using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using DotNetty.Buffers;
using DotNetty.Codecs;
using DotNetty.Transport.Channels;
using System;
using System.Collections.Generic;
using System.Net;
using System.Numerics;
using System.Text.RegularExpressions;
using HybirdFrameworkEntity;
using HybirdFrameworkServices.ChargerManage;
using HybirdFrameworkServices.ChargerManage.Msg;

namespace HybirdFrameworkServices
{
    public class CustomFrameDecoder : ByteToMessageDecoder
    {

      
        private readonly IByteBuffer[] delimiters;
        private readonly bool stripDelimiter;
        private readonly bool failFast;

        public CustomFrameDecoder(IByteBuffer[] delimiters, bool stripDelimiter, bool failFast)
        {
            this.delimiters = delimiters;
            this.stripDelimiter = stripDelimiter;
            this.failFast = failFast;
        }

        protected override void Decode(IChannelHandlerContext ctx, IByteBuffer buffer, List<object> output)
        {
            // 查找分隔符
            IByteBuffer delimiter = FindDelimiter(buffer);
            if (delimiter != null)
            {
                int delimiterIndex = IndexOf(buffer, delimiter);//分隔符索引
                int frameLengthIndex = delimiterIndex + delimiter.Capacity;//帧长度索引

                if (delimiterIndex > 0)
                {
                    buffer.SkipBytes(delimiterIndex);
                    return;
                }

                if (buffer.ReadableBytes < frameLengthIndex + 7)
                {
                    // 数据不足，等待更多数据
                    return;
                }

                // 读取长度字段
                int frameLength = buffer.GetUnsignedShortLE(buffer.ReaderIndex + frameLengthIndex);

                if (buffer.ReadableBytes < frameLength)
                {
                    // 数据不足，等待更多数据
                    return;
                }
                ;
                IPEndPoint remoteAddress = (IPEndPoint)ctx.Channel.RemoteAddress;
                string clientIP = remoteAddress.Address.ToString();
                
                output.Add( this.Parse(buffer,clientIP));
            }
        }


        //将消息给每个充电机对象
        public  BaseMsg Parse(IByteBuffer byteBuffer,string clientIp)
        {
            BaseMsg baseMsg = null;
            //将cmd解析出来
            ushort cmd = byteBuffer.GetUnsignedShortLE(6);
            baseMsg = cmd switch
            {
                206 => new CMD206(byteBuffer,clientIp),
                202=> new CMD202(byteBuffer,clientIp),
                
                _ => new BaseMsg(byteBuffer,clientIp),
            };
            baseMsg.Parse();
  
           return baseMsg;
            
            
            
            
            
            
            
            
            
        }

        private IByteBuffer FindDelimiter(IByteBuffer buffer)
        {
            foreach (IByteBuffer delimiter in delimiters)
            {
                int delimiterIndex = IndexOf(buffer, delimiter);
                if (delimiterIndex >= 0)
                {
                    return delimiter;
                }
            }
            return null;
        }

        private static int IndexOf(IByteBuffer haystack, IByteBuffer needle)
        {
            for (int i = haystack.ReaderIndex; i < haystack.WriterIndex; i++)
            {
                int num = i;
                int j;
                for (j = 0; j < needle.Capacity && haystack.GetByte(num) == needle.GetByte(j); j++)
                {
                    num++;
                    if (num == haystack.WriterIndex && j != needle.Capacity - 1)
                    {
                        return -1;
                    }
                }

                if (j == needle.Capacity)
                {
                    return i - haystack.ReaderIndex;
                }
            }

            return -1;
        }

    }

}