using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO;

namespace pyxis.gemini.Protocol
{
	public class Server
	{
		private Request _request;

		private const int CONNECTION_BUFFER_SIZE = 2048;
		private byte[] _connection_buffer;
		private int _connection_buffer_length;

		public delegate void RequestEventDelegate(Server sender, Request request);
		public event RequestEventDelegate OnRequest;

		public Server()
		{
			this._connection_buffer = new byte[CONNECTION_BUFFER_SIZE];
			this._connection_buffer_length = 0;
		}

		public void Receive(byte[] data, int length)
		{
			// Copy read bytes into connection buffer
			for (int i = 0; i < length; i++)
			{
				if (i >= CONNECTION_BUFFER_SIZE)
				{
					throw new System.Exception("Connection buffer overflow");
				}
				this._connection_buffer[i + this._connection_buffer_length] = data[i];
			}

			this._connection_buffer_length += length;

			Request r;
			int consumed = Request.Parse(this._connection_buffer, this._connection_buffer_length, out r);

			if (consumed == 0)
			{
				if (length == 0)
				{
					throw new System.Exception("Stream closed without receiving request");
				}
				else
				{
					return;
				}
			}

			if (consumed != this._connection_buffer_length)
			{
				throw new Exception.ProtocolViolationException("Received trailing bytes after request");
			}

			if (this.OnRequest != null)
			{
				this.OnRequest(this, r);
			}
		}

	}
}