/**
 * @file llspeakingindicatormanager.cpp
 * @author Mike Antipov
 * @brief Implementation of SpeackerIndicatorManager class to process registered LLSpeackerIndicator
 * depend on avatars are in the same voice channel.
 *
 * $LicenseInfo:firstyear=2010&license=viewerlgpl$
 * 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
 * $/LicenseInfo$
 */

#include "llviewerprecompiledheaders.h"
#include "llspeakingindicatormanager.h"


#include "llvoicechannel.h"
#include "llvoiceclient.h"

/**
 * This class intended to control visibility of avatar speaking indicators depend on whether avatars
 * are in the same voice channel.
 *
 * Speaking indicator should be visible for avatars in the same voice channel. See EXT-3976.
 *
 * It stores passed instances of LLOutputMonitorCtrl in a multimap by avatar LLUUID.
 * It observes changing of voice channel and changing of participant list in voice channel.
 * When voice channel or voice participant list is changed it updates visibility of an appropriate
 * speaking indicator.
 *
 * Several indicators can be registered for the same avatar.
 */
class SpeakingIndicatorManager : public LLSingleton<SpeakingIndicatorManager>, LLVoiceClientParticipantObserver
{
    LLSINGLETON(SpeakingIndicatorManager);
    ~SpeakingIndicatorManager();
    LOG_CLASS(SpeakingIndicatorManager);

protected:
    void                cleanupSingleton() override;

public:

    /**
     * Stores passed speaking indicator to control its visibility.
     *
     * Registered indicator is set visible if an appropriate avatar is in the same voice channel with Agent.
     * It ignores instances of Agent's indicator.
     *
     * @param speaker_id LLUUID of an avatar whose speaking indicator is registered.
     * @param speaking_indicator instance of the speaking indicator to be registered.
     * @param session_id session UUID for which indicator should be shown only.
     *      If this parameter is set registered indicator will be shown only in voice channel
     *      which has the same session id (EXT-5562).
     */
    void registerSpeakingIndicator(const LLUUID& speaker_id, LLSpeakingIndicator* const speaking_indicator,
        const LLUUID& session_id = LLUUID::null);

    /**
     * Removes passed speaking indicator from observing.
     *
     * @param speaker_id LLUUID of an avatar whose speaking indicator should be unregistered.
     * @param speaking_indicator instance of the speaking indicator to be unregistered.
     */
    void unregisterSpeakingIndicator(const LLUUID& speaker_id, const LLSpeakingIndicator* const speaking_indicator);

    /**
     * Callback of changing voice participant list (from LLVoiceClientParticipantObserver).
     *
     * Switches off indicators had been switched on and switches on indicators of current participants list.
     * There is only a few indicators in lists should be switched off/on.
     * So, method does not calculate difference between these list it only switches off already
     * switched on indicators and switches on indicators of voice channel participants
     */
    void onParticipantsChanged() override;

private:
    typedef std::set<LLUUID> speaker_ids_t;
    typedef std::multimap<LLUUID, LLSpeakingIndicator*> speaking_indicators_mmap_t;
    typedef speaking_indicators_mmap_t::value_type speaking_indicator_value_t;
    typedef speaking_indicators_mmap_t::const_iterator indicator_const_iterator;
    typedef std::pair<indicator_const_iterator, indicator_const_iterator> indicator_range_t;

    /**
     * Callback to determine when voice channel is changed.
     *
     * It switches all registered speaking indicators off.
     * To reduce overheads only switched on indicators are processed.
     */
    void sOnCurrentChannelChanged(const LLUUID& session_id);

    /**
     * Changes state of indicators specified by LLUUIDs
     *
     * @param speakers_uuids - avatars' LLUUIDs whose speaking indicators should be switched
     * @param switch_on - if true specified indicator will be switched on, off otherwise.
     */
    void switchSpeakerIndicators(const speaker_ids_t& speakers_uuids, bool switch_on);

    /**
     * Ensures that passed instance of Speaking Indicator does not exist among registered ones.
     * If yes, it will be removed.
     */
    void ensureInstanceDoesNotExist(LLSpeakingIndicator* const speaking_indicator);


