package musicbrainz

import (
	"context"
	"net/http"
	"net/http/httptest"
	"testing"
	"time"

	"golang.org/x/time/rate"
	"naviwatcher/internal/config"
	"naviwatcher/internal/database"
)

// mbReleaseGroupXML is a helper to build a single release-group XML element.
func mbReleaseGroupXML(id, title, rgType, status, artistID, artistName, releaseDate string) string {
	statusAttr := ""
	if status != "" {
		statusAttr = ` status="` + status + `"`
	}
	return `<release-group id="` + id + `" type="` + rgType + `"` + statusAttr + `>` +
		`<title>` + title + `</title>` +
		`<artist-credit><name-credit><artist id="` + artistID + `">` +
		`<name>` + artistName + `</name>` +
		`</artist></name-credit></artist-credit>` +
		`<first-release-date>` + releaseDate + `</first-release-date>` +
		`</release-group>`
}

// mbReleaseGroupListResponse builds a full MusicBrainz XML response for a release-group list.
func mbReleaseGroupListResponse(groups string, count int) string {
	return `<?xml version="1.0" encoding="UTF-8"?>
<metadata xmlns="http://musicbrainz.org/ns/mmd-2.0#">
  <release-group-list count="` + itoa(count) + `">` +
		groups +
		`</release-group-list>
</metadata>`
}

// itoa converts an int to a string without importing strconv.
func itoa(n int) string {
	if n == 0 {
		return "0"
	}
	var buf [20]byte
	i := len(buf)
	for n > 0 {
		i--
		buf[i] = byte('0' + n%10)
		n /= 10
	}
	return string(buf[i:])
}

// newTestMBServer creates a mock MusicBrainz HTTP server.
func newTestMBServer(handler http.HandlerFunc) *httptest.Server {
	return httptest.NewServer(handler)
}

// newTestDB creates an in-memory SQLite database with all migrations applied.
func newTestDB(t *testing.T) *database.DB {
	t.Helper()
	db, err := database.New(":memory:")
	if err != nil {
		t.Fatalf("database.New() error: %v", err)
	}
	return db
}

// newTestClient creates a MusicBrainzClient pointing at the given test server
// with a relaxed rate limiter (100 req/sec) for fast test execution.
func newTestClient(serverURL string) *MusicBrainzClient {
	cfg := config.MusicBrainzConfig{
		UserAgent: "test-agent/1.0",
	}
	return &MusicBrainzClient{
		httpClient:  &http.Client{},
		userAgent:   cfg.UserAgent,
		baseURL:     serverURL,
		rateLimiter: rate.NewLimiter(rate.Limit(100), 100),
	}
}

// seedArtist inserts a minimal artist_settings row so foreign key constraints pass.
func seedArtist(t *testing.T, db *database.DB, id, name string) {
	t.Helper()
	if err := database.SaveArtistSettings(db, &database.ArtistSettings{
		ID:        id,
		Name:      name,
		Monitored: true,
	}); err != nil {
		t.Fatalf("seedArtist(%s) error: %v", id, err)
	}
}

// -----------------------------------------------------------------------
// Test: SyncArtistDiscography fetches from API and upserts on cache miss
// -----------------------------------------------------------------------

func TestSyncArtistDiscography_CacheMiss_FetchesAndUpserts(t *testing.T) {
	artistMBID := "aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee"
	artistName := "Test Artist"

	server := newTestMBServer(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/xml")
		resp := mbReleaseGroupListResponse(
			mbReleaseGroupXML("rg1", "First Album", "Album", "", artistMBID, artistName, "2020-01-01")+
				mbReleaseGroupXML("rg2", "Second Album", "Album", "", artistMBID, artistName, "2022-06-15")+
				mbReleaseGroupXML("rg3", "A Single", "Single", "", artistMBID, artistName, "2021-03-10"),
			3,
		)
		w.Write([]byte(resp))
	})
	defer server.Close()

	db := newTestDB(t)
	defer db.Close()
	seedArtist(t, db, artistMBID, artistName)

	client := newTestClient(server.URL)
	ctx := context.Background()
	ttl := 24 * time.Hour

	releases, err := SyncArtistDiscography(ctx, client, db, artistMBID, ttl)
	if err != nil {
		t.Fatalf("SyncArtistDiscography() error: %v", err)
	}

	if len(releases) != 3 {
		t.Fatalf("expected 3 releases, got %d", len(releases))
	}

