/**
 * @file lldispatcher.h
 * @brief LLDispatcher class header file.
 *
 * $LicenseInfo:firstyear=2004&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2010, Linden Research, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation;
 * version 2.1 of the License only.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
 * $/LicenseInfo$
 */

#ifndef LL_LLDISPATCHER_H
#define LL_LLDISPATCHER_H

#include <map>
#include <vector>
#include <string>

class LLDispatcher;
class LLMessageSystem;
class LLUUID;

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
// Class LLDispatchHandler
//
// Abstract base class for handling dispatches. Derive your own
// classes, construct them, and add them to the dispatcher you want to
// use.
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

class LLDispatchHandler
{
public:
    typedef std::vector<std::string> sparam_t;
    //typedef std::vector<S32> iparam_t;
    LLDispatchHandler() {}
    virtual ~LLDispatchHandler() {}
    virtual bool operator()(
        const LLDispatcher* dispatcher,
        const std::string& key,
        const LLUUID& invoice,
        const sparam_t& string) = 0;
    //const iparam_t& integers) = 0;
};

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
// Class LLDispatcher
//
// Basic utility class that handles dispatching keyed operations to
// function objects implemented as LLDispatchHandler derivations.
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
class LLDispatcher
{
public:
    typedef std::string key_t;
    typedef std::vector<std::string> keys_t;
    typedef std::vector<std::string> sparam_t;
    //typedef std::vector<S32> iparam_t;

    // construct a dispatcher.
    LLDispatcher();
    virtual ~LLDispatcher();

    // Returns if they keyed handler exists in this dispatcher.
    bool isHandlerPresent(const key_t& name) const;

    // copy all known keys onto keys_t structure
    void copyAllHandlerNames(keys_t& names) const;

    // Call this method with the name of the request that has come
    // in. If the handler is present, it is called with the params and
    // returns the return value from
    bool dispatch(
        const key_t& name,
        const LLUUID& invoice,
        const sparam_t& strings) const;
    //const iparam_t& itegers) const;

    // Add a handler. If one with the same key already exists, its
    // pointer is returned, otherwise returns NULL. This object does
    // not do memory management of the LLDispatchHandler, and relies
    // on the caller to delete the object if necessary.
    LLDispatchHandler* addHandler(const key_t& name, LLDispatchHandler* func);

    // Helper method to unpack the dispatcher message bus
    // format. Returns true on success.
    static bool unpackMessage(
        LLMessageSystem* msg,
        key_t& method,
        LLUUID& invoice,
        sparam_t& parameters);

    static bool unpackLargeMessage(
        LLMessageSystem* msg,
        key_t& method,
        LLUUID& invoice,
        sparam_t& parameters);

protected:
    typedef std::map<key_t, LLDispatchHandler*> dispatch_map_t;
    dispatch_map_t mHandlers;
};

#endif // LL_LLDISPATCHER_H