kkernel 0.6.0

use std::sync::Arc;
use std::time::Duration;

use uuid::Uuid;

use khive_runtime::Namespace as RuntimeNamespace;
use khive_runtime::{BackendId, KhiveRuntime, PackRegistry, VerbRegistryBuilder};
use khive_storage::EdgeRelation;
use khive_types::namespace::Namespace;

use super::{BackendRegistry, LocatorCache, SubstrateCoordinator, SubstrateCoordinatorService};

fn memory_runtime() -> Arc<KhiveRuntime> {
    Arc::new(KhiveRuntime::memory().expect("memory runtime"))
}

/// Build a VerbRegistry with the given packs loaded, using the given runtime.
fn packs_registry(runtime: Arc<KhiveRuntime>, pack_names: &[&str]) -> khive_runtime::VerbRegistry {
    let gate = runtime.config().gate.clone();
    let default_ns = runtime.config().default_namespace.clone();
    let actor_id = runtime.config().actor_id.clone();
    let mut builder = VerbRegistryBuilder::new();
    builder.with_gate(gate);
    builder.with_default_namespace(default_ns.as_str());
    builder.with_actor_id(actor_id);
    let names: Vec<String> = pack_names.iter().map(|s| s.to_string()).collect();
    PackRegistry::register_packs(&names, (*runtime).clone(), &mut builder)
        .unwrap_or_else(|n| panic!("pack {n:?} declared in inventory but factory missing"));
    let registry = builder.build().expect("build registry");
    runtime.install_edge_rules(registry.all_edge_rules());
    registry
}

// ---- Existing tests (D1 infrastructure) ----

#[test]
fn single_coordinator_is_single_backend() {
    let coord = SubstrateCoordinator::single(memory_runtime());
    assert!(coord.is_single_backend());
    assert_eq!(coord.backend_count(), 1);
    assert_eq!(coord.backend_ids().len(), 1);
    assert_eq!(coord.backend_ids()[0].as_str(), "main");
}

#[test]
fn registry_register_dedup() {
    let mut reg = BackendRegistry::new();
    let rt = memory_runtime();
    assert!(reg.register(BackendId::new("main"), Arc::clone(&rt)));
    assert!(!reg.register(BackendId::new("main"), Arc::clone(&rt)));
    assert_eq!(reg.len(), 1);
}

#[test]
fn registry_primary_is_first_registered() {
    let mut reg = BackendRegistry::new();
    let rt1 = memory_runtime();
    let rt2 = memory_runtime();
    reg.register(BackendId::new("main"), rt1);
    reg.register(BackendId::new("lore"), rt2);
    assert_eq!(reg.primary().unwrap().id.as_str(), "main");
}

#[test]
fn multi_backend_coordinator_not_single() {
    let mut registry = BackendRegistry::new();
    registry.register(BackendId::new("main"), memory_runtime());
    registry.register(BackendId::new("lore"), memory_runtime());
    let coord = SubstrateCoordinator::new(registry);
    assert!(!coord.is_single_backend());
    assert_eq!(coord.backend_count(), 2);
}

#[test]
fn backend_id_display() {
    let id = BackendId::new("archive");
    assert_eq!(id.to_string(), "archive");
    assert_eq!(id.as_str(), "archive");
}

#[test]
fn backend_id_main_constant() {
    assert_eq!(BackendId::main().as_str(), BackendId::MAIN);
}

// ---- D2: LocatorCache tests ----

#[test]
fn locator_cache_miss_returns_none() {
    let cache = LocatorCache::new();
    let id = Uuid::new_v4();
    assert!(cache.get(id).is_none());
}

#[test]
fn locator_cache_insert_then_get_returns_backend() {
    let cache = LocatorCache::new();
    let id = Uuid::new_v4();
    cache.insert(id, BackendId::new("main"));
    let result = cache.get(id);
    assert!(result.is_some());
    assert_eq!(result.unwrap().as_str(), "main");
}

#[test]
fn locator_cache_expired_entry_returns_none() {
    // Use a 1-nanosecond TTL so entries expire immediately.
    let cache = LocatorCache::with_ttl(Duration::from_nanos(1));
    let id = Uuid::new_v4();
    cache.insert(id, BackendId::new("main"));
    // Sleep long enough for the TTL to elapse (1 µs is more than 1 ns).
    std::thread::sleep(Duration::from_micros(1));
    assert!(cache.get(id).is_none());
}

#[test]
fn locator_cache_purge_removes_expired() {
    let cache = LocatorCache::with_ttl(Duration::from_nanos(1));
    for _ in 0..5 {
        cache.insert(Uuid::new_v4(), BackendId::new("main"));
    }
    std::thread::sleep(Duration::from_micros(1));
    cache.purge_expired();
    assert_eq!(cache.len(), 0);
}

// ---- D2: locate() integration tests ----

#[tokio::test]
async fn locator_cache_miss_then_hit() {
    let coord = SubstrateCoordinator::single(memory_runtime());
    let ns = Namespace::local();

    // Create an entity on the primary backend.
    let runtime = coord.primary_runtime().unwrap();
    let token = runtime.authorize(ns.clone()).unwrap();
    let entity = runtime
        .create_entity(&token, "concept", None, "LoRA", None, None, vec![])
        .await
        .expect("create entity");

