package labeler

import (
	"database/sql"
	"os"
	"path/filepath"
	"testing"
	"time"

	"github.com/bluesky-social/indigo/atproto/atcrypto"
)

func newTestKey(t *testing.T) *atcrypto.PrivateKeyK256 {
	t.Helper()
	k, err := atcrypto.GeneratePrivateKeyK256()
	if err != nil {
		t.Fatalf("generate key: %v", err)
	}
	return k
}

// openTestDB opens a fresh local-only labeler DB and registers cleanup. Returns the
// raw *sql.DB so existing tests can keep using it; the wrapper lifecycle is handled
// here so tests don't have to know about the embedded-replica machinery.
func openTestDB(t *testing.T, path string) *sql.DB {
	t.Helper()
	storage, err := OpenDB(path, LibsqlSync{})
	if err != nil {
		t.Fatalf("OpenDB: %v", err)
	}
	t.Cleanup(func() { _ = storage.Close() })
	return storage.DB
}

// signAndCreate is a helper that signs the label and inserts it; it returns the row id.
func signAndCreate(t *testing.T, db *sql.DB, key *atcrypto.PrivateKeyK256, l *Label) int64 {
	t.Helper()
	if err := l.Sign(key); err != nil {
		t.Fatalf("sign: %v", err)
	}
	id, err := CreateLabel(db, l)
	if err != nil {
		t.Fatalf("create: %v", err)
	}
	return id
}

func TestOpenDB(t *testing.T) {
	dir := t.TempDir()
	dbPath := filepath.Join(dir, "subdir", "test.db")

	storage, err := OpenDB(dbPath, LibsqlSync{})
	if err != nil {
		t.Fatalf("OpenDB failed: %v", err)
	}
	defer storage.Close()

	if _, err := os.Stat(filepath.Dir(dbPath)); os.IsNotExist(err) {
		t.Error("expected directory to be created")
	}

	var count int
	if err := storage.DB.QueryRow("SELECT COUNT(*) FROM labels").Scan(&count); err != nil {
		t.Fatalf("failed to query labels table: %v", err)
	}
	if count != 0 {
		t.Errorf("expected 0 labels, got %d", count)
	}
}

func TestCreateLabel(t *testing.T) {
	dir := t.TempDir()
	db := openTestDB(t, filepath.Join(dir, "test.db"))
	key := newTestKey(t)

	now := time.Now().UTC().Truncate(time.Second)
	label := &Label{
		Src:         "did:plc:labeler-1",
		URI:         "at://did:plc:abc/io.atcr.manifest/sha256-123",
		Val:         "!takedown",
		Cts:         now,
		SubjectDID:  "did:plc:abc",
		SubjectRepo: "myimage",
	}
	id := signAndCreate(t, db, key, label)
	if id <= 0 {
		t.Errorf("expected positive id, got %d", id)
	}
	if len(label.Sig) == 0 {
		t.Error("expected signature populated by Sign()")
	}

	labels, err := GetLabelsSince(db, 0, 10)
	if err != nil {
		t.Fatal(err)
	}
	if len(labels) != 1 {
		t.Fatalf("expected 1 label, got %d", len(labels))
	}
	if labels[0].Src != label.Src {
		t.Errorf("Src = %s, want %s", labels[0].Src, label.Src)
	}
	if labels[0].SubjectDID != "did:plc:abc" {
		t.Errorf("SubjectDID = %s", labels[0].SubjectDID)
	}
	if labels[0].SubjectRepo != "myimage" {
		t.Errorf("SubjectRepo = %s", labels[0].SubjectRepo)
	}
	if labels[0].Ver != LabelVersion {
		t.Errorf("Ver = %d, want %d", labels[0].Ver, LabelVersion)
	}
	if len(labels[0].Sig) == 0 {
		t.Error("expected stored sig to be populated")
	}
}

func TestCreateLabel_RejectsUnsigned(t *testing.T) {
	dir := t.TempDir()
	db := openTestDB(t, filepath.Join(dir, "test.db"))

