//go:build integration

package playback

import (
	"context"
	"os"
	"sync"
	"testing"

	"github.com/google/uuid"
	"github.com/jackc/pgx/v5"
	"github.com/stretchr/testify/require"
	"pipu/api/internal/api/gen"
	"pipu/api/internal/auth"
	"pipu/api/internal/library"
	"pipu/api/internal/platform/apperr"
	"pipu/api/internal/platform/db"
)

func TestPlaylistPersistenceAndIsolation(t *testing.T) {
	url := os.Getenv("TEST_DATABASE_URL")
	if url == "" {
		t.Skip("TEST_DATABASE_URL is not set")
	}
	ctx := context.Background()
	pool, err := db.Connect(ctx, url)
	require.NoError(t, err)
	defer pool.Close()
	require.NoError(t, db.Migrate(ctx, pool))
	owner, other, artist, album, first, second, id := uuid.New(), uuid.New(), uuid.New(), uuid.New(), uuid.New(), uuid.New(), uuid.New()
	_, err = pool.Exec(ctx, `INSERT INTO users(id,username,password_hash,role) VALUES($1,$2,'x','user'),($3,$4,'x','user')`, owner, owner.String(), other, other.String())
	require.NoError(t, err)
	defer pool.Exec(ctx, `DELETE FROM users WHERE id=ANY($1)`, []uuid.UUID{owner, other})
	_, err = pool.Exec(ctx, `INSERT INTO artists(id,name,sort_name,name_norm) VALUES($1,'Artist','artist',$2)`, artist, artist.String())
	require.NoError(t, err)
	defer pool.Exec(ctx, `DELETE FROM artists WHERE id=$1`, artist)
	_, err = pool.Exec(ctx, `INSERT INTO albums(id,title,title_norm,album_artist_id) VALUES($1,'Album','album',$2)`, album, artist)
	require.NoError(t, err)
	defer pool.Exec(ctx, `DELETE FROM albums WHERE id=$1`, album)
	_, err = pool.Exec(ctx, `INSERT INTO tracks(id,title,title_norm,album_id,duration_ms) VALUES($1,'First','first',$3,1000),($2,'Second','second',$3,2000)`, first, second, album)
	require.NoError(t, err)
	defer pool.Exec(ctx, `DELETE FROM tracks WHERE id=ANY($1)`, []uuid.UUID{first, second})
	st := NewStore(pool)
	h := &Handler{store: st, catalog: library.NewStore(pool), dto: library.DTO{}}
	require.NoError(t, st.savePlaylist(ctx, owner, id, " Mix ", "Description", []uuid.UUID{first, second}, 0, true))
	got, err := h.playlist(ctx, owner, id)
	require.NoError(t, err)
	require.Equal(t, "Mix", got.Name)
	require.Equal(t, int64(3000), got.DurationMs)
	require.Equal(t, first, got.Tracks[0].Id)
	_, err = h.playlist(ctx, other, id)
	require.ErrorIs(t, err, apperr.NotFound("playlist.not_found", ""))
	require.ErrorIs(t, st.savePlaylist(ctx, other, id, "stolen", "", nil, 1, false), apperr.NotFound("playlist.not_found", ""))
	_, err = h.DeletePlaylist(auth.WithPrincipal(ctx, auth.Principal{UserID: other}), gen.DeletePlaylistRequestObject{Id: id})
	require.ErrorIs(t, err, apperr.NotFound("playlist.not_found", ""))
	require.NoError(t, st.savePlaylist(ctx, owner, id, "Mix", "", []uuid.UUID{second, first}, 1, false))
	require.ErrorIs(t, st.savePlaylist(ctx, owner, id, "stale", "", nil, 1, false), apperr.Conflict("playlist.conflict", ""))
	// A missing track rolls back both metadata and membership.
	require.Error(t, st.savePlaylist(ctx, owner, id, "broken", "", []uuid.UUID{uuid.New()}, 2, false))
	got, err = h.playlist(ctx, owner, id)
	require.NoError(t, err)
	require.Equal(t, 2, got.Revision)
	require.Equal(t, "Mix", got.Name)
	require.Equal(t, second, got.Tracks[0].Id)
	// Exactly one concurrent write may consume a revision.
	results := make(chan error, 2)
	var wg sync.WaitGroup
	for range 2 {
		wg.Add(1)
		go func() {
			defer wg.Done()
			results <- st.savePlaylist(ctx, owner, id, "Updated", "", []uuid.UUID{first}, 2, false)
		}()
	}
	wg.Wait()
	close(results)
	successes := 0
	for e := range results {
		if e == nil {
			successes++
		} else {
			require.ErrorIs(t, e, apperr.Conflict("playlist.conflict", ""))
		}
	}
	require.Equal(t, 1, successes)
	_, err = h.DeletePlaylist(auth.WithPrincipal(ctx, auth.Principal{UserID: owner}), gen.DeletePlaylistRequestObject{Id: id})
	require.NoError(t, err)
	var remaining int
	require.NoError(t, pool.QueryRow(ctx, `SELECT count(*) FROM playlist_tracks WHERE playlist_id=$1`, id).Scan(&remaining))
	require.Zero(t, remaining)
	// Deleting a playlist never deletes catalog tracks.
	require.NoError(t, pool.QueryRow(ctx, `SELECT count(*) FROM tracks WHERE id=ANY($1)`, []uuid.UUID{first, second}).Scan(&remaining))
	require.Equal(t, 2, remaining)
	rows, err := pool.Query(ctx, `SELECT id FROM playlists WHERE id=$1`, id)
	require.NoError(t, err)
	ids, err := pgx.CollectRows(rows, pgx.RowTo[uuid.UUID])
	require.NoError(t, err)
	require.Empty(t, ids)
}