/**

 * vim: set ts=4 :

 * =============================================================================

 * SourceMod

 * Copyright (C) 2004-2008 AlliedModders LLC.  All rights reserved.

 * =============================================================================

 *

 * This program is free software; you can redistribute it and/or modify it under

 * the terms of the GNU General Public License, version 3.0, as published by the

 * Free Software Foundation.

 * 

 * This program is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS

 * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more

 * details.

 *

 * You should have received a copy of the GNU General Public License along with

 * this program.  If not, see <http://www.gnu.org/licenses/>.

 *

 * As a special exception, AlliedModders LLC gives you permission to link the

 * code of this program (as well as its derivative works) to "Half-Life 2," the

 * "Source Engine," the "SourcePawn JIT," and any Game MODs that run on software

 * by the Valve Corporation.  You must obey the GNU General Public License in

 * all respects for all other code used.  Additionally, AlliedModders LLC grants

 * this exception to all derivative works.  AlliedModders LLC defines further

 * exceptions, found in LICENSE.txt (as of this writing, version JULY-31-2007),

 * or <http://www.sourcemod.net/license.php>.

 *

 * Version: $Id$

 */

#ifndef _INCLUDE_SOURCEMOD_INTERFACE_USERMESSAGES_H_

#define _INCLUDE_SOURCEMOD_INTERFACE_USERMESSAGES_H_

#include <IShareSys.h>

#include <sp_vm_api.h>

#include <IForwardSys.h>

#include <irecipientfilter.h>

namespace google { namespace protobuf {

	class Message;

} };

class bf_write;

/**

 * @file IUserMessages.h

 * @brief Contains functions for advanced usermessage hooking.

 */

#define SMINTERFACE_USERMSGS_NAME		"IUserMessages"

#define SMINTERFACE_USERMSGS_VERSION	4

namespace SourceMod

{

	enum UserMessageType

	{

		UM_BitBuf,

		UM_Protobuf,

	};

	/**

	 * @brief Listens to user messages sent from the server.

	 */

	class IUserMessageListener

	{

	public:

		/**

		 * @brief Called when a hooked user message is sent, regardless of the hook type.

		 *

		 * Note: This is called regardless of the API version, though it only happens if the 

		 * message is successfully sent.

		 *

		 * @param msg_id		Message Id.

		 */

		virtual void OnUserMessageSent(int msg_id)

		{

		}

		/**

		 * @brief Returns the user message API version.

		 */

		virtual unsigned int GetUserMessageAPIVersion()

		{

			return SMINTERFACE_USERMSGS_VERSION;

		}

		/**

		 * @brief Called when a hooked user message hook is finished, regardless of the hook type.

		 *

		 * Note: this is only called if hooked using the new API (version 2 or greater).

		 * 

		 * @param msg_id		Message Id.

		 * @param sent			True if message was sent, false if blocked.

		 */

		virtual void OnPostUserMessage(int msg_id, bool sent)

		{

		}

		virtual UserMessageType GetUserMessageType() const =0;

	};

	class IBitBufUserMessageListener : public IUserMessageListener

	{

	public:

		/**

		 * @brief Called when a hooked user message is being sent 

		 * and all interceptions have finished.

		 *

		 * @param msg_id		Message Id.

		 * @param bf			bf_write structure containing written bytes.

		 * @param pFilter		Recipient filter.

		 */

		virtual void OnUserMessage(int msg_id, bf_write *bf, IRecipientFilter *pFilter)

		{

		}

		/**

		 * @brief Called when a hooked user message is intercepted.

		 * 

		 * @param msg_id		Message Id.

		 * @param bf			bf_write structure containing written bytes.

		 * @param pFilter		Recipient filter.

		 * @return				Pl_Continue to allow message, Pl_Stop or Pl_Handled to scrap it.

		 */

		virtual ResultType InterceptUserMessage(int msg_id, bf_write *bf, IRecipientFilter *pFilter)

		{

			return Pl_Continue;

		}

		virtual UserMessageType GetUserMessageType() const

		{

			return UM_BitBuf;

		}

	};

	class IProtobufUserMessageListener : public IUserMessageListener

	{

	public:

		/**

		 * @brief Called when a hooked user message is being sent 

		 * and all interceptions have finished.

		 *

		 * @param msg_id		Message Id.

		 * @param msg			Protobuf Message structure containing message data.

		 * @param pFilter		Recipient filter.

		 */

		virtual void OnUserMessage(int msg_id, google::protobuf::Message *msg, IRecipientFilter *pFilter)

		{

		}

		/**

		 * @brief Called when a hooked user message is intercepted.

		 * 

		 * @param msg_id		Message Id.

		 * @param msg			Protobuf Message structure containing message data.

