package scanner

import (
	"context"
	"testing"

	"naviwatcher/internal/database"
)

// 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
}

// seedArtist inserts a minimal artist_settings row so FK 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)
	}
}

// seedLocalAlbum inserts a local_albums row for an artist.
func seedLocalAlbum(t *testing.T, db *database.DB, id, artistID, title string) {
	t.Helper()
	if err := database.SaveLocalAlbum(db, &database.LocalAlbum{
		ID:       id,
		ArtistID: artistID,
		Title:    title,
	}); err != nil {
		t.Fatalf("seedLocalAlbum(%s) error: %v", id, err)
	}
}

// seedExternalRelease inserts an external_releases row for an artist.
func seedExternalRelease(t *testing.T, db *database.DB, rgid, artistID, title string, ignored bool) {
	t.Helper()
	if err := database.SaveExternalRelease(db, &database.ExternalRelease{
		RGID:      rgid,
		ArtistID:  artistID,
		Title:     title,
		IsIgnored: ignored,
	}); err != nil {
		t.Fatalf("seedExternalRelease(%s) error: %v", rgid, err)
	}
}

func TestScanArtist(t *testing.T) {
	db := newTestDB(t)
	defer db.Close()

	seedArtist(t, db, "artist-1", "Pink Floyd")

	// Local collection has "The Wall" but not "Animals".
	seedLocalAlbum(t, db, "l1", "artist-1", "The Wall")
	seedExternalRelease(t, db, "rg1", "artist-1", "The Wall", false)
	seedExternalRelease(t, db, "rg2", "artist-1", "Animals", false)

	missing, err := ScanArtist(context.Background(), db, "artist-1", 0)
	if err != nil {
		t.Fatalf("ScanArtist() error: %v", err)
	}

	rgids := map[string]bool{}
	for _, m := range missing {
		rgids[m.RGID] = true
	}
	if !rgids["rg2"] {
		t.Errorf("expected rg2 (Animals) to be missing, got %v", rgids)
	}
	if rgids["rg1"] {
		t.Errorf("did not expect rg1 (The Wall) to be missing, got %v", rgids)
	}
}

func TestScanArtist_IgnoredNotReported(t *testing.T) {
	db := newTestDB(t)
	defer db.Close()

	seedArtist(t, db, "artist-1", "Pink Floyd")
	seedExternalRelease(t, db, "rg1", "artist-1", "Animals", true)

	missing, err := ScanArtist(context.Background(), db, "artist-1", 0.85)
	if err != nil {
		t.Fatalf("ScanArtist() error: %v", err)
	}
	if len(missing) != 0 {
		t.Errorf("ignored release should not be reported, got %v", missing)
	}
}

func TestScanArtist_RemasteredVariantNotMissing(t *testing.T) {
	db := newTestDB(t)
	defer db.Close()

	seedArtist(t, db, "artist-1", "Pink Floyd")
	seedLocalAlbum(t, db, "l1", "artist-1", "The Wall (Remastered)")
	seedExternalRelease(t, db, "rg1", "artist-1", "The Wall", false)

	missing, err := ScanArtist(context.Background(), db, "artist-1", 0)
	if err != nil {
		t.Fatalf("ScanArtist() error: %v", err)
	}
	if len(missing) != 0 {
		t.Errorf("remastered local should match external, got %v", missing)
	}
}

func TestScanArtist_CtxCancelled(t *testing.T) {
	db := newTestDB(t)
	defer db.Close()
	seedArtist(t, db, "artist-1", "Pink Floyd")

	ctx, cancel := context.WithCancel(context.Background())
	cancel()

	if _, err := ScanArtist(ctx, db, "artist-1", 0.85); err == nil {
		t.Fatal("expected error from cancelled context, got nil")
	}
}

func TestScanAll(t *testing.T) {
	db := newTestDB(t)
	defer db.Close()

	// Monitored artist with one missing release.
	seedArtist(t, db, "artist-1", "Pink Floyd")
	seedLocalAlbum(t, db, "l1", "artist-1", "The Wall")
	seedExternalRelease(t, db, "rg1", "artist-1", "The Wall", false)
	seedExternalRelease(t, db, "rg2", "artist-1", "Animals", false)

	// Unmonitored artist — must be skipped entirely.
	seedArtistUnmonitored(t, db, "artist-2", "Other")
	seedExternalRelease(t, db, "rg3", "artist-2", "Some Album", false)

	missing, err := ScanAll(context.Background(), db, 0)
	if err != nil {
		t.Fatalf("ScanAll() error: %v", err)
	}

	rgids := map[string]bool{}
	for _, m := range missing {
		rgids[m.RGID] = true
	}
	if !rgids["rg2"] {
		t.Errorf("expected rg2 (Animals) missing, got %v", rgids)
	}
	if rgids["rg1"] {
		t.Errorf("did not expect rg1 (The Wall) missing, got %v", rgids)
	}
	if rgids["rg3"] {
		t.Errorf("unmonitored artist's release must not be scanned, got %v", rgids)
	}
}

func TestScanAll_CtxCancelledMidIteration(t *testing.T) {
	db := newTestDB(t)
	defer db.Close()

	seedArtist(t, db, "artist-1", "Pink Floyd")
	seedArtist(t, db, "artist-2", "Other")

	// Cancel before scanning starts.
	ctx, cancel := context.WithCancel(context.Background())
	cancel()

	missing, err := ScanAll(ctx, db, 0.85)
	if err == nil {
		t.Fatal("expected error from cancelled context, got nil")
	}
	if missing != nil {
		t.Errorf("expected nil results on early cancellation, got %v", missing)
	}
}

// seedArtistUnmonitored inserts an artist_settings row with Monitored=false.
func seedArtistUnmonitored(t *testing.T, db *database.DB, id, name string) {
	t.Helper()
	if err := database.SaveArtistSettings(db, &database.ArtistSettings{
		ID:        id,
		Name:      name,
		Monitored: false,
	}); err != nil {
		t.Fatalf("seedArtistUnmonitored(%s) error: %v", id, err)
	}
}