using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Connections;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.VisualStudio.TestTools.UnitTesting;

using System;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using MQTTnet.Adapter;
using MQTTnet.AspNetCore.Tests.Mockups;
using MQTTnet.Client.Options;
using MQTTnet.Exceptions;
using MQTTnet.Formatter;
using MQTTnet.Packets;
using System.Net;

namespace MQTTnet.AspNetCore.Tests
{
    [TestClass]
    public class MqttConnectionContextTest
    {
        [TestMethod]
        public async Task TestReceivePacketAsyncThrowsWhenReaderCompleted()
        {
            var serializer = new MqttPacketFormatterAdapter(MqttProtocolVersion.V311);
            var pipe = new DuplexPipeMockup();
            var connection = new DefaultConnectionContext();
            connection.Transport = pipe;
            var ctx = new MqttConnectionContext(serializer, connection);

            pipe.Receive.Writer.Complete();

            await Assert.ThrowsExceptionAsync<MqttCommunicationException>(() => ctx.ReceivePacketAsync(TimeSpan.Zero, CancellationToken.None));
        }
        
        [TestMethod]
        public async Task TestParallelWrites()
        {
            var serializer = new MqttPacketFormatterAdapter(MqttProtocolVersion.V311);
            var pipe = new DuplexPipeMockup();
            var connection = new DefaultConnectionContext();
            connection.Transport = pipe;
            var ctx = new MqttConnectionContext(serializer, connection);

            var tasks = Enumerable.Range(1, 10).Select(_ => Task.Run(async () => 
            {
                for (int i = 0; i < 100; i++)
                {
                    await ctx.SendPacketAsync(new MqttPublishPacket(), TimeSpan.Zero, CancellationToken.None).ConfigureAwait(false);
                }
            }));

            await Task.WhenAll(tasks).ConfigureAwait(false);
        }


        [TestMethod]
        public async Task TestLargePacket()
        {
            var serializer = new MqttPacketFormatterAdapter(MqttProtocolVersion.V311);
            var pipe = new DuplexPipeMockup();
            var connection = new DefaultConnectionContext();
            connection.Transport = pipe;
            var ctx = new MqttConnectionContext(serializer, connection);

            await ctx.SendPacketAsync(new MqttPublishPacket() { Payload = new byte[20_000] }, TimeSpan.Zero, CancellationToken.None).ConfigureAwait(false);

            var readResult = await pipe.Send.Reader.ReadAsync();
            Assert.IsTrue(readResult.Buffer.Length > 20000);
        }

        private class Startup 
        {
            public void Configure(IApplicationBuilder app)
            { 
            }
        }

        [TestMethod]
        public async Task TestEndpoint()
        {
            var mockup = new ConnectionHandlerMockup();


            using (var host = new WebHostBuilder()
                .UseKestrel(kestrel => kestrel.ListenLocalhost(1883, listener => listener.Use((ctx, next) => mockup.OnConnectedAsync(ctx))))
                .UseStartup<Startup>()
                .ConfigureServices((hostContext, services) =>
                {
                    services.AddHostedMqttServer(o => o.WithoutDefaultEndpoint());
                    services.AddSingleton<IMqttServerAdapter>(mockup);
                })
                .Build())
            using (var client = new MqttFactory().CreateMqttClient())
            {
                host.Start();
                await client.ConnectAsync(new MqttClientOptionsBuilder()
                    .WithTcpServer("localhost")
                    .Build(), CancellationToken.None);

                var ctx = await mockup.Context.Task;
#if NETCOREAPP3_1
                var ep = IPEndPoint.Parse(ctx.Endpoint);
                Assert.IsNotNull(ep);
#endif
                Assert.IsNotNull(ctx);
            }               
        }
    }
}