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

using FakeItEasy;
using Squidex.Domain.Apps.Core.HandleRules;
using Squidex.Domain.Apps.Core.Rules;
using Squidex.Domain.Apps.Core.Rules.EnrichedEvents;
using Squidex.Domain.Apps.Core.Rules.Triggers;
using Squidex.Domain.Apps.Core.Scripting;
using Squidex.Domain.Apps.Core.TestHelpers;
using Squidex.Domain.Apps.Entities.Assets.Repositories;
using Squidex.Domain.Apps.Events;
using Squidex.Domain.Apps.Events.Assets;
using Squidex.Domain.Apps.Events.Contents;
using Squidex.Infrastructure;
using Squidex.Infrastructure.EventSourcing;
using Xunit;

namespace Squidex.Domain.Apps.Entities.Assets
{
    public class AssetChangedTriggerHandlerTests
    {
        private readonly CancellationTokenSource cts = new CancellationTokenSource();
        private readonly CancellationToken ct;
        private readonly IScriptEngine scriptEngine = A.Fake<IScriptEngine>();
        private readonly IAssetLoader assetLoader = A.Fake<IAssetLoader>();
        private readonly IAssetRepository assetRepository = A.Fake<IAssetRepository>();
        private readonly IRuleTriggerHandler sut;

        public AssetChangedTriggerHandlerTests()
        {
            ct = cts.Token;

            A.CallTo(() => scriptEngine.Evaluate(A<ScriptVars>._, "true", default))
                .Returns(true);

            A.CallTo(() => scriptEngine.Evaluate(A<ScriptVars>._, "false", default))
                .Returns(false);

            sut = new AssetChangedTriggerHandler(scriptEngine, assetLoader, assetRepository);
        }

        public static IEnumerable<object[]> TestEvents()
        {
            yield return new object[] { TestUtils.CreateEvent<AssetCreated>(), EnrichedAssetEventType.Created };
            yield return new object[] { TestUtils.CreateEvent<AssetUpdated>(), EnrichedAssetEventType.Updated };
            yield return new object[] { TestUtils.CreateEvent<AssetAnnotated>(), EnrichedAssetEventType.Annotated };
            yield return new object[] { TestUtils.CreateEvent<AssetDeleted>(), EnrichedAssetEventType.Deleted };
        }

        [Fact]
        public void Should_return_true_if_asking_for_snapshot_support()
        {
            Assert.True(sut.CanCreateSnapshotEvents);
        }

        [Fact]
        public void Should_handle_asset_event()
        {
            Assert.True(sut.Handles(new AssetCreated()));
        }

        [Fact]
        public void Should_not_handle_asset_moved_event()
        {
            Assert.False(sut.Handles(new AssetMoved()));
        }

        [Fact]
        public void Should_not_handle_other_event()
        {
            Assert.False(sut.Handles(new ContentCreated()));
        }

        [Fact]
        public async Task Should_create_events_from_snapshots()
        {
            var ctx = Context();

            A.CallTo(() => assetRepository.StreamAll(ctx.AppId.Id, ct))
                .Returns(new List<AssetEntity>
                {
                    new AssetEntity(),
                    new AssetEntity()
                }.ToAsyncEnumerable());

            var actual = await sut.CreateSnapshotEventsAsync(ctx, ct).ToListAsync(ct);

            var typed = actual.OfType<EnrichedAssetEvent>().ToList();

            Assert.Equal(2, typed.Count);
            Assert.Equal(2, typed.Count(x => x.Type == EnrichedAssetEventType.Created && x.Name == "AssetQueried"));
        }

        [Theory]
        [MemberData(nameof(TestEvents))]
        public async Task Should_create_enriched_events(AssetEvent @event, EnrichedAssetEventType type)
        {
            var ctx = Context(appId: @event.AppId);

            var envelope = Envelope.Create<AppEvent>(@event).SetEventStreamNumber(12);

            A.CallTo(() => assetLoader.GetAsync(ctx.AppId.Id, @event.AssetId, 12, ct))
                .Returns(new AssetEntity());

            var actual = await sut.CreateEnrichedEventsAsync(envelope, ctx, ct).ToListAsync(ct);

            var enrichedEvent = (EnrichedAssetEvent)actual.Single();

            Assert.Equal(type, enrichedEvent.Type);
            Assert.Equal(@event.Actor, enrichedEvent.Actor);
            Assert.Equal(@event.AppId, enrichedEvent.AppId);
            Assert.Equal(@event.AppId.Id, enrichedEvent.AppId.Id);
        }

        [Fact]
        public void Should_trigger_check_if_condition_is_empty()
        {
            TestForCondition(string.Empty, ctx =>
            {
                var @event = new EnrichedAssetEvent();

                var actual = sut.Trigger(@event, ctx);

                Assert.True(actual);
            });
        }

        [Fact]
        public void Should_trigger_check_if_condition_matchs()
        {
            TestForCondition("true", ctx =>
            {
                var @event = new EnrichedAssetEvent();

                var actual = sut.Trigger(@event, ctx);

                Assert.True(actual);
            });
        }

        [Fact]
        public void Should_not_trigger_check_if_condition_does_not_matchs()
        {
            TestForCondition("false", ctx =>
            {
                var @event = new EnrichedAssetEvent();

                var actual = sut.Trigger(@event, ctx);

                Assert.False(actual);
            });
        }

        private void TestForCondition(string condition, Action<RuleContext> action)
        {
            var trigger = new AssetChangedTriggerV2
            {
                Condition = condition
            };

            action(Context(trigger));

            if (string.IsNullOrWhiteSpace(condition))
            {
                A.CallTo(() => scriptEngine.Evaluate(A<ScriptVars>._, condition, default))
                    .MustNotHaveHappened();
            }
            else
            {
                A.CallTo(() => scriptEngine.Evaluate(A<ScriptVars>._, condition, default))
                    .MustHaveHappened();
            }
        }

        private static RuleContext Context(RuleTrigger? trigger = null, NamedId<DomainId>? appId = null)
        {
            trigger ??= new AssetChangedTriggerV2();

            return new RuleContext
            {
                AppId = appId ?? NamedId.Of(DomainId.NewGuid(), "my-app"),
                Rule = new Rule(trigger, A.Fake<RuleAction>()),
                RuleId = DomainId.NewGuid()
            };
        }
    }
}