	label := &Label{
		Src: "did:plc:labeler-1", URI: "at://did:plc:abc",
		Val: "!takedown", Cts: time.Now().UTC(),
		SubjectDID: "did:plc:abc",
	}
	if _, err := CreateLabel(db, label); err == nil {
		t.Fatal("expected CreateLabel to reject an unsigned label")
	}
}

func TestSignAndVerify(t *testing.T) {
	key := newTestKey(t)
	label := &Label{
		Src: "did:plc:labeler-1",
		URI: "at://did:plc:abc",
		Val: "!takedown",
		Cts: time.Now().UTC(),
		Ver: LabelVersion,
	}
	if err := label.Sign(key); err != nil {
		t.Fatal(err)
	}

	pub, err := key.PublicKey()
	if err != nil {
		t.Fatal(err)
	}
	wire := label.ToLabeling()
	if err := wire.VerifySignature(pub); err != nil {
		t.Fatalf("signature did not verify: %v", err)
	}
}

func TestListTakedowns(t *testing.T) {
	dir := t.TempDir()
	db := openTestDB(t, filepath.Join(dir, "test.db"))
	key := newTestKey(t)

	src := "did:plc:labeler-1"
	now := time.Now().UTC()

	// Create three takedown events, each with a single summary label, so the
	// label_count subquery has something to count.
	var ids []int64
	for i, repo := range []string{"repo1", "repo2", "repo3"} {
		td := &Takedown{
			Input:       "atcr.io/r/did:plc:abc/" + repo,
			SubjectDID:  "did:plc:abc",
			SubjectRepo: repo,
			CreatedAt:   now.Add(time.Duration(i) * time.Minute),
		}
		id, err := CreateTakedown(db, td)
		if err != nil {
			t.Fatalf("CreateTakedown: %v", err)
		}
		ids = append(ids, id)
		signAndCreate(t, db, key, &Label{
			Src: src, URI: "at://did:plc:abc/io.atcr.repo/" + repo,
			Val: "!takedown", Cts: td.CreatedAt,
			SubjectDID: "did:plc:abc", SubjectRepo: repo,
			TakedownID: &id,
		})
	}

	tds, total, err := ListTakedowns(db, TakedownActive, 10, 0)
	if err != nil {
		t.Fatal(err)
	}
	if total != 3 || len(tds) != 3 {
		t.Errorf("expected 3 active takedowns, got total=%d returned=%d", total, len(tds))
	}
	for _, td := range tds {
		if td.LabelCount != 1 {
			t.Errorf("takedown %d label_count = %d, want 1", td.ID, td.LabelCount)
		}
	}

	// Reverse the middle takedown.
	if _, err := NegateTakedownLabels(db, key, src, ids[1]); err != nil {
		t.Fatal(err)
	}
	if err := MarkTakedownReversed(db, ids[1], "did:plc:operator", time.Now().UTC()); err != nil {
		t.Fatal(err)
	}

	_, activeTotal, err := ListTakedowns(db, TakedownActive, 10, 0)
	if err != nil {
		t.Fatal(err)
	}
	if activeTotal != 2 {
		t.Errorf("expected 2 active takedowns after reversal, got %d", activeTotal)
	}
	revs, revTotal, err := ListTakedowns(db, TakedownReversed, 10, 0)
	if err != nil {
		t.Fatal(err)
	}
	if revTotal != 1 || len(revs) != 1 {
		t.Errorf("expected 1 reversed takedown, got total=%d returned=%d", revTotal, len(revs))
	}
	if revs[0].ID != ids[1] || revs[0].ReversedAt == nil || revs[0].ReversedBy != "did:plc:operator" {
		t.Errorf("reversed takedown row has wrong fields: %+v", revs[0])
	}
}

func TestNegateTakedownLabels(t *testing.T) {
	dir := t.TempDir()
	db := openTestDB(t, filepath.Join(dir, "test.db"))
	key := newTestKey(t)

