker { run_id, token },
                &dispatcher,
            )
            .await
        }
        Err(error) => ResponseEnvelope::failure(None, error),
    };

    let encoded = serde_json::to_vec(&response).map_err(io::Error::other)?;
    stream.write_all(&encoded).await?;
    stream.write_all(b"\n").await?;
    stream.shutdown().await
}

async fn dispatch_envelope(
    envelope: RequestEnvelope,
    origin: RequestOrigin,
    dispatcher: &mpsc::Sender<DispatcherMessage>,
) -> ResponseEnvelope {
    let (reply_tx, reply_rx) = oneshot::channel();
    let id = envelope.id;
    if dispatcher
        .send(DispatcherMessage {
            id: id.clone(),
            request: envelope.request,
            origin,
            reply: reply_tx,
        })
        .await
        .is_err()
    {
        ResponseEnvelope::failure(Some(id), internal("dispatcher is unavailable"))
    } else {
        reply_rx.await.unwrap_or_else(|_| {
            ResponseEnvelope::failure(Some(id), internal("dispatcher dropped response"))
        })
    }
}

struct DispatcherMessage {
    id: RequestId,
    request: Request,
    origin: RequestOrigin,
    reply: oneshot::Sender<ResponseEnvelope>,
}

/// Which socket a request arrived on. Worker requests carry the run whose
/// socket accepted the connection plus the token the caller presented; the
/// dispatcher owns the comparison against the run's issued token.
enum RequestOrigin {
    Operator,
    Worker {
        run_id: String,
        token: Option<String>,
    },
}

struct DispatcherState {
    pid: u32,
    paused: bool,
    max_agents: usize,
    ticket_prefix: String,
    running_hours: Option<RunningHours>,
    agent: Option<AgentConfig>,
    flows: BTreeMap<String, Flow>,
    default_flow: String,
    aftercare_test_cmd: Option<Vec<String>>,
    root: PathBuf,
    ticket_dir: PathBuf,
    worktree_dir: PathBuf,
    state_dir: PathBuf,
    runtime_dir: PathBuf,
    socket: PathBuf,
    daemon_log: PathBuf,
    store: Store,
    /// Run IDs with a live supervised process; its size is the capacity gate.
    active: HashSet<String>,
    /// Run IDs whose cancellation was requested but whose exit has not been
    /// resolved yet; mirrors the durable `cancel_requested` evidence.
    cancelling: HashSet<String>,
    /// Tokens issued to live runs; a worker request must present its run's
    /// token exactly. Entries die with the run.
    worker_tokens: HashMap<String, String>,
    /// Accept-loop tasks for live per-run worker sockets, aborted at settle.
    worker_listeners: HashMap<String, tokio::task::JoinHandle<()>>,
    worker_socket_paths: HashMap<String, PathBuf>,
    /// Exit evidence remains here until its atomic store transaction commits.
    /// The dispatcher retries these records on every reconciliation pass.
    pending_exits: HashMap<String, RunEvent>,
    /// The dispatcher's own request channel, cloned into each worker
    /// accept loop so every request funnels through the single owner.
    requests_tx: mpsc::Sender<DispatcherMessage>,
    log: OperationalLog,
    clock: Arc<dyn Clock>,
    /// Signals the accept loop to end the process; used by daemon-side
    /// exits such as the project-root liveness check.
    shutdown: mpsc::Sender<()>,
    shutdown_flag: Arc<AtomicBool>,
}

/// One executed test stage as observed by the supervisor.
struct StageResult {
    outcome: StageOutcome,
    exit_code: Option<i32>,
    started_at_ms: i64,
    finished_at_ms: i64,
}

/// Internal dispatcher events reported by effect tasks, never by clients.
enum RunEvent {
    Exited {
        run_id: String,
        exit_code: Option<i32>,
        /// False when a pipe reader failed to durably record every chunk;
        /// the loss becomes explicit run evidence instead of silence.
        capture_complete: bool,
        /// Commits on the run branch that were not on the default branch at
        /// agent exit, before aftercare could fast-forward the default branch.
        commits: Vec<String>,
        tests: Option<StageResult>,
        merge: Option<MergeOutcome>,
        recovery: Option<RecoveryClassification>,
    },
}

#[derive(Debug, Clone, Copy, PartialEq, Eq)]
enum RecoveryClassification {
    Aftercare,
    Orphaned,
}

async fn run_dispatcher(
    mut state: DispatcherState,
    mut requests: mpsc::Receiver<DispatcherMessage>,
    mut events: mpsc::Receiver<RunEvent>,
    events_tx: mpsc::Sender<RunEvent>,
    log: OperationalLog,
) {
    reconcile(&mut state, &events_tx, &log);
    loop {
        let deadline = next_dispatch_deadline(&state);
        let clock = state.clock.clone();
        tokio::select! {
            message = requests.recv() => {
                let Some(message) = message else { break };
                let response = match message.origin {
                    RequestOrigin::Operator => dispatch(&mut state, message.id, message.request),
                    RequestOrigin::Worker { run_id, token } => dispatch_worker(
                        &mut state,
                        message.id,
                        message.request,
                        &run_id,
                        token.as_deref(),
                    ),
                };
                let _ = message.reply.send(response);
                log.emit(LogLevel::Info, "sloop::dispatcher", "request_handled");
            }
            event = events.recv() => {
                let Some(event) = event else { break };
                settle_run_exit(&mut state, event, &log);
            }
            () = wait_for_deadline(clock, deadline) => {
                log.emit(LogLevel::Info, "sloop::dispatcher", "timer_fired");
            }
            // Wall-clock is deliberate: this is a liveness probe, not
            // decision logic, so the manual test clock must not gate it.
            () = tokio::time::sleep(std::time::Duration::from_secs(2)) => {
                if !state.root.join(".git").exists() {
                    log.emit(LogLevel::Error, "sloop::dispatcher", "project_root_missing");
                    let _ = state.shutdown.send(()).await;
                    break;
                }
            }
        }
        reconcile(&mut state, &events_tx, &log);
    }
}

async fn wait_for_deadline(clock: Arc<dyn Clock>, deadline: Option<i64>) {
    match deadline {
        Some(deadline) => clock.sleep_until(deadline).await,
        None => std::future::pending().await,
    }
}

/// Resolves one finished run: derives the outcome from the gathered evidence
/// and commits the whole settlement in one store transaction. Cancellation
/// intent recorded before the exit wins over every other reading, keeping a
/// racing `cancel` and natural exit idempotent.
fn settle_run_exit(state: &mut DispatcherState, event: RunEvent, log: &OperationalLog) {
    let run_id = match &event {
        RunEvent::Exited { run_id, .. } => run_id.clone(),
    };
    state.pending_exits.insert(run_id, event);
    settle_pending_exits(state, log);
}

fn settle_pending_exits(state: &mut DispatcherState, log: &OperationalLog) {
    let run_ids: Vec<String> = state.pending_exits.keys().cloned().collect();
    for run_id in run_ids {
        let Some(event) = state.pending_exits.remove(&run_id) else {
            continue;
        };
        match try_settle_run_exit(state, &event) {
            Ok(outcome) => {
                state.cancelling.remove(&run_id);
                state.active.remove(&run_id);
                close_worker_socket(state, &run_id);
                log.emit_with_fields(
                    LogLevel::Info,
                    "sloop::dispatcher",
                    "run_exited",
                    json!({"run_id": run_id, "outcome": outcome.as_str()}),
                );
            }
            Err(error) => {
                log.emit_with_fields(
                    LogLevel::Error,
                    "sloop::dispatcher",
                    "run_exit_persist_failed",
                    json!({"run_id": run_id, "error": error.to_string()}),
                );
                state.pending_exits.insert(run_id, event);
            }
        }
    }
}

fn try_settle_run_exit(
    state: &mut DispatcherState,
    event: &RunEvent,
) -> Result<crate::outcome::Outcome, StoreError> {
    let RunEvent::Exited {
        run_id,
        exit_code,
        capture_complete,
        commits,
        tests,
        merge,
        recovery,
    } = event;

    let cancelled =
        state.cancelling.contains(run_id) || state.store.cancellation_requested(run_id)?;
    let commit_count = commits.len() as u64;
    let evidence = RunEvidence {
        cancelled,
        exit: classify_exit(*exit_code),
        commit_count,
        tests: tests.as_ref().map(|stage| stage.outcome),
        merge: *merge,
    };
    let outcome = if *recovery == Some(RecoveryClassification::Orphaned) && !cancelled {
        crate::outcome::Outcome::Orphaned
    } else {
        derive_outcome(&evidence)
    };

    let mut records = vec![
        EvidenceRecord {
            kind: "exit_classified",
            data_json: json!({"exit_code": exit_code}).to_string(),
        },
        EvidenceRecord {
            kind: "commits_observed",
            data_json: json!({"count": commit_count, "oids": commits}).to_string(),
        },
    ];
    if let Some(classification) = recovery {
        records.push(EvidenceRecord {
            kind: "recovery_classified",
            data_json: json!({
                "classification": match classification {
                    RecoveryClassification::Aftercare => "aftercare",
                    RecoveryClassification::Orphaned => "orphaned",
                }
            })
            .to_string(),
        });
    }
    if let Some(stage) = &tests {
        records.push(EvidenceRecord {
            kind: "test_result",
            data_json: json!({
                "passed": stage.outcome == StageOutcome::Passed,
                "exit_code": stage.exit_code,
            })
            .to_string(),
        });
    }
    if let Some(merge) = *merge {
        records.push(EvidenceRecord {
            kind: "merge_result",
            data_json: json!({"merged": merge == MergeOutcome::Merged}).to_string(),
        });
    }
    if !capture_complete {
        records.push(EvidenceRecord {
            kind: "capture_incomplete",
            data_json: json!({}).to_string(),
        });
    }
    let stage_row = tests.as_ref().map(|stage| StageRecord {
        stage: "test",
        state: match stage.outcome {
            StageOutcome::Passed => "passed",
            StageOutcome::Failed => "failed",
        },
        started_at_ms: stage.started_at_ms,
        finished_at_ms: stage.finished_at_ms,
        exit_code: stage.exit_code,
    });

    let ticket_id = state
        .store
        .run(run_id)?
        .ok_or_else(|| StoreError::RunNotFound {
            run_id: run_id.clone(),
        })?
        .ticket_id;
    state.store.finish_run(
        run_id,
        &ticket_id,
        *exit_code,
        outcome,
        &records,
        stage_row.as_ref(),
        state.clock.now_ms(),
    )?;
    Ok(outcome)
}

/// Tears down a run's worker boundary: the token stops validating, the
/// accept loop ends, and the socket file disappears. Idempotent, so crash
/// recovery and racing settlements can call it freely.
fn close_worker_socket(state: &mut DispatcherState, run_id: &str) {
    state.worker_tokens.remove(run_id);
    if let Some(listener) = state.worker_listeners.remove(run_id) {
        listener.abort();
    }
    let socket_path = state
        .worker_socket_paths
        .remove(run_id)
        .unwrap_or_else(|| worker_socket_path(&state.runtime_dir, run_id));
    let _ = fs::remove_file(socket_path);
}