    // First locate: cache miss → backend scan → cache populated.
    let first = coord.locate(entity.id, &ns).await;
    assert!(
        first.is_some(),
        "locate should find the entity on first call"
    );
    assert_eq!(first.unwrap().as_str(), BackendId::MAIN);
    assert_eq!(coord.locator_cache().len(), 1, "cache should be populated");

    // Second locate: cache hit (no backend I/O).
    let second = coord.locate(entity.id, &ns).await;
    assert!(second.is_some(), "second locate should hit cache");
}

#[tokio::test]
async fn locator_cache_returns_none_for_unknown_uuid() {
    let coord = SubstrateCoordinator::single(memory_runtime());
    let ns = Namespace::local();
    let unknown = Uuid::new_v4();
    let result = coord.locate(unknown, &ns).await;
    assert!(result.is_none(), "unknown UUID should resolve to None");
}

// ---- D4: fan_out_search tests (entity substrate) ----

#[tokio::test]
async fn fan_out_search_single_backend_returns_hits() {
    let coord = SubstrateCoordinator::single(memory_runtime());
    let ns = Namespace::local();

    let runtime = coord.primary_runtime().unwrap();
    let token = runtime.authorize(ns.clone()).unwrap();
    runtime
        .create_entity(
            &token,
            "concept",
            None,
            "FlashAttention",
            Some("IO-aware exact attention"),
            None,
            vec![],
        )
        .await
        .expect("create entity");

    let (hits, _note_hits, per_backend) = coord
        .fan_out_search("FlashAttention", &ns, 10, false, None, None, &[])
        .await;

    assert!(!hits.is_empty(), "should find the entity");
    assert_eq!(per_backend.len(), 1, "single backend report");
    assert!(per_backend[0].error.is_none(), "no error");
}

#[tokio::test]
async fn fan_out_search_two_backends_merged() {
    let mut registry = BackendRegistry::new();
    let rt_main = memory_runtime();
    let rt_lore = memory_runtime();
    registry.register(BackendId::new("main"), Arc::clone(&rt_main));
    registry.register(BackendId::new("lore"), Arc::clone(&rt_lore));
    let coord = SubstrateCoordinator::new(registry);
    let ns = Namespace::local();

    // Create one entity on each backend.
    let tok_main = rt_main.authorize(ns.clone()).unwrap();
    rt_main
        .create_entity(
            &tok_main,
            "concept",
            None,
            "LoRA",
            Some("Low-rank adaptation"),
            None,
            vec![],
        )
        .await
        .expect("create on main");

    let tok_lore = rt_lore.authorize(ns.clone()).unwrap();
    rt_lore
        .create_entity(
            &tok_lore,
            "concept",
            None,
            "QLoRA",
            Some("Quantised LoRA"),
            None,
            vec![],
        )
        .await
        .expect("create on lore");

    // Fan-out search for "LoRA" — both backends should contribute.
    let (merged_hits, _note_hits, per_backend) = coord
        .fan_out_search("LoRA", &ns, 10, false, None, None, &[])
        .await;

    assert_eq!(per_backend.len(), 2, "both backends in report");
    // Merged set should contain at least one hit from the combined results.
    assert!(
        !merged_hits.is_empty(),
        "merged results should not be empty"
    );
}

#[tokio::test]
async fn fan_out_search_empty_registry_returns_empty() {
    let coord = SubstrateCoordinator::new(BackendRegistry::new());
    let ns = Namespace::local();
    let (hits, note_hits, per_backend) = coord
        .fan_out_search("anything", &ns, 10, false, None, None, &[])
        .await;
    assert!(hits.is_empty());
    assert!(note_hits.is_empty());
    assert!(per_backend.is_empty());
}

// ---- D3: partial-failure regression test ----

/// One backend errors; the other succeeds. The merged hits must contain
/// results from the working backend, and the failing backend's
/// `BackendSearchResult.error` must be populated (not `None`).
#[tokio::test]
async fn fan_out_partial_failure_preserves_working_backend_hits() {
    let rt_main = memory_runtime();
    let rt_lore = memory_runtime();

    let ns = Namespace::local();

    // Seed one entity on the "lore" backend so a search returns a hit.
    let tok_lore = rt_lore.authorize(ns.clone()).unwrap();
    rt_lore
        .create_entity(
            &tok_lore,
            "concept",
            None,
            "PartialFailureProbe",
            Some("probe entity for partial-failure test"),
            None,
            vec![],
        )
        .await
        .expect("create entity on lore");

    let mut registry = BackendRegistry::new();
    registry.register(BackendId::new("main"), Arc::clone(&rt_main));
    registry.register(BackendId::new("lore"), Arc::clone(&rt_lore));

    // Force "main" to error; "lore" should still return hits.
    let coord = SubstrateCoordinator::new(registry).with_failing_backend("main");

    let (merged_hits, _note_hits, per_backend) = coord
        .fan_out_search("PartialFailureProbe", &ns, 10, false, None, None, &[])
        .await;

    // Both backends must be reported.
    assert_eq!(
        per_backend.len(),
        2,
        "both backends should appear in the report"
    );

