using UnityEngine;
using System.Collections;
using System;
using System.Reflection;

namespace Engine.Net
{
    /// <summary>消息对象</summary>
    public class NetMsg
    {

        /// <summary>创建一个NetMsg对象</summary>
        public static NetMsg OnCreateNetMsg(int msgCode = 0)
        {
            return new NetMsg(msgCode);
        }

        /// <summary>创建一个NetMsg对象</summary>
        public static NetMsg OnCreateNetMsg(byte[] bytes)
        {
            return new NetMsg(bytes);
        }

        /// <summary>接受消息的最大长度</summary>
        public const int MAX_MSG_LEN = 81920;
        /// <summary>消息的固定最小长度</summary>
        public const int MIN_MSG_LEN = 12;

        /// <summary>消息内容长度</summary>
        public int nBodyLeng = 0;
        /// <summary>消息编号</summary>
        public int nCode = 0;
        public int UserId = -1;
        /// <summary>消息时序</summary>
        public short nSequence = 0;

        /// <summary>消息内容</summary>
        public NetBytes arrData = null;
        /// <summary>读取位置</summary>
        protected int nPos;

        public NetMsg()
        {
            arrData = new NetBytes();
        }

        public NetMsg(int msgCode)
        {
            nCode = msgCode;
            arrData = new NetBytes();
        }

        public NetMsg(byte[] bytes)
        {
            arrData = new NetBytes(bytes);
        }

        // 解包参数
        public virtual void UnPackMsg<T>(ref T x)
        {
            Type t = x.GetType();
            FieldInfo[] fields = t.GetFields();
            foreach (FieldInfo f in fields)
            {
                if (f.FieldType == typeof(int))
                {
                    f.SetValue(x, arrData.ReadInt());
                }
                else if (f.FieldType == typeof(short))
                {
                    f.SetValue(x, arrData.ReadShort());
                }
                else if (f.FieldType == typeof(byte))
                {
                    f.SetValue(x, arrData.ReadByte());
                }
                else if (f.FieldType == typeof(byte[]))
                {
                    f.SetValue(x, arrData.ReadByteArray());
                }
                else if (f.FieldType == typeof(bool))
                {
                    f.SetValue(x, arrData.ReadBool());
                }
                else if (f.FieldType == typeof(float))
                {
                    f.SetValue(x, arrData.ReadFloat());
                }
                else if (f.FieldType == typeof(Vector3))
                {
                    f.SetValue(x, arrData.ReadVector3());
                }
                else if (f.FieldType == typeof(string))
                {
                    f.SetValue(x, arrData.ReadString().Replace("\0", ""));//标准化;
                }
                else if(f.FieldType == typeof(char[]))
                {
                    f.SetValue(x, arrData.ReadChars());
                }
            }
        }

        // 封装参数
        public virtual void PackMsg<T>(T x)
        {
            Type t = x.GetType();
            FieldInfo[] fields = t.GetFields();
            foreach (FieldInfo f in fields)
            {
                if (f.FieldType == typeof(int))
                {
                    arrData.WriteInt((int)f.GetValue(x));
                }
                else if (f.FieldType == typeof(short))
                {
                    arrData.WriteShort((short)f.GetValue(x));
                }
                else if (f.FieldType == typeof(byte))
                {
                    arrData.WriteByte((byte)f.GetValue(x));
                }
                else if (f.FieldType == typeof(byte[]))
                {
                    arrData.WriteByteArray((byte[])f.GetValue(x));
                }
                else if (f.FieldType == typeof(bool))
                {
                    arrData.WriteBool((bool)f.GetValue(x));
                }
                else if (f.FieldType == typeof(float))
                {
                    arrData.WriteFloat((float)f.GetValue(x));
                }
                else if (f.FieldType == typeof(Vector3))
                {
                    arrData.WriteVector3((Vector3)f.GetValue(x));
                }
                else if (f.FieldType == typeof(string))
                {
                    arrData.WriteString((string)f.GetValue(x),  20);
                }
                else if (f.FieldType == typeof(char[]))
                {
                    arrData.WriteChars((char[])f.GetValue(x));
                }
                else
                {
                    //CDebug.Log("打包数组参数" + f.FieldType);
                    if (f.FieldType.IsArray)
                    {
                        System.Object[] datas = (System.Object[])f.GetValue(x);
                        for(int i=0; i< datas.Length; i++)
                        {
                            PackMsg(datas[i]);
                        }
                    }
                }
            }
        }

        /// <summary>读取消息</summary>
        public virtual bool ReadMessage(byte[] buff, int nMsgSize)
        {
            if (buff != null)
            {
                if(nMsgSize< MIN_MSG_LEN)
                {
                    return false;
                }
                //读取连接ID
                nCode = arrData.ReadInt();
                //读取用户id
                UserId = arrData.ReadInt(); 
                //消息包内容长度
                nBodyLeng = nMsgSize - MIN_MSG_LEN;
                if (nBodyLeng > MAX_MSG_LEN)
                {
                    return false;
                }
                else
                {
                    if (nBodyLeng <= 0)
                    {
                        return true;
                    }
                    //拷贝消息数据
                    arrData.Data = new byte[nBodyLeng];
                    Array.Copy(buff, MIN_MSG_LEN, arrData.Data, 0, nBodyLeng);
                    arrData.Position = 0;
                    return true;
                }
            }
            else
            {
                return false;
            }
        }

        /// <summary>消息打包</summary>
        public virtual byte[] FastPackMsg()
        {
            int packageSize = arrData.Length + MIN_MSG_LEN;
            NetBytes netBytes = new NetBytes();

            // 写入总长度
            netBytes.WriteInt(packageSize);
            // 写入消息号
            netBytes.WriteInt(nCode);
            // 写入用户id
            netBytes.WriteInt(UserId);
            // 写入其他数据
            if (arrData.Length > 0)
                netBytes.WriteBytes(arrData.Data, false);

            return netBytes.Data;
        }

        /// <summary>确保消息长度不会溢出</summary>
        private bool EnsureCap(int nCap)
        {
            if (arrData != null && arrData.Length >= nCap)
                return true;

            if (nCap > MAX_MSG_LEN)
                return false;

            int nCurSize = arrData == null ? 0 : arrData.Length;
            int nNewSize = Mathf.Max(nCurSize * 2, nCap);
            nNewSize = Mathf.Min(nNewSize, MAX_MSG_LEN);

            if (arrData == null)
            {
                arrData = new NetBytes(new byte[nNewSize]);
            }
            else
            {
                byte[] arrBytes = null;
                Array.Resize<byte>(ref arrBytes, nNewSize);
                arrData.Data = arrBytes;
                arrData.Position = 0;
            }
            return true;
        }

    }
}