	// Verify each release has CachedAt set.
	for _, r := range releases {
		if r.CachedAt.IsZero() {
			t.Errorf("release %s: CachedAt should be set, got zero", r.RGID)
		}
		if r.ArtistID != artistMBID {
			t.Errorf("release %s: expected ArtistID %q, got %q", r.RGID, artistMBID, r.ArtistID)
		}
	}

	// Verify data was persisted in the database.
	stored, err := database.GetExternalReleasesByArtist(db, artistMBID)
	if err != nil {
		t.Fatalf("GetExternalReleasesByArtist() error: %v", err)
	}
	if len(stored) != 3 {
		t.Errorf("expected 3 stored releases, got %d", len(stored))
	}
}

// -----------------------------------------------------------------------
// Test: SyncArtistDiscography returns cached data on cache hit
// -----------------------------------------------------------------------

func TestSyncArtistDiscography_CacheHit_ReturnsCached(t *testing.T) {
	artistMBID := "bbbbbbbb-cccc-dddd-eeee-ffffffffffff"

	db := newTestDB(t)
	defer db.Close()
	seedArtist(t, db, artistMBID, "Cached Artist")

	// Pre-populate the cache with one release.
	now := time.Now()
	if err := database.SaveExternalRelease(db, &database.ExternalRelease{
		RGID:        "rg-cached",
		ArtistID:    artistMBID,
		Title:       "Cached Album",
		Type:        "Album",
		ReleaseDate: "2019-05-01",
		CachedAt:    now,
	}); err != nil {
		t.Fatalf("SaveExternalRelease() error: %v", err)
	}

	// Server that would be called on cache miss — should NOT be called.
	serverCalled := false
	server := newTestMBServer(func(w http.ResponseWriter, r *http.Request) {
		serverCalled = true
		w.Header().Set("Content-Type", "application/xml")
		w.Write([]byte(mbReleaseGroupListResponse("", 0)))
	})
	defer server.Close()

	client := newTestClient(server.URL)
	ctx := context.Background()
	ttl := 24 * time.Hour

	releases, err := SyncArtistDiscography(ctx, client, db, artistMBID, ttl)
	if err != nil {
		t.Fatalf("SyncArtistDiscography() error: %v", err)
	}

	if serverCalled {
		t.Error("expected cache hit but server was called (cache miss)")
	}

	if len(releases) != 1 {
		t.Fatalf("expected 1 cached release, got %d", len(releases))
	}

	if releases[0].RGID != "rg-cached" {
		t.Errorf("expected RGID 'rg-cached', got %q", releases[0].RGID)
	}
	if releases[0].Title != "Cached Album" {
		t.Errorf("expected Title 'Cached Album', got %q", releases[0].Title)
	}
}

// -----------------------------------------------------------------------
// Test: SyncArtistDiscography applies filtering (excluded statuses)
// -----------------------------------------------------------------------

func TestSyncArtistDiscography_FiltersExcludedStatuses(t *testing.T) {
	artistMBID := "cccccccc-dddd-eeee-ffff-000000000000"

	server := newTestMBServer(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/xml")
		// Include a Bootleg and a Promotion that should be filtered out.
		resp := mbReleaseGroupListResponse(
			mbReleaseGroupXML("rg-legit", "Legit Album", "Album", "", artistMBID, "Artist", "2020-01-01")+
				mbReleaseGroupXML("rg-bootleg", "Bootleg Album", "Album", "Bootleg", artistMBID, "Artist", "2020-02-01")+
				mbReleaseGroupXML("rg-promo", "Promo Album", "Album", "Promotion", artistMBID, "Artist", "2020-03-01")+
				mbReleaseGroupXML("rg-pseudo", "Pseudo Album", "Album", "Pseudo-Release", artistMBID, "Artist", "2020-04-01"),
			4,
		)
		w.Write([]byte(resp))
	})
	defer server.Close()

	db := newTestDB(t)
	defer db.Close()
	seedArtist(t, db, artistMBID, "Filter Artist")

	client := newTestClient(server.URL)
	ctx := context.Background()
	ttl := 24 * time.Hour

	releases, err := SyncArtistDiscography(ctx, client, db, artistMBID, ttl)
	if err != nil {
		t.Fatalf("SyncArtistDiscography() error: %v", err)
	}

	// Only the legit album should remain after filtering.
	if len(releases) != 1 {
		t.Fatalf("expected 1 release after filtering, got %d", len(releases))
	}
	if releases[0].RGID != "rg-legit" {
		t.Errorf("expected RGID 'rg-legit', got %q", releases[0].RGID)
	}
}

