using System;
using System.Net.Sockets;
using System.Threading.Tasks;
using System.Net;
using SBRL.Utilities;
using System.IO;

namespace PixelServer
{
	/// <summary>
	/// Provides the server component of the Hull Pixelbot server that can be used to control any number of pixel bots at once.
	/// </summary>
	public class PixelServer
	{
		TextWriter logger;
		IPAddress bindAddress = IPAddress.Any;
		int port;

		TcpListener server;
		/// <summary>
		/// Whether the Hull Pixelbot serve is currently active and listening.
		/// </summary>
		public bool Active { get; private set; } = false;
		public IPAddress BindAddress
		{
			get {
				return bindAddress;
			}
			set {
				if (Active == true)
					throw new InvalidOperationException("Error: The bind address can't be changed once the server has started listening!");
				bindAddress = value;
			}
		}
		public int Port
		{
			get {
				return port;
			}
			set {
				if (Active == true)
					throw new InvalidOperationException("Error: The port can't be changed once the server has started listening!");
				port = value;
			}
		}
		public IPEndPoint Endpoint
		{
			get {
				return new IPEndPoint(BindAddress, Port);
			}
		}

		public PixelServer(int inPort, TextWriter inLogger)
		{
			Port = inPort;
			logger = inLogger;
		}
		public PixelServer(int inPort) : this(inPort, Console.Out)
		{
		}

		public async Task Listen()
		{
			server = new TcpListener(Endpoint);
			logger.WriteLine("TCP Listener set up on {0}.", Endpoint);
			Active = true;
			while(true)
			{
				TcpClient nextClient = await server.AcceptTcpClientAsync();
				AsyncTools.ForgetTask(Handle(nextClient));
			}
			// TODO: Add an shutdown CancellationToken thingy here
			//Active = false;
		}

		private async Task Handle(TcpClient client)
		{
			logger.WriteLine("Accepted connection from {0}.", client.Client.RemoteEndPoint);

			using (StreamReader incoming = new StreamReader(client.GetStream()))
			using (StreamWriter outgoing = new StreamWriter(client.GetStream()) { AutoFlush = true })
			{
				string nextLine;
				while((nextLine = await incoming.ReadLineAsync()) != null)
				{
					Console.WriteLine("Got message from client: '{0}'", nextLine.Trim());
				}
			}

			Console.WriteLine("Lost connection from {0}.", client.Client.RemoteEndPoint);
		}
	}
}