// fg_fx.cxx -- Sound effect management class implementation
//
// Started by David Megginson, October 2001
// (Reuses some code from main.cxx, probably by Curtis Olson)
//
// Copyright (C) 2001  Curtis L. Olson - http://www.flightgear.org/~curt
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License as
// published by the Free Software Foundation; either version 2 of the
// License, or (at your option) any later version.
//
// 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, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
//
// $Id$

#ifdef _MSC_VER
#pragma warning (disable: 4786)
#endif

#ifdef HAVE_CONFIG_H
#  include <config.h>
#endif

#include "fg_fx.hxx"

#include <simgear/debug/logstream.hxx>
#include <simgear/structure/exception.hxx>
#include <simgear/misc/sg_path.hxx>
#include <simgear/props/props.hxx>
#include <simgear/sound/xmlsound.hxx>
#include <simgear/sound/soundmgr_openal.hxx>

#include <Main/fg_props.hxx>

#include <simgear/scene/model/placement.hxx>
#include <Model/acmodel.hxx>
#include <Main/viewer.hxx>

FGFX::FGFX () :
    last_visitor_pos(SGVec3d::zeros()),
    last_model_pos(SGVec3d::zeros()),
    last_pause( true ),
    last_volume( 0.0 ),
    _pause( fgGetNode("/sim/sound/pause") ),
    _volume( fgGetNode("/sim/sound/volume") )
{
}

FGFX::~FGFX ()
{
    unsigned int i;
    for ( i = 0; i < _sound.size(); i++ ) {
        delete _sound[i];
    }
    _sound.clear();

    while ( _samplequeue.size() > 0 ) {
        delete _samplequeue.front();
        _samplequeue.pop();
    }
}

void
FGFX::init()
{
    SGPropertyNode *node = fgGetNode("/sim/sound", true);

    string path_str = node->getStringValue("path");
    SGPath path( globals->get_fg_root() );
    if (path_str.empty()) {
        SG_LOG(SG_GENERAL, SG_ALERT, "No path in /sim/sound/path");
        return;
    }

    path.append(path_str.c_str());
    SG_LOG(SG_GENERAL, SG_INFO, "Reading sound " << node->getName()
           << " from " << path.str());

    SGPropertyNode root;
    try {
        readProperties(path.str(), &root);
    } catch (const sg_exception &) {
        SG_LOG(SG_GENERAL, SG_ALERT,
               "Error reading file '" << path.str() << '\'');
        return;
    }

    node = root.getNode("fx");
    if(node) {
        for (int i = 0; i < node->nChildren(); ++i) {
            SGXmlSound *sound = new SGXmlSound();
  
            try {
                sound->init(globals->get_props(), node->getChild(i),
                            globals->get_soundmgr(), globals->get_fg_root());
  
                _sound.push_back(sound);
            } catch ( sg_exception &e ) {
                SG_LOG(SG_GENERAL, SG_ALERT, e.getFormattedMessage());
                delete sound;
            }
        }
    }
}

void
FGFX::reinit()
{
   _sound.clear();
   init();
};

void
FGFX::bind ()
{
}

void
FGFX::unbind ()
{
}

void
FGFX::update (double dt)
{
    SGSoundMgr *smgr = globals->get_soundmgr();

    if (smgr->is_working() == false) {
        return;
    }

    // command sound manger
    bool pause = _pause->getBoolValue();
    if ( pause != last_pause ) {
        if ( pause ) {
            smgr->pause();
        } else {
            smgr->resume();
        }
        last_pause = pause;
    }

    // process mesage queue
    const string msgid = "Sequential Audio Message";
    bool is_playing = false;
    if ( smgr->exists( msgid ) ) {
        if ( smgr->is_playing( msgid ) ) {
            // still playing, do nothing
            is_playing = true;
        } else {
            // current message finished, stop and remove
            smgr->stop( msgid );   // removes source
            smgr->remove( msgid ); // removes buffer
        }
    }
    if ( !is_playing ) {
        // message queue idle, add next sound if we have one
        if ( _samplequeue.size() > 0 ) {
            smgr->add( _samplequeue.front(), msgid );
            _samplequeue.pop();
            smgr->play_once( msgid );
        }
    }

    double volume = _volume->getDoubleValue();
    if ( volume != last_volume ) {
        smgr->set_volume( volume );        
        last_volume = volume;
    }

