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

using FakeItEasy;
using Microsoft.Extensions.Caching.Memory;
using Microsoft.Extensions.Options;
using Squidex.Caching;
using Squidex.Domain.Apps.Core.TestHelpers;
using Squidex.Domain.Apps.Entities.Apps.Commands;
using Squidex.Domain.Apps.Entities.Apps.Repositories;
using Squidex.Infrastructure;
using Squidex.Infrastructure.Commands;
using Squidex.Infrastructure.Security;
using Squidex.Infrastructure.States;
using Squidex.Infrastructure.TestHelpers;
using Squidex.Infrastructure.Validation;
using Squidex.Messaging;
using Xunit;

namespace Squidex.Domain.Apps.Entities.Apps.Indexes
{
    public class AppsIndexTests
    {
        private readonly CancellationTokenSource cts = new CancellationTokenSource();
        private readonly CancellationToken ct;
        private readonly TestState<NameReservationState.State> state;
        private readonly IAppRepository appRepository = A.Fake<IAppRepository>();
        private readonly ICommandBus commandBus = A.Fake<ICommandBus>();
        private readonly NamedId<DomainId> appId = NamedId.Of(DomainId.NewGuid(), "my-app");
        private readonly string userId = "user1";
        private readonly AppsIndex sut;

        public AppsIndexTests()
        {
            state = new TestState<NameReservationState.State>("Apps");

            ct = cts.Token;

            var replicatedCache =
                new ReplicatedCache(new MemoryCache(Options.Create(new MemoryCacheOptions())), A.Fake<IMessageBus>(),
                    Options.Create(new ReplicatedCacheOptions { Enable = true }));

            sut = new AppsIndex(appRepository, replicatedCache, state.PersistenceFactory);
        }

        [Fact]
        public async Task Should_resolve_app_by_name()
        {
            var expected = CreateApp();

            A.CallTo(() => appRepository.FindAsync(appId.Name, ct))
                .Returns(expected);

            var actual1 = await sut.GetAppAsync(appId.Name, false, ct);
            var actual2 = await sut.GetAppAsync(appId.Name, false, ct);

            Assert.Same(expected, actual1);
            Assert.Same(expected, actual2);

            A.CallTo(() => appRepository.FindAsync(appId.Name, ct))
                .MustHaveHappenedTwiceExactly();
        }

        [Fact]
        public async Task Should_resolve_app_by_name_and_id_if_cached_before()
        {
            var expected = CreateApp();

            A.CallTo(() => appRepository.FindAsync(appId.Name, ct))
                .Returns(expected);

            var actual1 = await sut.GetAppAsync(appId.Name, true, ct);
            var actual2 = await sut.GetAppAsync(appId.Name, true, ct);
            var actual3 = await sut.GetAppAsync(appId.Id, true, ct);

            Assert.Same(expected, actual1);
            Assert.Same(expected, actual2);
            Assert.Same(expected, actual3);

            A.CallTo(() => appRepository.FindAsync(appId.Name, ct))
                .MustHaveHappenedOnceExactly();
        }

        [Fact]
        public async Task Should_resolve_app_by_id()
        {
            var expected = CreateApp();

            A.CallTo(() => appRepository.FindAsync(appId.Id, ct))
                .Returns(expected);

            var actual1 = await sut.GetAppAsync(appId.Id, false, ct);
            var actual2 = await sut.GetAppAsync(appId.Id, false, ct);

            Assert.Same(expected, actual1);
            Assert.Same(expected, actual2);

            A.CallTo(() => appRepository.FindAsync(appId.Id, ct))
                .MustHaveHappenedTwiceExactly();
        }

        [Fact]
        public async Task Should_resolve_app_by_id_and_name_if_cached_before()
        {
            var expected = CreateApp();

            A.CallTo(() => appRepository.FindAsync(appId.Id, ct))
                .Returns(expected);

            var actual1 = await sut.GetAppAsync(appId.Id, true, ct);
            var actual2 = await sut.GetAppAsync(appId.Id, true, ct);
            var actual3 = await sut.GetAppAsync(appId.Name, true, ct);

            Assert.Same(expected, actual1);
            Assert.Same(expected, actual2);
            Assert.Same(expected, actual3);

            A.CallTo(() => appRepository.FindAsync(appId.Id, ct))
                .MustHaveHappenedOnceExactly();
        }

        [Fact]
        public async Task Should_resolve_all_apps_from_user_permissions()
        {
            var expected = CreateApp();

            A.CallTo(() => appRepository.QueryAllAsync(userId, A<IEnumerable<string>>.That.Is(appId.Name), ct))
                .Returns(new List<IAppEntity> { expected });

            var actual = await sut.GetAppsForUserAsync(userId, new PermissionSet($"squidex.apps.{appId.Name}"), ct);

            Assert.Same(expected, actual[0]);
        }

        [Fact]
        public async Task Should_resolve_all_apps_from_user()
        {
            var expected = CreateApp();