// -----------------------------------------------------------------------
// Test: SyncArtistDiscography applies type filtering
// -----------------------------------------------------------------------

func TestSyncArtistDiscography_FiltersExcludedTypes(t *testing.T) {
	artistMBID := "dddddddd-eeee-ffff-0000-111111111111"

	server := newTestMBServer(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/xml")
		resp := mbReleaseGroupListResponse(
			mbReleaseGroupXML("rg-album", "An Album", "Album", "", artistMBID, "Artist", "2020-01-01")+
				mbReleaseGroupXML("rg-single", "A Single", "Single", "", artistMBID, "Artist", "2020-02-01")+
				mbReleaseGroupXML("rg-ep", "An EP", "EP", "", artistMBID, "Artist", "2020-03-01")+
				mbReleaseGroupXML("rg-comp", "A Compilation", "Compilation", "", artistMBID, "Artist", "2020-04-01")+
				mbReleaseGroupXML("rg-soundtrack", "A Soundtrack", "Soundtrack", "", artistMBID, "Artist", "2020-05-01"),
			5,
		)
		w.Write([]byte(resp))
	})
	defer server.Close()

	db := newTestDB(t)
	defer db.Close()
	seedArtist(t, db, artistMBID, "Type Filter Artist")

	client := newTestClient(server.URL)
	ctx := context.Background()
	ttl := 24 * time.Hour

	releases, err := SyncArtistDiscography(ctx, client, db, artistMBID, ttl)
	if err != nil {
		t.Fatalf("SyncArtistDiscography() error: %v", err)
	}

	// Soundtrack should be excluded (not in includedTypes).
	if len(releases) != 4 {
		t.Fatalf("expected 4 releases after type filtering, got %d", len(releases))
	}

	rgIDs := make(map[string]bool)
	for _, r := range releases {
		rgIDs[r.RGID] = true
	}
	if rgIDs["rg-soundtrack"] {
		t.Error("Soundtrack type should have been filtered out")
	}
}

// -----------------------------------------------------------------------
// Test: SyncArtistDiscography with context cancellation
// -----------------------------------------------------------------------

func TestSyncArtistDiscography_ContextCancellation(t *testing.T) {
	artistMBID := "eeeeeeee-ffff-0000-1111-222222222222"

	server := newTestMBServer(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/xml")
		resp := mbReleaseGroupListResponse(
			mbReleaseGroupXML("rg1", "Album One", "Album", "", artistMBID, "Artist", "2020-01-01"),
			1,
		)
		w.Write([]byte(resp))
	})
	defer server.Close()

	db := newTestDB(t)
	defer db.Close()
	seedArtist(t, db, artistMBID, "Cancel Artist")

	client := newTestClient(server.URL)
	ttl := 24 * time.Hour

	// Create a context that is already cancelled.
	ctx, cancel := context.WithCancel(context.Background())
	cancel()

	_, err := SyncArtistDiscography(ctx, client, db, artistMBID, ttl)
	if err == nil {
		t.Fatal("SyncArtistDiscography() expected error for cancelled context, got nil")
	}
}

// -----------------------------------------------------------------------
// Test: SyncArtistDiscography upsert is idempotent (re-sync replaces)
// -----------------------------------------------------------------------

func TestSyncArtistDiscography_IdempotentResync(t *testing.T) {
	artistMBID := "ffffffff-0000-1111-2222-333333333333"

	callCount := 0
	server := newTestMBServer(func(w http.ResponseWriter, r *http.Request) {
		callCount++
		w.Header().Set("Content-Type", "application/xml")
		resp := mbReleaseGroupListResponse(
			mbReleaseGroupXML("rg1", "Album One", "Album", "", artistMBID, "Artist", "2020-01-01")+
				mbReleaseGroupXML("rg2", "Album Two", "Album", "", artistMBID, "Artist", "2021-01-01"),
			2,
		)
		w.Write([]byte(resp))
	})
	defer server.Close()

	db := newTestDB(t)
	defer db.Close()
	seedArtist(t, db, artistMBID, "Idempotent Artist")

	client := newTestClient(server.URL)
	ctx := context.Background()