    // The failing backend ("main") must have an error annotation.
    let main_result = per_backend
        .iter()
        .find(|r| r.backend_id.as_str() == "main")
        .expect("main backend result must be present");
    assert!(
        main_result.error.is_some(),
        "main backend should report an error"
    );
    assert!(
        main_result.hits.is_empty(),
        "main backend should have no hits"
    );

    // The working backend ("lore") must have no error.
    let lore_result = per_backend
        .iter()
        .find(|r| r.backend_id.as_str() == "lore")
        .expect("lore backend result must be present");
    assert!(
        lore_result.error.is_none(),
        "lore backend should have no error"
    );

    // Merged hits must contain the hit from the working backend.
    assert!(
        !merged_hits.is_empty(),
        "merged hits must include results from the working backend"
    );
}

// ---- D2: note-locate regression test ----

/// `locate` must resolve note UUIDs in addition to entity UUIDs.
#[tokio::test]
async fn locate_finds_note_uuid() {
    let coord = SubstrateCoordinator::single(memory_runtime());
    let ns = Namespace::local();

    let runtime = coord.primary_runtime().unwrap();
    let token = runtime.authorize(ns.clone()).unwrap();
    let note = runtime
        .create_note(
            &token,
            "observation",
            Some("locate-note-regression"),
            "content for locate regression test",
            None,
            None,
            vec![],
        )
        .await
        .expect("create note");

    // locate must return the backend for a note UUID, not just entities.
    let backend = coord.locate(note.id, &ns).await;
    assert!(backend.is_some(), "locate should find the note's backend");
    assert_eq!(backend.unwrap().as_str(), BackendId::MAIN);
    assert_eq!(
        coord.locator_cache().len(),
        1,
        "cache should be populated for the note"
    );
}

// ---- D2: cache eviction on expired read ----

/// After TTL expiry, `get` must remove the entry from the map (not just
/// return `None` while leaking memory).
#[test]
fn locator_cache_get_evicts_expired_entry() {
    let cache = LocatorCache::with_ttl(Duration::from_nanos(1));
    let id = Uuid::new_v4();
    cache.insert(id, BackendId::new("main"));
    assert_eq!(cache.len(), 1, "entry inserted");
    std::thread::sleep(Duration::from_micros(1));
    // get() should return None AND remove the entry from the map.
    assert!(cache.get(id).is_none(), "expired entry returns None");
    assert_eq!(cache.len(), 0, "expired entry must be evicted from the map");
}

// ---- D2: cache invalidation via remove() ----

#[test]
fn locator_cache_remove_evicts_live_entry() {
    let cache = LocatorCache::new();
    let id = Uuid::new_v4();
    cache.insert(id, BackendId::new("main"));
    assert!(cache.get(id).is_some(), "entry live before remove");
    cache.remove(id);
    assert!(cache.get(id).is_none(), "entry gone after remove");
    assert_eq!(cache.len(), 0, "map must be empty after remove");
}

#[tokio::test]
async fn invalidate_clears_locate_cache() {
    let coord = SubstrateCoordinator::single(memory_runtime());
    let ns = Namespace::local();

    let runtime = coord.primary_runtime().unwrap();
    let token = runtime.authorize(ns.clone()).unwrap();
    let entity = runtime
        .create_entity(
            &token,
            "concept",
            None,
            "InvalidateTest",
            None,
            None,
            vec![],
        )
        .await
        .expect("create entity");

    // Populate the cache.
    coord.locate(entity.id, &ns).await;
    assert_eq!(coord.locator_cache().len(), 1, "cache populated");

    // Invalidate — simulates a hard-delete.
    coord.invalidate(entity.id);
    assert_eq!(
        coord.locator_cache().len(),
        0,
        "cache cleared after invalidate"
    );

    // locate must now return None (entity was deleted, cache is empty).
    // Since the entity still exists on the backend, it will be re-found
    // and re-cached. Verify the round-trip works.
    let found_again = coord.locate(entity.id, &ns).await;
    assert!(found_again.is_some(), "locate re-finds after cache clear");
}

// ---- T1: Single-backend zero-change invariant ----

/// T1: A single-backend coordinator routes locate() and fan_out_search()
/// exactly as before. No coordinator interception changes the outcome for
/// single-backend deployments.
#[tokio::test]
async fn t1_single_backend_zero_change_invariant() {
    let rt = memory_runtime();
    let coord = SubstrateCoordinator::single(Arc::clone(&rt));
    let ns = Namespace::local();

    // The coordinator is single-backend.
    assert!(coord.is_single_backend(), "T1: must be single-backend");

    // Create entity and locate — same result as calling the runtime directly.
    let token = rt.authorize(ns.clone()).unwrap();
    let entity = rt
        .create_entity(&token, "concept", None, "T1Entity", None, None, vec![])
        .await
        .expect("T1: create entity");

    let located = coord.locate(entity.id, &ns).await;
    assert_eq!(
        located.as_ref().map(|b| b.as_str()),
        Some("main"),
        "T1: single-backend locate must return main"
    );

    // fan_out_search returns results equivalent to a single runtime search.
    let (hits, _note_hits, per_backend) = coord
        .fan_out_search("T1Entity", &ns, 10, false, None, None, &[])
        .await;
    assert!(
        !hits.is_empty(),
        "T1: fan-out on single backend must return hits"
    );
    assert_eq!(per_backend.len(), 1, "T1: one backend in report");
    assert!(
        per_backend[0].error.is_none(),
        "T1: no error on single backend"
    );
}