	src := "did:plc:labeler-1"
	now := time.Now().UTC()
	did := "did:plc:abc"

	tdID, err := CreateTakedown(db, &Takedown{
		Input: "atcr.io/r/did:plc:abc/myimage", SubjectDID: did, SubjectRepo: "myimage",
		CreatedAt: now,
	})
	if err != nil {
		t.Fatal(err)
	}

	uris := []string{
		"at://did:plc:abc/io.atcr.manifest/sha256-111",
		"at://did:plc:abc/io.atcr.manifest/sha256-222",
		"at://did:plc:abc/io.atcr.tag/myimage-latest",
	}
	for _, uri := range uris {
		signAndCreate(t, db, key, &Label{
			Src: src, URI: uri, Val: "!takedown", Cts: now,
			SubjectDID: did, SubjectRepo: "myimage", TakedownID: &tdID,
		})
	}

	negs, err := NegateTakedownLabels(db, key, src, tdID)
	if err != nil {
		t.Fatal(err)
	}
	if len(negs) != len(uris) {
		t.Errorf("expected %d negation labels, got %d", len(uris), len(negs))
	}

	// Negations must carry the same takedown_id so they're part of the audit trail.
	all, err := GetLabelsByTakedown(db, tdID)
	if err != nil {
		t.Fatal(err)
	}
	if len(all) != 2*len(uris) {
		t.Errorf("expected %d labels (positive + negation) for takedown %d, got %d", 2*len(uris), tdID, len(all))
	}
	var pos, neg int
	for _, l := range all {
		if l.TakedownID == nil || *l.TakedownID != tdID {
			t.Errorf("label %d takedown_id = %v, want %d", l.ID, l.TakedownID, tdID)
		}
		if l.Neg {
			neg++
		} else {
			pos++
		}
	}
	if pos != len(uris) || neg != len(uris) {
		t.Errorf("expected pos=%d neg=%d, got pos=%d neg=%d", len(uris), len(uris), pos, neg)
	}

	// Calling negate again must be a no-op (no remaining positive labels to flip).
	negs2, err := NegateTakedownLabels(db, key, src, tdID)
	if err != nil {
		t.Fatal(err)
	}
	if len(negs2) != 0 {
		t.Errorf("expected 0 negations on second call, got %d", len(negs2))
	}
}

func TestMarkTakedownReversed_RefusesDoubleReverse(t *testing.T) {
	dir := t.TempDir()
	db := openTestDB(t, filepath.Join(dir, "test.db"))

	id, err := CreateTakedown(db, &Takedown{
		Input: "did:plc:abc", SubjectDID: "did:plc:abc",
	})
	if err != nil {
		t.Fatal(err)
	}
	if err := MarkTakedownReversed(db, id, "did:plc:op", time.Now().UTC()); err != nil {
		t.Fatalf("first reverse: %v", err)
	}
	if err := MarkTakedownReversed(db, id, "did:plc:op", time.Now().UTC()); err == nil {
		t.Error("expected second reverse to fail (already reversed)")
	}
	if err := MarkTakedownReversed(db, 9999, "did:plc:op", time.Now().UTC()); err == nil {
		t.Error("expected reverse on unknown id to fail")
	}
}

func TestGetLabelsSince(t *testing.T) {
	dir := t.TempDir()
	db := openTestDB(t, filepath.Join(dir, "test.db"))
	key := newTestKey(t)

	src := "did:plc:labeler-1"
	now := time.Now().UTC()

	for i := range 5 {
		signAndCreate(t, db, key, &Label{
			Src: src, URI: "at://did:plc:abc/io.atcr.manifest/" + string(rune('a'+i)),
			Val: "!takedown", Cts: now.Add(time.Duration(i) * time.Minute),
			SubjectDID: "did:plc:abc", SubjectRepo: "repo",
		})
	}

	labels, err := GetLabelsSince(db, 0, 10)
	if err != nil {
		t.Fatal(err)
	}
	if len(labels) != 5 {
		t.Errorf("expected 5 labels, got %d", len(labels))
	}