		 * @param pFilter		Recipient filter.

		 * @return				Pl_Continue to allow message, Pl_Stop or Pl_Handled to scrap it.

		 */

		virtual ResultType InterceptUserMessage(int msg_id, google::protobuf::Message *msg, IRecipientFilter *pFilter)

		{

			return Pl_Continue;

		}

		virtual UserMessageType GetUserMessageType() const

		{

			return UM_Protobuf;

		}

	};

	#define USERMSG_RELIABLE			(1<<2)		/**< Message will be set to reliable */

	#define USERMSG_INITMSG				(1<<3)		/**< Message will be considered to be an initmsg */

	#define USERMSG_BLOCKHOOKS			(1<<7)		/**< Prevents the message from triggering SourceMod and Metamod hooks */

	/**

	 * @brief Contains functions for hooking user messages.

	 */

	class IUserMessages : public SMInterface

	{

	public:

		virtual unsigned int GetInterfaceVersion()

		{

			return SMINTERFACE_USERMSGS_VERSION;

		}

		virtual const char *GetInterfaceName()

		{

			return SMINTERFACE_USERMSGS_NAME;

		}

	public:

		/**

		 * @brief Finds a message id by name.

		 *

		 * @param msg		Case-sensitive string containing the message.

		 * @return			A message index, or -1 on failure.

		 */

		virtual int GetMessageIndex(const char *msg) =0;

		/**

		 * @brief Sets a hook on a user message.

		 *

		 * @param msg_id		Message Id.

		 * @param pListener		Pointer to an IUserMessageListener.

		 * @param intercept		If true, message will be intercepted rather than merely hooked.

		 * @return				True on success, false otherwise.

		 */

		virtual bool HookUserMessage(int msg_id,

			IUserMessageListener *pListener,

			bool intercept=false) =0;

		/**

		 * @brief Unhooks a user message.

		 *

		 * @param msg_id		Message Id.

		 * @param pListener		Pointer to an IUserMessageListener.

		 * @param intercept		If true, message is removed from interception pool rather than the

		 *						normal hook pool.

		 * @return				True on success, false otherwise.

		 */

		virtual bool UnhookUserMessage(int msg_id,

			IUserMessageListener *pListener,

			bool intercept=false) =0;

		/**

		 * @brief Wrapper around UserMessageBegin for more options.

		 * 

		 * @param msg_id		Message Id.

		 * @param players		Array containing player indexes.

		 * @param playersNum	Number of players in the array.

		 * @param flags			Flags to use for sending the message.

		 * @return				bf_write structure to write message with, or NULL on failure.

		 */

		virtual bf_write *StartBitBufMessage(int msg_id,

			const cell_t players[],

			unsigned int playersNum,

			int flags) =0;

		virtual google::protobuf::Message *StartProtobufMessage(int msg_id,

			const cell_t players[],

			unsigned int playersNum,

			int flags) =0;

		/**

		 * @brief Wrapper around UserMessageEnd for use with StartMessage().

		 * @return				True on success, false otherwise.

		 */

		virtual bool EndMessage() =0;

		/**

		 * @brief Sets a hook on a user message using the newer API (OnPostUserMessage).

		 *

		 * @param msg_id		Message Id.

		 * @param pListener		Pointer to an IUserMessageListener.

		 * @param intercept		If true, message will be intercepted rather than merely hooked.

		 * @return				True on success, false otherwise.

		 */

		virtual bool HookUserMessage2(int msg_id,

			IUserMessageListener *pListener,

			bool intercept=false) =0;

		/**

		 * @brief Unhooks a user message using the newer API (OnPostUserMessage).

		 *

		 * @param msg_id		Message Id.

		 * @param pListener		Pointer to an IUserMessageListener.

		 * @param intercept		If true, message is removed from interception pool rather than the

		 *						normal hook pool.

		 * @return				True on success, false otherwise.

		 */

		virtual bool UnhookUserMessage2(int msg_id,

			IUserMessageListener *pListener,

			bool intercept=false) =0;

		/**

		 * @brief Finds a message name by id.

		 *

		 * @param msgid		The message index.

		 * @param buffer	Buffer string to hold the message name in.

		 * @param maxlength	Size of the buffer.

		 * @return			A message index, or -1 on failure.

		 */

		virtual bool GetMessageName(int msgid, char *buffer, size_t maxlength) const =0;

		/**

		 * @brief Returns usermessage serialization type used for the current engine.

		 *

		 * @return			The supported usermessage type.

		 */

		virtual UserMessageType GetUserMessageType() const =0;

	};

}

#endif //_INCLUDE_SOURCEMOD_INTERFACE_USERMESSAGES_H_