using PUtility;
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.IO.Compression;
using System.Linq;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading.Tasks;

namespace PComm
{
	public class PClient
	{
		private readonly int BUFF_SIZE = 8192;

		public delegate void ClientReceivedHandler(PClient sender, PDataType dataType, byte[] data);
		public event ClientReceivedHandler OnReceived;

		public delegate void ClientDisconnectedHandler(PClient sender);
		public event ClientDisconnectedHandler Disconnected;

		public string ID { get; set; }

		public IPEndPoint EndPoint { get; private set; }

		public bool Connected { get { return socket.Connected; } }

		public bool DataCompression { get; set; } = false;

		private Socket socket;

		public PClient(string ip, int port, string id = null)
		{
			if (string.IsNullOrEmpty(id))
				id = Guid.NewGuid().ToString();

			socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
			this.ID = id;
			this.EndPoint = new IPEndPoint(IPAddress.Parse(ip), port);
			socket.Connect(this.EndPoint);

			// send ID
			this.Send(PDataType.ClientID, Encoding.UTF8.GetBytes(this.ID));

			socket.BeginReceive(new byte[] { 0 }, 0, 0, 0, AcceptCallback, null);
		}

		public PClient(Socket accepted)
		{
			if (string.IsNullOrEmpty(this.ID))
				this.ID = Guid.NewGuid().ToString();

			socket = accepted;
			this.EndPoint = (IPEndPoint)socket.RemoteEndPoint;
			socket.BeginReceive(new byte[] { 0 }, 0, 0, 0, AcceptCallback, null);
		}

		public void Reconnect()
		{
			if (socket.Connected)
				return;

			socket.Connect(this.EndPoint);
			
			this.Send(PDataType.ClientID, Encoding.UTF8.GetBytes(this.ID));

			socket.BeginReceive(new byte[] { 0 }, 0, 0, 0, AcceptCallback, null);
		}

		private int SendData(byte[] data)
		{
			byte[] toSendData;
			// 데이터 크기 100B 이하 또는 50MB 이상 압축하지 않음 (CPU 부하시간 더 큼)
			// 압축한 경우 1 전송, 아닌경우 0 전송
			if (DataCompression == false || data.Length <= 100 || data.Length >= 50000000)
			{
				byte[] isCompressed = BitConverter.GetBytes(false);
				socket.Send(isCompressed, SocketFlags.None);
				toSendData = data;
			}
			else
			{
				byte[] isCompressed = BitConverter.GetBytes(true);
				socket.Send(isCompressed, SocketFlags.None);
				toSendData = PUtil.CompressBytes(data, CompressionLevel.Optimal);
			}

			byte[] length = BitConverter.GetBytes(toSendData.Length);
			socket.Send(length, 0, 4, SocketFlags.None);

			return socket.Send(toSendData, SocketFlags.None);
		}

		public int Send(string msg)
		{
			socket.Send(BitConverter.GetBytes((int)PDataType.SimpleString), 0, 4, 0);
			byte[] data = Encoding.UTF8.GetBytes(msg);
			//byte[] length = BitConverter.GetBytes(data.Length);
			//socket.Send(length, 0, 4, 0);

			//return socket.Send(data, SocketFlags.None);
			return SendData(data);
		}

		public int Send(PDataType dataType, byte[] data)
		{
			socket.Send(BitConverter.GetBytes((int)dataType), 0, 4, 0);
			//byte[] length = BitConverter.GetBytes(data.Length);
			//socket.Send(length, 0, 4, 0);

			//return socket.Send(data, SocketFlags.None);
			return SendData(data);
		}

		private void AcceptCallback(IAsyncResult ar)
		{
			try
			{
				socket.EndReceive(ar);

				// get data type
				byte[] dataTypeBuff = new byte[4];
				socket.Receive(dataTypeBuff, dataTypeBuff.Length, SocketFlags.None);
				PDataType dataType = (PDataType)BitConverter.ToInt32(dataTypeBuff, 0);

				// check compressed
				byte[] isCompressedBuff = new byte[1];
				socket.Receive(isCompressedBuff, isCompressedBuff.Length, SocketFlags.None);
				bool isCompressed = BitConverter.ToBoolean(isCompressedBuff, 0);

				// get data size
				byte[] sizeBuff = new byte[4];
				socket.Receive(sizeBuff, sizeBuff.Length, SocketFlags.None);
				int dataSize = BitConverter.ToInt32(sizeBuff, 0);
				

				using (MemoryStream ms = new MemoryStream())
				{
					while (dataSize > 0)
					{
						byte[] buff;
						if (dataSize < BUFF_SIZE)
							buff = new byte[dataSize];
						else
							buff = new byte[BUFF_SIZE];

						int receiveSize = socket.Receive(buff, buff.Length, SocketFlags.None);

						ms.Write(buff, 0, buff.Length);
						dataSize -= receiveSize;
					}

					byte[] receivedData = ms.ToArray();
					byte[] data;
					if (isCompressed)
						data = PUtil.DecompressBytes(receivedData);
					else
						data = receivedData;

					if (OnReceived != null)
						OnReceived(this, dataType, data);

					socket.BeginReceive(new byte[] { 0 }, 0, 0, 0, AcceptCallback, null);
				}
			}
			catch (Exception ex)
			{
				Debug.WriteLine($"[ERROR] CleintAcceptCallback: {ex.Message}");
				PFileManager.Instance.WriteLog($"[ERROR] CleintAcceptCallback: {ex.Message}");

				if (CheckSocketConnection(socket))
				{
					socket.BeginReceive(new byte[] { 0 }, 0, 0, 0, AcceptCallback, null);
				}
				else
				{
					Debug.WriteLine($"[ERROR] Close socket {socket.RemoteEndPoint.ToString()}");
					PFileManager.Instance.WriteLog($"[ERROR] Close socket {socket.RemoteEndPoint.ToString()}");

					Close();

					if (Disconnected != null)
						Disconnected(this);
				}
			}
		}

		private bool CheckSocketConnection(Socket socket)
		{
			bool availability = socket.Available == 0;
			bool poll = socket.Poll(1000, SelectMode.SelectRead);
			if (availability && poll)
				return false;
			else
				return true;
		}

		public void Close()
		{
			socket.Close();
			socket.Dispose();
		}
	}
}