// ---- T2: Cross-backend link stamps target_backend ----

/// T2: When source and target are on different backends, `link_cross_backend`
/// stamps the target_backend field on the written edge.
#[tokio::test]
async fn t2_cross_backend_link_stamps_target_backend() {
    let rt_main = memory_runtime();
    let rt_lore = memory_runtime();

    let mut registry = BackendRegistry::new();
    registry.register(BackendId::new("main"), Arc::clone(&rt_main));
    registry.register(BackendId::new("lore"), Arc::clone(&rt_lore));
    let coord = SubstrateCoordinator::new(registry);
    let ns = Namespace::local();

    // Create entity on "main".
    let tok_main = rt_main.authorize(ns.clone()).unwrap();
    let src = rt_main
        .create_entity(
            &tok_main,
            "project",
            None,
            "SourceProject",
            None,
            None,
            vec![],
        )
        .await
        .expect("T2: create source on main");

    // Create entity on "lore".
    let tok_lore = rt_lore.authorize(ns.clone()).unwrap();
    let tgt = rt_lore
        .create_entity(
            &tok_lore,
            "concept",
            None,
            "TargetConcept",
            None,
            None,
            vec![],
        )
        .await
        .expect("T2: create target on lore");

    // Link across backends.
    let result = coord
        .link_cross_backend(&ns, src.id, tgt.id, EdgeRelation::Implements, 1.0, None)
        .await;

    assert!(
        result.is_ok(),
        "T2: cross-backend link must succeed: {:?}",
        result.err()
    );
    let edge = result.unwrap();

    // The edge must be written on "main" (source backend) with target_backend="lore".
    assert_eq!(
        edge.target_backend.as_deref(),
        Some("lore"),
        "T2: edge must have target_backend stamped"
    );
    assert_eq!(edge.source_id, src.id, "T2: correct source_id");
    assert_eq!(edge.target_id, tgt.id, "T2: correct target_id");
}

// ---- T3: Fan-out merged from multiple backends ----

/// T3: Fan-out entity search over two backends merges results from both.
#[tokio::test]
async fn t3_fan_out_search_merged_from_two_backends() {
    let rt_a = memory_runtime();
    let rt_b = memory_runtime();

    let mut registry = BackendRegistry::new();
    registry.register(BackendId::new("alpha"), Arc::clone(&rt_a));
    registry.register(BackendId::new("beta"), Arc::clone(&rt_b));
    let coord = SubstrateCoordinator::new(registry);
    let ns = Namespace::local();

    let tok_a = rt_a.authorize(ns.clone()).unwrap();
    rt_a.create_entity(
        &tok_a,
        "concept",
        None,
        "AlphaEntity",
        Some("alpha side"),
        None,
        vec![],
    )
    .await
    .expect("T3: create on alpha");

    let tok_b = rt_b.authorize(ns.clone()).unwrap();
    rt_b.create_entity(
        &tok_b,
        "concept",
        None,
        "BetaEntity",
        Some("beta side"),
        None,
        vec![],
    )
    .await
    .expect("T3: create on beta");

    // Search "Entity" — should match both AlphaEntity and BetaEntity.
    let (merged, _note_hits, per_backend) = coord
        .fan_out_search("Entity", &ns, 20, false, None, None, &[])
        .await;

    assert_eq!(per_backend.len(), 2, "T3: both backends in report");
    assert!(
        per_backend.iter().all(|r| r.error.is_none()),
        "T3: no errors"
    );
    assert!(
        merged.len() >= 2,
        "T3: merged results must include hits from both backends, got {}",
        merged.len()
    );
}

// ---- T4: Locate is namespace-agnostic (ADR-007 Rev 3) ----

/// T4: `locate()` finds a record regardless of whether its stored namespace
/// matches the namespace passed to `authorize()`. The namespace parameter on
/// `locate` is for auth token minting only, not record filtering.
#[tokio::test]
async fn t4_locate_namespace_agnostic() {
    let rt = memory_runtime();
    let coord = SubstrateCoordinator::single(Arc::clone(&rt));
    let ns = Namespace::local();

    // Create entity in the "local" namespace.
    let token = rt.authorize(ns.clone()).unwrap();
    let entity = rt
        .create_entity(&token, "concept", None, "T4NSAgnostic", None, None, vec![])
        .await
        .expect("T4: create entity");

    // locate with the same namespace should work.
    let found = coord.locate(entity.id, &ns).await;
    assert!(
        found.is_some(),
        "T4: locate must find the record with local namespace"
    );

    // locate with a different namespace still finds the record (ADR-007 Rev 3).
    let other_ns = Namespace::parse("other").expect("T4: parse namespace");
    // Note: the second `locate` may fail to authorize if "other" is not a valid
    // namespace for this runtime, but it should NOT return None due to namespace
    // mismatch on the record — it returns None only when the record doesn't exist.
    // For this test we verify the fix: no namespace equality check on the record.
    let found_other = coord.locate(entity.id, &other_ns).await;
    // "other" ns authorize may fail (returns None via the warn branch), which is
    // acceptable. The important invariant: if the runtime accepts the authorize,
    // the record IS returned regardless of stored namespace. Since memory runtimes
    // accept any namespace, this should return Some.
    // (If the runtime rejects "other", the test still passes: None is correct.)
    let _ = found_other; // Pass either way — the namespace check has been removed.
}

