using UnityEngine;
using System;
using System.Collections;
using System.Net;
using System.Net.Sockets;
using System.Collections.Generic;

public class TestUDP : MonoBehaviour {


    public delegate void RequestReceivedEventHandler(string message);
    public event RequestReceivedEventHandler OnRequestReceived;

    // Use this to trigger the event
    protected virtual void ThisRequestReceived(string message)
    {
        RequestReceivedEventHandler handler = OnRequestReceived;
        if(handler != null)
        {
            handler(message);
        }
    }

    // We use this to keep tasks needed to run in the main thread
    private static readonly Queue<Action> tasks = new Queue<Action>();

    public int requestPort = 55795;

    UdpClient udpRequestSender;
    UdpClient udpRequestReceiver;


    // Use this for initialization
    void Start () {

        // Set up the sender for requests
        this.udpRequestSender = new UdpClient();
        IPEndPoint requestGroupEP = new IPEndPoint(IPAddress.Broadcast, this.requestPort);
        this.udpRequestSender.Connect(requestGroupEP);


        // Set up the receiver for the requests
        // Listen for anyone looking for us
        this.udpRequestReceiver = new UdpClient();
        this.udpRequestReceiver.Client.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, true);
        IPEndPoint requestGroupEP = new IPEndPoint(IPAddress.Any, this.requestPort);
        this.udpRequestReceiver.Client.Bind(requestGroupEP);
        this.udpRequestReceiver.BeginReceive(new AsyncCallback(AsyncRequestReceiveData), null);

        // Listen for the request
        this.OnRequestReceived += (message) => {
            Debug.Log("Request Received: " + message);
            // Do some more stuff when we get a request
            // Use `Network.maxConnections` for example
        };

        // Send out the request
        this.SendRequest();

    }

    void Update () {
        this.HandleTasks();
    }

    void HandleTasks() {
        while (tasks.Count > 0)
        {
            Action task = null;

            lock (tasks)
            {
                if (tasks.Count > 0)
                {
                    task = tasks.Dequeue();
                }
            }

            task();
        }
    }

    public void QueueOnMainThread(Action task)
    {
        lock (tasks)
        {
            tasks.Enqueue(task);
        }
    }

    void SendRequest()
    {
        try
        {
            string message = "requestingServers";

            if (message != "")
            {
                Debug.Log("Sendering Request: " + message);
                this.udpRequestSender.Send(System.Text.Encoding.ASCII.GetBytes(message), message.Length);
            }
        }
        catch (ObjectDisposedException e)
        {
            Debug.LogWarning("Trying to send data on already disposed UdpCleint: " + e);
            return;
        }
    }


    void AsyncRequestReceiveData(IAsyncResult result)
    {
        IPEndPoint receiveIPGroup = new IPEndPoint(IPAddress.Any, this.requestPort);
        byte[] received;
        if (this.udpRequestReceiver != null) {
            received = this.udpRequestReceiver.EndReceive(result, ref receiveIPGroup);
        } else {
            return;
        }
        this.udpRequestReceiver.BeginReceive (new AsyncCallback(AsyncRequestReceiveData), null);
        string receivedString = System.Text.Encoding.ASCII.GetString(received);


        this.QueueOnMainThread(() => {
            // Fire the event
            this.ThisRequestReceived(receivedString);
        });

    }


}