            A.CallTo(() => appRepository.QueryAllAsync(userId, A<IEnumerable<string>>.That.IsEmpty(), ct))
                .Returns(new List<IAppEntity> { expected });

            var actual = await sut.GetAppsForUserAsync(userId, PermissionSet.Empty, ct);

            Assert.Same(expected, actual[0]);
        }

        [Fact]
        public async Task Should_return_empty_apps_if_app_not_created()
        {
            var expected = CreateApp(EtagVersion.Empty);

            A.CallTo(() => appRepository.QueryAllAsync(userId, A<IEnumerable<string>>.That.IsEmpty(), ct))
                .Returns(new List<IAppEntity> { expected });

            var actual = await sut.GetAppsForUserAsync(userId, PermissionSet.Empty, ct);

            Assert.Empty(actual);
        }

        [Fact]
        public async Task Should_return_empty_apps_if_app_deleted()
        {
            var expected = CreateApp(0, true);

            A.CallTo(() => appRepository.QueryAllAsync(userId, A<IEnumerable<string>>.That.IsEmpty(), ct))
                .Returns(new List<IAppEntity> { expected });

            var actual = await sut.GetAppsForUserAsync(userId, PermissionSet.Empty, ct);

            Assert.Empty(actual);
        }

        [Fact]
        public async Task Should_take_and_remove_reservation_if_created()
        {
            A.CallTo(() => appRepository.FindAsync(appId.Name, ct))
                .Returns(Task.FromResult<IAppEntity?>(null));

            var command = Create(appId.Name);

            var context =
                new CommandContext(command, commandBus)
                    .Complete();

            NameReservation? madeReservation = null;

            await sut.HandleAsync(context, (c, ct) =>
            {
                madeReservation = state.Snapshot.Reservations.FirstOrDefault();

                return Task.CompletedTask;
            }, ct);

            Assert.Empty(state.Snapshot.Reservations);

            Assert.Equal(appId.Id, madeReservation?.Id);
            Assert.Equal(appId.Name, madeReservation?.Name);
        }

        [Fact]
        public async Task Should_clear_reservation_if_app_creation_failed()
        {
            A.CallTo(() => appRepository.FindAsync(appId.Name, ct))
                .Returns(Task.FromResult<IAppEntity?>(null));

            var command = Create(appId.Name);

            var context =
                new CommandContext(command, commandBus)
                    .Complete();

            NameReservation? madeReservation = null;

            await Assert.ThrowsAnyAsync<Exception>(() => sut.HandleAsync(context, (c, ct) =>
            {
                madeReservation = state.Snapshot.Reservations.FirstOrDefault();

                throw new InvalidOperationException();
            }, ct));

            Assert.Empty(state.Snapshot.Reservations);

            Assert.Equal(appId.Id, madeReservation?.Id);
            Assert.Equal(appId.Name, madeReservation?.Name);
        }

        [Fact]
        public async Task Should_not_create_app_if_name_is_reserved()
        {
            state.Snapshot.Reservations.Add(new NameReservation(RandomHash.Simple(), appId.Name, DomainId.NewGuid()));

            A.CallTo(() => appRepository.FindAsync(appId.Name, ct))
                .Returns(Task.FromResult<IAppEntity?>(null));

            var command = Create(appId.Name);

            var context =
                new CommandContext(command, commandBus)
                    .Complete();

            await Assert.ThrowsAsync<ValidationException>(() => sut.HandleAsync(context, ct));
        }

        [Fact]
        public async Task Should_not_create_app_if_name_is_taken()
        {
            A.CallTo(() => appRepository.FindAsync(appId.Name, ct))
                .Returns(CreateApp());

            var command = Create(appId.Name);

            var context =
                new CommandContext(command, commandBus)
                    .Complete();

            await Assert.ThrowsAsync<ValidationException>(() => sut.HandleAsync(context, ct));

            A.CallTo(() => state.Persistence.WriteSnapshotAsync(A<NameReservationState.State>._, A<CancellationToken>._))
                .MustNotHaveHappened();
        }

        [Fact]
        public async Task Should_not_make_an_update_for_other_command()
        {
            var app = CreateApp();

            var command = new UpdateApp { AppId = appId };

            var context =
                new CommandContext(command, commandBus)
                    .Complete(app);

            await sut.HandleAsync(context, ct);

            A.CallTo(() => state.Persistence.WriteSnapshotAsync(A<NameReservationState.State>._, A<CancellationToken>._))
                .MustNotHaveHappened();
        }

        private CreateApp Create(string name)
        {
            return new CreateApp { AppId = appId.Id, Name = name };
        }

        private IAppEntity CreateApp(long version = 0, bool isDeleted = false)
        {
            var app = A.Fake<IAppEntity>();

            A.CallTo(() => app.Id).Returns(appId.Id);
            A.CallTo(() => app.Name).Returns(appId.Name);
            A.CallTo(() => app.Version).Returns(version);
            A.CallTo(() => app.IsDeleted).Returns(isDeleted);

            return app;
        }
    }
}