	// First sync.
	releases1, err := SyncArtistDiscography(ctx, client, db, artistMBID, 24*time.Hour)
	if err != nil {
		t.Fatalf("first SyncArtistDiscography() error: %v", err)
	}
	if len(releases1) != 2 {
		t.Fatalf("expected 2 releases after first sync, got %d", len(releases1))
	}
	if callCount != 1 {
		t.Fatalf("expected 1 server call after first sync, got %d", callCount)
	}

	// Force cache expiry by setting cached_at to the past.
	_, err = db.Conn().Exec("UPDATE external_releases SET cached_at = ? WHERE artist_id = ?",
		time.Now().Add(-48*time.Hour).Format("2006-01-02 15:04:05"), artistMBID)
	if err != nil {
		t.Fatalf("expire cache: %v", err)
	}

	// Second sync should re-fetch from API (cache expired).
	releases2, err := SyncArtistDiscography(ctx, client, db, artistMBID, 24*time.Hour)
	if err != nil {
		t.Fatalf("second SyncArtistDiscography() error: %v", err)
	}
	if len(releases2) != 2 {
		t.Fatalf("expected 2 releases after second sync, got %d", len(releases2))
	}
	if callCount != 2 {
		t.Fatalf("expected 2 server calls after forced re-sync, got %d", callCount)
	}

	// Verify no duplicates in the database (transactional delete + insert).
	stored, err := database.GetExternalReleasesByArtist(db, artistMBID)
	if err != nil {
		t.Fatalf("GetExternalReleasesByArtist() error: %v", err)
	}
	if len(stored) != 2 {
		t.Errorf("expected 2 stored releases (no duplicates), got %d", len(stored))
	}
}

// -----------------------------------------------------------------------
// Test: SyncArtistDiscography with empty response (no release groups)
// -----------------------------------------------------------------------

func TestSyncArtistDiscography_EmptyResponse(t *testing.T) {
	artistMBID := "33333333-4444-5555-6666-777777777777"

	server := newTestMBServer(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/xml")
		w.Write([]byte(mbReleaseGroupListResponse("", 0)))
	})
	defer server.Close()

	db := newTestDB(t)
	defer db.Close()
	seedArtist(t, db, artistMBID, "Empty Artist")

	client := newTestClient(server.URL)
	ctx := context.Background()
	ttl := 24 * time.Hour

	releases, err := SyncArtistDiscography(ctx, client, db, artistMBID, ttl)
	if err != nil {
		t.Fatalf("SyncArtistDiscography() error: %v", err)
	}

	if len(releases) != 0 {
		t.Fatalf("expected 0 releases for empty response, got %d", len(releases))
	}

	// Verify nothing in DB.
	stored, err := database.GetExternalReleasesByArtist(db, artistMBID)
	if err != nil {
		t.Fatalf("GetExternalReleasesByArtist() error: %v", err)
	}
	if len(stored) != 0 {
		t.Errorf("expected 0 stored releases, got %d", len(stored))
	}
}

// -----------------------------------------------------------------------
// Test: SyncArtistDiscography API error propagation
// -----------------------------------------------------------------------

func TestSyncArtistDiscography_APIError(t *testing.T) {
	artistMBID := "44444444-5555-6666-7777-888888888888"

	server := newTestMBServer(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusInternalServerError)
		w.Write([]byte("internal server error"))
	})
	defer server.Close()

	db := newTestDB(t)
	defer db.Close()
	seedArtist(t, db, artistMBID, "Error Artist")

	client := newTestClient(server.URL)
	ctx := context.Background()
	ttl := 24 * time.Hour

	_, err := SyncArtistDiscography(ctx, client, db, artistMBID, ttl)
	if err == nil {
		t.Fatal("SyncArtistDiscography() expected error for API failure, got nil")
	}
}

// -----------------------------------------------------------------------
// Test: Verify XML parsing integration — full pipeline with realistic XML
// -----------------------------------------------------------------------

func TestSyncArtistDiscography_FullXMLPipeline(t *testing.T) {
	artistMBID := "66666666-7777-8888-9999-000000000000"

	xmlBody := `<?xml version="1.0" encoding="UTF-8"?>
<metadata>
  <release-group-list count="2">
    <release-group id="rg-real-1" type="Album">
      <title>Real Album One</title>
      <artist-credit>
        <name-credit>
          <artist id="` + artistMBID + `">
            <name>Real Artist</name>
          </artist>
        </name-credit>
      </artist-credit>
      <first-release-date>2019-03-15</first-release-date>
    </release-group>
    <release-group id="rg-real-2" type="Single">
      <title>Real Single Two</title>
      <artist-credit>
        <name-credit>
          <artist id="` + artistMBID + `">
            <name>Real Artist</name>
          </artist>
        </name-credit>
      </artist-credit>
      <first-release-date>2020-07-20</first-release-date>
    </release-group>
  </release-group-list>
</metadata>`