/// Classifies every durable lease before normal dispatch. Matching processes
/// consume capacity and are monitored by identity; dead or reused PIDs are
/// settled from the work preserved in their branches.
fn recover_inflight_runs(
    state: &mut DispatcherState,
    events: &mpsc::Sender<RunEvent>,
    log: &OperationalLog,
) -> Result<(), DaemonError> {
    let runs = state.store.recoverable_runs().map_err(DaemonError::Store)?;
    for run in runs {
        // Every durable lease consumes capacity until adoption or settlement
        // succeeds; a transient database error must never permit double-spawn.
        state.active.insert(run.id.clone());
        if recoverable_process_matches(&run) {
            let cancellation_requested = state
                .store
                .cancellation_requested(&run.id)
                .map_err(DaemonError::Store)?;
            if cancellation_requested {
                state.cancelling.insert(run.id.clone());
                if recoverable_process_matches(&run)
                    && let Some(group) = run.process_group_id
                {
                    unsafe {
                        libc::kill(-(group as libc::pid_t), libc::SIGKILL);
                    }
                }
            }
            if let Err(error) = restore_worker_socket(state, &run) {
                log.emit_with_fields(
                    LogLevel::Error,
                    "sloop::recovery",
                    "worker_socket_restore_failed",
                    json!({"run_id": run.id, "error": error}),
                );
            }
            monitor_recovered_run(state, events.clone(), run.clone());
            log.emit_with_fields(
                LogLevel::Info,
                "sloop::recovery",
                "run_readopted",
                json!({"run_id": run.id, "ticket_id": run.ticket_id}),
            );
        } else {
            if run.state == "aftercare" {
                spawn_aftercare_recovery(state, events.clone(), run, log.clone());
            } else {
                spawn_dead_run_recovery(state, events.clone(), run, log.clone());
            }
        }
    }
    Ok(())
}

fn restore_worker_socket(state: &mut DispatcherState, run: &RecoverableRun) -> Result<(), String> {
    let token = run
        .worker_token
        .as_ref()
        .ok_or_else(|| "the persisted run has no worker token".to_owned())?;
    let socket_path = run
        .worker_socket_path
        .as_deref()
        .map(PathBuf::from)
        .unwrap_or_else(|| worker_socket_path(&state.runtime_dir, &run.id));
    fs::create_dir_all(socket_path.parent().expect("worker sockets have a parent"))
        .map_err(|error| error.to_string())?;
    let _ = fs::remove_file(&socket_path);
    let listener = UnixListener::bind(&socket_path).map_err(|error| error.to_string())?;
    fs::set_permissions(&socket_path, fs::Permissions::from_mode(0o600))
        .map_err(|error| error.to_string())?;
    state.worker_tokens.insert(run.id.clone(), token.clone());
    state
        .worker_socket_paths
        .insert(run.id.clone(), socket_path.clone());
    let accept_loop = tokio::spawn(serve_worker_socket(
        listener,
        run.id.clone(),
        state.requests_tx.clone(),
        state.log.clone(),
    ));
    state.worker_listeners.insert(run.id.clone(), accept_loop);
    Ok(())
}

fn monitor_recovered_run(
    state: &DispatcherState,
    events: mpsc::Sender<RunEvent>,
    run: RecoverableRun,
) {
    let root = state.root.clone();
    let log = state.log.clone();
    let shutdown = state.shutdown_flag.clone();
    tokio::task::spawn_blocking(move || {
        while recoverable_process_matches(&run) {
            if shutdown.load(Ordering::Acquire) {
                return;
            }
            std::thread::sleep(Duration::from_millis(100));
        }
        while !shutdown.load(Ordering::Acquire) {
            match recovered_exit_event(&root, &run) {
                Ok(event) => {
                    let _ = events.blocking_send(event);
                    break;
                }
                Err(error) => {
                    log.emit_with_fields(
                        LogLevel::Error,
                        "sloop::recovery",
                        "run_observation_failed",
                        json!({"run_id": run.id, "error": error}),
                    );
                    std::thread::sleep(Duration::from_secs(1));
                }
            }
        }
    });
}

fn spawn_dead_run_recovery(
    state: &DispatcherState,
    events: mpsc::Sender<RunEvent>,
    run: RecoverableRun,
    log: OperationalLog,
) {
    let root = state.root.clone();
    let shutdown = state.shutdown_flag.clone();
    tokio::task::spawn_blocking(move || {
        while !shutdown.load(Ordering::Acquire) {
            match recovered_exit_event(&root, &run) {
                Ok(event) => {
                    let _ = events.blocking_send(event);
                    break;
                }
                Err(error) => {
                    log.emit_with_fields(
                        LogLevel::Error,
                        "sloop::recovery",
                        "run_observation_failed",
                        json!({"run_id": run.id, "error": error}),
                    );
                    std::thread::sleep(Duration::from_secs(1));
                }
            }
        }
    });
}

fn recovered_exit_event(root: &Path, run: &RecoverableRun) -> Result<RunEvent, String> {
    let commits = run
        .branch
        .as_deref()
        .map(|branch| try_commits_on_branch(root, branch))
        .transpose()?
        .unwrap_or_default();
    let recovery = if commits.is_empty() {
        RecoveryClassification::Orphaned
    } else {
        RecoveryClassification::Aftercare
    };
    Ok(RunEvent::Exited {
        run_id: run.id.clone(),
        exit_code: None,
        capture_complete: false,
        commits,
        tests: None,
        merge: None,
        recovery: Some(recovery),
    })
}

fn spawn_aftercare_recovery(
    state: &DispatcherState,
    events: mpsc::Sender<RunEvent>,
    run: RecoverableRun,
    log: OperationalLog,
) {
    let root = state.root.clone();
    let state_dir = state.state_dir.clone();
    let test_cmd = state.aftercare_test_cmd.clone();
    let clock = state.clock.clone();
    let db_path = state.state_dir.join("sloop.db");
    let shutdown = state.shutdown_flag.clone();
    tokio::task::spawn_blocking(move || {
        while !shutdown.load(Ordering::Acquire) {
            let result = Store::open(&db_path, clock.now_ms())
                .map_err(|error| error.to_string())
                .and_then(|store| {
                    resume_aftercare(
                        &root,
                        &state_dir,
                        test_cmd.as_deref(),
                        clock.as_ref(),
                        &store,
                        &run,
                        &log,
                    )
                });
            match result {
                Ok(event) => {
                    let _ = events.blocking_send(event);
                    break;
                }
                Err(error) => {
                    log.emit_with_fields(
                        LogLevel::Error,
                        "sloop::recovery",
                        "aftercare_resume_failed",
                        json!({"run_id": run.id, "error": error}),
                    );
                    std::thread::sleep(Duration::from_secs(1));
                }
            }
        }
    });
}

#[allow(clippy::too_many_arguments)]
fn resume_aftercare(
    root: &Path,
    state_dir: &Path,
    test_cmd: Option<&[String]>,
    clock: &dyn Clock,
    store: &Store,
    run: &RecoverableRun,
    log: &OperationalLog,
) -> Result<RunEvent, String> {
    let rows = store
        .run_evidence(&run.id)
        .map_err(|error| error.to_string())?;
    let value = |kind: &str| {
        rows.iter()
            .find(|(candidate, _)| candidate == kind)
            .and_then(|(_, data)| serde_json::from_str::<serde_json::Value>(data).ok())
    };
    let commits = value("commits_observed")
        .and_then(|data| {
            data["oids"].as_array().map(|oids| {
                oids.iter()
                    .filter_map(|oid| oid.as_str().map(str::to_owned))
                    .collect::<Vec<_>>()
            })
        })
        .ok_or_else(|| "the aftercare checkpoint has no valid commit evidence".to_owned())?;
    let exit_code = run.exit_code.and_then(|code| i32::try_from(code).ok());
    let exit = classify_exit(exit_code);
    let output_log = RunLogWriter::open(&run_output_path(state_dir, &run.id))
        .map_err(|error| format!("cannot open run output: {error}"))?;

    let mut tests = value("test_result").map(|data| StageResult {
        outcome: if data["passed"].as_bool() == Some(true) {
            StageOutcome::Passed
        } else {
            StageOutcome::Failed
        },
        exit_code: data["exit_code"]
            .as_i64()
            .and_then(|code| i32::try_from(code).ok()),
        started_at_ms: data["started_at_ms"]
            .as_i64()
            .unwrap_or_else(|| clock.now_ms()),
        finished_at_ms: data["finished_at_ms"]
            .as_i64()
            .unwrap_or_else(|| clock.now_ms()),
    });
    if aftercare_cancelled(store, &run.id, log) {
        return Ok(RunEvent::Exited {
            run_id: run.id.clone(),
            exit_code,
            capture_complete: !rows.iter().any(|(kind, _)| kind == "capture_incomplete"),
            commits,
            tests,
            merge: None,
            recovery: Some(RecoveryClassification::Aftercare),
        });
    }
    if tests.is_none()
        && wants_tests(exit, commits.len() as u64)
        && let Some(cmd) = test_cmd
    {
        stop_interrupted_process(&rows, "test_process")?;
        let worktree = run
            .worktree_path
            .as_deref()
            .ok_or_else(|| "the aftercare checkpoint has no worktree".to_owned())?;
        let stage = run_test_stage(
            Path::new(worktree),
            cmd,
            &output_log,
            clock,
            Some(store),
            &run.id,
            log,
        );
        store
            .record_aftercare_evidence(
                &run.id,
                "test_result",
                &test_result_json(&stage),
                clock.now_ms(),
            )
            .map_err(|error| error.to_string())?;
        tests = Some(stage);
    }

    let mut merge = value("merge_result").map(|data| {
        if data["merged"].as_bool() == Some(true) {
            MergeOutcome::Merged
        } else {
            MergeOutcome::Diverged
        }
    });
    if !aftercare_cancelled(store, &run.id, log)
        && merge.is_none()
        && wants_merge(
            exit,
            commits.len() as u64,
            tests.as_ref().map(|stage| stage.outcome),
        )
        && let Some(branch) = run.branch.as_deref()
    {
        stop_interrupted_process(&rows, "merge_process")?;
        let outcome = attempt_merge(root, branch, Some(store), &run.id, clock, log);
        store
            .record_aftercare_evidence(
                &run.id,
                "merge_result",
                &merge_result_json(outcome),
                clock.now_ms(),
            )
            .map_err(|error| error.to_string())?;
        merge = Some(outcome);
    }

    Ok(RunEvent::Exited {
        run_id: run.id.clone(),
        exit_code,
        capture_complete: !rows.iter().any(|(kind, _)| kind == "capture_incomplete"),
        commits,
        tests,
        merge,
        recovery: Some(RecoveryClassification::Aftercare),
    })
}

fn stop_interrupted_process(rows: &[(String, String)], kind: &str) -> Result<(), String> {
    let Some((pid, start_time, group)) = aftercare_process_identity(rows, kind)? else {
        return Ok(());
    };
    if !process_identity_matches(pid, Some(start_time)) {
        return Ok(());
    }
    unsafe {
        libc::kill(-(group as libc::pid_t), libc::SIGKILL);
    }
    let deadline = Instant::now() + Duration::from_secs(5);
    while process_identity_matches(pid, Some(start_time)) {
        if Instant::now() >= deadline {
            return Err("the interrupted test process did not exit".into());
        }
        std::thread::sleep(Duration::from_millis(20));
    }
    Ok(())
}

fn aftercare_process_identity(
    rows: &[(String, String)],
    kind: &str,
) -> Result<Option<(u32, i64, i64)>, String> {
    let Some(data) = rows
        .iter()
        .find(|(candidate, _)| candidate == kind)
        .and_then(|(_, data)| serde_json::from_str::<serde_json::Value>(data).ok())
    else {
        return Ok(None);
    };
    let pid = data["pid"]
        .as_u64()
        .and_then(|pid| u32::try_from(pid).ok())
        .ok_or_else(|| "the interrupted test has no valid pid".to_owned())?;
    let start_time = data["pid_start_time"]
        .as_i64()
        .ok_or_else(|| "the interrupted test has no valid start time".to_owned())?;
    let group = data["process_group_id"]
        .as_i64()
        .ok_or_else(|| "the interrupted test has no valid process group".to_owned())?;
    Ok(Some((pid, start_time, group)))
}

fn recoverable_process_matches(run: &RecoverableRun) -> bool {
    if run.state != "running" {
        return false;
    }
    let Some(pid) = run.pid.and_then(|pid| u32::try_from(pid).ok()) else {
        return false;
    };
    process_identity_matches(pid, run.pid_start_time)
}

fn process_identity_matches(pid: u32, expected_start_time: Option<i64>) -> bool {
    matches!(
        (expected_start_time, process_start_time(pid)),
        (Some(expected), Some(actual)) if expected == actual
    )
}

fn worker_socket_path(runtime_dir: &Path, run_id: &str) -> PathBuf {
    runtime_dir.join("workers").join(format!("{run_id}.sock"))
}

