/************************************************************************************
Filename    :   OVRMessenger.cs
Content     :   Base component OVR class
Created     :   January 8, 2013
Authors     :   Peter Giokaris
Copyright   :   Copyright 2014 Oculus VR, LLC. All Rights reserved.

Use of this software is subject to the terms of the Oculus LLC license
agreement provided at the time of installation or download, or which
otherwise accompanies this software in either electronic or hard copy form.

 Messenger.cs from Unity3d: http://wiki.unity3d.com/index.php/Advanced_CSharp_Messenger

 Renamed to OVRMessenger

 * Advanced C# messenger by Ilya Suzdalnitski. V1.0
 * 
 * Based on Rod Hyde's "CSharpMessenger" and Magnus Wolffelt's "CSharpMessenger Extended".
 * 
 * Features:
 	* Prevents a MissingReferenceException because of a reference to a destroyed message handler.
 	* Option to log all messages
 	* Extensive error detection, preventing silent bugs
 * 
 * Usage examples:
 	1. Messenger.AddListener<GameObject>("prop collected", PropCollected);
 	   Messenger.Broadcast<GameObject>("prop collected", prop);
 	2. Messenger.AddListener<float>("speed changed", SpeedChanged);
 	   Messenger.Broadcast<float>("speed changed", 0.5f);
 * 
 * Messenger cleans up its evenTable automatically upon loading of a new level.
 * 
 * Don't forget that the messages that should survive the cleanup, should be marked with Messenger.MarkAsPermanent(string)
 * 

************************************************************************************/
//#define LOG_ALL_MESSAGES
//#define LOG_ADD_LISTENER
//#define LOG_BROADCAST_MESSAGE
//#define REQUIRE_LISTENER

using System;
using System.Collections.Generic;
using UnityEngine;

 // Add more delegate types here and implement them the same way below..
public delegate void OVRCallback();
public delegate void OVRCallback<T>(T arg1);
public delegate void OVRCallback<T, U>(T arg1, U arg2);
public delegate void OVRCallback<T, U, V>(T arg1, U arg2, V arg3);

static internal class OVRMessenger {

#region Internal variables
	//Disable the unused variable warning
#pragma warning disable 0414
	//Ensures that the MessengerHelper will be created automatically upon start of the game.
	static private MessengerHelper messengerHelper = ( new GameObject("MessengerHelper") ).AddComponent< MessengerHelper >();
#pragma warning restore 0414

 	static public Dictionary<string, Delegate> eventTable = new Dictionary<string, Delegate>();

 	//Message handlers that should never be removed, regardless of calling Cleanup
	static public List< string > permanentMessages = new List< string > ();
#endregion

#region Helper methods

	/// <summary>
	/// Marks a certain message as permanent.
	/// </summary>
	/// <param name="eventType">Event type.</param>
    static public void MarkAsPermanent(string eventType) 
    {
#if LOG_ALL_MESSAGES
		Debug.Log("Messenger MarkAsPermanent \t\"" + eventType + "\"");
#endif
		permanentMessages.Add( eventType );
	}

 	/// <summary>
 	/// Cleanup this instance.
 	/// </summary>
	static public void Cleanup()
	{
#if LOG_ALL_MESSAGES
		Debug.Log("MESSENGER Cleanup. Make sure that none of necessary listeners are removed.");
#endif
		List< string > messagesToRemove = new List<string>();

		foreach (KeyValuePair<string, Delegate> pair in eventTable) {
			bool wasFound = false;

			foreach (string message in permanentMessages) {

				if (pair.Key == message) {
					wasFound = true;
					break;
				}
			}

			if (!wasFound)
				messagesToRemove.Add( pair.Key );
		}

 
		foreach (string message in messagesToRemove) {
			eventTable.Remove( message );
		}
	}

	/// <summary>
	/// Prints the event table.
	/// </summary>
	static public void PrintEventTable()
	{
		Debug.Log("\t\t\t=== MESSENGER PrintEventTable ===");

		foreach (KeyValuePair<string, Delegate> pair in eventTable) {
			Debug.Log("\t\t\t" + pair.Key + "\t\t" + pair.Value);
		}