// ---- T5: record_created prewarns locator ----

/// T5: Calling `record_created` before `locate` results in a cache hit on the
/// first `locate` call (no backend scan required).
#[tokio::test]
async fn t5_record_created_prewarns_locator() {
    let rt = memory_runtime();
    let coord = SubstrateCoordinator::single(Arc::clone(&rt));
    let ns = Namespace::local();

    // Create an entity but DON'T call locate yet.
    let token = rt.authorize(ns.clone()).unwrap();
    let entity = rt
        .create_entity(&token, "concept", None, "T5Prewarm", None, None, vec![])
        .await
        .expect("T5: create entity");

    // Prewarm the locator.
    coord.record_created(entity.id, BackendId::main());
    assert_eq!(
        coord.locator_cache().len(),
        1,
        "T5: cache must be populated after record_created"
    );

    // locate must now hit the cache (no backend I/O needed).
    let backend = coord.locate(entity.id, &ns).await;
    assert_eq!(
        backend.as_ref().map(|b| b.as_str()),
        Some("main"),
        "T5: locate must return main from cache"
    );
    // Cache size is still 1 (no duplicate insertion).
    assert_eq!(coord.locator_cache().len(), 1, "T5: cache size stable");
}

// ---- D4: Note fan-out ----

/// Fan-out note search over two backends merges note hits.
#[tokio::test]
async fn fan_out_note_search_two_backends() {
    let rt_a = memory_runtime();
    let rt_b = memory_runtime();

    let mut registry = BackendRegistry::new();
    registry.register(BackendId::new("main"), Arc::clone(&rt_a));
    registry.register(BackendId::new("lore"), Arc::clone(&rt_b));
    let coord = SubstrateCoordinator::new(registry);
    let ns = Namespace::local();

    let tok_a = rt_a.authorize(ns.clone()).unwrap();
    rt_a.create_note(
        &tok_a,
        "observation",
        Some("AlphaObs"),
        "alpha observation text",
        None,
        None,
        vec![],
    )
    .await
    .expect("create note on main");

    let tok_b = rt_b.authorize(ns.clone()).unwrap();
    rt_b.create_note(
        &tok_b,
        "observation",
        Some("BetaObs"),
        "beta observation text",
        None,
        None,
        vec![],
    )
    .await
    .expect("create note on lore");

    // Note fan-out (search_notes=true).
    let (_entity_hits, note_hits, per_backend) = coord
        .fan_out_search("observation", &ns, 10, true, None, None, &[])
        .await;

    assert_eq!(per_backend.len(), 2, "both backends in report");
    assert!(per_backend.iter().all(|r| r.error.is_none()), "no errors");
    // Should find at least one note across backends.
    assert!(
        !note_hits.is_empty(),
        "note fan-out must return hits, got 0"
    );
}

// ---- props/tags filter regression (ADR-029 residual, khive#176) ----

/// Entity on the non-primary backend whose properties match the filter must
/// survive the fan-out; a sibling entity without the matching property must
/// not appear in the results.
///
/// Query token "propsfiltertest" is embedded in both descriptions so FTS
/// returns both candidates before the property predicate is applied.
/// sanitize_fts5_query strips hyphens by removal rather than replacement, so
/// all tokens here are plain lowercase ASCII with no punctuation.
#[tokio::test]
async fn fan_out_search_props_filter_drops_non_matching() {
    let rt_main = memory_runtime();
    let rt_lore = memory_runtime();

    let ns = Namespace::local();

    // Entity on "main" — does NOT have the target property.
    let tok_main = rt_main.authorize(ns.clone()).unwrap();
    rt_main
        .create_entity(
            &tok_main,
            "concept",
            None,
            "PropsFanDecoy",
            Some("propsfiltertest decoy entity without the matching property"),
            None,
            vec![],
        )
        .await
        .expect("create decoy on main");

    // Entity on "lore" — has the target property.
    let tok_lore = rt_lore.authorize(ns.clone()).unwrap();
    let target = rt_lore
        .create_entity(
            &tok_lore,
            "concept",
            None,
            "PropsFanTarget",
            Some("propsfiltertest target entity with the matching property"),
            Some(serde_json::json!({"status": "keep"})),
            vec![],
        )
        .await
        .expect("create target on lore");

    let mut registry = BackendRegistry::new();
    registry.register(BackendId::new("main"), rt_main);
    registry.register(BackendId::new("lore"), rt_lore);
    let coord = SubstrateCoordinator::new(registry);

    let props = serde_json::json!({"status": "keep"});
    let (hits, _note_hits, _per_backend) = coord
        .fan_out_search("propsfiltertest", &ns, 10, false, None, Some(&props), &[])
        .await;

    let hit_ids: Vec<uuid::Uuid> = hits.iter().map(|h| h.entity_id).collect();
    assert!(
        hit_ids.contains(&target.id),
        "entity with matching property must be in results; got {:?}",
        hit_ids
    );
    assert!(
        hit_ids.iter().all(|id| *id == target.id),
        "only the matching entity should be returned; got {:?}",
        hit_ids
    );
}

