/** 
 * @file llviewercommunication.cpp
 * @brief LLViewerCommunication definition
 * @author Dale Glass
 *
 * Copyright (c) 2005-2007, Linden Research, Inc.
 * 
 * Second Life Viewer Source Code
 * The source code in this file ("Source Code") is provided by Linden Lab
 * to you under the terms of the GNU General Public License, version 2.0
 * ("GPL"), unless you have obtained a separate licensing agreement
 * ("Other License"), formally executed by you and Linden Lab.  Terms of
 * the GPL can be found in doc/GPL-license.txt in this distribution, or
 * online at http://secondlife.com/developers/opensource/gplv2
 * 
 * There are special exceptions to the terms and conditions of the GPL as
 * it is applied to this Source Code. View the full text of the exception
 * in the file doc/FLOSS-exception.txt in this software distribution, or
 * online at http://secondlife.com/developers/opensource/flossexception
 * 
 * By copying, modifying or distributing this software, you acknowledge
 * that you have read and understood your obligations described above,
 * and agree to abide by those obligations.
 * 
 * ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO
 * WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY,
 * COMPLETENESS OR PERFORMANCE.
 */

#ifndef LL_LLVIEWERCOMMUNICATION_H
#define LL_LLVIEWERCOMMUNICATION_H

#include <map>

/**
 * @brief Viewer/LSL script communication circuit
 * This object describes a connection between the viewer and an object.
 *
 * When an object sends a message to the viewer, the LLViewerCommunication class
 * calls the registered callback, and passes a reference to this object so that 
 * it can reply to the request.
 */
class LLViewerCircuit
{
public:
	LLViewerCircuit(U32 channel) : mChannel(channel) {};
	LLViewerCircuit() : mChannel(0) {}

	/**
	 * @brief Returns the chat channel the object requested
	 */
	U32 getChannel() const { return mChannel; }

	/**
	 * @brief Sends a reply to the object that made the request
	 * @param data Text to send
	 */
	void sendReply(const LLString& data);
protected:
	U32 mChannel;
};



typedef void(*viewer_extension_callback_t)(LLString& data, LLViewerCircuit& circuit, void *user_data);


/**
 * @brief Viewer extension class
 * Describes a Second Life viewer extension
 */
class LLViewerExtension
{
public:
	/**
	 * @brief Creates a LLViewerExtension
	 * @param name Extension name
	 * @param version Extension's version
	 * @param callback Callback to call when a script tries to communicate with this extension
	 * @param user_data arbitrary data to pass to the callback
	 * @param author Extension's author
	 * @param description Extension's description
	 */
	LLViewerExtension(const LLString& name = "<unknown>", const U32 version = 0, viewer_extension_callback_t callback = NULL, void *user_data = NULL, const LLString& author = "", const LLString& description = "") :
		mName(name), mAuthor(author), mDescription(description), mVersion(version), mCallback(callback), mUserData(user_data) {};

	LLString asString() const { return mName; }

	LLString getName() const { return mName; }
	LLString getAuthor() const { return mAuthor; }
	LLString getDescription() const { return mDescription; }
	U32 getVersion() const { return mVersion; }

	/**
	 * @brief Notifies the extension that a message has arrived
	 * @param data String the object sent to the extension
	 * @param circuit Circuit between viewer and object. Used to reply to the request.
	 */
	void notify(LLString& data, LLViewerCircuit& circuit) { mCallback(data, circuit, mUserData); }
protected:
	LLString mName;
	LLString mAuthor;
	LLString mDescription;
	U32 mVersion;

	viewer_extension_callback_t mCallback;
	void *mUserData;
};



/**
 * @brief Implements viewer/object communication
 * This object manages the process by registering extensions and handling
 * parsing of the protocol
 */
class LLViewerCommunication
{
public:
	LLViewerCommunication();

	/**
	 * @brief Parses a chat message and extracts protocol data from it if present
	 * @param text Chat message
	 * @param speaker Speaker's key
	 * @returns TRUE if the message was a protocol message, FALSE otherwise.
	 */
	bool parse(const LLString &text, const LLUUID& speaker);
	bool parse(char *text, const LLUUID& speaker) { LLString tmp = text; return parse(tmp, speaker); }

	void registerExtension(LLViewerExtension ext) { mExtensions[ext.getName()] = ext; }
	

protected:
	std::map<LLString, LLViewerExtension> mExtensions;
	std::map<LLUUID, LLViewerCircuit> mCircuits;
};

extern LLViewerCommunication *gViewerCommunication;

#endif