    if ( !pause ) {
        // update sound effects if not paused
        for ( unsigned int i = 0; i < _sound.size(); i++ ) {
            _sound[i]->update(dt);
        }
    }
}

void
FGFX::update_fx_late(double dt)
{
  SGSoundMgr *smgr = globals->get_soundmgr();
  if (!smgr->is_working()) {
    return;
  }

  smgr->update(dt);
  update_pos_and_orientation(smgr, dt);
}

/**
 * add a sound sample to the message queue which is played sequentially
 * in order.
 */
void
FGFX::play_message( SGSoundSample *_sample )
{
    _samplequeue.push( _sample );
}
void
FGFX::play_message( const std::string& path, const std::string& fname, double volume )
{
    if (globals->get_soundmgr()->is_working() == true) {
        SGSoundSample *sample;
        sample = new SGSoundSample( path.c_str(), fname.c_str() );
        sample->set_volume( volume );
        play_message( sample );
    }
}

void
FGFX::update_pos_and_orientation(SGSoundMgr *smgr, double dt)
{
    SGModelPlacement *model = globals->get_aircraft_model()->get3DModel();
    FGViewer *observer = globals->get_current_view();

    // Right now we make a simplifying assumption that the primary
    // aircraft is the source of all sounds and that all sounds are
    // positioned in the aircraft base
    // EMH: Note: this is fine, to hear multiple aircraft simulataniously
    //      we just have to trigger one instance of the FGFX class for every
    //      aircraft

    // get the orientation
    const SGQuatd view_or = observer->getViewOrientation();
    SGQuatd surf_or = SGQuatd::fromLonLat(observer->getPosition());
    
    SGQuatd model_or = SGQuatd::fromYawPitchRollDeg(
                                model->getHeadingDeg(),
                                model->getPitchDeg(),
                                model->getRollDeg());

    // get the up and at vector in the aircraft base
    // (ok, the up vector is a down vector, but the coordinates
    // are finally calculated in a left hand system and openal
    // lives in a right hand system. Therefore we need to pass
    // the down vector to get correct stereo sound.)
    SGVec3d sgv_up
      = model_or.rotateBack(surf_or.rotateBack(view_or.rotate(SGVec3d(0,1,0))));
    SGVec3d sgv_at
      = model_or.rotateBack(surf_or.rotateBack(view_or.rotate(SGVec3d(0,0,1))));

    // get the location data for the primary FDM (now hardcoded to ac model)...
    // EMH: to add multiple sound sources this should be replaced
    SGVec3d absolute_view_pos = SGVec3d::fromGeod(model->getPosition());

    // calculate speed of visitor and model
    SGVec3d moved = last_visitor_pos - observer->get_view_pos();
    last_visitor_pos = observer->get_view_pos();
    SGVec3f listener_vel(model_or.rotateBack(surf_or.rotateBack(moved)));

    moved = last_model_pos - absolute_view_pos;
    last_model_pos = absolute_view_pos;
    SGVec3f model_vel(model_or.rotateBack(surf_or.rotateBack(moved)));
    
    if (dt > 0) {
      model_vel /= dt;
      listener_vel /= dt;
    }

    // checking, if the listener pos has moved suddenly
    if (length(listener_vel) > 1000) {
        // check if the relative speed model vs listener has moved suddenly, too
        SGVec3f delta_vel = listener_vel - model_vel;
        if (length(delta_vel) > 1000)
            // a sane value
            smgr->set_listener_vel(model_vel.data());
        else
            smgr->set_listener_vel(listener_vel.data());
    } else {
      smgr->set_listener_vel( listener_vel.data());
    }
    
    // set positional offset for sources
    SGVec3d dsource_pos_offset = observer->get_view_pos() - absolute_view_pos;
    dsource_pos_offset = model_or.rotateBack(surf_or.rotateBack(
                                   dsource_pos_offset
                                ));

    smgr->set_source_pos_all( SGVec3f(dsource_pos_offset).data() );
    smgr->set_source_vel_all(model_vel.data() );

    float orient[6];
    for (int i = 0; i < 3; i++) {
        orient[i] = sgv_at[i];
        orient[i + 3] = sgv_up[i];
    }
    smgr->set_listener_orientation( orient );

    // The listener is always positioned at the origin.
    smgr->set_listener_pos( SGVec3f::zeros().data() );
}

// end of fg_fx.cxx