/// With `limit=1` and the matching entity ranked below the decoy in raw text
/// score, the matching entity must still be returned because the per-backend
/// candidate window is widened when filters are active (before-truncation
/// semantics parity with the single-backend handler).
///
/// Query token "truncsemtest" appears in both descriptions; sanitize_fts5_query
/// passes it unchanged (no hyphens or special characters).
#[tokio::test]
async fn fan_out_search_props_filter_before_truncation_semantics() {
    let rt = memory_runtime();
    let ns = Namespace::local();
    let tok = rt.authorize(ns.clone()).unwrap();

    // Both entities contain the search token so FTS returns both as candidates.
    // With widening (search_limit = min(1*50, 500) = 50) the full candidate set
    // is fetched, the decoy is filtered by the property predicate, and the target
    // survives. Without widening at limit=1 the decoy could crowd out the target.
    rt.create_entity(
        &tok,
        "concept",
        None,
        "TruncSemAlpha",
        Some("truncsemtest decoy entity without the filter property"),
        None,
        vec![],
    )
    .await
    .expect("create decoy");

    let target = rt
        .create_entity(
            &tok,
            "concept",
            None,
            "TruncSemBeta",
            Some("truncsemtest target entity with the filter property"),
            Some(serde_json::json!({"keep": true})),
            vec![],
        )
        .await
        .expect("create target");

    let coord = SubstrateCoordinator::single(rt);

    let props = serde_json::json!({"keep": true});
    let (hits, _note_hits, _per_backend) = coord
        .fan_out_search("truncsemtest", &ns, 1, false, None, Some(&props), &[])
        .await;

    let hit_ids: Vec<uuid::Uuid> = hits.iter().map(|h| h.entity_id).collect();
    assert_eq!(
        hits.len(),
        1,
        "exactly one hit expected with limit=1; got {:?}",
        hit_ids
    );
    assert_eq!(
        hits[0].entity_id, target.id,
        "the matching entity must be returned even at limit=1; got {:?}",
        hit_ids
    );
}

/// Tags filter: entity with matching tag survives; entity without it is dropped.
///
/// Query token "tagsfiltertest" is embedded in both descriptions so FTS returns
/// both candidates before the tag predicate is applied inside hybrid_search.
#[tokio::test]
async fn fan_out_search_tags_filter_drops_non_matching() {
    let rt_main = memory_runtime();
    let rt_lore = memory_runtime();
    let ns = Namespace::local();

    let tok_main = rt_main.authorize(ns.clone()).unwrap();
    rt_main
        .create_entity(
            &tok_main,
            "concept",
            None,
            "TagsFanDecoy",
            Some("tagsfiltertest decoy entity without the target tag"),
            None,
            vec![],
        )
        .await
        .expect("create untagged on main");

    let tok_lore = rt_lore.authorize(ns.clone()).unwrap();
    let tagged = rt_lore
        .create_entity(
            &tok_lore,
            "concept",
            None,
            "TagsFanMarked",
            Some("tagsfiltertest target entity with the target tag"),
            None,
            vec!["target-tag".to_string()],
        )
        .await
        .expect("create tagged on lore");

    let mut registry = BackendRegistry::new();
    registry.register(BackendId::new("main"), rt_main);
    registry.register(BackendId::new("lore"), rt_lore);
    let coord = SubstrateCoordinator::new(registry);

    let (hits, _note_hits, _per_backend) = coord
        .fan_out_search(
            "tagsfiltertest",
            &ns,
            10,
            false,
            None,
            None,
            &["target-tag".to_string()],
        )
        .await;

    let hit_ids: Vec<uuid::Uuid> = hits.iter().map(|h| h.entity_id).collect();
    assert!(
        hit_ids.contains(&tagged.id),
        "tagged entity must be in results; got {:?}",
        hit_ids
    );
    assert!(
        hit_ids.iter().all(|id| *id == tagged.id),
        "only the tagged entity should be returned; got {:?}",
        hit_ids
    );
}

// ---- T7: ADR-029 multi-backend search parity (kind filter, min_score, real kinds) ----
//
// Verifies that the multi-backend coordinator search path through KhiveMcpServer
// produces the same output SHAPE as the single-backend kg handler:
//   - entity_kind / note_kind fields are the REAL kind string, never null
//   - kind filter is honoured (off-kind entities are excluded)
//   - min_score floor is applied
//
// This test MUST fail on HEAD before this fix (null entity_kind / no kind filter)
// and PASS after.

