// ==========================================================================
//  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.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.Events;
using Squidex.Domain.Apps.Events.Comments;
using Squidex.Domain.Apps.Events.Contents;
using Squidex.Infrastructure;
using Squidex.Infrastructure.EventSourcing;
using Squidex.Shared.Users;
using Xunit;

namespace Squidex.Domain.Apps.Entities.Comments
{
    public class CommentTriggerHandlerTests
    {
        private readonly IScriptEngine scriptEngine = A.Fake<IScriptEngine>();
        private readonly IUserResolver userResolver = A.Fake<IUserResolver>();
        private readonly IRuleTriggerHandler sut;

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

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

            sut = new CommentTriggerHandler(scriptEngine, userResolver);
        }

        [Fact]
        public void Should_return_false_if_asking_for_snapshot_support()
        {
            Assert.False(sut.CanCreateSnapshotEvents);
        }

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

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

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

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

            var user1 = UserMocks.User("1");
            var user2 = UserMocks.User("2");

            var users = new List<IUser> { user1, user2 };
            var userIds = users.Select(x => x.Id).ToArray();

            var @event = new CommentCreated { Mentions = userIds };
            var envelope = Envelope.Create<AppEvent>(@event);

            A.CallTo(() => userResolver.QueryManyAsync(userIds, default))
                .Returns(users.ToDictionary(x => x.Id));

            var result = await sut.CreateEnrichedEventsAsync(envelope, ctx, default).ToListAsync();

            Assert.Equal(2, result.Count);

            var enrichedEvent1 = result[0] as EnrichedCommentEvent;
            var enrichedEvent2 = result[1] as EnrichedCommentEvent;

            Assert.Equal(user1, enrichedEvent1!.MentionedUser);
            Assert.Equal(user2, enrichedEvent2!.MentionedUser);
            Assert.Equal("UserMentioned", enrichedEvent1.Name);
            Assert.Equal("UserMentioned", enrichedEvent2.Name);
        }

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

            var user1 = UserMocks.User("1");
            var user2 = UserMocks.User("2");

            var users = new List<IUser> { user1, user2 };
            var userIds = users.Select(x => x.Id).ToArray();

            var @event = new CommentCreated { Mentions = userIds };
            var envelope = Envelope.Create<AppEvent>(@event);

            var result = await sut.CreateEnrichedEventsAsync(envelope, ctx, default).ToListAsync();

            Assert.Empty(result);
        }

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

            var @event = new CommentCreated { Mentions = null };
            var envelope = Envelope.Create<AppEvent>(@event);

            var result = await sut.CreateEnrichedEventsAsync(envelope, ctx, default).ToListAsync();

            Assert.Empty(result);

            A.CallTo(() => userResolver.QueryManyAsync(A<string[]>._, A<CancellationToken>._))
                .MustNotHaveHappened();
        }

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

            var @event = new CommentCreated { Mentions = Array.Empty<string>() };
            var envelope = Envelope.Create<AppEvent>(@event);

            var result = await sut.CreateEnrichedEventsAsync(envelope, ctx, default).ToListAsync();

            Assert.Empty(result);

            A.CallTo(() => userResolver.QueryManyAsync(A<string[]>._, A<CancellationToken>._))
                .MustNotHaveHappened();
        }

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

                var result = sut.Trigger(Envelope.Create<AppEvent>(@event), ctx);

                Assert.True(result);
            });
        }

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

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

                Assert.True(result);
            });
        }

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

                var result = sut.Trigger(new EnrichedCommentEvent(), ctx);

                Assert.True(result);
            });
        }

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

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

                Assert.False(result);
            });
        }

        [Fact]
        public void Should_trigger_check_if_email_is_correct()
        {
            TestForRealCondition("event.mentionedUser.email == '1@email.com'", (handler, ctx) =>
            {
                var @event = new EnrichedCommentEvent
                {
                    MentionedUser = UserMocks.User("1", "1@email.com")
                };

                var result = handler.Trigger(@event, ctx);

                Assert.True(result);
            });
        }

        [Fact]
        public void Should_not_trigger_check_if_email_is_not_correct()
        {
            TestForRealCondition("event.mentionedUser.email == 'other@squidex.io'", (handler, ctx) =>
            {
                var @event = new EnrichedCommentEvent
                {
                    MentionedUser = UserMocks.User("1", "1@email.com")
                };

                var result = handler.Trigger(@event, ctx);

                Assert.False(result);
            });
        }

        [Fact]
        public void Should_trigger_check_if_text_is_urgent()
        {
            TestForRealCondition("event.text.indexOf('urgent') >= 0", (handler, ctx) =>
            {
                var @event = new EnrichedCommentEvent
                {
                    Text = "very_urgent_text"
                };

                var result = handler.Trigger(@event, ctx);

                Assert.True(result);
            });
        }

        [Fact]
        public void Should_not_trigger_check_if_text_is_not_urgent()
        {
            TestForRealCondition("event.text.indexOf('urgent') >= 0", (handler, ctx) =>
            {
                var @event = new EnrichedCommentEvent
                {
                    Text = "just_gossip"
                };

                var result = handler.Trigger(@event, ctx);

                Assert.False(result);
            });
        }

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

            var realScriptEngine =
                new JintScriptEngine(new MemoryCache(Options.Create(new MemoryCacheOptions())),
                    Options.Create(new JintScriptOptions
                    {
                        TimeoutScript = TimeSpan.FromSeconds(2),
                        TimeoutExecution = TimeSpan.FromSeconds(10)
                    }));

            var handler = new CommentTriggerHandler(realScriptEngine, userResolver);

            action(handler, Context(trigger));
        }

        private void TestForCondition(string condition, Action<RuleContext> action)
        {
            var trigger = new CommentTrigger
            {
                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)
        {
            trigger ??= new CommentTrigger();

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