/// The single spawn decision point: every queued activation passes the same
/// pause and capacity gates, selects deterministically, claims conditionally,
/// and only then touches Git and processes.
fn reconcile(state: &mut DispatcherState, events: &mpsc::Sender<RunEvent>, log: &OperationalLog) {
    settle_pending_exits(state, log);
    let now_ms = state.clock.now_ms();
    if state.paused || state.agent.is_none() || !running_hours_open(state, now_ms) {
        return;
    }
    let activations = match state.store.queued_dispatchable_activations() {
        Ok(activations) => activations,
        Err(error) => {
            log.emit_with_fields(
                LogLevel::Error,
                "sloop::dispatcher",
                "activation_scan_failed",
                json!({"error": error.to_string()}),
            );
            return;
        }
    };

    for activation in activations {
        if state.active.len() >= state.max_agents {
            break;
        }
        let Some(ticket_id) = eligible_ticket(&state.store, &activation) else {
            continue;
        };

        let now_ms = state.clock.now_ms();
        let Ok(run_ordinal) = state.store.next_run_ordinal() else {
            continue;
        };
        let run_id = format!("R{run_ordinal}");
        let owner = format!("daemon-{}", state.pid);
        let claim = ClaimRequest {
            ticket_id: &ticket_id,
            run_id: &run_id,
            activation_id: &activation.id,
            owner_id: &owner,
            lease_ms: DEFAULT_LEASE_MS,
        };
        let claimed = match state.store.claim_ticket(&claim, now_ms) {
            Ok(claimed) => claimed,
            // Not ready right now; the activation stays queued for later.
            Err(StoreError::TicketNotReady { .. }) => continue,
            Err(error) => {
                log.emit_with_fields(
                    LogLevel::Error,
                    "sloop::dispatcher",
                    "claim_failed",
                    json!({
                        "activation_id": activation.id,
                        "ticket_id": ticket_id,
                        "run_id": run_id,
                        "error": error.to_string(),
                    }),
                );
                continue;
            }
        };
        // Immediate and auto activations are one-shot: producing a run
        // consumes them, even if the launch below fails.
        if let Err(error) = state.store.complete_activation(&activation.id, now_ms) {
            log.emit_with_fields(
                LogLevel::Error,
                "sloop::dispatcher",
                "activation_update_failed",
                json!({"activation_id": activation.id, "error": error.to_string()}),
            );
        }

        match launch_agent(state, &run_id, &ticket_id, claimed.attempt) {
            Ok(launched) => {
                state.active.insert(run_id.clone());
                let events = events.clone();
                let exited_run = run_id.clone();
                let root = state.root.clone();
                let test_cmd = state.aftercare_test_cmd.clone();
                let clock = state.clock.clone();
                let supervisor_log = log.clone();
                let db_path = state.state_dir.join("sloop.db");
                let LaunchedRun {
                    mut child,
                    readers,
                    worktree,
                    branch,
                    output_log,
                    worker_listener,
                    worker_token,
                    worker_socket_path,
                } = launched;
                state.worker_tokens.insert(run_id.clone(), worker_token);
                state
                    .worker_socket_paths
                    .insert(run_id.clone(), worker_socket_path);
                let accept_loop = tokio::spawn(serve_worker_socket(
                    worker_listener,
                    run_id.clone(),
                    state.requests_tx.clone(),
                    state.log.clone(),
                ));
                state.worker_listeners.insert(run_id.clone(), accept_loop);
                let pid = child.id();
                tokio::task::spawn_blocking(move || {
                    let exit_code = match child.wait() {
                        Ok(status) => status.code(),
                        Err(error) => {
                            supervisor_log.emit_with_fields(
                                LogLevel::Error,
                                "sloop::supervisor",
                                "agent_wait_failed",
                                json!({"run_id": exited_run, "error": error.to_string()}),
                            );
                            None
                        }
                    };
                    // Capture must be complete on disk before the exit is
                    // reported; the readers end when the pipes close.
                    let capture_complete = readers
                        .into_iter()
                        .all(|reader| reader.join().unwrap_or(false));
                    let mut checkpoint_store = match Store::open(&db_path, clock.now_ms()) {
                        Ok(store) => Some(store),
                        Err(error) => {
                            supervisor_log.emit_with_fields(
                                LogLevel::Error,
                                "sloop::supervisor",
                                "aftercare_checkpoint_open_failed",
                                json!({"run_id": exited_run, "error": error.to_string()}),
                            );
                            None
                        }
                    };
                    let (commits, tests, merge) = gather_exit_evidence(
                        &exited_run,
                        &root,
                        &worktree,
                        &branch,
                        test_cmd.as_deref(),
                        clock.as_ref(),
                        &output_log,
                        exit_code,
                        capture_complete,
                        checkpoint_store.as_mut(),
                        &supervisor_log,
                    );
                    let _ = events.blocking_send(RunEvent::Exited {
                        run_id: exited_run,
                        exit_code,
                        capture_complete,
                        commits,
                        tests,
                        merge,
                        recovery: None,
                    });
                });
                log.emit_with_fields(
                    LogLevel::Info,
                    "sloop::dispatcher",
                    "run_started",
                    json!({"run_id": run_id, "ticket_id": ticket_id, "pid": pid}),
                );
            }
            Err(error) => {
                if let Err(abort_error) =
                    state
                        .store
                        .abort_claim(&run_id, &ticket_id, state.clock.now_ms())
                {
                    log.emit_with_fields(
                        LogLevel::Error,
                        "sloop::dispatcher",
                        "claim_abort_failed",
                        json!({
                            "run_id": run_id,
                            "ticket_id": ticket_id,
                            "error": abort_error.to_string(),
                        }),
                    );
                }
                // A launch can fail after the worker socket was bound.
                close_worker_socket(state, &run_id);
                log.emit_with_fields(
                    LogLevel::Error,
                    "sloop::dispatcher",
                    "run_launch_failed",
                    json!({
                        "run_id": run_id,
                        "ticket_id": ticket_id,
                        "error": error,
                    }),
                );
            }
        }
    }
}

fn running_hours_open(state: &DispatcherState, now_ms: i64) -> bool {
    state
        .running_hours
        .as_ref()
        .is_none_or(|hours| hours.is_open(state.clock.local_minute(now_ms)))
}

fn next_dispatch_deadline(state: &DispatcherState) -> Option<i64> {
    let hours = state.running_hours.as_ref()?;
    let now_ms = state.clock.now_ms();
    if hours.is_open(state.clock.local_minute(now_ms)) {
        return None;
    }
    let has_demand = state
        .store
        .queued_dispatchable_activations()
        .is_ok_and(|activations| !activations.is_empty());
    has_demand.then(|| hours.next_opening_ms(state.clock.as_ref(), now_ms))
}

fn eligible_ticket(store: &Store, activation: &QueuedActivation) -> Option<String> {
    match &activation.ticket_id {
        Some(ticket) => Some(ticket.clone()),
        None => store.select_ready_ticket(activation).ok().flatten(),
    }
}

/// A supervised agent process plus the reader threads draining its pipes;
/// the readers finish when the pipes close, and joining them guarantees
/// capture is flushed before exit evidence is reported. Worktree, branch,
/// and log writer stay with the supervisor for evidence gathering after
/// the exit.
struct LaunchedRun {
    child: Child,
    readers: Vec<std::thread::JoinHandle<bool>>,
    worktree: PathBuf,
    branch: String,
    output_log: RunLogWriter,
    /// The bound per-run worker socket, handed to an accept-loop task once
    /// the launch is registered.
    worker_listener: UnixListener,
    worker_token: String,
    worker_socket_path: PathBuf,
}

/// Gathers post-exit evidence in the supervisor thread, keeping slow Git and
/// test work out of the dispatcher: commits on the run branch, the configured
/// test stage when the exit and commits justify it, and the merge attempt
/// when policy allows.
#[allow(clippy::too_many_arguments)]
fn gather_exit_evidence(
    run_id: &str,
    root: &Path,
    worktree: &Path,
    branch: &str,
    test_cmd: Option<&[String]>,
    clock: &dyn Clock,
    output_log: &RunLogWriter,
    exit_code: Option<i32>,
    capture_complete: bool,
    mut checkpoint_store: Option<&mut Store>,
    operational_log: &OperationalLog,
) -> (Vec<String>, Option<StageResult>, Option<MergeOutcome>) {
    let exit = classify_exit(exit_code);
    let commits = commits_on_branch(root, branch);
    let commit_count = commits.len() as u64;
    let checkpointed = if let Some(store) = checkpoint_store.as_deref_mut() {
        match store.record_agent_exit(
            run_id,
            exit_code,
            capture_complete,
            &json!({"count": commit_count, "oids": commits}).to_string(),
            clock.now_ms(),
        ) {
            Ok(()) => true,
            Err(error) => {
                operational_log.emit_with_fields(
                    LogLevel::Error,
                    "sloop::supervisor",
                    "agent_exit_checkpoint_failed",
                    json!({"run_id": run_id, "error": error.to_string()}),
                );
                false
            }
        }
    } else {
        false
    };
    // Tests and merge can have side effects. Without the pre-aftercare
    // checkpoint, preserve committed work for review rather than performing
    // an action that recovery could no longer prove or resume.
    if !checkpointed
        || checkpoint_store
            .as_deref()
            .is_some_and(|store| aftercare_cancelled(store, run_id, operational_log))
    {
        return (commits, None, None);
    }

    let tests = match test_cmd {
        Some(cmd) if wants_tests(exit, commit_count) => {
            let stage = run_test_stage(
                worktree,
                cmd,
                output_log,
                clock,
                checkpoint_store.as_deref(),
                run_id,
                operational_log,
            );
            let test_checkpointed = if let Some(store) = checkpoint_store.as_deref()
                && let Err(error) = store.record_aftercare_evidence(
                    run_id,
                    "test_result",
                    &test_result_json(&stage),
                    clock.now_ms(),
                ) {
                operational_log.emit_with_fields(
                    LogLevel::Error,
                    "sloop::supervisor",
                    "aftercare_checkpoint_failed",
                    json!({"run_id": run_id, "stage": "test", "error": error.to_string()}),
                );
                false
            } else {
                true
            };
            if !test_checkpointed {
                return (commits, Some(stage), None);
            }
            Some(stage)
        }
        _ => None,
    };

    let merge = if !checkpoint_store
        .as_deref()
        .is_some_and(|store| aftercare_cancelled(store, run_id, operational_log))
        && wants_merge(
            exit,
            commit_count,
            tests.as_ref().map(|stage| stage.outcome),
        ) {
        let outcome = attempt_merge(
            root,
            branch,
            checkpoint_store.as_deref(),
            run_id,
            clock,
            operational_log,
        );
        if let Some(store) = checkpoint_store.as_deref()
            && let Err(error) = store.record_aftercare_evidence(
                run_id,
                "merge_result",
                &merge_result_json(outcome),
                clock.now_ms(),
            )
        {
            operational_log.emit_with_fields(
                LogLevel::Error,
                "sloop::supervisor",
                "aftercare_checkpoint_failed",
                json!({"run_id": run_id, "stage": "merge", "error": error.to_string()}),
            );
        }
        Some(outcome)
    } else {
        None
    };
    (commits, tests, merge)
}

fn aftercare_cancelled(store: &Store, run_id: &str, log: &OperationalLog) -> bool {
    match store.cancellation_requested(run_id) {
        Ok(cancelled) => cancelled,
        Err(error) => {
            log.emit_with_fields(
                LogLevel::Error,
                "sloop::supervisor",
                "cancellation_read_failed",
                json!({"run_id": run_id, "error": error.to_string()}),
            );
            true
        }
    }
}

fn test_result_json(stage: &StageResult) -> String {
    json!({
        "passed": stage.outcome == StageOutcome::Passed,
        "exit_code": stage.exit_code,
        "started_at_ms": stage.started_at_ms,
        "finished_at_ms": stage.finished_at_ms,
    })
    .to_string()
}

fn merge_result_json(outcome: MergeOutcome) -> String {
    json!({"merged": outcome == MergeOutcome::Merged}).to_string()
}

