using DotNetty.Buffers;
using DotNetty.Codecs;
using DotNetty.Handlers.Timeout;
using DotNetty.Transport.Bootstrapping;
using DotNetty.Transport.Channels;
using DotNetty.Transport.Channels.Sockets;
using DotNetty.Transport.Libuv;
using JT809Netty.Core.Configs;
using JT809Netty.Core.Handlers;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Options;
using System;
using System.Collections.Generic;
using System.Net;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace JT809Netty.Core
{
    /// <summary>
    /// 下级平台主链路
    /// </summary
    public class JT809DownMasterLinkNettyService : IHostedService
    {
        IEventLoopGroup workerGroup;

        Bootstrap bootstrap;

        readonly IServiceProvider serviceProvider;

        readonly IOptionsMonitor<JT809NettyOptions> nettyOptions;

        public JT809DownMasterLinkNettyService(
            IOptionsMonitor<JT809NettyOptions> nettyOptionsAccessor,
            IServiceProvider serviceProvider)
        {
            nettyOptions = nettyOptionsAccessor;
            this.serviceProvider = serviceProvider;
        }

        public Task StartAsync(CancellationToken cancellationToken)
        {
            Task.Run(async () => 
            {
                try
                {
                    workerGroup = new MultithreadEventLoopGroup();
                    bootstrap = new Bootstrap();
                    bootstrap.Group(workerGroup)
                             .Channel<TcpSocketChannel>()
                             .Handler(new ActionChannelInitializer<IChannel>(channel =>
                             {
                                 InitChannel(channel);
                             }))
                           .Option(ChannelOption.SoBacklog, 1048576);
                    IChannel clientChannel = await bootstrap.ConnectAsync(new IPEndPoint(IPAddress.Parse(nettyOptions.CurrentValue.Host), nettyOptions.CurrentValue.Port));
                }
                catch (Exception ex)
                {

                }
            });
            return Task.CompletedTask;
        }

        public Task StopAsync(CancellationToken cancellationToken)
        {
            try
            {
                Task.WhenAll(workerGroup.ShutdownGracefullyAsync(TimeSpan.FromMilliseconds(100), TimeSpan.FromSeconds(1)));
            }
            catch (Exception ex)
            {

            }
            return Task.CompletedTask;
        }

        private void InitChannel(IChannel channel)
        {
            var scope = serviceProvider.CreateScope();
            try
            {
                //下级平台应每 1min 发送一个主链路保持清求数据包到上级平台以保持链路连接
                channel.Pipeline.AddLast("systemIdleState", new WriteTimeoutHandler(60));
                channel.Pipeline.AddLast("jt809DownMasterLinkConnection", scope.ServiceProvider.GetRequiredService<JT809DownMasterLinkConnectionHandler>());
                channel.Pipeline.AddLast("jt809Buffer", new DelimiterBasedFrameDecoder(int.MaxValue, Unpooled.CopiedBuffer(new byte[] { JT809.Protocol.JT809Package.BEGINFLAG }), Unpooled.CopiedBuffer(new byte[] { JT809.Protocol.JT809Package.ENDFLAG })));
                channel.Pipeline.AddLast("jt809Decode", scope.ServiceProvider.GetRequiredService<JT809DecodeHandler>());
                channel.Pipeline.AddLast("jT809DownMasterLinkServiceHandler", scope.ServiceProvider.GetRequiredService<JT809DownMasterLinkServiceHandler>());
            }
            finally
            {
                scope.Dispose();
            }
        }
    }
}