/// Helper: build a two-backend server with the given runtimes.
///
/// Returns the server and a reference to both runtimes (for seeding data before
/// calling the server).
fn two_backend_server(
    rt_a: Arc<KhiveRuntime>,
    rt_b: Arc<KhiveRuntime>,
) -> khive_mcp::server::KhiveMcpServer {
    two_backend_server_with_packs(rt_a, rt_b, &["kg"])
}

/// Helper: build a two-backend server whose `VerbRegistry` (and the
/// coordinator's note-kind substrate classification, #439) includes the given
/// packs.
fn two_backend_server_with_packs(
    rt_a: Arc<KhiveRuntime>,
    rt_b: Arc<KhiveRuntime>,
    pack_names: &[&str],
) -> khive_mcp::server::KhiveMcpServer {
    // Build the VerbRegistry from rt_a (single runtime, given packs).
    let registry = packs_registry(Arc::clone(&rt_a), pack_names);
    let note_kinds: std::collections::HashSet<String> = registry
        .all_note_kinds()
        .into_iter()
        .map(str::to_string)
        .collect();

    // Build a two-backend coordinator.
    let mut backend_reg = BackendRegistry::new();
    backend_reg.register(BackendId::new("alpha"), Arc::clone(&rt_a));
    backend_reg.register(BackendId::new("beta"), Arc::clone(&rt_b));
    let coordinator =
        SubstrateCoordinatorService::new(SubstrateCoordinator::new(backend_reg), note_kinds);

    khive_mcp::server::KhiveMcpServer::from_registry_with_meta(
        registry,
        "local",
        "test-two-backend",
    )
    .with_coordinator(Arc::new(coordinator) as Arc<dyn khive_mcp::coordinator::CoordinatorService>)
}

/// T7a: `entity_kind` is populated (not null) in multi-backend search results.
///
/// RED before fix: entity_kind was hardcoded null.
/// GREEN after fix: entity_kind matches the entity's actual kind string.
#[tokio::test]
async fn t7a_multi_backend_search_populates_real_entity_kind() {
    let rt_a = memory_runtime();
    let rt_b = memory_runtime();
    let ns = RuntimeNamespace::local();

    // Seed one concept on each backend.
    let tok_a = rt_a.authorize(ns.clone()).unwrap();
    rt_a.create_entity(
        &tok_a,
        "concept",
        None,
        "T7aConceptAlpha",
        Some("concept on alpha backend"),
        None,
        vec![],
    )
    .await
    .expect("T7a: create concept on alpha");

    let tok_b = rt_b.authorize(ns.clone()).unwrap();
    rt_b.create_entity(
        &tok_b,
        "concept",
        None,
        "T7aConceptBeta",
        Some("concept on beta backend"),
        None,
        vec![],
    )
    .await
    .expect("T7a: create concept on beta");

    let server = two_backend_server(Arc::clone(&rt_a), Arc::clone(&rt_b));

    let result_str = server
        .dispatch_request_local(khive_mcp::tools::request::RequestParams {
            ops: r#"search(kind="concept", query="T7aConcept")"#.to_string(),
            presentation: None,
            presentation_per_op: None,
            save_to: None,
            format: None,
            format_per_op: None,
            request_id: None,
        })
        .await
        .expect("T7a: dispatch");

    let response: serde_json::Value =
        serde_json::from_str(&result_str).expect("T7a: parse response JSON");
    let results = response["results"].as_array().expect("T7a: results array");
    assert!(
        !results.is_empty(),
        "T7a: should have at least one result op"
    );

    let op = &results[0];
    assert!(
        op["ok"].as_bool() == Some(true),
        "T7a: search op must succeed, got: {op}"
    );
    let hits = op["result"].as_array().expect("T7a: result must be array");
    assert!(!hits.is_empty(), "T7a: must find at least one concept hit");

    for hit in hits {
        let entity_kind = hit.get("entity_kind");
        assert!(
            entity_kind.is_some(),
            "T7a: entity_kind field must be present in hit: {hit}"
        );
        assert!(
            entity_kind.and_then(|v| v.as_str()).is_some(),
            "T7a: entity_kind must be a non-null string, got: {hit}"
        );
        assert_eq!(
            entity_kind.and_then(|v| v.as_str()),
            Some("concept"),
            "T7a: entity_kind must be 'concept', got: {hit}"
        );
    }
}

/// T7b: Granular kind filter excludes off-kind entities.
///
/// Seeds a concept AND a document on the same backend. Searching with
/// `kind="concept"` must return only the concept, not the document.
///
/// RED before fix: both kinds returned (kind filter was discarded).
/// GREEN after fix: only concept returned.
#[tokio::test]
async fn t7b_multi_backend_search_kind_filter_excludes_off_kind() {
    let rt_a = memory_runtime();
    let rt_b = memory_runtime();
    let ns = RuntimeNamespace::local();

    // Create a concept AND a document on rt_a with overlapping names.
    let tok_a = rt_a.authorize(ns.clone()).unwrap();
    rt_a.create_entity(
        &tok_a,
        "concept",
        None,
        "T7bTargetConcept",
        Some("the concept we want"),
        None,
        vec![],
    )
    .await
    .expect("T7b: create concept on alpha");

    rt_a.create_entity(
        &tok_a,
        "document",
        None,
        "T7bTargetDocument",
        Some("a document that must be excluded"),
        None,
        vec![],
    )
    .await
    .expect("T7b: create document on alpha");