/// Commits on the run branch that the root checkout does not have. A Git
/// failure reads as no commits: evidence that cannot be observed is not claimed.
fn commits_on_branch(root: &Path, branch: &str) -> Vec<String> {
    try_commits_on_branch(root, branch).unwrap_or_default()
}

fn try_commits_on_branch(root: &Path, branch: &str) -> Result<Vec<String>, String> {
    let output = Command::new("git")
        .args(["rev-list", "--reverse", &format!("HEAD..{branch}")])
        .current_dir(root)
        .output()
        .map_err(|error| error.to_string())?;
    match output {
        output if output.status.success() => Ok(String::from_utf8_lossy(&output.stdout)
            .lines()
            .map(str::to_owned)
            .collect()),
        output => Err(format!(
            "git rev-list failed: {}",
            String::from_utf8_lossy(&output.stderr).trim()
        )),
    }
}

/// Runs the configured test command in the run's worktree, capturing its
/// output as `aftercare` evidence in the same ordered run log.
fn run_test_stage(
    worktree: &Path,
    cmd: &[String],
    output_log: &RunLogWriter,
    clock: &dyn Clock,
    checkpoint_store: Option<&Store>,
    run_id: &str,
    operational_log: &OperationalLog,
) -> StageResult {
    let started_at_ms = clock.now_ms();
    let failed = |finished_at_ms| StageResult {
        outcome: StageOutcome::Failed,
        exit_code: None,
        started_at_ms,
        finished_at_ms,
    };

    let mut command = Command::new(&cmd[0]);
    command
        .args(&cmd[1..])
        .current_dir(worktree)
        .stdin(Stdio::null())
        .stdout(Stdio::piped())
        .stderr(Stdio::piped())
        .process_group(0);
    let Ok(mut child) = command.spawn() else {
        return failed(clock.now_ms());
    };
    let pid = child.id();
    let Some(pid_start_time) = process_start_time(pid) else {
        unsafe {
            libc::kill(-(pid as libc::pid_t), libc::SIGKILL);
        }
        let _ = child.wait();
        return failed(clock.now_ms());
    };
    let readers = vec![
        spawn_output_reader(
            child.stdout.take().expect("stdout was piped"),
            output_log.clone(),
            OutputSource::Aftercare,
            Some("test"),
            OutputStream::Stdout,
        ),
        spawn_output_reader(
            child.stderr.take().expect("stderr was piped"),
            output_log.clone(),
            OutputSource::Aftercare,
            Some("test"),
            OutputStream::Stderr,
        ),
    ];
    wait_for_test_hook("before-test-process-checkpoint");
    if let Some(store) = checkpoint_store
        && let Err(error) = store.record_aftercare_evidence(
            run_id,
            "test_process",
            &json!({
                "pid": pid,
                "pid_start_time": pid_start_time,
                "process_group_id": pid,
            })
            .to_string(),
            clock.now_ms(),
        )
    {
        operational_log.emit_with_fields(
            LogLevel::Error,
            "sloop::supervisor",
            "aftercare_process_checkpoint_failed",
            json!({"run_id": run_id, "stage": "test", "error": error.to_string()}),
        );
        if process_identity_matches(pid, Some(pid_start_time)) {
            unsafe {
                libc::kill(-(pid as libc::pid_t), libc::SIGKILL);
            }
        }
        let _ = child.wait();
        for reader in readers {
            let _ = reader.join();
        }
        return failed(clock.now_ms());
    }
    if checkpoint_store.is_some_and(|store| aftercare_cancelled(store, run_id, operational_log)) {
        if process_identity_matches(pid, Some(pid_start_time)) {
            unsafe {
                libc::kill(-(pid as libc::pid_t), libc::SIGKILL);
            }
        }
        let _ = child.wait();
        for reader in readers {
            let _ = reader.join();
        }
        return failed(clock.now_ms());
    }

    let status = child.wait();
    for reader in readers {
        let _ = reader.join();
    }
    let Ok(status) = status else {
        return failed(clock.now_ms());
    };
    StageResult {
        outcome: if status.success() {
            StageOutcome::Passed
        } else {
            StageOutcome::Failed
        },
        exit_code: status.code(),
        started_at_ms,
        finished_at_ms: clock.now_ms(),
    }
}

/// Attempts the policy merge into the default branch: fast-forward when
/// possible, otherwise a merge commit. Only a textual conflict needs a
/// human; the merge is aborted so the checkout stays clean and the run
/// branch survives as evidence.
#[allow(clippy::too_many_arguments)]
fn attempt_merge(
    root: &Path,
    branch: &str,
    checkpoint_store: Option<&Store>,
    run_id: &str,
    clock: &dyn Clock,
    operational_log: &OperationalLog,
) -> MergeOutcome {
    let Ok(_guard) = MERGE_LOCK.lock() else {
        return MergeOutcome::Diverged;
    };
    let message = format!("Merge run branch '{branch}'");
    // The merge commit is sloop's own action, not the operator's or the
    // agent's, so it carries sloop's identity; a fast-forward creates no
    // commit and ignores these.
    let mut command = Command::new("git");
    command
        .args([
            "-c",
            "user.name=sloop",
            "-c",
            "user.email=sloop@sloop.invalid",
            "merge",
            "--quiet",
            "-m",
            &message,
            branch,
        ])
        .current_dir(root)
        .stdin(Stdio::null())
        .stdout(Stdio::null())
        .stderr(Stdio::null())
        .process_group(0);
    let Ok(mut child) = command.spawn() else {
        return MergeOutcome::Diverged;
    };
    let pid = child.id();
    let Some(pid_start_time) = process_start_time(pid) else {
        unsafe {
            libc::kill(-(pid as libc::pid_t), libc::SIGKILL);
        }
        let _ = child.wait();
        return MergeOutcome::Diverged;
    };
    if let Some(store) = checkpoint_store {
        let checkpoint = json!({
            "pid": pid,
            "pid_start_time": pid_start_time,
            "process_group_id": pid,
        })
        .to_string();
        if let Err(error) =
            store.record_aftercare_evidence(run_id, "merge_process", &checkpoint, clock.now_ms())
        {
            operational_log.emit_with_fields(
                LogLevel::Error,
                "sloop::supervisor",
                "aftercare_process_checkpoint_failed",
                json!({"run_id": run_id, "stage": "merge", "error": error.to_string()}),
            );
            unsafe {
                libc::kill(-(pid as libc::pid_t), libc::SIGKILL);
            }
            let _ = child.wait();
            return MergeOutcome::Diverged;
        }
        if aftercare_cancelled(store, run_id, operational_log) {
            unsafe {
                libc::kill(-(pid as libc::pid_t), libc::SIGKILL);
            }
            let _ = child.wait();
            return MergeOutcome::Diverged;
        }
    }
    match child.wait() {
        Ok(status) if status.success() => MergeOutcome::Merged,
        _ => {
            let _ = Command::new("git")
                .args(["merge", "--abort"])
                .current_dir(root)
                .output();
            MergeOutcome::Diverged
        }
    }
}

fn run_output_path(state_dir: &Path, run_id: &str) -> PathBuf {
    state_dir.join("runs").join(run_id).join("output.ndjson")
}

/// Continuously drains one child pipe into the run log so a verbose agent
/// can never fill the pipe and deadlock. Returns whether every chunk was
/// durably captured.
fn spawn_output_reader(
    pipe: impl Read + Send + 'static,
    log: RunLogWriter,
    source: OutputSource,
    stage: Option<&'static str>,
    stream: OutputStream,
) -> std::thread::JoinHandle<bool> {
    std::thread::spawn(move || {
        let mut pipe = pipe;
        let mut buffer = [0u8; 8192];
        loop {
            match pipe.read(&mut buffer) {
                Ok(0) => return true,
                Ok(read) => {
                    if log.append(source, stage, stream, &buffer[..read]).is_err() {
                        return false;
                    }
                }
                Err(error) if error.kind() == io::ErrorKind::Interrupted => continue,
                Err(_) => return false,
            }
        }
    })
}

/// Creates the run's branch and isolated worktree, starts the configured
/// agent as its own process group, and records durable process identity.
fn launch_agent(
    state: &DispatcherState,
    run_id: &str,
    ticket_id: &str,
    attempt: i64,
) -> Result<LaunchedRun, String> {
    let agent = state
        .agent
        .as_ref()
        .ok_or_else(|| "no agent targets configured".to_owned())?;
    let ticket = state
        .store
        .ticket(ticket_id)
        .map_err(|error| error.to_string())?
        .ok_or_else(|| format!("ticket `{ticket_id}` no longer exists"))?;
    let target = ticket
        .target
        .as_deref()
        .ok_or_else(|| format!("ticket `{ticket_id}` does not specify an agent target"))?;
    let template = agent
        .targets
        .get(target)
        .ok_or_else(|| format!("ticket `{ticket_id}` names unknown agent target `{target}`"))?;
    let prompt = compose_worker_prompt(&state.root)?;
    let cmd = expand_agent_cmd(
        template,
        ticket.model.as_deref(),
        ticket.effort.as_deref(),
        &prompt,
    )
    .map_err(|error| format!("ticket `{ticket_id}` {error}"))?;
    let executable = std::env::current_exe()
        .map_err(|error| format!("cannot locate sloop executable: {error}"))?;
    let executable_dir = executable
        .parent()
        .ok_or_else(|| "sloop executable has no parent directory".to_owned())?;
    let mut path_entries = vec![executable_dir.to_path_buf()];
    if let Some(path) = std::env::var_os("PATH") {
        path_entries.extend(std::env::split_paths(&path));
    }
    let path = std::env::join_paths(path_entries)
        .map_err(|error| format!("cannot construct agent PATH: {error}"))?;
    // `retry` resets attempts, so the run ID keeps preserved failed branches
    // from colliding with a later run's first attempt.
    let branch = format!("sloop/{ticket_id}-a{attempt}-{run_id}");
    fs::create_dir_all(&state.worktree_dir).map_err(|error| error.to_string())?;
    let worktree = state.worktree_dir.join(run_id);