		Debug.Log("\n");
	}
#endregion

 #region Message logging and exception throwing
	/// <summary>
	/// Raises the listener adding event.
	/// </summary>
	/// <param name="eventType">Event type.</param>
	/// <param name="listenerBeingAdded">Listener being added.</param>
    static public void OnListenerAdding(string eventType, Delegate listenerBeingAdded) 
	{
#if LOG_ALL_MESSAGES || LOG_ADD_LISTENER
		Debug.Log("MESSENGER OnListenerAdding \t\"" + eventType + "\"\t{" + listenerBeingAdded.Target + " -> " + listenerBeingAdded.Method + "}");
#endif

        if (!eventTable.ContainsKey(eventType)) {
            eventTable.Add(eventType, null );
        }

        Delegate d = eventTable[eventType];

        if (d != null && d.GetType() != listenerBeingAdded.GetType()) {
            throw new ListenerException(string.Format("Attempting to add listener with inconsistent signature for event type {0}. Current listeners have type {1} and listener being added has type {2}", eventType, d.GetType().Name, listenerBeingAdded.GetType().Name));
        }
    }

	/// <summary>
	/// Raises the listener removing event.
	/// </summary>
	/// <param name="eventType">Event type.</param>
	/// <param name="listenerBeingRemoved">Listener being removed.</param>
    static public void OnListenerRemoving(string eventType, Delegate listenerBeingRemoved) 
	{

#if LOG_ALL_MESSAGES
		Debug.Log("MESSENGER OnListenerRemoving \t\"" + eventType + "\"\t{" + listenerBeingRemoved.Target + " -> " + listenerBeingRemoved.Method + "}");
#endif

        if (eventTable.ContainsKey(eventType)) 
		{
            Delegate d = eventTable[eventType];

            if (d == null) 
			{
                throw new ListenerException(string.Format("Attempting to remove listener with for event type \"{0}\" but current listener is null.", eventType));
            } else if (d.GetType() != listenerBeingRemoved.GetType()) 
			{
                throw new ListenerException(string.Format("Attempting to remove listener with inconsistent signature for event type {0}. Current listeners have type {1} and listener being removed has type {2}", eventType, d.GetType().Name, listenerBeingRemoved.GetType().Name));
            }
        } 
		else 
		{
            throw new ListenerException(string.Format("Attempting to remove listener for type \"{0}\" but Messenger doesn't know about this event type.", eventType));
        }
    }

	/// <summary>
	/// Raises the listener removed event.
	/// </summary>
	/// <param name="eventType">Event type.</param>
    static public void OnListenerRemoved(string eventType) {

        if (eventTable[eventType] == null) {
            eventTable.Remove(eventType);
        }
    }

	/// <summary>
	/// Raises the broadcasting event.
	/// </summary>
	/// <param name="eventType">Event type.</param>
    static public void OnBroadcasting(string eventType) 
	{

#if REQUIRE_LISTENER
        if (!eventTable.ContainsKey(eventType)) {
            throw new BroadcastException(string.Format("Broadcasting message \"{0}\" but no listener found. Try marking the message with Messenger.MarkAsPermanent.", eventType));
        }
#endif
    } 

	/// <summary>
	/// Creates the broadcast signature exception.
	/// </summary>
	/// <returns>The broadcast signature exception.</returns>
	/// <param name="eventType">Event type.</param>
    static public BroadcastException CreateBroadcastSignatureException(string eventType) 
	{
        return new BroadcastException(string.Format("Broadcasting message \"{0}\" but listeners have a different signature than the broadcaster.", eventType));
    }
 
    public class BroadcastException : Exception 
	{
        public BroadcastException(string msg)
            : base(msg) 
		{
        }
    }

    public class ListenerException : Exception 
	{
        public ListenerException(string msg)
            : base(msg) 
		{
        }
    }
#endregion

#region AddListener
	/// <summary>
	/// No parameters.
	/// </summary>
	/// <param name="eventType">Event type.</param>
	/// <param name="handler">Handler.</param>
    static public void AddListener(string eventType, OVRCallback handler) 
	{
        OnListenerAdding(eventType, handler);
        eventTable[eventType] = (OVRCallback)eventTable[eventType] + handler;
    }

