Musify/backend/Tests/Musify.Application.Tests/Albums/GetAlbumsQueryHandlerTests.cs

using Musify.Application.Albums;
using Musify.Application.Tests.TestSupport;
using Xunit;

namespace Musify.Application.Tests.Albums
{
    public sealed class GetAlbumsQueryHandlerTests : HandlerTestBase
    {
        private GetAlbumsQueryHandler CreateHandler() => new(Database);

        [Fact]
        public async Task Handle_NoTitleFilter_ReturnsAllAlbumsPaged()
        {
            var owner = TestEntities.User();
            await SeedAsync(owner, TestEntities.Album(owner.Id, "Alpha"), TestEntities.Album(owner.Id, "Beta"));

            var result = await CreateHandler().Handle(new GetAlbumsQuery(Title: null, PageNumber: 1, PageSize: 10), TestContext.Current.CancellationToken);
            Assert.Equal(2, result.TotalItemCount);
            Assert.All(result.Items, item => Assert.NotNull(item));
        }

        [Fact]
        public async Task Handle_TitleFilter_ReturnsMatchingAlbumsOnly()
        {
            var owner = TestEntities.User();
            await SeedAsync(owner, TestEntities.Album(owner.Id, "Rock Classics"), TestEntities.Album(owner.Id, "Jazz Favorites"));

            var result = await CreateHandler().Handle(new GetAlbumsQuery(Title: "rock", PageNumber: 1, PageSize: 10), TestContext.Current.CancellationToken);
            var item = Assert.Single(result.Items);
            Assert.Equal("Rock Classics", item.Title);
        }

        [Fact]
        public async Task Handle_PageSizeSmallerThanTotal_ReportsHasNextPage()
        {
            var owner = TestEntities.User();
            await SeedAsync(owner, TestEntities.Album(owner.Id, "One"), TestEntities.Album(owner.Id, "Two"), TestEntities.Album(owner.Id, "Three"));

            var result = await CreateHandler().Handle(new GetAlbumsQuery(Title: null, PageNumber: 1, PageSize: 2), TestContext.Current.CancellationToken);
            Assert.Equal(2, result.Items.Count);
            Assert.True(result.HasNextPage);
        }
    }
}