    let git = Command::new("git")
        .args(["worktree", "add", "--quiet", "-b", &branch])
        .arg(&worktree)
        .current_dir(&state.root)
        .output()
        .map_err(|error| error.to_string())?;
    if !git.status.success() {
        return Err(format!(
            "git worktree add failed: {}",
            String::from_utf8_lossy(&git.stderr).trim()
        ));
    }

    let output_log = RunLogWriter::open(&run_output_path(&state.state_dir, run_id))
        .map_err(|error| error.to_string())?;

    let worker_token = generate_worker_token()?;
    let socket_path = worker_socket_path(&state.runtime_dir, run_id);
    fs::create_dir_all(socket_path.parent().expect("worker sockets have a parent"))
        .map_err(|error| error.to_string())?;
    let _ = fs::remove_file(&socket_path);
    let worker_listener = UnixListener::bind(&socket_path).map_err(|error| error.to_string())?;
    fs::set_permissions(&socket_path, fs::Permissions::from_mode(0o600))
        .map_err(|error| error.to_string())?;

    let mut command = Command::new(&cmd[0]);
    command
        .args(&cmd[1..])
        .current_dir(&worktree)
        .env("SLOOP_RUN_ID", run_id)
        .env("SLOOP_TICKET_ID", ticket_id)
        .env("SLOOP_BIN", &executable)
        .env("PATH", path)
        .env("SLOOP_SOCKET", &socket_path)
        .env("SLOOP_TOKEN", &worker_token)
        .stdin(Stdio::null())
        .stdout(Stdio::piped())
        .stderr(Stdio::piped())
        .process_group(0);
    let mut child = command.spawn().map_err(|error| error.to_string())?;
    let readers = vec![
        spawn_output_reader(
            child.stdout.take().expect("stdout was piped"),
            output_log.clone(),
            OutputSource::Agent,
            None,
            OutputStream::Stdout,
        ),
        spawn_output_reader(
            child.stderr.take().expect("stderr was piped"),
            output_log.clone(),
            OutputSource::Agent,
            None,
            OutputStream::Stderr,
        ),
    ];

    let pid = child.id();
    if let Err(error) = state.store.mark_run_running(
        run_id,
        &branch,
        &worktree.to_string_lossy(),
        pid,
        process_start_time(pid),
        pid, // process_group(0) makes the child its own group leader
        &worker_token,
        &socket_path.to_string_lossy(),
        state.clock.now_ms(),
    ) {
        unsafe {
            libc::kill(-(pid as libc::pid_t), libc::SIGKILL);
        }
        let _ = child.wait();
        for reader in readers {
            let _ = reader.join();
        }
        return Err(error.to_string());
    }
    Ok(LaunchedRun {
        child,
        readers,
        worktree,
        branch,
        output_log,
        worker_listener,
        worker_token,
        worker_socket_path: socket_path,
    })
}

fn compose_worker_prompt(root: &Path) -> Result<String, String> {
    let path = root.join(".agents/sloop/instructions.md");
    match fs::read_to_string(&path) {
        Ok(instructions) => Ok(format!("{WORKER_BOOTSTRAP_PROMPT}\n\n{instructions}")),
        Err(error) if error.kind() == io::ErrorKind::NotFound => {
            Ok(WORKER_BOOTSTRAP_PROMPT.to_owned())
        }
        Err(error) => Err(format!("cannot read {}: {error}", path.display())),
    }
}

/// 32 random bytes from the kernel, encoded for an environment variable.
/// Guessing it stops accidents, which is the threat model; same-uid
/// isolation needs a real sandbox.
fn generate_worker_token() -> Result<String, String> {
    let mut bytes = [0u8; 32];
    let mut urandom = fs::File::open("/dev/urandom").map_err(|error| error.to_string())?;
    urandom
        .read_exact(&mut bytes)
        .map_err(|error| error.to_string())?;
    Ok(BASE64_TOKEN.encode(bytes))
}

/// Identity of the daemon owning a project's lockfile: PID plus process start
/// time, mirroring the identity rule used for supervised agents.
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct LockIdentity {
    pub pid: u32,
    pub started_at_ms: Option<i64>,
    pub socket: Option<PathBuf>,
}

pub fn read_lock_identity(path: &Path) -> Option<LockIdentity> {
    let content = fs::read_to_string(path).ok()?;
    let value: serde_json::Value = serde_json::from_str(content.trim()).ok()?;
    Some(LockIdentity {
        pid: u32::try_from(value["pid"].as_u64()?).ok()?,
        started_at_ms: value["started_at_ms"].as_i64(),
        socket: value["socket"].as_str().map(PathBuf::from),
    })
}

/// Reads a stable start-time token for a PID, the second half of the durable
/// process identity. Linux exposes clock ticks directly; other Unix systems
/// use a stable hash of `ps`'s process start timestamp.
fn process_start_time(pid: u32) -> Option<i64> {
    #[cfg(target_os = "linux")]
    {
        let stat = fs::read_to_string(format!("/proc/{pid}/stat")).ok()?;
        let after_command = &stat[stat.rfind(')')? + 1..];
        after_command
            .split_whitespace()
            .nth(19)
            .and_then(|field| field.parse().ok())
    }

    #[cfg(not(target_os = "linux"))]
    {
        let output = Command::new("ps")
            .args(["-o", "lstart=", "-p", &pid.to_string()])
            .output()
            .ok()?;
        if !output.status.success() || output.stdout.iter().all(u8::is_ascii_whitespace) {
            return None;
        }
        let mut hash = 0xcbf29ce484222325_u64;
        for byte in output.stdout {
            hash ^= u64::from(byte);
            hash = hash.wrapping_mul(0x100000001b3);
        }
        Some(hash as i64)
    }
}

#[cfg(debug_assertions)]
fn wait_for_test_hook(name: &str) {
    let Some(directory) = std::env::var_os("SLOOP_TEST_HOOK_DIR").map(PathBuf::from) else {
        return;
    };
    let armed = directory.join(format!("{name}.armed"));
    if !armed.is_file() {
        return;
    }
    let reached = directory.join(format!("{name}.reached"));
    let release = directory.join(format!("{name}.release"));
    if fs::write(&reached, b"").is_err() {
        return;
    }
    while !release.is_file() {
        std::thread::sleep(Duration::from_millis(10));
    }
}

#[cfg(not(debug_assertions))]
fn wait_for_test_hook(_name: &str) {}

/// Accepts connections on one run's worker socket until the settle path
/// aborts this task. Each connection is one request, mirroring the
/// operator socket.
async fn serve_worker_socket(
    listener: UnixListener,
    run_id: String,
    dispatcher: mpsc::Sender<DispatcherMessage>,
    log: OperationalLog,
) {
    loop {
        let Ok((stream, _)) = listener.accept().await else {
            return;
        };
        let run_id = run_id.clone();
        let dispatcher = dispatcher.clone();
        let log = log.clone();
        tokio::spawn(async move {
            if let Err(error) = handle_worker_connection(stream, run_id.clone(), dispatcher).await {
                log.emit_with_fields(
                    LogLevel::Error,
                    "sloop::socket",
                    "worker_connection_failed",
                    json!({"run_id": run_id, "error": error.to_string()}),
                );
            }
        });
    }
}

/// Serves a worker verb after proving the caller holds the run's token.
/// Everything an agent can reach flows through here: `brief` and `show` are
/// scoped reads, `note` is the only write and moves nothing.
fn dispatch_worker(
    state: &mut DispatcherState,
    id: RequestId,
    request: Request,
    run_id: &str,
    token: Option<&str>,
) -> ResponseEnvelope {
    let valid = token.is_some_and(|presented| {
        state
            .worker_tokens
            .get(run_id)
            .is_some_and(|issued| issued == presented)
    });
    if !valid {
        return ResponseEnvelope::failure(
            Some(id),
            unauthorized("the presented token is not valid for this run"),
        );
    }

    let data = match request {
        Request::Brief(_) => handle_brief(state, run_id),
        Request::Show(args) => handle_show(state, run_id, &args.reference),
        Request::Note(args) => handle_note(state, run_id, &args.text),
        // The connection handler already rejected operator verbs.
        _ => Err(unauthorized(
            "operator verbs are not available on a worker socket",
        )),
    };
    match data {
        Ok(data) => ResponseEnvelope::success(Some(id), data),
        Err(error) => ResponseEnvelope::failure(Some(id), error),
    }
}

/// Everything the agent needs to work, re-readable after a compaction: the
/// ticket body from its committed file, the isolated workspace, and the
/// evidence-based definition of done.
fn handle_brief(state: &DispatcherState, run_id: &str) -> Result<serde_json::Value, ErrorBody> {
    let run = lookup(state, |store| store.run(run_id))?
        .ok_or_else(|| internal("the run for this token no longer exists"))?;
    let ticket = lookup(state, |store| store.ticket(&run.ticket_id))?
        .ok_or_else(|| internal("the ticket for this run no longer exists"))?;
    let body = ticket
        .file_path
        .as_ref()
        .and_then(|file_path| fs::read_to_string(state.root.join(file_path)).ok())
        .unwrap_or_default();

    let mut definition_of_done = vec!["Commit your work to the run branch".to_owned()];
    if state.aftercare_test_cmd.is_some() {
        definition_of_done.push("The configured test command passes".to_owned());
    }

    Ok(json!({
        "run": run_id,
        "ticket": {
            "id": ticket.id,
            "name": ticket.name,
            "blocked_by": ticket.blocked_by,
            "worktree": ticket.worktree,
            "body": body,
            "acceptance": [],
            "target": ticket.target,
            "model": ticket.model,
            "effort": ticket.effort,
        },
        "worktree": run.worktree_path,
        "branch": run.branch,
        "definition_of_done": definition_of_done,
    }))
}

/// Read-only lookup, scoped to the run's own ticket. Whether a foreign
/// reference exists is not the worker's to learn: everything else is
/// uniformly unauthorized.
fn handle_show(
    state: &DispatcherState,
    run_id: &str,
    reference: &str,
) -> Result<serde_json::Value, ErrorBody> {
    let run = lookup(state, |store| store.run(run_id))?
        .ok_or_else(|| internal("the run for this token no longer exists"))?;
    if reference != run.ticket_id {
        return Err(unauthorized("workers may only show their own run's ticket"));
    }
    let ticket = lookup(state, |store| store.ticket(&run.ticket_id))?
        .ok_or_else(|| internal("the ticket for this run no longer exists"))?;
    Ok(ticket_show(reference, &ticket))
}

fn ticket_show(reference: &str, ticket: &crate::store::TicketRecord) -> serde_json::Value {
    json!({
        "ref": reference,
        "kind": "ticket",
        "value": {
            "id": ticket.id,
            "project": ticket.project_id,
            "state": ticket.state,
            "file": ticket.file_path,
            "name": ticket.name,
            "blocked_by": ticket.blocked_by,
            "worktree": ticket.worktree,
            "target": ticket.target,
            "model": ticket.model,
            "effort": ticket.effort,
        },
    })
}

fn handle_operator_show(
    state: &DispatcherState,
    reference: &str,
) -> Result<serde_json::Value, ErrorBody> {
    if let Some(ticket) = lookup(state, |store| store.ticket(reference))? {
        return Ok(ticket_show(reference, &ticket));
    }
    let project = lookup(state, |store| store.project(reference))?
        .ok_or_else(|| not_found(&format!("reference `{reference}` is not indexed")))?;
    let tickets = lookup(state, |store| store.tickets_for_project(reference))?;

    let mut notes: HashMap<String, Vec<serde_json::Value>> = HashMap::new();
    for note in lookup(state, |store| store.notes_for_project(reference))? {
        notes.entry(note.ticket_id).or_default().push(json!({
            "id": note.id,
            "run": note.run_id,
            "text": note.text,
            "recorded_at_ms": note.recorded_at_ms,
        }));
    }

    let mut commits: HashMap<String, Vec<serde_json::Value>> = HashMap::new();
    for evidence in lookup(state, |store| store.commit_evidence_for_project(reference))? {
        let data: serde_json::Value = serde_json::from_str(&evidence.data_json)
            .map_err(|error| internal(&format!("cannot decode commit evidence: {error}")))?;
        for oid in data["oids"]
            .as_array()
            .map(Vec::as_slice)
            .unwrap_or_default()
            .iter()
            .filter_map(serde_json::Value::as_str)
        {
            let (short_hash, message) = git_commit(&state.root, oid)?;
            commits
                .entry(evidence.ticket_id.clone())
                .or_default()
                .push(json!({
                    "run": evidence.run_id.clone(),
                    "hash": short_hash,
                    "message": message,
                }));
        }
    }

    let activity = tickets
        .into_iter()
        .map(|ticket| {
            let ticket_notes = notes.remove(&ticket.id).unwrap_or_default();
            let ticket_commits = commits.remove(&ticket.id).unwrap_or_default();
            json!({
                "id": ticket.id,
                "name": ticket.name,
                "state": ticket.state,
                "notes": ticket_notes,
                "commits": ticket_commits,
            })
        })
        .collect::<Vec<_>>();

