// submodel.cxx - models a releasable submodel.
// Written by Dave Culp, started Aug 2004
//
// This file is in the Public Domain and comes with no warranty.

#include "submodel.hxx"

#include <simgear/structure/exception.hxx>
#include <simgear/misc/sg_path.hxx>

#include <Main/fg_props.hxx>
#include <Main/util.hxx>
#include <AIModel/AIManager.hxx>
#include <AIModel/AIBallistic.hxx>


const double FGSubmodelMgr::lbs_to_slugs = 0.031080950172;

FGSubmodelMgr::FGSubmodelMgr ()
{
    
  x_offset = y_offset = 0.0;
  z_offset = -4.0;
  pitch_offset = 2.0;
  yaw_offset = 0.0;
  
  out[0] = out[1] = out[2] = 0;
  in[3] = out[3] = 1;
  string contents_node;
  contrail_altitude = 30000.0;
}

FGSubmodelMgr::~FGSubmodelMgr ()
{
}

void
FGSubmodelMgr::init ()
{
    load();
    _serviceable_node = fgGetNode("/sim/submodels/serviceable", true);

    _user_lat_node = fgGetNode("/position/latitude-deg", true);
    _user_lon_node = fgGetNode("/position/longitude-deg", true);
    _user_alt_node = fgGetNode("/position/altitude-ft", true);

    _user_heading_node = fgGetNode("/orientation/heading-deg", true);
    _user_pitch_node =   fgGetNode("/orientation/pitch-deg", true);
    _user_roll_node =    fgGetNode("/orientation/roll-deg", true);
    _user_yaw_node =     fgGetNode("/orientation/yaw-deg", true);
    _user_alpha_node =   fgGetNode("/orientation/alpha-deg", true);

    _user_speed_node = fgGetNode("/velocities/uBody-fps", true);

    _user_wind_from_east_node  = fgGetNode("/environment/wind-from-east-fps",true);
    _user_wind_from_north_node = fgGetNode("/environment/wind-from-north-fps",true);

    _user_speed_down_fps_node   = fgGetNode("/velocities/speed-down-fps",true);
    _user_speed_east_fps_node   = fgGetNode("/velocities/speed-east-fps",true);
    _user_speed_north_fps_node  = fgGetNode("/velocities/speed-north-fps",true);

    _contrail_altitude_node = fgGetNode("/environment/params/contrail-altitude", true);
    contrail_altitude = _contrail_altitude_node->getDoubleValue();
    _contrail_trigger = fgGetNode("ai/submodels/contrails", true);
    _contrail_trigger->setBoolValue(false);

    ai = (FGAIManager*)globals->get_subsystem("ai_model");

}

void
FGSubmodelMgr::bind ()
{
}

void
FGSubmodelMgr::unbind ()
{
  submodel_iterator = submodels.begin();
  while(submodel_iterator != submodels.end()) {
    (*submodel_iterator)->prop->untie("count");
    ++submodel_iterator;
  }
}

void
FGSubmodelMgr::update (double dt)
{
  if (!(_serviceable_node->getBoolValue())) return;
  int i=-1;

  _contrail_trigger->setBoolValue(_user_alt_node->getDoubleValue() > contrail_altitude);

  submodel_iterator = submodels.begin();
  while(submodel_iterator != submodels.end()) {
    i++;
    if ((*submodel_iterator)->trigger->getBoolValue()) {
        if ((*submodel_iterator)->count != 0) {
          release( (*submodel_iterator), dt);
        } 
    } else {
      (*submodel_iterator)->first_time = true;
    }  
    ++submodel_iterator;
  }
   
}

bool
FGSubmodelMgr::release (submodel* sm, double dt)
{
  // only run if first time or repeat is set to true
  if (!sm->first_time && !sm->repeat) return false;

  sm->timer += dt;
  if (sm->timer < sm->delay) return false;
  sm->timer = 0.0;

  if (sm->first_time) {
    dt = 0.0;
    sm->first_time = false;
  }

  transform(sm);  // calculate submodel's initial conditions in world-coordinates

  FGAIBallistic* ballist = new FGAIBallistic;
  ballist->setPath(sm->model.c_str());
  ballist->setLatitude(IC.lat);
  ballist->setLongitude(IC.lon);
  ballist->setAltitude(IC.alt);
  ballist->setAzimuth(IC.azimuth);
  ballist->setElevation(IC.elevation);
  ballist->setRoll(IC.roll);
  ballist->setSpeed(IC.speed);
  ballist->setDragArea(sm->drag_area);
  ballist->setLife(sm->life);
  ballist->setBuoyancy(sm->buoyancy);
  ballist->setWind_from_east(IC.wind_from_east);
  ballist->setWind_from_north(IC.wind_from_north);
  ballist->setWind(sm->wind);
  ballist->setCd(sm->cd);
  ballist->setMass(IC.mass);
  ballist->setStabilisation(sm->aero_stabilised);
  ai->attach(ballist);
 