	server := newTestMBServer(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/xml")
		w.Write([]byte(xmlBody))
	})
	defer server.Close()

	db := newTestDB(t)
	defer db.Close()
	seedArtist(t, db, artistMBID, "Real Artist")

	client := newTestClient(server.URL)
	ctx := context.Background()
	ttl := 24 * time.Hour

	releases, err := SyncArtistDiscography(ctx, client, db, artistMBID, ttl)
	if err != nil {
		t.Fatalf("SyncArtistDiscography() error: %v", err)
	}

	if len(releases) != 2 {
		t.Fatalf("expected 2 releases, got %d", len(releases))
	}

	byID := make(map[string]database.ExternalRelease)
	for _, r := range releases {
		byID[r.RGID] = r
	}

	rg1, ok := byID["rg-real-1"]
	if !ok {
		t.Fatal("expected rg-real-1 in results")
	}
	if rg1.Title != "Real Album One" {
		t.Errorf("rg-real-1 title = %q, want %q", rg1.Title, "Real Album One")
	}
	if rg1.Type != "Album" {
		t.Errorf("rg-real-1 type = %q, want %q", rg1.Type, "Album")
	}
	if rg1.ReleaseDate != "2019-03-15" {
		t.Errorf("rg-real-1 release_date = %q, want %q", rg1.ReleaseDate, "2019-03-15")
	}

	rg2, ok := byID["rg-real-2"]
	if !ok {
		t.Fatal("expected rg-real-2 in results")
	}
	if rg2.Type != "Single" {
		t.Errorf("rg-real-2 type = %q, want %q", rg2.Type, "Single")
	}
}

// -----------------------------------------------------------------------
// Test: Verify CachedAt timestamps are consistent across a sync batch
// -----------------------------------------------------------------------

func TestSyncArtistDiscography_ConsistentCachedAtTimestamp(t *testing.T) {
	artistMBID := "77777777-8888-9999-0000-111111111111"

	server := newTestMBServer(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/xml")
		resp := mbReleaseGroupListResponse(
			mbReleaseGroupXML("rg-ts-1", "Album A", "Album", "", artistMBID, "Artist", "2020-01-01")+
				mbReleaseGroupXML("rg-ts-2", "Album B", "Album", "", artistMBID, "Artist", "2021-01-01")+
				mbReleaseGroupXML("rg-ts-3", "Album C", "Album", "", artistMBID, "Artist", "2022-01-01"),
			3,
		)
		w.Write([]byte(resp))
	})
	defer server.Close()

	db := newTestDB(t)
	defer db.Close()
	seedArtist(t, db, artistMBID, "Timestamp Artist")

	client := newTestClient(server.URL)
	ctx := context.Background()
	ttl := 24 * time.Hour

	releases, err := SyncArtistDiscography(ctx, client, db, artistMBID, ttl)
	if err != nil {
		t.Fatalf("SyncArtistDiscography() error: %v", err)
	}

	// All releases in a batch should have the same CachedAt timestamp.
	if len(releases) != 3 {
		t.Fatalf("expected 3 releases, got %d", len(releases))
	}

	first := releases[0].CachedAt
	for _, r := range releases[1:] {
		if !r.CachedAt.Equal(first) {
			t.Errorf("CachedAt mismatch: %v vs %v for release %s", first, r.CachedAt, r.RGID)
		}
	}
}

// -----------------------------------------------------------------------
// Test: Verify XML edge case — release-group with no type attribute
// -----------------------------------------------------------------------

func TestSyncArtistDiscography_XMLNoTypeAttribute(t *testing.T) {
	artistMBID := "88888888-9999-0000-1111-222222222222"

	xmlBody := `<?xml version="1.0" encoding="UTF-8"?>
<metadata>
  <release-group-list count="2">
    <release-group id="rg-notype" type="">
      <title>No Type Album</title>
      <artist-credit>
        <name-credit>
          <artist id="` + artistMBID + `">
            <name>Artist</name>
          </artist>
        </name-credit>
      </artist-credit>
      <first-release-date>2020-01-01</first-release-date>
    </release-group>
    <release-group id="rg-withtype" type="Album">
      <title>Typed Album</title>
      <artist-credit>
        <name-credit>
          <artist id="` + artistMBID + `">
            <name>Artist</name>
          </artist>
        </name-credit>
      </artist-credit>
      <first-release-date>2021-01-01</first-release-date>
    </release-group>
  </release-group-list>
</metadata>`

