using System;
using System.IO;
using System.Net;
using System.Net.Sockets;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Formatters.Binary;
using System.Text;
using System.Threading;

namespace Masuit.Tools.Net
{
    /// <summary>
    /// Socket客户端操作类
    /// </summary>
    public static class SocketClient
    {
        #region 私有字段

        /// <summary>
        /// 设置数据缓冲区大小 默认1024
        /// </summary>
        private static readonly int m_maxpacket = 1024 * 4;

        #endregion

        #region 服务器侦听

        /// <summary>
        /// 服务器侦听方法 返回null则说明没有链接上
        /// </summary>
        /// <returns>返回一个套接字(Socket)</returns>
        public static Socket ListenerSocket(this TcpListener listener)
        {
            try
            {
                return listener.AcceptSocket();
            }
            catch (Exception)
            {
                return null;
            }
        }

        /// <summary>
        /// 服务器侦听方法 返回null则说明没有链接上
        /// </summary>
        /// <param name="listener">TCP监听对象</param>
        /// <returns>返回一个网络流</returns>
        public static NetworkStream ListenerStream(this TcpListener listener)
        {
            try
            {
                return listener.AcceptTcpClient().GetStream();
            }
            catch (Exception)
            {
                return null;
            }
        }

        #endregion

        #region 客户端连接

        /// <summary>
        /// 从客户端连接获取socket对象
        /// </summary>
        /// <param name="tcpclient">TCP客户端</param>
        /// <param name="ipendpoint">客户端节点</param>
        /// <returns>客户端socket</returns>
        public static Socket ConnectSocket(this TcpClient tcpclient, IPEndPoint ipendpoint)
        {
            try
            {
                tcpclient.Connect(ipendpoint);
                return tcpclient.Client;
            }
            catch (Exception)
            {
                return null;
            }
        }

        /// <summary>
        /// 从客户端连接获取socket对象
        /// </summary>
        /// <param name="tcpclient">TCP客户端</param>
        /// <param name="ipadd">IP地址</param>
        /// <param name="port">端口号</param>
        /// <returns>客户端socket</returns>
        public static Socket ConnectSocket(this TcpClient tcpclient, IPAddress ipadd, int port)
        {
            try
            {
                tcpclient.Connect(ipadd, port);
                return tcpclient.Client;
            }
            catch (Exception)
            {
                return null;
            }
        }

        /// <summary>
        /// 从客户端获取网络流对象
        /// </summary>
        /// <param name="tcpclient">TCP客户端</param>
        /// <param name="ipendpoint">客户端节点</param>
        /// <returns>客户端的网络流</returns>
        public static NetworkStream ConnectStream(this TcpClient tcpclient, IPEndPoint ipendpoint)
        {
            try
            {
                tcpclient.Connect(ipendpoint);
                return tcpclient.GetStream();
            }
            catch (Exception)
            {
                return null;
            }
        }

        /// <summary>
        /// 从客户端获取网络流对象
        /// </summary>
        /// <param name="tcpclient">TCP客户端</param>
        /// <param name="ipadd">IP地址</param>
        /// <param name="port">端口号</param>
        /// <returns>客户端网络流对象</returns>
        public static NetworkStream ConnectStream(this TcpClient tcpclient, IPAddress ipadd, int port)
        {
            try
            {
                tcpclient.Connect(ipadd, port);
                return tcpclient.GetStream();
            }
            catch (Exception)
            {
                return null;
            }
        }

        #endregion

        #region Socket接收数据

        /// <summary>
        /// 接受固定长度字符串
        /// </summary>
        /// <param name="socket">socket对象</param>
        /// <param name="size">字符串长度</param>
        /// <returns>字节数据</returns>
        public static byte[] ReceiveFixData(this Socket socket, int size)
        {
            int offset = 0;
            int dataleft = size;
            byte[] msg = new byte[size];
            while (dataleft > 0)
            {
                var recv = socket.Receive(msg, offset, dataleft, 0);
                if (recv == 0)
                {
                    break;
                }

