package playback

import (
	"context"
	"errors"
	"testing"
	"time"

	"github.com/google/uuid"
	"github.com/stretchr/testify/require"

	"pipu/api/internal/api/gen"
	"pipu/api/internal/auth"
	"pipu/api/internal/library"
	"pipu/api/internal/platform/sign"
)

type reactionReaderFunc func(context.Context, uuid.UUID, []uuid.UUID) (map[uuid.UUID]string, error)

func (f reactionReaderFunc) Reactions(ctx context.Context, user uuid.UUID, ids []uuid.UUID) (map[uuid.UUID]string, error) {
	return f(ctx, user, ids)
}

func TestPersonalizerBatch(t *testing.T) {
	user, first, second := uuid.New(), uuid.New(), uuid.New()
	calls := 0
	reader := reactionReaderFunc(func(_ context.Context, got uuid.UUID, ids []uuid.UUID) (map[uuid.UUID]string, error) {
		calls++
		require.Equal(t, user, got)
		require.Equal(t, []uuid.UUID{first, second}, ids)
		return map[uuid.UUID]string{second: "dislike"}, nil
	})
	signer, err := sign.New("")
	require.NoError(t, err)
	p := NewPersonalizer(reader, signer)
	now := time.Now().UTC()
	p.now = func() time.Time { return now }
	rows := []library.TrackRow{{ID: first}, {ID: second}}
	out := []gen.Track{{Available: true}, {Available: false}}
	require.NoError(t, p.Personalize(context.Background(), rows, out))
	require.Zero(t, calls, "anonymous catalog does not query personal data")
	ctx := auth.WithPrincipal(context.Background(), auth.Principal{UserID: user})
	require.NoError(t, p.Personalize(ctx, rows, out))
	require.Equal(t, 1, calls, "one reaction query for the entire batch")
	require.Equal(t, StreamURL(signer, user, first, now), *out[0].StreamUrl)
	require.Nil(t, out[1].StreamUrl, "unavailable tracks must not receive stream links")
	require.Equal(t, gen.Reaction("dislike"), *out[1].Reaction)
}

func TestPersonalizerReadFailure(t *testing.T) {
	failure := errors.New("database unavailable")
	p := NewPersonalizer(reactionReaderFunc(func(context.Context, uuid.UUID, []uuid.UUID) (map[uuid.UUID]string, error) { return nil, failure }), nil)
	ctx := auth.WithPrincipal(context.Background(), auth.Principal{UserID: uuid.New()})
	require.ErrorIs(t, p.Personalize(ctx, nil, nil), failure)
}