using System;
using System.Collections.Generic;
namespace Mozi.IoT
{
    /// <summary>
    /// CoAP对等端
    /// </summary>
    public class CoAPPeer
    {
        /// <summary>
        /// 最大数据包尺寸 包含所有头信息和有效荷载 Byte
        /// </summary>
        private int _maxTransferPackSize = 512;
        private int _blockSize = 128;
        private ulong _packetSendCount, _totalSendBytes, _packetReceived = 0, _totalReceivedBytes;
        protected UDPSocketIOCP _socket;
        protected int BindPort = CoAPProtocol.Port;
        /// <summary>
        /// 最小分块大小,单位Byte
        /// </summary>
        public const int MinBlockSize = 16;
        /// <summary>
        /// 最大分块大小,单位Byte
        /// </summary>
        public const int MaxBlockSize = 2048;
        /// <summary>
        /// 当前端默认采用块大小,默认值为128bytes,单位Byte
        /// </summary>
        /// <remarks>在通讯两方没有进行协商的情况下，默认采用此值作为分块大小。取值区间为{<see cref="MinBlockSize"/>~<see cref="MaxBlockSize"/>}</remarks>
        public int BlockSize { get { return _blockSize; } set { _blockSize = value; } }
        /// <summary>s
        /// 受支持的请求方法
        /// </summary>
        protected List<CoAPCode> SupportedRequest = new List<CoAPCode> { CoAPRequestMethod.Get, CoAPRequestMethod.Post, CoAPRequestMethod.Put, CoAPRequestMethod.Delete };
        /// <summary>
        /// 数据包接收事件，字节流数据包
        /// </summary>
        public PackageReceive DatagramReceived;
        /// <summary>
        /// 服务端口
        /// </summary>
        public int Port { get { return BindPort; } protected set { BindPort = value; } }
        /// <summary>
        /// 启动时间
        /// </summary>
        public DateTime StartTime { get; private set; }
        /// <summary>
        /// 服务器运行状态
        /// </summary>
        public bool Running
        {
            get; set;
        }
        /// <summary>
        /// 最大数据包尺寸 包含所有头信息和有效荷载
        /// </summary>
        internal int MaxTransferPackSize { get => _maxTransferPackSize; set => _maxTransferPackSize = value; }
        /// <summary>
        /// 累计接收到的包的数量
        /// </summary>
        public ulong PacketReceivedCount { get => _packetReceived; }
        /// <summary>
        /// 累计接收的字节数
        /// </summary>
        public ulong TotalReceivedBytes { get => _totalReceivedBytes; }
        /// <summary>
        /// 累计发出的包的数量
        /// </summary>
        public ulong PacketSendCount => _packetSendCount;
        /// <summary>                                                               
        /// 累计发出的字节数                                                                
        /// </summary>
        public ulong TotalSendBytes => _totalSendBytes; 

        public CoAPPeer()
        {
            _socket = new UDPSocketIOCP();
            _socket.AfterReceiveEnd += Socket_AfterReceiveEnd;
        }
        /// <summary>
        /// 以指定端口启动<see cref="F:Port"/>，如果不配置端口则使用默认端口
        /// </summary>
        public void Start()
        {
            Start(BindPort);
        }
        /// <summary>
        /// 启动本端服务 默认5683端口
        /// </summary>
        /// <param name="port"></param>
        public void Start(int port)
        {
            BindPort = port;
            _socket.Start(BindPort);
            StartTime = DateTime.Now;
            Running = true;
        }
        /// <summary>
        /// 端口下线
        /// </summary>
        public void Shutdown()
        {
            _socket.Shutdown();
            StartTime = DateTime.MinValue;
            Running = false;
        }
        /// <summary>
        /// 数据接收完成回调
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="args"></param>
        /// <remarks>继承类如果覆盖该事件，则可以接管数据处理</remarks>
        protected virtual void Socket_AfterReceiveEnd(object sender, DataTransferArgs args)
        {
            _packetReceived++;
            _totalReceivedBytes += args.Data != null ? (uint)args.Data.Length : 0;
            if (DatagramReceived != null)
            {
                DatagramReceived(args.IP, args.Port, args.Data);
            }
        }
    }
}

 private Cache.MessageCacheManager _cm;

/// <summary>
/// 接收到请求
/// </summary>
public MessageTransmit RequestReceived;
/// <summary>
/// 发起响应请求
/// </summary>
public MessageTransmit Responsed;
private bool _proxyPassed = false;
private uint maxBodySize=20*1024*1024;
/// <summary>
/// 服务端能处理的最大POST资源大小 单位byte
/// </summary>
public uint MaxBodySize { get => maxBodySize; set => maxBodySize = value; }
/// <summary>
/// 服务器根目录
/// </summary>
public string Root = AppDomain.CurrentDomain.BaseDirectory;