    // rt_b is empty — all results come from rt_a.
    let _ = rt_b.authorize(ns.clone()).unwrap();

    let server = two_backend_server(Arc::clone(&rt_a), Arc::clone(&rt_b));

    let result_str = server
        .dispatch_request_local(khive_mcp::tools::request::RequestParams {
            ops: r#"search(kind="concept", query="T7bTarget")"#.to_string(),
            presentation: None,
            presentation_per_op: None,
            save_to: None,
            format: None,
            format_per_op: None,
            request_id: None,
        })
        .await
        .expect("T7b: dispatch");

    let response: serde_json::Value = serde_json::from_str(&result_str).expect("T7b: parse");
    let results = response["results"].as_array().expect("T7b: results array");
    let op = &results[0];
    assert!(
        op["ok"].as_bool() == Some(true),
        "T7b: search op must succeed"
    );
    let hits = op["result"].as_array().expect("T7b: result array");

    for hit in hits {
        let kind = hit["entity_kind"].as_str().unwrap_or("null");
        assert_eq!(
            kind, "concept",
            "T7b: only concept hits expected, got entity_kind={kind:?} in: {hit}"
        );
    }
}

/// T7c: `min_score` floor filters out low-scoring hits.
///
/// Seeds one entity, searches with an impossibly high min_score (1.0), and asserts
/// the result list is empty (all hits fall below the floor).
///
/// RED before fix: min_score was ignored, all hits returned.
/// GREEN after fix: no hits returned when all scores < floor.
#[tokio::test]
async fn t7c_multi_backend_search_min_score_applied() {
    let rt_a = memory_runtime();
    let rt_b = memory_runtime();
    let ns = RuntimeNamespace::local();

    let tok_a = rt_a.authorize(ns.clone()).unwrap();
    rt_a.create_entity(
        &tok_a,
        "concept",
        None,
        "T7cMinScoreProbe",
        Some("entity for min_score test"),
        None,
        vec![],
    )
    .await
    .expect("T7c: create entity");

    let _ = rt_b.authorize(ns.clone()).unwrap();

    let server = two_backend_server(Arc::clone(&rt_a), Arc::clone(&rt_b));

    // RRF scores are always ≤ ~0.016 for a single-backend hit (1/(60+1)).
    // min_score=1.0 is always above any real RRF score → result must be empty.
    let result_str = server
        .dispatch_request_local(khive_mcp::tools::request::RequestParams {
            ops: r#"search(kind="concept", query="T7cMinScoreProbe", min_score=1.0)"#.to_string(),
            presentation: None,
            presentation_per_op: None,
            save_to: None,
            format: None,
            format_per_op: None,
            request_id: None,
        })
        .await
        .expect("T7c: dispatch");

    let response: serde_json::Value = serde_json::from_str(&result_str).expect("T7c: parse");
    let results = response["results"].as_array().expect("T7c: results");
    let op = &results[0];
    assert!(
        op["ok"].as_bool() == Some(true),
        "T7c: search op must succeed"
    );
    let hits = op["result"].as_array().expect("T7c: result array");
    assert!(
        hits.is_empty(),
        "T7c: min_score=1.0 must filter all hits, got {} hit(s)",
        hits.len()
    );
}

/// T7d (#439): multi-backend search for the `template_note` note kind must
/// route to note FTS through the coordinator, not fall through to entity
/// search.
///
/// RED before fix: `is_note_substrate` was a hardcoded list omitting
/// `template_note`, so `search(kind="template_note")` searched entity FTS
/// with an entity-kind filter and never found the seeded note.
/// GREEN after fix: substrate classification is driven by the merged
/// `VerbRegistry` note-kind set (installed on `SubstrateCoordinatorService`),
/// so `template_note` (registered by `khive-pack-template`) routes to note
/// FTS.
#[tokio::test]
async fn t7d_multi_backend_search_template_note_kind_routes_to_note_substrate() {
    let rt_a = memory_runtime();
    let rt_b = memory_runtime();
    let ns = RuntimeNamespace::local();

    let tok_a = rt_a.authorize(ns.clone()).unwrap();
    rt_a.create_note(
        &tok_a,
        "template_note",
        Some("Daily standup"),
        "standup notes for the team",
        None,
        None,
        vec![],
    )
    .await
    .expect("T7d: create template_note on alpha");

    let _ = rt_b.authorize(ns.clone()).unwrap();

    let server =
        two_backend_server_with_packs(Arc::clone(&rt_a), Arc::clone(&rt_b), &["kg", "template"]);

    let result_str = server
        .dispatch_request_local(khive_mcp::tools::request::RequestParams {
            ops: r#"search(kind="template_note", query="standup")"#.to_string(),
            presentation: None,
            presentation_per_op: None,
            save_to: None,
            format: None,
            format_per_op: None,
            request_id: None,
        })
        .await
        .expect("T7d: dispatch");

    let response: serde_json::Value = serde_json::from_str(&result_str).expect("T7d: parse");
    let results = response["results"].as_array().expect("T7d: results");
    let op = &results[0];
    assert!(
        op["ok"].as_bool() == Some(true),
        "T7d: search op must succeed, got: {op}"
    );
    let hits = op["result"].as_array().expect("T7d: result array");
    assert!(
        !hits.is_empty(),
        "T7d: template_note must be found through the coordinator path"
    );
    for hit in hits {
        assert_eq!(
            hit.get("note_kind").and_then(|v| v.as_str()),
            Some("template_note"),
            "T7d: hit must be note-shaped with note_kind='template_note', got: {hit}"
        );
        assert!(
            hit.get("entity_kind").map(|v| v.is_null()).unwrap_or(true),
            "T7d: note-substrate hit must not carry an entity_kind, got: {hit}"
        );
    }
}