using System;
using System.Net;
using System.Net.Sockets;
using System.Text;

namespace AllocsFixes.NetConnections.Servers.Telnet
{
	public class TelnetConnection : IConnection
	{
		private bool authenticated = false;
		private bool authEnabled;
		private TcpClient client;
		private NetworkStream stream;
		private int lineBufferLength = 0;
		private byte[] lineBuffer = new byte[200];
		private EndPoint endpoint;

		public TelnetConnection (TcpClient client, bool authEnabled)
		{
			this.authEnabled = authEnabled;
			this.client = client;
			this.stream = client.GetStream ();
			this.endpoint = client.Client.RemoteEndPoint;
		}

		public EndPoint GetEndPoint ()
		{
			return endpoint;
		}

		private void WriteByte (byte v)
		{
			if (!IsClosed () && stream.CanWrite) {
				stream.WriteByte (v);
			}
		}

		public void WriteLine (string s)
		{
			try {
				if (!IsClosed () && stream.CanWrite) {
					byte[] utfData = Encoding.UTF8.GetBytes (s);
					stream.Write (utfData, 0, utfData.Length);
					WriteByte (13);
					WriteByte (10);
				}
			} catch (Exception e) {
				Log.Out ("Error writing to client: " + e);
			}
		}

		public void Close ()
		{
			if (client != null)
				client.Close ();
			client = null;
		}

		public bool IsClosed ()
		{
			if (client != null && !client.Connected) {
				Log.Out ("Telnet connection interrupted: " + endpoint);
			}
			return (client == null) || (!client.Connected);
		}

		public bool IsAuthenticated ()
		{
			return !authEnabled || authenticated;
		}

		public void SetAuthenticated ()
		{
			authenticated = true;
		}

		public bool Read ()
		{
			while (!IsClosed() && stream.CanRead && stream.DataAvailable) {
				int b = stream.ReadByte ();
				if (b == '\r' || b == '\n') {
					if (lineBufferLength > 0) {
						return true;
					}
				} else if (b >= 0) {
					lineBuffer [lineBufferLength] = (byte)b;
					lineBufferLength++;
				}
			}
			return false;
		}

		public string GetLine ()
		{
			string res = Encoding.UTF8.GetString (lineBuffer, 0, lineBufferLength);
			lineBufferLength = 0;
			return res;
		}

	}
}