	server := newTestMBServer(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/xml")
		w.Write([]byte(xmlBody))
	})
	defer server.Close()

	db := newTestDB(t)
	defer db.Close()
	seedArtist(t, db, artistMBID, "No Type Artist")

	client := newTestClient(server.URL)
	ctx := context.Background()
	ttl := 24 * time.Hour

	releases, err := SyncArtistDiscography(ctx, client, db, artistMBID, ttl)
	if err != nil {
		t.Fatalf("SyncArtistDiscography() error: %v", err)
	}

	// The release-group with no type should be filtered out (empty string is not in includedTypes).
	if len(releases) != 1 {
		t.Fatalf("expected 1 release (empty type filtered), got %d", len(releases))
	}
	if releases[0].RGID != "rg-withtype" {
		t.Errorf("expected rg-withtype, got %s", releases[0].RGID)
	}
}

// -----------------------------------------------------------------------
// Test: Stale releases are cleaned up on re-sync
// -----------------------------------------------------------------------

func TestSyncArtistDiscography_CleansStaleReleases(t *testing.T) {
	artistMBID := "99999999-0000-1111-2222-333333333333"

	callCount := 0
	server := newTestMBServer(func(w http.ResponseWriter, r *http.Request) {
		callCount++
		w.Header().Set("Content-Type", "application/xml")
		if callCount == 1 {
			// First call: return 3 releases.
			resp := mbReleaseGroupListResponse(
				mbReleaseGroupXML("rg-old-1", "Old Album 1", "Album", "", artistMBID, "Artist", "2018-01-01")+
					mbReleaseGroupXML("rg-old-2", "Old Album 2", "Album", "", artistMBID, "Artist", "2019-01-01")+
					mbReleaseGroupXML("rg-old-3", "Old Album 3", "Album", "", artistMBID, "Artist", "2020-01-01"),
				3,
			)
			w.Write([]byte(resp))
		} else {
			// Second call: return only 2 (one was removed).
			resp := mbReleaseGroupListResponse(
				mbReleaseGroupXML("rg-old-1", "Old Album 1", "Album", "", artistMBID, "Artist", "2018-01-01")+
					mbReleaseGroupXML("rg-old-2", "Old Album 2", "Album", "", artistMBID, "Artist", "2019-01-01"),
				2,
			)
			w.Write([]byte(resp))
		}
	})
	defer server.Close()

	db := newTestDB(t)
	defer db.Close()
	seedArtist(t, db, artistMBID, "Stale Artist")

	client := newTestClient(server.URL)
	ctx := context.Background()

	// First sync: 3 releases.
	releases1, err := SyncArtistDiscography(ctx, client, db, artistMBID, 24*time.Hour)
	if err != nil {
		t.Fatalf("first SyncArtistDiscography() error: %v", err)
	}
	if len(releases1) != 3 {
		t.Fatalf("expected 3 releases after first sync, got %d", len(releases1))
	}

	// Force cache expiry by setting cached_at to the past.
	_, err = db.Conn().Exec("UPDATE external_releases SET cached_at = ? WHERE artist_id = ?",
		time.Now().Add(-48*time.Hour).Format("2006-01-02 15:04:05"), artistMBID)
	if err != nil {
		t.Fatalf("expire cache: %v", err)
	}

	// Second sync should re-fetch from API (cache expired).
	releases2, err := SyncArtistDiscography(ctx, client, db, artistMBID, 24*time.Hour)
	if err != nil {
		t.Fatalf("second SyncArtistDiscography() error: %v", err)
	}
	if len(releases2) != 2 {
		t.Fatalf("expected 2 releases after second sync, got %d", len(releases2))
	}

	// Verify stale release was cleaned from DB.
	stored, err := database.GetExternalReleasesByArtist(db, artistMBID)
	if err != nil {
		t.Fatalf("GetExternalReleasesByArtist() error: %v", err)
	}
	if len(stored) != 2 {
		t.Errorf("expected 2 stored releases (stale cleaned), got %d", len(stored))
	}
	for _, r := range stored {
		if r.RGID == "rg-old-3" {
			t.Error("stale release rg-old-3 should have been removed")
		}
	}
}