                offset += recv;
                dataleft -= recv;
            }

            return msg;
        }

        /// <summary>
        /// 接收变长字符串
        /// 为了处理粘包问题 ,每次发送数据时 包头(数据字节长度) + 正文
        /// 这个发送小数据
        /// 设置包头的字节为8,不能超过8位数的字节数组
        /// </summary>
        /// <param name="socket">客户端socket</param>
        /// <returns>byte[]数组</returns>
        public static byte[] ReceiveVarData(this Socket socket)
        {
            //每次接受数据时,接收固定长度的包头,包头长度为8
            byte[] lengthbyte = ReceiveFixData(socket, 8);
            //length得到字符长度 然后加工处理得到数字
            int length = GetPacketLength(lengthbyte);
            //得到正文
            return ReceiveFixData(socket, length);
        }

        /// <summary>
        /// 接收T类对象,反序列化
        /// </summary>
        /// <typeparam name="T">接收T类对象,T类必须是一个可序列化类</typeparam>
        /// <param name="socket">客户端socket</param>
        /// <returns>强类型对象</returns>
        public static T ReceiveVarData<T>(this Socket socket)
        {
            //先接收包头长度 固定8个字节
            byte[] lengthbyte = ReceiveFixData(socket, 8);
            //得到字节长度
            int length = GetPacketLength(lengthbyte);
            byte[] bytecoll = new byte[m_maxpacket];
            IFormatter format = new BinaryFormatter();
            MemoryStream stream = new MemoryStream();
            int offset = 0; //接收字节个数
            int lastdata = length; //还剩下多少没有接收,初始大小等于实际大小
            int receivedata = m_maxpacket; //每次接收大小
            //循环接收
            int mark = 0; //标记几次接收到的数据为0长度
            while (true)
            {
                //剩下的字节数是否小于缓存大小
                if (lastdata < m_maxpacket)
                {
                    receivedata = lastdata; //就只接收剩下的字节数
                }

                int count = socket.Receive(bytecoll, 0, receivedata, 0);
                if (count > 0)
                {
                    stream.Write(bytecoll, 0, count);
                    offset += count;
                    lastdata -= count;
                    mark = 0;
                }
                else
                {
                    mark++;
                    if (mark == 10)
                    {
                        break;
                    }
                }

                if (offset == length)
                {
                    break;
                }
            }

            stream.Seek(0, SeekOrigin.Begin); //必须要这个 或者stream.Position = 0;
            T t = (T)format.Deserialize(stream);
            return t;
        }

        /// <summary>
        /// 在预先得到文件的文件名和大小
        /// 调用此方法接收文件
        /// </summary>
        /// <param name="socket">socket服务端</param>
        /// <param name="path">路径必须存在</param>
        /// <param name="filename">文件名</param>
        /// <param name="size">预先知道的文件大小</param>
        /// <param name="progress">处理过程</param>
        public static bool ReceiveFile(this Socket socket, string path, string filename, long size, Action<int> progress)
        {
            if (!Directory.Exists(path))
            {
                return false;
            }

            //主要是防止有重名文件
            string savepath = GetPath(path, filename); //得到文件路径
            //缓冲区
            byte[] file = new byte[m_maxpacket];
            int receivedata = m_maxpacket; //每次要接收的长度
            long offset = 0; //循环接收的总长度
            long lastdata = size; //剩余多少还没接收
            int mark = 0;
            using var fs = new FileStream(savepath, FileMode.OpenOrCreate, FileAccess.Write);
            if (size <= 0)
            {
                return false;
            }

            bool ret = false;
            while (true)
            {
                if (lastdata < receivedata)
                {
                    receivedata = Convert.ToInt32(lastdata);
                }

                var count = socket.Receive(file, 0, receivedata, SocketFlags.None); //每次接收的实际长度
                if (count > 0)
                {
                    fs.Write(file, 0, count);
                    offset += count;
                    lastdata -= count;
                    mark = 0;
                }
                else
                {
                    mark++; //连续5次接收为0字节 则跳出循环
                    if (mark == 10)
                    {
                        break;
                    }
                }