    /**
     * Multimap with all registered speaking indicators
     */
    speaking_indicators_mmap_t mSpeakingIndicators;

    /**
     * LUUIDs of avatar for which we have speaking indicators switched on.
     *
     * Is used to switch off all previously ON indicators when voice participant list is changed.
     *
     * @see onChange()
     */
    speaker_ids_t mSwitchedIndicatorsOn;

    boost::signals2::connection mVoiceChannelChanged;
};

//////////////////////////////////////////////////////////////////////////
// PUBLIC SECTION
//////////////////////////////////////////////////////////////////////////
void SpeakingIndicatorManager::registerSpeakingIndicator(const LLUUID& speaker_id, LLSpeakingIndicator* const speaking_indicator,
                                                         const LLUUID& session_id)
{
    // do not exclude agent's indicators. They should be processed in the same way as others. See EXT-3889.

    LL_DEBUGS("SpeakingIndicator") << "Registering indicator: " << speaker_id << "|"<< speaking_indicator << ", session: " << session_id << LL_ENDL;


    ensureInstanceDoesNotExist(speaking_indicator);

    speaking_indicator->setTargetSessionID(session_id);

    speaking_indicator_value_t value_type(speaker_id, speaking_indicator);
    mSpeakingIndicators.insert(value_type);

    speaker_ids_t speakers_uuids;
    bool is_in_same_voice = LLVoiceClient::getInstance()->isParticipant(speaker_id);

    speakers_uuids.insert(speaker_id);
    switchSpeakerIndicators(speakers_uuids, is_in_same_voice);
}

void SpeakingIndicatorManager::unregisterSpeakingIndicator(const LLUUID& speaker_id, const LLSpeakingIndicator* const speaking_indicator)
{
    LL_DEBUGS("SpeakingIndicator") << "Unregistering indicator: " << speaker_id << "|"<< speaking_indicator << LL_ENDL;
    speaking_indicators_mmap_t::iterator it;
    it = mSpeakingIndicators.find(speaker_id);
    for (;it != mSpeakingIndicators.end(); ++it)
    {
        if (it->second == speaking_indicator)
        {
            LL_DEBUGS("SpeakingIndicator") << "Unregistered." << LL_ENDL;
            mSpeakingIndicators.erase(it);
            break;
        }
    }
}

//////////////////////////////////////////////////////////////////////////
// PRIVATE SECTION
//////////////////////////////////////////////////////////////////////////
SpeakingIndicatorManager::SpeakingIndicatorManager()
{
    mVoiceChannelChanged = LLVoiceChannel::setCurrentVoiceChannelChangedCallback(boost::bind(&SpeakingIndicatorManager::sOnCurrentChannelChanged, this, _1));
    LLVoiceClient::addObserver(this);
}

SpeakingIndicatorManager::~SpeakingIndicatorManager()
{
}

void SpeakingIndicatorManager::cleanupSingleton()
{
    // Don't use LLVoiceClient::getInstance() here without a check,
    // singleton MAY have already been destroyed.
    LLVoiceClient::removeObserver(this);
}

void SpeakingIndicatorManager::sOnCurrentChannelChanged(const LLUUID& /*session_id*/)
{
    switchSpeakerIndicators(mSwitchedIndicatorsOn, false);
    mSwitchedIndicatorsOn.clear();
}

void SpeakingIndicatorManager::onParticipantsChanged()
{
    LL_DEBUGS("SpeakingIndicator") << "Voice participant list was changed, updating indicators" << LL_ENDL;

    speaker_ids_t speakers_uuids;
    LLVoiceClient::getInstance()->getParticipantList(speakers_uuids);

    LL_DEBUGS("SpeakingIndicator") << "Switching all OFF, count: " << mSwitchedIndicatorsOn.size() << LL_ENDL;
    // switch all indicators off
    switchSpeakerIndicators(mSwitchedIndicatorsOn, false);
    mSwitchedIndicatorsOn.clear();