	/// <summary>
	/// Single parameter.
	/// </summary>
	/// <param name="eventType">Event type.</param>
	/// <param name="handler">Handler.</param>
	/// <typeparam name="T">The 1st type parameter.</typeparam>
	static public void AddListener<T>(string eventType, OVRCallback<T> handler) 
	{
        OnListenerAdding(eventType, handler);
        eventTable[eventType] = (OVRCallback<T>)eventTable[eventType] + handler;
    }

	/// <summary>
	/// Two parameters.
	/// </summary>
	/// <param name="eventType">Event type.</param>
	/// <param name="handler">Handler.</param>
	/// <typeparam name="T">The 1st type parameter.</typeparam>
	/// <typeparam name="U">The 2nd type parameter.</typeparam>
	static public void AddListener<T, U>(string eventType, OVRCallback<T, U> handler) 
	{
        OnListenerAdding(eventType, handler);
        eventTable[eventType] = (OVRCallback<T, U>)eventTable[eventType] + handler;
    }

	/// <summary>
	/// Three parameters
	/// </summary
	/// <param name="eventType">Event type.</param>
	/// <param name="handler">Handler.</param>
	/// <typeparam name="T">The 1st type parameter.</typeparam>
	/// <typeparam name="U">The 2nd type parameter.</typeparam>
	/// <typeparam name="V">The 3rd type parameter.</typeparam>
	static public void AddListener<T, U, V>(string eventType, OVRCallback<T, U, V> handler) 
	{
        OnListenerAdding(eventType, handler);
        eventTable[eventType] = (OVRCallback<T, U, V>)eventTable[eventType] + handler;
    }
#endregion
 
#region RemoveListener
	/// <summary>
	/// No parameters
	/// </summary>
	/// <param name="eventType">Event type.</param>
	/// <param name="handler">Handler.</param>
    static public void RemoveListener(string eventType, OVRCallback handler) 
	{
        OnListenerRemoving(eventType, handler);   
        eventTable[eventType] = (OVRCallback)eventTable[eventType] - handler;
        OnListenerRemoved(eventType);
    }
 
	/// <summary>
	/// Single parameter
	/// </summary>
	/// <param name="eventType">Event type.</param>
	/// <param name="handler">Handler.</param>
	/// <typeparam name="T">The 1st type parameter.</typeparam>
	static public void RemoveListener<T>(string eventType, OVRCallback<T> handler) 
	{
        OnListenerRemoving(eventType, handler);
        eventTable[eventType] = (OVRCallback<T>)eventTable[eventType] - handler;
        OnListenerRemoved(eventType);
    }

	/// <summary>
	/// Two parameters
	/// </summary>
	/// <param name="eventType">Event type.</param>
	/// <param name="handler">Handler.</param>
	/// <typeparam name="T">The 1st type parameter.</typeparam>
	/// <typeparam name="U">The 2nd type parameter.</typeparam>
	static public void RemoveListener<T, U>(string eventType, OVRCallback<T, U> handler) 
	{
        OnListenerRemoving(eventType, handler);
        eventTable[eventType] = (OVRCallback<T, U>)eventTable[eventType] - handler;
        OnListenerRemoved(eventType);
    }

	/// <summary>
	//Three parameters.
	/// </summary>
	/// <param name="eventType">Event type.</param>
	/// <param name="handler">Handler.</param>
	/// <typeparam name="T">The 1st type parameter.</typeparam>
	/// <typeparam name="U">The 2nd type parameter.</typeparam>
	/// <typeparam name="V">The 3rd type parameter.</typeparam>
	static public void RemoveListener<T, U, V>(string eventType, OVRCallback<T, U, V> handler) 
	{
        OnListenerRemoving(eventType, handler);
        eventTable[eventType] = (OVRCallback<T, U, V>)eventTable[eventType] - handler;
        OnListenerRemoved(eventType);
    }

#endregion

#region Broadcast
    /// <summary>
	/// Broadcast the specified eventType.
	/// </summary>
	/// <param name="eventType">Event type.</param>
    static public void Broadcast(string eventType) 
	{
#if LOG_ALL_MESSAGES || LOG_BROADCAST_MESSAGE
		Debug.Log("MESSENGER\t" + System.DateTime.Now.ToString("hh:mm:ss.fff") + "\t\t\tInvoking \t\"" + eventType + "\"");
#endif
        OnBroadcasting(eventType); 