                //接收进度
                progress(Convert.ToInt32(Convert.ToDouble(offset) / Convert.ToDouble(size) * 100));
                //接收完毕
                if (offset == size)
                {
                    ret = true;
                    break;
                }
            }

            return ret;
        }

        /// <summary>
        /// 从socket服务端接收文件
        /// </summary>
        /// <param name="socket">socket服务端</param>
        /// <param name="path">文件保存路径(必须存在)</param>
        /// <param name="filename">文件名</param>
        /// <param name="size">预先知道的文件大小</param>
        /// <returns>处理结果</returns>
        public static bool ReceiveFile(this Socket socket, string path, string filename, long size)
        {
            return ReceiveFile(socket, path, filename, size, null);
        }

        /// <summary>
        /// 预先不知道文件名和文件大小 用此方法接收
        /// 此方法对于的发送方法是SendFile()
        /// </summary>
        /// <param name="socket">socket服务端</param>
        /// <param name="path">要保存的目录</param>
        public static void ReceiveFile(this Socket socket, string path)
        {
            //得到包头信息字节数组 (文件名 + 文件大小 的字符串长度)
            //取前8位
            byte[] info_bt = ReceiveFixData(socket, 8);
            //得到包头信息字符长度
            int info_length = GetPacketLength(info_bt);
            //提取包头信息,(文件名 + 文件大小 的字符串长度)
            byte[] info = ReceiveFixData(socket, info_length);
            //得到文件信息字符串 (文件名 + 文件大小)
            string info_str = Encoding.UTF8.GetString(info);
            string[] strs = info_str.Split('|');
            string filename = strs[0]; //文件名
            long length = Convert.ToInt64(strs[1]); //文件大小
            //开始接收文件
            ReceiveFile(socket, path, filename, length);
        }

        private static int GetPacketLength(byte[] length)
        {
            string str = Encoding.UTF8.GetString(length);
            str = str.TrimEnd('*');
            return int.TryParse(str, out var _length) ? _length : 0;
        }

        private static int i;

        private static string markPath = string.Empty;

        /// <summary>
        /// 得到文件路径(防止有文件名重复)
        ///  如:aaa.txt已经在directory目录下存在,则会得到文件aaa(1).txt
        /// </summary>
        /// <param name="directory">目录名</param>
        /// <param name="file">文件名</param>
        /// <returns>文件路径</returns>
        public static string GetPath(string directory, string file)
        {
            if (markPath == string.Empty)
            {
                markPath = Path.Combine(directory, file);
            }

            string path = Path.Combine(directory, file);
            if (File.Exists(path))
            {
                i++;
                string filename = Path.GetFileNameWithoutExtension(markPath) + "(" + i + ")";
                string extension = Path.GetExtension(markPath);
                return GetPath(directory, filename + extension);
            }

            i = 0;
            markPath = string.Empty;
            return path;
        }

        #endregion

        #region Socket发送数据

        /// <summary>
        /// 发送固定长度消息
        /// 发送字节数不能大于int型最大值
        /// </summary>
        /// <param name="socket">源socket</param>
        /// <param name="msg">消息的字节数组</param>
        /// <returns>返回发送字节个数</returns>
        public static int SendFixData(this Socket socket, byte[] msg)
        {
            int size = msg.Length; //要发送字节长度
            int offset = 0; //已经发送长度
            int dataleft = size; //剩下字符
            int senddata = m_maxpacket; //每次发送大小
            while (true)
            {
                //如过剩下的字节数 小于 每次发送字节数
                if (dataleft < senddata)
                {
                    senddata = dataleft;
                }

                int count = socket.Send(msg, offset, senddata, SocketFlags.None);
                offset += count;
                dataleft -= count;
                if (offset == size)
                {
                    break;
                }
            }

            return offset;
        }

        /// <summary>
        /// 发送变长信息 格式 包头(包头占8位) + 正文
        /// </summary>
        /// <param name="socket">发送方socket对象</param>
        /// <param name="contact">发送文本</param>
        /// <returns>发送的数据内容长度</returns>
        public static int SendVarData(this Socket socket, string contact)
        {
            //得到字符长度
            int size = Encoding.UTF8.GetBytes(contact).Length;
            //包头字符
            string length = GetSendPacketLengthStr(size);
            //包头 + 正文
            byte[] sendbyte = Encoding.UTF8.GetBytes(length + contact);
            //发送
            return SendFixData(socket, sendbyte);
        }

