// FGAIStorm - FGAIBase-derived class creates an AI thunderstorm or cloud
//
// Written by David Culp, started Feb 2004.
//
// SPDX-FileCopyrightText: Copyright (C) 2004  David P. Culp - davidculp2@comcast.net
// SPDX-License-Identifier: GPL-2.0-or-later

#include <cmath>
#include <cstdlib>
#include <string>
#include <time.h>

#include <Main/fg_props.hxx>
#include <Main/globals.hxx>
#include <Scenery/scenery.hxx>

#include "AIStorm.hxx"


FGAIStorm::FGAIStorm() : FGAIBase(object_type::otStorm, false)
{
   delay = 3.6;
   subflashes = 1;
   timer = 0.0;
   random_delay = 3.6;
   flash_node = fgGetNode("/environment/lightning/flash", true);
   flash_node->setBoolValue(false);
   flashed = 0;
   flashing = false;
   subflash_index = -1;
   subflash_array[0] =  1;
   subflash_array[1] =  2;
   subflash_array[2] =  1;
   subflash_array[3] =  3;
   subflash_array[4] =  2;
   subflash_array[5] =  1;
   subflash_array[6] =  1;
   subflash_array[7] =  2;

   turb_mag_node = fgGetNode("/environment/turbulence/magnitude-norm", true);
   turb_rate_node = fgGetNode("/environment/turbulence/rate-hz", true);
}


void FGAIStorm::readFromScenario(SGPropertyNode* scFileNode) {
  if (!scFileNode)
    return;

  FGAIBase::readFromScenario(scFileNode);

  setDiameter(scFileNode->getDoubleValue("diameter-ft", 0.0)/6076.11549);
  setHeight(scFileNode->getDoubleValue("height-msl", 5000.0));
  setStrengthNorm(scFileNode->getDoubleValue("strength-norm", 1.0));
}

void FGAIStorm::update(double dt) {
   FGAIBase::update(dt);
   Run(dt);
   Transform();
}


void FGAIStorm::Run(double dt) {
   double speed_north_deg_sec;
   double speed_east_deg_sec;

   // convert speed to degrees per second
    speed_north_deg_sec = cos(hdg / SG_RADIANS_TO_DEGREES) * speed * 1.686 / ft_per_deg_lat;
    speed_east_deg_sec = sin(hdg / SG_RADIANS_TO_DEGREES) * speed * 1.686 / ft_per_deg_lon;

   // set new position
   pos.setLatitudeDeg( pos.getLatitudeDeg() + speed_north_deg_sec * dt);
   pos.setLongitudeDeg(pos.getLongitudeDeg() + speed_east_deg_sec * dt);

   // do calculations for weather radar display
   UpdateRadar(manager);

   // **************************************************
   // *     do lightning                               *
   // **************************************************

   if (timer > random_delay) {
     srand((unsigned)time(0));
     random_delay = delay + (rand()%3) - 1.0;
     //cout << "random_delay = " << random_delay << endl;
     timer = 0.0;
     flashing = true;
     subflash_index++;
     if (subflash_index == 8) subflash_index = 0;
     subflashes = subflash_array[subflash_index];
   }

   if (flashing) {
     if (flashed < subflashes) {
         timer += dt;
         if (timer < 0.1) {
             flash_node->setBoolValue(true);
         } else {
             flash_node->setBoolValue(false);
             if (timer > 0.2) {
                 timer = 0.0;
                 flashed++;
             }
         }
     } else {
       flashing = false;
       timer = 0.0;
       flashed = 0;
     }
    } else {
     timer += dt;
    }

   // ***************************************************
   // *      do turbulence                              *
   // ***************************************************

   // copy user's position from the AIManager
   double d = dist(SGVec3d::fromGeod(pos), globals->get_aircraft_position_cart());
   double rangeNm =  d * SG_METER_TO_NM;
   double user_altitude = globals->get_aircraft_position().getElevationFt();

   if (rangeNm < (diameter * 0.5) &&
       user_altitude > (altitude_ft - 1000.0) &&
       user_altitude < height) {
              turb_mag_node->setDoubleValue(strength_norm);
              turb_rate_node->setDoubleValue(0.5);
   }
}