    Ok(json!({
        "ref": reference,
        "kind": "project",
        "value": {
            "id": project.id,
            "title": project.title,
            "file": project.file_path,
            "tickets": activity,
        },
    }))
}

fn git_commit(root: &Path, oid: &str) -> Result<(String, String), ErrorBody> {
    let output = Command::new("git")
        .args(["show", "--no-patch", "--format=%h%x00%s", oid, "--"])
        .current_dir(root)
        .output()
        .map_err(|error| internal(&format!("cannot read commit `{oid}`: {error}")))?;
    if !output.status.success() {
        return Err(internal(&format!(
            "cannot read commit `{oid}`: {}",
            String::from_utf8_lossy(&output.stderr).trim()
        )));
    }
    let rendered = String::from_utf8_lossy(&output.stdout);
    let (hash, message) = rendered
        .trim_end()
        .split_once('\0')
        .ok_or_else(|| internal(&format!("Git returned malformed data for commit `{oid}`")))?;
    Ok((hash.to_owned(), message.to_owned()))
}

/// The agent's only write: an advisory note recorded against its run. It
/// transitions nothing.
fn handle_note(
    state: &DispatcherState,
    run_id: &str,
    text: &str,
) -> Result<serde_json::Value, ErrorBody> {
    let ordinal = lookup(state, |store| store.next_note_ordinal())?;
    let note_id = format!("N{ordinal}");
    state
        .store
        .insert_note(&note_id, run_id, text, state.clock.now_ms())
        .map_err(|error| internal(&format!("cannot record note: {error}")))?;
    Ok(json!({"note": {"id": note_id, "run": run_id, "text": text}}))
}

fn dispatch(state: &mut DispatcherState, id: RequestId, request: Request) -> ResponseEnvelope {
    let data = match request {
        Request::Show(args) => match handle_operator_show(state, &args.reference) {
            Ok(data) => data,
            Err(error) => return ResponseEnvelope::failure(Some(id), error),
        },
        Request::Run(args) => match handle_run(state, &args) {
            Ok(data) => data,
            Err(error) => return ResponseEnvelope::failure(Some(id), error),
        },
        Request::Daemon(_) => json!({
            "pid": state.pid,
            "socket": state.socket.to_string_lossy(),
            "state_dir": state.state_dir.to_string_lossy(),
            "log": state.daemon_log.to_string_lossy(),
            "version": env!("CARGO_PKG_VERSION"),
            "started": false
        }),
        Request::Post(args) => {
            match crate::post::handle(
                &state.root,
                &state.ticket_dir,
                &state.store,
                &args,
                state.clock.now_ms(),
                &state.ticket_prefix,
                state.agent.as_ref(),
                &state.flows,
                &state.default_flow,
            ) {
                Ok(data) => data,
                Err(error) => {
                    return ResponseEnvelope::failure(Some(id), post_error_body(&error));
                }
            }
        }
        Request::List(_) => match handle_list(state) {
            Ok(data) => data,
            Err(error) => return ResponseEnvelope::failure(Some(id), error),
        },
        Request::Status(_) => {
            let tickets = match state.store.ticket_counts() {
                Ok(counts) => counts,
                Err(error) => {
                    return ResponseEnvelope::failure(
                        Some(id),
                        internal(&format!("cannot read ticket counts: {error}")),
                    );
                }
            };
            let runs: Vec<_> = match state.store.active_runs() {
                Ok(runs) => runs
                    .into_iter()
                    .map(|run| {
                        json!({
                            "id": run.id,
                            "project": run.project_id,
                            "ticket": run.ticket_id,
                            "state": run.state,
                        })
                    })
                    .collect(),
                Err(error) => {
                    return ResponseEnvelope::failure(
                        Some(id),
                        internal(&format!("cannot read active runs: {error}")),
                    );
                }
            };
            let queued: Vec<_> = match state.store.queued_dispatchable_activations() {
                Ok(activations) => activations
                    .into_iter()
                    .map(|activation| {
                        json!({
                            "id": activation.id,
                            "ticket": activation.ticket_id,
                            "project": activation.project_id,
                            "state": "queued",
                        })
                    })
                    .collect(),
                Err(error) => {
                    return ResponseEnvelope::failure(
                        Some(id),
                        internal(&format!("cannot read queued activations: {error}")),
                    );
                }
            };
            let now_ms = state.clock.now_ms();
            let mut gate = json!({
                "active_agents": state.active.len(),
                "max_agents": state.max_agents,
            });
            if let Some(hours) = &state.running_hours {
                gate["running_hours"] = json!({
                    "start": hours.start,
                    "end": hours.end,
                    "open": hours.is_open(state.clock.local_minute(now_ms)),
                });
            }
            let mut snapshot = json!({
                "daemon": {"pid": state.pid, "paused": state.paused},
                "gate": gate,
                "runs": runs,
                "queued_activations": queued,
                "tickets": {
                    "ready": tickets.ready,
                    "held": tickets.held,
                    "blocked": tickets.blocked,
                    "claimed": tickets.claimed,
                    "merged": tickets.merged,
                    "failed": tickets.failed,
                    "needs_review": tickets.needs_review
                }
            });
            if let Some(deadline) = next_dispatch_deadline(state)
                && let Some(formatted) = format_timestamp(deadline)
            {
                snapshot["next_wake"] = json!(formatted);
            }
            snapshot
        }
        Request::Pause(_) => {
            if let Err(error) = state.store.set_paused(true, state.clock.now_ms()) {
                return ResponseEnvelope::failure(
                    Some(id),
                    internal(&format!("cannot pause scheduler: {error}")),
                );
            }
            state.paused = true;
            json!({"paused": true})
        }
        Request::Resume(_) => {
            if let Err(error) = state.store.set_paused(false, state.clock.now_ms()) {
                return ResponseEnvelope::failure(
                    Some(id),
                    internal(&format!("cannot resume scheduler: {error}")),
                );
            }
            state.paused = false;
            json!({"paused": false})
        }
        Request::Hold(args) => match handle_hold(state, &args) {
            Ok(data) => data,
            Err(error) => return ResponseEnvelope::failure(Some(id), error),
        },
        Request::Ready(args) => match handle_ready(state, &args) {
            Ok(data) => data,
            Err(error) => return ResponseEnvelope::failure(Some(id), error),
        },
        Request::Retry(args) => match handle_retry(state, &args) {
            Ok(data) => data,
            Err(error) => return ResponseEnvelope::failure(Some(id), error),
        },
        Request::Logs(args) => match handle_logs(state, &args) {
            Ok(data) => data,
            Err(error) => return ResponseEnvelope::failure(Some(id), error),
        },
        Request::Cancel(args) => match handle_cancel(state, &args) {
            Ok(data) => data,
            Err(error) => return ResponseEnvelope::failure(Some(id), error),
        },
        Request::Stop(args) => match handle_stop(state, &args) {
            Ok(data) => data,
            Err(error) => return ResponseEnvelope::failure(Some(id), error),
        },
        Request::Wait(args) => match handle_wait(state, &args) {
            Ok(data) => data,
            Err(error) => return ResponseEnvelope::failure(Some(id), error),
        },
        request => {
            return ResponseEnvelope::failure(
                Some(id),
                ErrorBody {
                    code: ErrorCode::InvalidRequest,
                    message: format!("verb `{}` is not implemented by the daemon", request.verb()),
                    details: json!({"verb": request.verb()}),
                },
            );
        }
    };
    ResponseEnvelope::success(Some(id), data)
}

fn handle_list(state: &DispatcherState) -> Result<serde_json::Value, ErrorBody> {
    let now_ms = state.clock.now_ms();
    let gates = crate::eligibility::Gates {
        paused: state.paused,
        agent_configured: state.agent.is_some(),
        hours_open: running_hours_open(state, now_ms),
        at_capacity: state.active.len() >= state.max_agents,
        has_queued_activation: !lookup(state, Store::queued_dispatchable_activations)?.is_empty(),
    };
    let mut rows = Vec::new();
    for ticket in lookup(state, Store::tickets)? {
        let active_run = lookup(state, |store| store.active_run_for_ticket(&ticket.id))?;
        let reason = crate::eligibility::ticket_ineligibility(
            &ticket.state,
            ticket.attempts,
            active_run.as_deref(),
            &gates,
        )
        .map(|reason| reason.describe());
        rows.push(json!({
            "id": ticket.id,
            "project": ticket.project_id,
            "state": ticket.state,
            "run": active_run,
            "reason": reason,
        }));
    }
    Ok(json!({"tickets": rows}))
}

fn spawn_daemon(project: &Project) -> Result<(), DaemonError> {
    let executable = std::env::current_exe().map_err(DaemonError::CurrentExecutable)?;
    Command::new(executable)
        .args(["daemon", "--foreground"])
        .current_dir(&project.root)
        .stdin(Stdio::null())
        .stdout(Stdio::null())
        .stderr(Stdio::null())
        .spawn()
        .map(|_| ())
        .map_err(DaemonError::Spawn)
}

fn send_existing(project: &Project, request: Request) -> Result<ResponseEnvelope, DaemonError> {
    match send(&project.operator_socket, request.clone()) {
        Ok(response) => Ok(response),
        Err(current_error) => {
            let Some(identity) = read_lock_identity(&project.lock_path) else {
                return Err(current_error);
            };
            if !process_identity_matches(identity.pid, identity.started_at_ms) {
                return Err(current_error);
            }
            let Some(socket) = identity.socket else {
                return Err(current_error);
            };
            if socket == project.operator_socket {
                return Err(current_error);
            }
            send(&socket, request)
        }
    }
}

fn send(socket: &Path, request: Request) -> Result<ResponseEnvelope, DaemonError> {
    let mut stream = StdUnixStream::connect(socket).map_err(DaemonError::Connect)?;
    stream
        .set_read_timeout(Some(CLIENT_TIMEOUT))
        .map_err(DaemonError::Connect)?;
    stream
        .set_write_timeout(Some(CLIENT_TIMEOUT))
        .map_err(DaemonError::Connect)?;

    let sequence = NEXT_REQUEST_ID.fetch_add(1, Ordering::Relaxed);
    let envelope = RequestEnvelope::new(
        RequestId::new(format!("req-{}-{sequence}", std::process::id())),
        request,
        None,
    );
    serde_json::to_writer(&mut stream, &envelope).map_err(DaemonError::Encode)?;
    stream.write_all(b"\n").map_err(DaemonError::Write)?;

    let mut line = String::new();
    let mut reader = BufReader::new(stream).take(MAX_ENVELOPE_BYTES + 1);
    reader.read_line(&mut line).map_err(DaemonError::Read)?;
    if line.len() as u64 > MAX_ENVELOPE_BYTES {
        return Err(DaemonError::InvalidResponse(
            "response envelope is too large".into(),
        ));
    }
    serde_json::from_str(line.trim_end()).map_err(DaemonError::Decode)
}