        Delegate d;
        if (eventTable.TryGetValue(eventType, out d)) {
            OVRCallback callback = d as OVRCallback;
 
            if (callback != null) {
                callback();
            } else {
                throw CreateBroadcastSignatureException(eventType);
            }
        }
    }
 
	/// <summary>
	/// Broadcast the specified eventType and arg1.
	/// </summary>
	/// <param name="eventType">Event type.</param>
	/// <param name="arg1">Arg1.</param>
	/// <typeparam name="T">The 1st type parameter.</typeparam>
    static public void Broadcast<T>(string eventType, T arg1) {
#if LOG_ALL_MESSAGES || LOG_BROADCAST_MESSAGE
		Debug.Log("MESSENGER\t" + System.DateTime.Now.ToString("hh:mm:ss.fff") + "\t\t\tInvoking \t\"" + eventType + "\"");
#endif
        OnBroadcasting(eventType);

        Delegate d;

        if (eventTable.TryGetValue(eventType, out d)) {
            OVRCallback<T> callback = d as OVRCallback<T>;
 
            if (callback != null) {
                callback(arg1);
            } else {
                throw CreateBroadcastSignatureException(eventType);
            }
        }
	}

	/// <summary>
	/// Broadcast the specified eventType, arg1 and arg2.
	/// </summary>
	/// <param name="eventType">Event type.</param>
	/// <param name="arg1">Arg1.</param>
	/// <param name="arg2">Arg2.</param>
	/// <typeparam name="T">The 1st type parameter.</typeparam>
	/// <typeparam name="U">The 2nd type parameter.</typeparam>
    static public void Broadcast<T, U>(string eventType, T arg1, U arg2) 
	{
#if LOG_ALL_MESSAGES || LOG_BROADCAST_MESSAGE
		Debug.Log("MESSENGER\t" + System.DateTime.Now.ToString("hh:mm:ss.fff") + "\t\t\tInvoking \t\"" + eventType + "\"");
#endif
        OnBroadcasting(eventType);
 
        Delegate d;

        if (eventTable.TryGetValue(eventType, out d)) {
            OVRCallback<T, U> callback = d as OVRCallback<T, U>;
 
            if (callback != null) {
                callback(arg1, arg2);
            } else {
                throw CreateBroadcastSignatureException(eventType);
            }
        }
    }
 
	/// <summary>
	/// Broadcast the specified eventType, arg1, arg2 and arg3.
	/// </summary>
	/// <param name="eventType">Event type.</param>
	/// <param name="arg1">Arg1.</param>
	/// <param name="arg2">Arg2.</param>
	/// <param name="arg3">Arg3.</param>
	/// <typeparam name="T">The 1st type parameter.</typeparam>
	/// <typeparam name="U">The 2nd type parameter.</typeparam>
	/// <typeparam name="V">The 3rd type parameter.</typeparam>
    static public void Broadcast<T, U, V>(string eventType, T arg1, U arg2, V arg3) 
	{
#if LOG_ALL_MESSAGES || LOG_BROADCAST_MESSAGE
		Debug.Log("MESSENGER\t" + System.DateTime.Now.ToString("hh:mm:ss.fff") + "\t\t\tInvoking \t\"" + eventType + "\"");
#endif
        OnBroadcasting(eventType);

        Delegate d;
        if (eventTable.TryGetValue(eventType, out d)) {
            OVRCallback<T, U, V> callback = d as OVRCallback<T, U, V>;
 
            if (callback != null) {
                callback(arg1, arg2, arg3);
            } else {
                throw CreateBroadcastSignatureException(eventType);
            }
        }
    }
#endregion
}

/// <summary>
/// Messenger helper.
/// This manager will ensure that the messenger's eventTable will be cleaned up upon loading of a new level.
/// </summary>
public sealed class MessengerHelper : MonoBehaviour 
{
	/// <summary>
	/// Awake this instance.
	/// </summary>
	void Awake ()
	{
		DontDestroyOnLoad(gameObject);	
	}

	/// <summary>
	/// Raises the disable event.
	/// </summary>
	public void OnDisable() 
	{
		OVRMessenger.Cleanup();
	}
}