  if (sm->count > 0) (sm->count)--; 

  return true;                    
}

void
FGSubmodelMgr::load ()
{
    SGPropertyNode *path = fgGetNode("/sim/submodels/path");
    SGPropertyNode root;

    if (path) {
      SGPath config( globals->get_fg_root() );
      config.append( path->getStringValue() );

      try {
        readProperties(config.str(), &root);
      } catch (const sg_exception &e) {
        SG_LOG(SG_GENERAL, SG_ALERT,
        "Unable to read submodels file: ");
        cout << config.str() << endl;
        return;
      }
    }

   vector<SGPropertyNode_ptr> children = root.getChildren("submodel");
   vector<SGPropertyNode_ptr>::iterator it = children.begin();
   vector<SGPropertyNode_ptr>::iterator end = children.end();
   for (int i = 0; it != end; ++it, i++) {

     // cout << "Reading submodel " << (*it)->getPath() << endl;
     submodel* sm = new submodel;
     SGPropertyNode * entry_node = *it;
     sm->trigger        = fgGetNode(entry_node->getStringValue("trigger", "none"), true);
     sm->name           = entry_node->getStringValue("name", "none_defined");
     sm->model          = entry_node->getStringValue("model", "Models/Geometry/rocket.ac");
     sm->speed          = entry_node->getDoubleValue("speed", 2329.4 );
     sm->repeat         = entry_node->getBoolValue  ("repeat", false); 
     sm->delay          = entry_node->getDoubleValue("delay", 0.25); 
     sm->count          = entry_node->getIntValue   ("count", 1); 
     sm->slaved         = entry_node->getBoolValue  ("slaved", false); 
     sm->x_offset       = entry_node->getDoubleValue("x-offset", 0.0); 
     sm->y_offset       = entry_node->getDoubleValue("y-offset", 0.0); 
     sm->z_offset       = entry_node->getDoubleValue("z-offset", 0.0); 
     sm->yaw_offset     = entry_node->getDoubleValue("yaw-offset", 0.0); 
     sm->pitch_offset   = entry_node->getDoubleValue("pitch-offset", 0.0);
     sm->drag_area      = entry_node->getDoubleValue("eda", 0.034);
     sm->life           = entry_node->getDoubleValue("life", 900.0);
     sm->buoyancy       = entry_node->getDoubleValue("buoyancy", 0);
     sm->wind           = entry_node->getBoolValue  ("wind", false); 
     sm->first_time     = false;
     sm->cd             = entry_node->getDoubleValue("cd", 0.193);
     sm->weight         = entry_node->getDoubleValue("weight", 0.25);
     sm->aero_stabilised = entry_node->getBoolValue  ("aero-stabilised", true);
     sm->contents_node  = fgGetNode(entry_node->getStringValue("contents", "none"), true);

     sm->trigger->setBoolValue(false);
     sm->timer = sm->delay;
 
     sm->contents = sm->contents_node->getDoubleValue();
 
     sm->prop = fgGetNode("/ai/submodels/submodel", i, true);
     sm->prop->tie("count", SGRawValuePointer<int>(&(sm->count)));
     sm->prop->tie("repeat", SGRawValuePointer<bool>(&(sm->repeat)));

//   sm->prop->tie("contents", SGRawValuePointer<double>(&(sm->contents)));
//   sm->prop->tie("contents path", SGRawValuePointer<const char *>(&(sm->contents_node)));
     submodels.push_back( sm );
   }

  submodel_iterator = submodels.begin();
  
}


void
FGSubmodelMgr::transform( submodel* sm) 
{

// get initial conditions 
 
// get the weight of the contents (lbs) and convert to mass (slugs)
  sm->contents = sm->contents_node->getDoubleValue();
  
  IC.mass = (sm->weight + sm->contents) * lbs_to_slugs;;
//  cout << IC.mass << endl;
    
// set contents to 0 in the parent
   sm->contents_node->setDoubleValue(0); 
    
  IC.lat =        _user_lat_node->getDoubleValue();    
  IC.lon =        _user_lon_node->getDoubleValue();   
  IC.alt =        _user_alt_node->getDoubleValue();    
  IC.roll =       _user_roll_node->getDoubleValue();    // rotation about x axis 
  IC.elevation =  _user_pitch_node->getDoubleValue();   // rotation about y axis 
  IC.azimuth =    _user_heading_node->getDoubleValue(); // rotation about z axis
  
  IC.speed =           _user_speed_node->getDoubleValue();
  IC.wind_from_east =  _user_wind_from_east_node->getDoubleValue();
  IC.wind_from_north = _user_wind_from_north_node->getDoubleValue();
  
  IC.speed_down_fps =   _user_speed_down_fps_node->getDoubleValue();
  IC.speed_east_fps =   _user_speed_east_fps_node->getDoubleValue();
  IC.speed_north_fps =  _user_speed_north_fps_node->getDoubleValue();

  
  in[0] = sm->x_offset;
  in[1] = sm->y_offset;
  in[2] = sm->z_offset; 
 
