using Microsoft.Extensions.DependencyInjection;
using Moq;
using System;
using AsbCloudInfrastructure.Services.Background;
using System.Threading;
using System.Threading.Tasks;
using Xunit;
using Org.BouncyCastle.Asn1.X509.Qualified;

namespace AsbCloudWebApi.Tests.ServicesTests
{
    public class BackgroundWorkerServiceTest
    {
        private readonly Mock<IServiceProvider> mockServiceProvider;
        private readonly Mock<IServiceScopeFactory> mockServiceScopeFactory;

        public BackgroundWorkerServiceTest()
        {
            var mockServiceScope = new Mock<IServiceScope>();
            mockServiceScopeFactory = new Mock<IServiceScopeFactory>();
            mockServiceProvider = new Mock<IServiceProvider>();

            mockServiceScope.SetReturnsDefault(mockServiceProvider.Object);
            mockServiceProvider.SetReturnsDefault(mockServiceScopeFactory.Object);
            mockServiceProvider.Setup(s=>s.GetService(It.IsAny<Type>()))
                .Returns(mockServiceScopeFactory.Object);
            mockServiceScopeFactory.SetReturnsDefault(mockServiceScope.Object);
        }

        [Fact]
        public async Task Push_makes_new_scope_after_start()
        {
            mockServiceScopeFactory.Invocations.Clear();

            var backgroundService = new BackgroundWorkerService(mockServiceProvider.Object);            
            var work = new WorkBase("", (_, _, _) => Task.CompletedTask );
            backgroundService.Push(work);
            await backgroundService.StartAsync(CancellationToken.None);
            await Task.Delay(10);

            mockServiceScopeFactory.Verify(f => f.CreateScope());
        }

        [Fact]
        public async Task Push_makes_primary_work_done()
        {
            var backgroundService = new BackgroundWorkerService(mockServiceProvider.Object);
            var workDone = false;
            var work = new WorkBase("", (_, _, _) =>
            {
                workDone = true;
                return Task.CompletedTask;
            });
            backgroundService.Push(work);
            await backgroundService.StartAsync(CancellationToken.None);
            await Task.Delay(10);

            Assert.True(workDone);
        }

        [Fact]
        public async Task Push_makes_pperiodic_work_done()
        {
            var backgroundService = new BackgroundWorkerService(mockServiceProvider.Object);
            var workDone = false;
            var work = new WorkPeriodic("", (_, _, _) =>
            {
                workDone = true;
                return Task.CompletedTask;
            },
            TimeSpan.FromMilliseconds(10));
            backgroundService.Push(work);
            await backgroundService.StartAsync(CancellationToken.None);
            await Task.Delay(10);

            Assert.True(workDone);
        }

        [Fact]
        public async Task Aborts_long_work()
        {
            var backgroundService = new BackgroundWorkerService(mockServiceProvider.Object);
            var workCanceled = false;
            var work = new WorkBase("", async(_, _, _) => await Task.Delay(1000000));
            work.Timeout = TimeSpan.FromMilliseconds(1);
            work.OnErrorAsync = async (id, ex, token) =>
            {
                workCanceled = ex is System.TimeoutException;
                await Task.CompletedTask;
            };

            backgroundService.Push(work);
            await backgroundService.StartAsync(CancellationToken.None);
            await Task.Delay(20*4);

            Assert.True(workCanceled);
        }

        [Fact]
        public async Task Execution_continues_after_work_exception()
        {
            var backgroundService = new BackgroundWorkerService(mockServiceProvider.Object);
            var work2done = false;
            var work1 = new WorkBase("1", (_, _, _) => throw new Exception());
            var work2 = new WorkBase("2", (_, _, _) =>
            {
                work2done = true;
                return Task.CompletedTask;
            });

            backgroundService.Push(work1);
            backgroundService.Push(work2);

            await backgroundService.StartAsync(CancellationToken.None);
            await Task.Delay(2_100);

            Assert.True(work2done);
        }
    }
}