	cursor := labels[2].ID
	after, err := GetLabelsSince(db, cursor, 10)
	if err != nil {
		t.Fatal(err)
	}
	if len(after) != 2 {
		t.Errorf("expected 2 labels after cursor %d, got %d", cursor, len(after))
	}

	limited, err := GetLabelsSince(db, 0, 2)
	if err != nil {
		t.Fatal(err)
	}
	if len(limited) != 2 {
		t.Errorf("expected 2 labels with limit, got %d", len(limited))
	}
}

func TestLatestSeq(t *testing.T) {
	dir := t.TempDir()
	db := openTestDB(t, filepath.Join(dir, "test.db"))
	key := newTestKey(t)

	if seq, err := LatestSeq(db); err != nil || seq != 0 {
		t.Fatalf("expected empty seq=0, got %d (err=%v)", seq, err)
	}

	id := signAndCreate(t, db, key, &Label{
		Src: "did:plc:labeler-1", URI: "at://did:plc:abc",
		Val: "!takedown", Cts: time.Now().UTC(),
		SubjectDID: "did:plc:abc",
	})
	seq, err := LatestSeq(db)
	if err != nil {
		t.Fatal(err)
	}
	if seq != id {
		t.Errorf("LatestSeq = %d, want %d", seq, id)
	}
}

func TestGetLabelsByTakedown(t *testing.T) {
	dir := t.TempDir()
	db := openTestDB(t, filepath.Join(dir, "test.db"))
	key := newTestKey(t)

	src := "did:plc:labeler-1"
	now := time.Now().UTC()

	tdA, err := CreateTakedown(db, &Takedown{Input: "did:plc:abc/repo1", SubjectDID: "did:plc:abc", SubjectRepo: "repo1", CreatedAt: now})
	if err != nil {
		t.Fatal(err)
	}
	tdB, err := CreateTakedown(db, &Takedown{Input: "did:plc:def/repo1", SubjectDID: "did:plc:def", SubjectRepo: "repo1", CreatedAt: now})
	if err != nil {
		t.Fatal(err)
	}

	signAndCreate(t, db, key, &Label{
		Src: src, URI: "at://did:plc:abc/io.atcr.repo/repo1",
		Val: "!takedown", Cts: now, SubjectDID: "did:plc:abc", SubjectRepo: "repo1", TakedownID: &tdA,
	})
	signAndCreate(t, db, key, &Label{
		Src: src, URI: "at://did:plc:abc/io.atcr.manifest/sha256-aaa",
		Val: "!takedown", Cts: now, SubjectDID: "did:plc:abc", SubjectRepo: "repo1", TakedownID: &tdA,
	})
	signAndCreate(t, db, key, &Label{
		Src: src, URI: "at://did:plc:def/io.atcr.repo/repo1",
		Val: "!takedown", Cts: now, SubjectDID: "did:plc:def", SubjectRepo: "repo1", TakedownID: &tdB,
	})

	labels, err := GetLabelsByTakedown(db, tdA)
	if err != nil {
		t.Fatal(err)
	}
	if len(labels) != 2 {
		t.Errorf("takedown A: expected 2 labels, got %d", len(labels))
	}
	for _, l := range labels {
		if l.TakedownID == nil || *l.TakedownID != tdA {
			t.Errorf("label %d has wrong takedown_id: %v", l.ID, l.TakedownID)
		}
	}

	labels, err = GetLabelsByTakedown(db, tdB)
	if err != nil {
		t.Fatal(err)
	}
	if len(labels) != 1 {
		t.Errorf("takedown B: expected 1 label, got %d", len(labels))
	}

	labels, err = GetLabelsByTakedown(db, 9999)
	if err != nil {
		t.Fatal(err)
	}
	if len(labels) != 0 {
		t.Errorf("unknown takedown id: expected 0 labels, got %d", len(labels))
	}
}