        /// <summary>
        /// 发送变成信息
        /// </summary>
        /// <param name="socket">发送方socket对象</param>
        /// <param name="bytes">消息的 字节数组</param>
        /// <returns>消息长度</returns>
        public static int SendVarData(this Socket socket, byte[] bytes)
        {
            //得到包头字节
            int size = bytes.Length;
            string length = GetSendPacketLengthStr(size);
            byte[] lengthbyte = Encoding.UTF8.GetBytes(length);
            //发送包头
            SendFixData(socket, lengthbyte); //因为不知道正文是什么编码所以没有合并
            //发送正文
            return SendFixData(socket, bytes);
        }

        /// <summary>
        /// 发送T类型对象,序列化
        /// </summary>
        /// <typeparam name="T">T类型</typeparam>
        /// <param name="socket">发送方的socket对象</param>
        /// <param name="obj">T类型对象,必须是可序列化的</param>
        /// <returns>消息长度</returns>
        public static int SendSerializeObject<T>(this Socket socket, T obj)
        {
            byte[] bytes = SerializeObject(obj);
            return SendVarData(socket, bytes);
        }

        /// <summary>
        /// 发送文件
        /// </summary>
        /// <param name="socket">socket对象</param>
        /// <param name="path">文件路径</param>
        /// <param name="issend">是否发送文件(头)信息,如果当前知道文件[大小,名称]则为false</param>
        /// <param name="progress">处理过程</param>
        /// <returns>处理结果</returns>
        public static bool SendFile(this Socket socket, string path, bool issend, Action<int> progress)
        {
            if (!File.Exists(path))
            {
                return false;
            }

            var fileinfo = new FileInfo(path);
            string filename = fileinfo.Name;
            long length = fileinfo.Length;
            //发送文件信息
            if (issend)
            {
                SendVarData(socket, filename + "|" + length);
            }

            //发送文件
            long offset = 0;
            byte[] b = new byte[m_maxpacket];
            int mark = 0;
            using var fs = new FileStream(path, FileMode.Open, FileAccess.Read);
            int senddata = b.Length;
            //循环读取发送
            while (true)
            {
                int count = fs.Read(b, 0, senddata);
                if (count > 0)
                {
                    socket.Send(b, 0, count, SocketFlags.None);
                    offset += count;
                    mark = 0;
                }
                else
                {
                    mark++;
                    if (mark == 10)
                    {
                        break;
                    }
                }

                progress(Convert.ToInt32(Convert.ToDouble(offset) / Convert.ToDouble(length) * 100));
                if (offset == length)
                {
                    return true;
                }

                Thread.Sleep(50); //设置等待时间,以免粘包
            }

            return false;
        }

        /// <summary>
        /// 发送文件,不需要进度信息
        /// </summary>
        /// <param name="socket">socket对象</param>
        /// <param name="path">文件路径</param>
        /// <param name="issend">是否发生(头)信息</param>
        /// <returns>处理结果</returns>
        public static bool SendFile(this Socket socket, string path, bool issend)
        {
            return SendFile(socket, path, issend, null);
        }

        /// <summary>
        /// 发送文件,不需要进度信息和(头)信息
        /// </summary>
        /// <param name="socket">socket对象</param>
        /// <param name="path">文件路径</param>
        /// <returns>处理结果</returns>
        public static bool SendFile(this Socket socket, string path)
        {
            return SendFile(socket, path, false, null);
        }

        private static byte[] SerializeObject(object obj)
        {
            IFormatter format = new BinaryFormatter();
            using var stream = new MemoryStream();
            format.Serialize(stream, obj);
            return stream.ToArray();
        }

        private static string GetSendPacketLengthStr(int size)
        {
            string length = size + "********"; //得到size的长度
            return length.Substring(0, 8); //截取前前8位
        }

        #endregion
    }
}