/// Validates a `run` request and persists one queued activation. Acceptance
/// never implies a spawn; reconciliation decides that separately.
fn handle_run(
    state: &mut DispatcherState,
    args: &crate::protocol::RunArgs,
) -> Result<serde_json::Value, ErrorBody> {
    use crate::protocol::RunActivation;

    if args.ticket.is_some() && args.project.is_some() {
        return Err(invalid_arguments(
            "a run may target a ticket or a project, not both",
        ));
    }
    if let Some(ticket_id) = &args.ticket {
        let Some(ticket) = lookup(state, |store| store.ticket(ticket_id))? else {
            return Err(not_found(&format!(
                "ticket `{ticket_id}` is not registered"
            )));
        };
        if ticket.state == TicketState::Held.as_str() {
            return Err(conflict(&format!(
                "ticket `{ticket_id}` is held; release it with `sloop ready {ticket_id}`"
            )));
        }
    }
    if let Some(project) = &args.project
        && !lookup(state, |store| store.project_exists(project))?
    {
        return Err(not_found(&format!("project `{project}` is not indexed")));
    }
    for only in &args.only {
        let Some(ticket) = lookup(state, |store| store.ticket(only))? else {
            return Err(not_found(&format!("ticket `{only}` is not registered")));
        };
        if let Some(project) = &args.project
            && &ticket.project_id != project
        {
            return Err(invalid_arguments(&format!(
                "ticket `{only}` belongs to project `{}`, not `{project}`",
                ticket.project_id
            )));
        }
    }

    let (kind, echo_kind, interval_ms) = match &args.activation {
        RunActivation::Now => (ActivationKind::Immediate, "now", None),
        RunActivation::At { .. } => (ActivationKind::At, "at", None),
        RunActivation::Every { interval_ms } => {
            (ActivationKind::Every, "every", Some(*interval_ms as i64))
        }
        RunActivation::Overnight => (ActivationKind::Overnight, "overnight", None),
    };

    let now_ms = state.clock.now_ms();
    let activation_id = format!(
        "A{}",
        lookup(state, |store| store.next_activation_ordinal())?
    );
    lookup(state, |store| {
        store.insert_activation(
            &NewActivation {
                id: &activation_id,
                kind,
                ticket_id: args.ticket.as_deref(),
                project_id: args.project.as_deref(),
                // Eligible times for scheduled kinds arrive with clock
                // support; queued recording preserves the request today.
                eligible_at_ms: None,
                interval_ms,
            },
            now_ms,
        )
    })?;
    for only in &args.only {
        lookup(state, |store| {
            store.insert_activation_filter(&activation_id, only)
        })?;
    }

    let mut activation = json!({
        "id": activation_id,
        "kind": echo_kind,
        "state": "queued",
    });
    if let Some(ticket) = &args.ticket {
        activation["ticket"] = json!(ticket);
    }
    if let Some(project) = &args.project {
        activation["project"] = json!(project);
    }
    Ok(json!({"activation": activation}))
}

fn handle_hold(
    state: &mut DispatcherState,
    args: &crate::protocol::TicketReferenceArgs,
) -> Result<serde_json::Value, ErrorBody> {
    let requested = TicketState::Held;
    let previous = state
        .store
        .set_ticket_hold(&args.ticket, requested, state.clock.now_ms())
        .map_err(|error| match error {
            StoreError::TicketNotFound { .. } => not_found(&error.to_string()),
            StoreError::TicketStateConflict { .. } => conflict(&error.to_string()),
            _ => internal(&error.to_string()),
        })?;
    Ok(json!({
        "ticket": args.ticket,
        "previous_state": previous,
        "state": requested.as_str(),
        "overridden": previous != requested.as_str(),
    }))
}

fn handle_ready(
    state: &mut DispatcherState,
    args: &crate::protocol::TicketReferenceArgs,
) -> Result<serde_json::Value, ErrorBody> {
    let requested = TicketState::Ready;
    let previous = state
        .store
        .set_ticket_hold(&args.ticket, requested, state.clock.now_ms())
        .map_err(|error| match error {
            StoreError::TicketNotFound { .. } => not_found(&error.to_string()),
            StoreError::TicketStateConflict { .. } => conflict(&error.to_string()),
            _ => internal(&error.to_string()),
        })?;
    Ok(json!({
        "ticket": args.ticket,
        "previous_state": previous,
        "state": requested.as_str(),
        "overridden": previous != requested.as_str(),
    }))
}

fn handle_retry(
    state: &mut DispatcherState,
    args: &crate::protocol::TicketReferenceArgs,
) -> Result<serde_json::Value, ErrorBody> {
    let previous = state
        .store
        .retry_ticket(&args.ticket, state.clock.now_ms())
        .map_err(|error| match error {
            StoreError::TicketNotFound { .. } => not_found(&error.to_string()),
            StoreError::TicketStateConflict { .. } => conflict(&error.to_string()),
            _ => internal(&error.to_string()),
        })?;
    Ok(json!({
        "ticket": args.ticket,
        "previous_state": previous,
        "state": TicketState::Ready.as_str(),
    }))
}

/// One non-blocking snapshot of a run's state; the client loops. Launch and
/// recovery closures are terminal alongside ordinary derived outcomes.
fn handle_wait(
    state: &DispatcherState,
    args: &crate::protocol::RunReferenceArgs,
) -> Result<serde_json::Value, ErrorBody> {
    let Some(run) = lookup(state, |store| store.run(&args.run))? else {
        return Err(not_found(&format!("run `{}` does not exist", args.run)));
    };
    let terminal = matches!(
        run.state.as_str(),
        "merged" | "failed" | "needs_review" | "cancelled" | "orphaned" | "aborted"
    );
    Ok(json!({
        "run": run.id,
        "state": run.state,
        "terminal": terminal,
        "exit_code": run.exit_code,
    }))
}

/// Returns one finite page of captured run output. Records are stored
/// escaped inside the response; raw agent bytes never reach Sloop's stdout.
fn handle_logs(
    state: &DispatcherState,
    args: &crate::protocol::RunReferenceArgs,
) -> Result<serde_json::Value, ErrorBody> {
    if lookup(state, |store| store.run(&args.run))?.is_none() {
        return Err(not_found(&format!("run `{}` does not exist", args.run)));
    }
    let page = crate::run_log::read_page(
        &run_output_path(&state.state_dir, &args.run),
        0,
        LOGS_PAGE_LIMIT,
    )
    .map_err(|error| internal(&format!("cannot read run log: {error}")))?;
    let entries = page
        .entries
        .iter()
        .map(serde_json::to_value)
        .collect::<Result<Vec<_>, _>>()
        .map_err(|error| internal(&format!("cannot encode run log: {error}")))?;
    Ok(json!({
        "run": args.run,
        "entries": entries,
        "next_cursor": page.next_cursor,
        "complete": page.complete,
    }))
}

/// Records cancellation intent durably, then kills the run's whole process
/// group. Termination is confirmed by the exit event, which reads the intent
/// and settles the outcome as `Cancelled`; the worktree, branch, and captured
/// logs are preserved as evidence.
fn handle_cancel(
    state: &mut DispatcherState,
    args: &crate::protocol::RunReferenceArgs,
) -> Result<serde_json::Value, ErrorBody> {
    let Some(run) = lookup(state, |store| store.run(&args.run))? else {
        return Err(not_found(&format!("run `{}` does not exist", args.run)));
    };
    if !matches!(run.state.as_str(), "running" | "aftercare") || run.exited_at_ms.is_some() {
        return Err(conflict(&format!(
            "run `{}` is `{}` and cannot be cancelled",
            run.id, run.state
        )));
    }

    // Intent must be durable before any signal: if the daemon dies between
    // the kill and the exit event, recovery still reads the cancellation.
    lookup(state, |store| {
        store.record_cancel_requested(&run.id, state.clock.now_ms())
    })?;
    state.cancelling.insert(run.id.clone());

    if run.state == "aftercare" {
        let rows = lookup(state, |store| store.run_evidence(&run.id))?;
        for kind in ["merge_process", "test_process"] {
            if let Some((pid, start_time, group)) =
                aftercare_process_identity(&rows, kind).map_err(|error| internal(&error))?
                && process_identity_matches(pid, Some(start_time))
            {
                unsafe {
                    libc::kill(-(group as libc::pid_t), libc::SIGKILL);
                }
                break;
            }
        }
    } else {
        let process_matches = run
            .pid
            .and_then(|pid| u32::try_from(pid).ok())
            .is_some_and(|pid| process_identity_matches(pid, run.pid_start_time));
        if process_matches && let Some(group) = run.process_group_id {
            // A negative PID signals the whole group, so grandchildren die too.
            // ESRCH means the group already exited; the race resolves through
            // the recorded intent.
            unsafe {
                libc::kill(-(group as libc::pid_t), libc::SIGKILL);
            }
        }
    }

    Ok(json!({
        "run": run.id,
        "state": "cancelling",
        "worktree": run.worktree_path,
        "preserved": true,
    }))
}

/// Validates a stop request and, when forced, cancels every active run
/// through the same durable-intent path as `cancel`. The connection handler
/// owns the actual exit so the reply always reaches the caller first.
fn handle_stop(
    state: &mut DispatcherState,
    args: &crate::protocol::StopArgs,
) -> Result<serde_json::Value, ErrorBody> {
    let mut active: Vec<String> = state.active.iter().cloned().collect();
    active.sort();
    if !active.is_empty() && !args.force {
        return Err(conflict(&format!(
            "{} active run(s): {}; stop --force cancels them",
            active.len(),
            active.join(", "),
        )));
    }
    let mut cancelled = Vec::new();
    for run_id in active {
        if handle_cancel(
            state,
            &crate::protocol::RunReferenceArgs {
                run: run_id.clone(),
            },
        )
        .is_ok()
        {
            cancelled.push(run_id);
        }
    }
    Ok(json!({
        "stopping": true,
        "pid": state.pid,
        "cancelled_runs": cancelled,
    }))
}

fn lookup<T>(
    state: &DispatcherState,
    query: impl FnOnce(&Store) -> Result<T, StoreError>,
) -> Result<T, ErrorBody> {
    query(&state.store).map_err(|error| internal(&error.to_string()))
}

fn invalid_arguments(message: &str) -> ErrorBody {
    ErrorBody {
        code: ErrorCode::InvalidArguments,
        message: message.into(),
        details: json!({}),
    }
}

fn not_found(message: &str) -> ErrorBody {
    ErrorBody {
        code: ErrorCode::NotFound,
        message: message.into(),
        details: json!({}),
    }
}

fn conflict(message: &str) -> ErrorBody {
    ErrorBody {
        code: ErrorCode::Conflict,
        message: message.into(),
        details: json!({}),
    }
}

fn post_error_body(error: &crate::post::PostError) -> ErrorBody {
    use crate::post::PostError;
    let code = match error {
        PostError::TicketFileNotFound(_)
        | PostError::UnknownProject(_)
        | PostError::UnknownFlow { .. }
        | PostError::UnknownBlockedBy { .. } => ErrorCode::NotFound,
        PostError::OutsideRepository(_)
        | PostError::OutsideTicketDirectory { .. }
        | PostError::InvalidTicket { .. }
        | PostError::MissingName { .. }
        | PostError::MissingBlockedBy { .. }
        | PostError::InvalidBlockedBy { .. }
        | PostError::EmptyBody { .. }
        | PostError::UnknownTarget(_)
        | PostError::MissingTargetValue { .. } => ErrorCode::InvalidArguments,
        PostError::ProjectConflict { .. }
        | PostError::FlowConflict { .. }
        | PostError::TicketIdTaken { .. }
        | PostError::DependencyCycle(_) => ErrorCode::Conflict,
        PostError::Io { .. } | PostError::Store(_) | PostError::IdAllocation(_) => {
            ErrorCode::Internal
        }
    };
    ErrorBody {
        code,
        message: error.to_string(),
        details: json!({}),
    }
}

fn protocol_error(message: &str) -> ErrorBody {
    ErrorBody {
        code: ErrorCode::InvalidRequest,
        message: message.into(),
        details: json!({}),
    }
}

fn unauthorized(message: &str) -> ErrorBody {
    ErrorBody {
        code: ErrorCode::Unauthorized,
        message: message.into(),
        details: json!({}),
    }
}

fn internal(message: &str) -> ErrorBody {
    ErrorBody {
        code: ErrorCode::Internal,
        message: message.into(),
        details: json!({}),
    }
}