    LL_DEBUGS("SpeakingIndicator") << "Switching all ON, count: " << speakers_uuids.size() << LL_ENDL;
    // then switch current voice participants indicators on
    switchSpeakerIndicators(speakers_uuids, true);
}

void SpeakingIndicatorManager::switchSpeakerIndicators(const speaker_ids_t& speakers_uuids, bool switch_on)
{
    LLVoiceChannel* voice_channel = LLVoiceChannel::getCurrentVoiceChannel();
    LLUUID session_id;
    if (voice_channel)
    {
        session_id = voice_channel->getSessionID();
    }

    speaker_ids_t::const_iterator it_uuid = speakers_uuids.begin();
    for (; it_uuid != speakers_uuids.end(); ++it_uuid)
    {
        LL_DEBUGS("SpeakingIndicator") << "Looking for indicator: " << *it_uuid << LL_ENDL;
        indicator_range_t it_range = mSpeakingIndicators.equal_range(*it_uuid);
        indicator_const_iterator it_indicator = it_range.first;
        bool was_found = false;
        bool was_switched_on = false;
        for (; it_indicator != it_range.second; ++it_indicator)
        {
            was_found = true;
            LLSpeakingIndicator* indicator = (*it_indicator).second;
            was_switched_on = was_switched_on || switch_on;

            indicator->switchIndicator(switch_on);
        }

        if (was_found)
        {
            LL_DEBUGS("SpeakingIndicator") << mSpeakingIndicators.count(*it_uuid) << " indicators were found" << LL_ENDL;

            if (switch_on && !was_switched_on)
            {
                LL_DEBUGS("SpeakingIndicator") << "but none of them were switched on" << LL_ENDL;
            }

            if (was_switched_on)
            {
                // store switched on indicator to be able switch it off
                mSwitchedIndicatorsOn.insert(*it_uuid);
            }
        }
    }
}

void SpeakingIndicatorManager::ensureInstanceDoesNotExist(LLSpeakingIndicator* const speaking_indicator)
{
    LL_DEBUGS("SpeakingIndicator") << "Searching for an registered indicator instance: " << speaking_indicator << LL_ENDL;
    speaking_indicators_mmap_t::iterator it = mSpeakingIndicators.begin();
    for (;it != mSpeakingIndicators.end(); ++it)
    {
        if (it->second == speaking_indicator)
        {
            LL_DEBUGS("SpeakingIndicator") << "Found" << LL_ENDL;
            break;
        }
    }

    // It is possible with LLOutputMonitorCtrl the same instance of indicator is registered several
    // times with different UUIDs. This leads to crash after instance is destroyed because the
    // only one (specified by UUID in unregisterSpeakingIndicator()) is removed from the map.
    // So, using stored deleted pointer leads to crash. See EXT-4782.
    if (it != mSpeakingIndicators.end())
    {
        LL_WARNS() << "The same instance of indicator has already been registered, removing it: " << it->first << "|"<< speaking_indicator << LL_ENDL;
        llassert(it == mSpeakingIndicators.end());
        mSpeakingIndicators.erase(it);
    }
}


/************************************************************************/
/*         LLSpeakingIndicatorManager namespace implementation          */
/************************************************************************/

void LLSpeakingIndicatorManager::registerSpeakingIndicator(const LLUUID& speaker_id, LLSpeakingIndicator* const speaking_indicator,
                                                           const LLUUID& session_id)
{
    SpeakingIndicatorManager::instance().registerSpeakingIndicator(speaker_id, speaking_indicator, session_id);
}

void LLSpeakingIndicatorManager::unregisterSpeakingIndicator(const LLUUID& speaker_id, const LLSpeakingIndicator* const speaking_indicator)
{
    if(SpeakingIndicatorManager::instanceExists())
    {
        SpeakingIndicatorManager::instance().unregisterSpeakingIndicator(speaker_id, speaking_indicator);
    }
}

void LLSpeakingIndicatorManager::updateSpeakingIndicators()
{
    if(SpeakingIndicatorManager::instanceExists())
    {
        SpeakingIndicatorManager::instance().onParticipantsChanged();
    }
}

// EOF