  
// pre-process the trig functions

    cosRx = cos(-IC.roll * SG_DEGREES_TO_RADIANS);
    sinRx = sin(-IC.roll * SG_DEGREES_TO_RADIANS);
    cosRy = cos(-IC.elevation * SG_DEGREES_TO_RADIANS);
    sinRy = sin(-IC.elevation * SG_DEGREES_TO_RADIANS);
    cosRz = cos(IC.azimuth * SG_DEGREES_TO_RADIANS);
    sinRz = sin(IC.azimuth * SG_DEGREES_TO_RADIANS);

// set up the transform matrix

    trans[0][0] =  cosRy * cosRz;
    trans[0][1] =  -1 * cosRx * sinRz + sinRx * sinRy * cosRz ;
    trans[0][2] =  sinRx * sinRz + cosRx * sinRy * cosRz;

    trans[1][0] =  cosRy * sinRz;
    trans[1][1] =  cosRx * cosRz + sinRx * sinRy * sinRz;
    trans[1][2] =  -1 * sinRx * cosRx + cosRx * sinRy * sinRz;

    trans[2][0] =  -1 * sinRy;
    trans[2][1] =  sinRx * cosRy;
    trans[2][2] =  cosRx * cosRy;


// multiply the input and transform matrices

   out[0] = in[0] * trans[0][0] + in[1] * trans[0][1] + in[2] * trans[0][2];
   out[1] = in[0] * trans[1][0] + in[1] * trans[1][1] + in[2] * trans[1][2];
   out[2] = in[0] * trans[2][0] + in[1] * trans[2][1] + in[2] * trans[2][2];

   // convert ft to degrees of latitude
   out[0] = out[0] /(366468.96 - 3717.12 * cos(IC.lat * SG_DEGREES_TO_RADIANS));

   // convert ft to degrees of longitude
   out[1] = out[1] /(365228.16 * cos(IC.lat * SG_DEGREES_TO_RADIANS));

   // set submodel initial position
   IC.lat += out[0];
   IC.lon += out[1];
   IC.alt += out[2];

   // get aircraft velocity vector angles in XZ and XY planes
    //double alpha = _user_alpha_node->getDoubleValue();
    //double velXZ = IC.elevation - alpha * cosRx;
    //double velXY = IC.azimuth - (IC.elevation - alpha * sinRx);
   
   // Get submodel initial velocity vector angles in XZ and XY planes.
   // This needs to be fixed. This vector should be added to aircraft's vector. 
   IC.elevation += (sm->yaw_offset * sinRx) + (sm->pitch_offset * cosRx);
   IC.azimuth   += (sm->yaw_offset * cosRx) - (sm->pitch_offset * sinRx);
 
   // For now assume vector is close to airplane's vector.  This needs to be fixed.
   //IC.speed += ; 

   // calcuate the total speed north

   IC.total_speed_north = sm->speed * cos(IC.elevation*SG_DEGREES_TO_RADIANS)*
                    cos(IC.azimuth*SG_DEGREES_TO_RADIANS) + IC.speed_north_fps;

   // calculate the total speed east

   IC.total_speed_east = sm->speed * cos(IC.elevation*SG_DEGREES_TO_RADIANS)*
                     sin(IC.azimuth*SG_DEGREES_TO_RADIANS) + IC.speed_east_fps;

   // calculate the total speed down
  
   IC.total_speed_down = sm->speed * -sin(IC.elevation*SG_DEGREES_TO_RADIANS) +
                        IC.speed_down_fps;

  // re-calculate speed, elevation and azimuth

   IC.speed = sqrt( IC.total_speed_north * IC.total_speed_north + 
                    IC.total_speed_east * IC.total_speed_east +
                    IC.total_speed_down * IC.total_speed_down);

   IC.azimuth = atan(IC.total_speed_east/IC.total_speed_north) * SG_RADIANS_TO_DEGREES;
   
   // rationalise the output
   
   if (IC.total_speed_north <= 0){
    IC.azimuth = 180 + IC.azimuth;
   }
   else{
     if(IC.total_speed_east <= 0){
     IC.azimuth = 360 + IC.azimuth;
   }
  }
 
    IC.elevation = -atan(IC.total_speed_down/sqrt(IC.total_speed_north * 
                       IC.total_speed_north + 
                       IC.total_speed_east * IC.total_speed_east)) * SG_RADIANS_TO_DEGREES;

}

void 
FGSubmodelMgr::updatelat(double lat) 
{
    double latitude = lat;
    ft_per_deg_latitude = 366468.96 - 3717.12 * cos(latitude / SG_RADIANS_TO_DEGREES);
    ft_per_deg_longitude = 365228.16 * cos(latitude / SG_RADIANS_TO_DEGREES);
}

// end of submodel.cxx