package watch

import (
	"net/http/httptest"
	"path/filepath"
	"testing"

	"github.com/david/knox/internal/db"
)

func tmpKnoxDB(t *testing.T) *db.KnoxDB {
	t.Helper()
	kdb, err := db.Open(filepath.Join(t.TempDir(), "index.db"))
	if err != nil {
		t.Fatalf("open db: %v", err)
	}
	t.Cleanup(func() { kdb.Close() })
	return kdb
}

func seedObs(k *db.KnoxDB, prefix string) {
	// Insert distinct observations only via RecordObservation so they get this
	// node's node_id and HCL.
	for i := 0; i < 3; i++ {
		_, _, err := k.RecordObservation(db.ObservationRecord{
			Fingerprint:     prefix + ":" + string(rune('a'+i)),
			SourceID:        "test",
			SourcePath:      prefix,
			Project:         "itest",
			ContentType:     "test",
			Title:           prefix + string(rune('a'+i)),
			Summary:         "summary " + prefix + string(rune('a'+i)),
			CreatedAt:       "2026-08-29T00:00:00Z",
			LineEnd:         0,
			Confidence:      0.9,
			IngesterVersion: "itest/v1",
		})
		if err != nil {
			panic(err)
		}
	}
}

// TestGossipConvergence starts two nodes, seeds disjoint observations, and runs
// a bidirectional handshake. Both must end with the concatenation of both logs.
func TestGossipConvergence(t *testing.T) {
	a := tmpKnoxDB(t)
	b := tmpKnoxDB(t)

	seedObs(a, "AAA")
	seedObs(b, "BBB")

	// Wire a and b as peer HTTP servers.
	nodeA := &Node{Kdb: a, Name: "A"}
	sa := httptest.NewServer(nodeA.Handler())
	defer sa.Close()

	nodeB := &Node{Kdb: b, Name: "B"}
	sb := httptest.NewServer(nodeB.Handler())
	defer sb.Close()

	// A pulls from B, then B pulls from A (bidirectional sweep).
	Run(a, []string{sb.URL})
	Run(b, []string{sa.URL})

	av, err := a.KnowledgeVector()
	if err != nil {
		t.Fatalf("a vector: %v", err)
	}
	bv, err := b.KnowledgeVector()
	if err != nil {
		t.Fatalf("b vector: %v", err)
	}

	if len(av) != 2 || len(bv) != 2 {
		t.Fatalf("expected both nodes to hold 2 source logs, got a=%v b=%v", av, bv)
	}

	// Same maximum HCL per origin node on both sides.
	for nid, hcl := range av {
		if bv[nid] != hcl {
			t.Errorf("node %s max hcl mismatch: a=%d b=%d", nid, hcl, bv[nid])
		}
	}
}

// TestGossipDiff ensures /v1/diff reports per-node observation fingerprints and
// tombstoned thread divergence.
func TestGossipDiff(t *testing.T) {
	a := tmpKnoxDB(t)
	b := tmpKnoxDB(t)

	seedObs(a, "AAA")
	seedObs(b, "BBB")

	nodeA := &Node{Kdb: a, Name: "A"}
	sa := httptest.NewServer(nodeA.Handler())
	defer sa.Close()

	c := &Client{Addr: sa.URL}
	d, err := c.Diff()
	if err != nil {
		t.Fatalf("diff: %v", err)
	}
	if d.NodeID != a.NodeID() {
		t.Errorf("diff node mismatch: %s != %s", d.NodeID, a.NodeID())
	}
	if len(d.Fingerprints) != 3 {
		t.Errorf("expected 3 fingerprints in diff, got %d", len(d.Fingerprints))
	}
}

// TestGossipDiffTombstones confirms resolved auto-threads surface in diff.
func TestGossipDiffTombstones(t *testing.T) {
	a := tmpKnoxDB(t)

	id, _, err := a.CreateThreadCluster("Test thread", "motivation", "medium", "[]", `{"trigger":"auto_thread"}`, "cluster:testkey")
	if err != nil {
		t.Fatalf("create thread: %v", err)
	}
	if err := a.CloseThread(id); err != nil {
		t.Fatalf("close thread: %v", err)
	}

	nodeA := &Node{Kdb: a, Name: "A"}
	sa := httptest.NewServer(nodeA.Handler())
	defer sa.Close()

	c := &Client{Addr: sa.URL}
	d, err := c.Diff()
	if err != nil {
		t.Fatalf("diff: %v", err)
	}
	if len(d.ThreadStatus) != 1 {
		t.Errorf("expected 1 thread in diff, got %d", len(d.ThreadStatus))
	}
	for k, st := range d.ThreadStatus {
		if k != "cluster:testkey" {
			t.Errorf("unexpected thread key %s", k)
		}
		if st != "resolved" {
			t.Errorf("thread %s should be resolved, got %q", k, st)
		}
	}
}

// TestGossipIdempotent ensures a repeated sweep does not duplicate observations.
func TestGossipIdempotent(t *testing.T) {
	a := tmpKnoxDB(t)
	b := tmpKnoxDB(t)

	seedObs(a, "AAA")

	nodeA := &Node{Kdb: a, Name: "A"}
	sa := httptest.NewServer(nodeA.Handler())
	defer sa.Close()
	nodeB := &Node{Kdb: b, Name: "B"}
	sb := httptest.NewServer(nodeB.Handler())
	defer sb.Close()

	Run(b, []string{sa.URL})
	before, err := b.EntryCount()
	if err != nil {
		t.Fatal(err)
	}
	Run(b, []string{sa.URL})
	after, err := b.EntryCount()
	if err != nil {
		t.Fatal(err)
	}
	if before != after {
		t.Errorf("second sweep changed entry count: %d -> %d", before, after)
	}
}