// ==========================================================================
//  Squidex Headless CMS
// ==========================================================================
//  Copyright (c) Squidex UG (haftungsbeschraenkt)
//  All rights reserved. Licensed under the MIT license.
// ==========================================================================

using FakeItEasy;
using Squidex.Domain.Apps.Entities.Contents.DomainObject;
using Squidex.Infrastructure;
using Squidex.Infrastructure.Commands;
using Xunit;

namespace Squidex.Domain.Apps.Entities.Contents.Queries
{
    public class ContentLoaderTests
    {
        private readonly CancellationTokenSource cts = new CancellationTokenSource();
        private readonly CancellationToken ct;
        private readonly IDomainObjectFactory domainObjectFactory = A.Fake<IDomainObjectFactory>();
        private readonly IDomainObjectCache domainObjectCache = A.Fake<IDomainObjectCache>();
        private readonly ContentDomainObject domainObject = A.Fake<ContentDomainObject>();
        private readonly DomainId appId = DomainId.NewGuid();
        private readonly DomainId id = DomainId.NewGuid();
        private readonly DomainId unqiueId;
        private readonly ContentLoader sut;

        public ContentLoaderTests()
        {
            ct = cts.Token;

            unqiueId = DomainId.Combine(appId, id);

            A.CallTo(() => domainObjectCache.GetAsync<ContentDomainObject.State>(A<DomainId>._, A<long>._, ct))
                .Returns(Task.FromResult<ContentDomainObject.State>(null!));

            A.CallTo(() => domainObjectFactory.Create<ContentDomainObject>(unqiueId))
                .Returns(domainObject);

            sut = new ContentLoader(domainObjectFactory, domainObjectCache);
        }

        [Fact]
        public async Task Should_return_null_if_no_state_returned()
        {
            var content = (ContentDomainObject.State)null!;

            A.CallTo(() => domainObject.GetSnapshotAsync(10, ct))
                .Returns(content);

            Assert.Null(await sut.GetAsync(appId, id, 10, ct));
        }

        [Fact]
        public async Task Should_return_null_if_state_empty()
        {
            var content = new ContentDomainObject.State { Version = EtagVersion.Empty };

            A.CallTo(() => domainObject.GetSnapshotAsync(10, ct))
                .Returns(content);

            Assert.Null(await sut.GetAsync(appId, id, 10, ct));
        }

        [Fact]
        public async Task Should_return_null_if_state_has_other_version()
        {
            var content = new ContentDomainObject.State { Version = 5 };

            A.CallTo(() => domainObject.GetSnapshotAsync(10, ct))
                .Returns(content);

            Assert.Null(await sut.GetAsync(appId, id, 10, ct));
        }

        [Fact]
        public async Task Should_not_return_null_if_state_has_other_version_than_any()
        {
            var content = new ContentDomainObject.State { Version = 5 };

            A.CallTo(() => domainObject.GetSnapshotAsync(EtagVersion.Any, ct))
                .Returns(content);

            var result = await sut.GetAsync(appId, id, EtagVersion.Any, ct);

            Assert.Same(content, result);
        }

        [Fact]
        public async Task Should_return_content_from_state()
        {
            var content = new ContentDomainObject.State { Version = 10 };

            A.CallTo(() => domainObject.GetSnapshotAsync(10, ct))
                .Returns(content);

            var result = await sut.GetAsync(appId, id, 10, ct);

            Assert.Same(content, result);
        }

        [Fact]
        public async Task Should_return_content_from_cache()
        {
            var content = new ContentDomainObject.State { Version = 10 };

            A.CallTo(() => domainObjectCache.GetAsync<ContentDomainObject.State>(DomainId.Combine(appId, id), 10, ct))
                .Returns(content);

            var result = await sut.GetAsync(appId, id, 10, ct);

            Assert.Same(content, result);

            A.CallTo(() => domainObjectFactory.Create<ContentDomainObject>(unqiueId))
                .MustNotHaveHappened();
        }
    }
}