/// <summary>
    /// CoAP资源
    /// </summary>
    public abstract class CoAPResource
    {
        /// <summary>
        /// 资源总大小
        /// </summary>
        public abstract uint ResourceSize { get; }
        /// <summary>
        /// 默认分块大小128，单位Bytes 
        /// </summary>
        /// <remarks>
        /// 如果资源尺寸过大，则必须合理配置此大小。
        /// 取值范围为16-2048Bytes BlockOptionValue中Size的数据容量。参考<see cref="BlockOptionValue"/>
        /// </remarks>
        public virtual uint BlockSize { get { return 128; } }
        /// <summary>
        /// GET方法
        /// </summary>
        /// <param name="ctx"></param>
        /// <returns></returns>
        public virtual CoAPPackage OnGet(CoAPContext ctx)
        {
            ctx.Response = new CoAPPackage { MessageType = CoAPMessageType.Acknowledgement, MesssageId = ctx.Request.MesssageId, Token = ctx.Request.Token, Code = CoAPResponseCode.Forbidden };
            return ctx.Response;
        }
        /// <summary>
        /// Post方法
        /// </summary>
        /// <param name="ctx"></param>
        /// <returns></returns>
        public virtual CoAPPackage OnPost(CoAPContext ctx)
        {
            ctx.Response = new CoAPPackage { MessageType = CoAPMessageType.Acknowledgement, MesssageId = ctx.Request.MesssageId, Token = ctx.Request.Token, Code = CoAPResponseCode.Forbidden };
            return ctx.Response;
        }
        /// <summary>
        /// PUT方法
        /// </summary>
        /// <param name="ctx"></param>
        /// <returns></returns>
        public virtual CoAPPackage OnPut(CoAPContext ctx)
        {
            ctx.Response = new CoAPPackage { MessageType = CoAPMessageType.Acknowledgement, MesssageId = ctx.Request.MesssageId, Token = ctx.Request.Token, Code = CoAPResponseCode.Forbidden };
            return ctx.Response;
        }
        /// <summary>
        /// Delete方法
        /// </summary>
        /// <param name="ctx"></param>
        /// <returns></returns>
        public virtual CoAPPackage OnDelete(CoAPContext ctx)
        {
            ctx.Response = new CoAPPackage { MessageType = CoAPMessageType.Acknowledgement, MesssageId = ctx.Request.MesssageId, Token = ctx.Request.Token, Code = CoAPResponseCode.Forbidden };
            return ctx.Response;
        }
        /// <summary>
        /// 分块查找
        /// </summary>
        /// <param name="indBlock"></param>
        /// <param name="blockSize"></param>
        /// <returns></returns>
        protected virtual byte[] Seek(int indBlock, int blockSize)
        {
            return new byte[] { };
        }
        /// <summary>
        /// Block2分块协商
        /// </summary>
        /// <param name="ctx"></param>
        /// <returns></returns>
        internal virtual void HandleBlock2Query(CoAPContext ctx)
        {
            CoAPOption opt = ctx.Request.Options.Find(x => x.Option == CoAPOptionDefine.Block2);
            if (opt != null)
            {
                OptionValue opt2 = new BlockOptionValue() { Pack = opt.Value.Pack };
                //if(opt2)
            }
        }
        /// <summary>
        /// 请求服务端资源大小，响应条件为 Get Size2=0
        /// </summary>
        /// <param name="ctx">响应上下文对象</param>
        /// <returns></returns>
        internal virtual bool HandleSize2Query(CoAPContext ctx)
        {
            CoAPOption opt = ctx.Request.Options.Find(x => x.Option == CoAPOptionDefine.Size2);
            if (opt != null && int.Parse(opt.Value.ToString()) ==0 && ctx.Request.Code == CoAPRequestMethod.Get)
            {

                ctx.Response = new CoAPPackage { MessageType = CoAPMessageType.Acknowledgement, MesssageId = ctx.Request.MesssageId, Token = ctx.Request.Token, Code = CoAPResponseCode.Content };

                CoAPOption optResp = new CoAPOption() { Option = CoAPOptionDefine.Size2, Value = new UnsignedIntegerOptionValue() { Value = ResourceSize } };
                
                ctx.Response.SetOption(optResp);
                return true;
            }
            else
            {
                return false;
            }
        }
    }

 public class ResourceDescriptionAttribute : Attribute
    {
        /// <summary>
        /// 命名空间
        /// </summary>
        public string Namespace { get; set; }
        /// <summary>
        /// 资源名称
        /// </summary>
        public string Name { get; set; }
        /// <summary>
        /// 文字描述
        /// </summary>
        public string Description { get; set; }
        /// <summary>
        /// 资源类型
        /// </summary>
        public string ResourceType { get; set; }
    }

static void Main(string[] args)
        {
            Console.WriteLine("你好!COAP服务端已开启，等待客户端连接......");
            //////服务端
            CoAPServer cs = new CoAPServer();
            cs.RequestReceived += new MessageTransmit((host, port, pack) =>
            {
                Console.WriteLine($"From:[{host}:{port}]");
                Console.WriteLine(pack.ToString());
                Console.Title = string.Format("elapsed:{2},count:{0},pps:{3},bytes:{1}", cs.PacketReceivedCount, cs.TotalReceivedBytes,FormatSeconds(sp.ElapsedMilliseconds),pps);
            });
            cs.Start();
            Console.ReadLine();
        }