#[derive(Debug)]
pub enum DaemonError {
    Config(ConfigError),
    Store(StoreError),
    CurrentDirectory(io::Error),
    CurrentExecutable(io::Error),
    Io {
        path: PathBuf,
        source: io::Error,
    },
    AlreadyRunning,
    Runtime(io::Error),
    Spawn(io::Error),
    Connect(io::Error),
    Write(io::Error),
    Read(io::Error),
    Encode(serde_json::Error),
    Decode(serde_json::Error),
    InvalidResponse(String),
    Frontmatter {
        path: PathBuf,
        error: FrontmatterError,
    },
    IdAllocation(IdError),
}

impl DaemonError {
    pub fn error_body(&self) -> ErrorBody {
        let code = match self {
            Self::Config(_) => ErrorCode::InvalidArguments,
            _ => ErrorCode::DaemonUnavailable,
        };
        ErrorBody {
            code,
            message: self.to_string(),
            details: json!({}),
        }
    }
}

impl From<ConfigError> for DaemonError {
    fn from(error: ConfigError) -> Self {
        Self::Config(error)
    }
}

impl From<IdError> for DaemonError {
    fn from(error: IdError) -> Self {
        Self::IdAllocation(error)
    }
}

impl std::fmt::Display for DaemonError {
    fn fmt(&self, formatter: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            Self::Config(error) => error.fmt(formatter),
            Self::Store(error) => error.fmt(formatter),
            Self::CurrentDirectory(error) => {
                write!(formatter, "cannot read current directory: {error}")
            }
            Self::CurrentExecutable(error) => {
                write!(formatter, "cannot locate sloop executable: {error}")
            }
            Self::Io { path, source } => write!(formatter, "{}: {source}", path.display()),
            Self::AlreadyRunning => formatter.write_str("another sloop daemon holds the lock"),
            Self::Runtime(error) => write!(formatter, "cannot start async runtime: {error}"),
            Self::Spawn(error) => write!(formatter, "cannot spawn daemon: {error}"),
            Self::Connect(error) => write!(formatter, "cannot connect to daemon: {error}"),
            Self::Write(error) => write!(formatter, "cannot write daemon request: {error}"),
            Self::Read(error) => write!(formatter, "cannot read daemon response: {error}"),
            Self::Encode(error) => write!(formatter, "cannot encode daemon request: {error}"),
            Self::Decode(error) => write!(formatter, "cannot decode daemon response: {error}"),
            Self::InvalidResponse(message) => formatter.write_str(message),
            Self::Frontmatter { path, error } => write!(formatter, "{}: {error}", path.display()),
            Self::IdAllocation(error) => error.fmt(formatter),
        }
    }
}

impl std::error::Error for DaemonError {}

#[cfg(test)]
mod tests {
    use std::fs;

    use tempfile::tempdir;

    use super::{
        WORKER_BOOTSTRAP_PROMPT, compose_worker_prompt, index_projects, process_start_time,
        recoverable_process_matches,
    };
    use crate::config::expand_agent_cmd;
    use crate::store::{RecoverableRun, Store};

    fn recoverable_current_process(start_time: Option<i64>) -> RecoverableRun {
        RecoverableRun {
            id: "R1".into(),
            ticket_id: "T1".into(),
            state: "running".into(),
            branch: None,
            worktree_path: None,
            pid: Some(i64::from(std::process::id())),
            pid_start_time: start_time,
            process_group_id: None,
            worker_token: None,
            worker_socket_path: None,
            exit_code: None,
            lease_expires_at_ms: 1,
        }
    }

    #[test]
    fn recovery_requires_both_pid_and_start_time_to_match() {
        let Some(start_time) = process_start_time(std::process::id()) else {
            return;
        };
        assert!(recoverable_process_matches(&recoverable_current_process(
            Some(start_time)
        )));
        assert!(!recoverable_process_matches(&recoverable_current_process(
            Some(start_time + 1)
        )));
        assert!(!recoverable_process_matches(&recoverable_current_process(
            None
        )));
    }

    #[test]
    fn agent_command_expands_ticket_model_and_effort() {
        let template = vec![
            "agent".to_owned(),
            "--model={model}".to_owned(),
            "--effort".to_owned(),
            "{effort}".to_owned(),
            "prompt={prompt}".to_owned(),
        ];

        assert_eq!(
            expand_agent_cmd(&template, Some("sonnet"), Some("medium"), "assignment").unwrap(),
            [
                "agent",
                "--model=sonnet",
                "--effort",
                "medium",
                "prompt=assignment"
            ]
        );
    }

    #[test]
    fn agent_command_rejects_a_missing_ticket_field() {
        let template = vec!["agent".to_owned(), "{model}".to_owned()];

        assert_eq!(
            expand_agent_cmd(&template, None, Some("medium"), "assignment"),
            Err("does not specify `model`".to_owned())
        );
    }

    #[test]
    fn worker_prompt_uses_the_builtin_when_instructions_are_absent() {
        let root = tempdir().unwrap();

        assert_eq!(
            compose_worker_prompt(root.path()).unwrap(),
            WORKER_BOOTSTRAP_PROMPT
        );
    }

    #[test]
    fn worker_prompt_appends_repository_instructions() {
        let root = tempdir().unwrap();
        fs::create_dir_all(root.path().join(".agents/sloop")).unwrap();
        fs::write(
            root.path().join(".agents/sloop/instructions.md"),
            "Use repository conventions.\n",
        )
        .unwrap();

        assert_eq!(
            compose_worker_prompt(root.path()).unwrap(),
            format!("{WORKER_BOOTSTRAP_PROMPT}\n\nUse repository conventions.\n")
        );
    }

    #[test]
    fn orphan_disposition_stamps_waits_then_deletes_unreferenced_rows() {
        use super::OrphanDisposition::{Delete, Keep, MarkMissing};
        use super::orphan_disposition;

        assert_eq!(orphan_disposition(None, false, 1_000, 100), MarkMissing);
        assert_eq!(orphan_disposition(Some(950), false, 1_000, 100), Keep);
        assert_eq!(orphan_disposition(Some(900), false, 1_000, 100), Delete);
        assert_eq!(orphan_disposition(Some(900), true, 1_000, 100), Keep);
    }

    #[test]
    fn reconcile_stamps_deletes_and_restores_tickets() {
        use crate::store::TicketState;

        let root = tempdir().unwrap();
        let tickets = root.path().join(".agents/sloop/tickets");
        fs::create_dir_all(&tickets).unwrap();
        fs::write(tickets.join("present.md"), "# Present\n").unwrap();
        let store = Store::open(&root.path().join("sloop.db"), 1_000).unwrap();
        store
            .insert_local_project(
                "default",
                ".agents/sloop/projects/default.md",
                "Default",
                1_000,
            )
            .unwrap();
        let insert = |id: &str, file: &str, blocked_by: &[String]| {
            store
                .insert_local_ticket(
                    id,
                    "default",
                    &format!(".agents/sloop/tickets/{file}"),
                    id,
                    blocked_by,
                    &format!("sloop/{id}"),
                    None,
                    None,
                    None,
                    "default",
                    TicketState::Ready,
                    1_000,
                )
                .unwrap();
        };
        insert("T1", "present.md", &[]);
        insert("T2", "gone.md", &[]);
        insert("T3", "blocked-gone.md", &[]);
        insert("T4", "dependent.md", &["T3".into()]);
        fs::write(tickets.join("dependent.md"), "# Dependent\n").unwrap();

        let window = 100;
        let stamps = |store: &Store| -> Vec<(String, Option<i64>)> {
            store
                .local_ticket_files()
                .unwrap()
                .into_iter()
                .map(|ticket| (ticket.id, ticket.missing_at_ms))
                .collect()
        };

        // First pass stamps the two tickets whose files are gone.
        super::reconcile_tickets(root.path(), &store, 2_000, window).unwrap();
        assert_eq!(
            stamps(&store),
            vec![
                ("T1".into(), None),
                ("T2".into(), Some(2_000)),
                ("T3".into(), Some(2_000)),
                ("T4".into(), None),
            ]
        );

        // Within the window nothing is deleted and stamps keep their origin.
        super::reconcile_tickets(root.path(), &store, 2_050, window).unwrap();
        assert_eq!(stamps(&store)[1], ("T2".into(), Some(2_000)));

        // Past the window the unreferenced orphan is deleted; T3 survives
        // because T4 still names it as a blocker.
        super::reconcile_tickets(root.path(), &store, 2_100, window).unwrap();
        assert_eq!(
            stamps(&store),
            vec![
                ("T1".into(), None),
                ("T3".into(), Some(2_000)),
                ("T4".into(), None),
            ]
        );

        // The file coming back clears the stamp even after the window.
        fs::write(tickets.join("blocked-gone.md"), "# Returned\n").unwrap();
        super::reconcile_tickets(root.path(), &store, 3_000, window).unwrap();
        assert_eq!(stamps(&store)[1], ("T3".into(), None));
    }

    #[test]
    fn project_allocation_uses_sorted_paths_after_explicit_high_water_marks() {
        let root = tempdir().unwrap();
        let projects = root.path().join(".agents/sloop/projects");
        fs::create_dir_all(&projects).unwrap();
        fs::write(projects.join("zeta.md"), "# Zeta\n").unwrap();
        fs::write(projects.join("alpha.md"), "# Alpha\n").unwrap();
        fs::write(
            projects.join("middle.md"),
            "---\nid: PROJ-7\ntitle: Explicit\n---\n",
        )
        .unwrap();
        let store = Store::open(&root.path().join("sloop.db"), 1_000).unwrap();

        index_projects(
            root.path(),
            std::path::Path::new(".agents/sloop/projects"),
            &store,
            1_000,
            "PROJ",
        )
        .unwrap();

        assert!(
            fs::read_to_string(projects.join("alpha.md"))
                .unwrap()
                .contains("id: PROJ-8")
        );
        assert!(
            fs::read_to_string(projects.join("zeta.md"))
                .unwrap()
                .contains("id: PROJ-9")
        );
    }
}