####  piston engine electrical system    ####
####    Syd Adams    ####

var ammeter_ave = 0.0;
var outPut      = "systems/electrical/outputs/";
var BattVolts   = props.globals.getNode("systems/electrical/batt-volts",1);
var Volts       = props.globals.getNode("/systems/electrical/volts",1);
var Amps        = props.globals.getNode("/systems/electrical/amps",1);
var EXT         = props.globals.getNode("/controls/electric/external-power",1);
var switch_list = [];
var output_list = [];
var watt_list   = [];

#var battery = Battery.new(switch-prop,volts,amps,amp_hours,charge_percent,charge_amps);
Battery = {
  new : func(swtch,vlt,amp,hr,chp,cha) {
    m = { parents : [Battery] };
    m.switch = props.globals.getNode(swtch,1);
    m.switch.setBoolValue(0);
    m.ideal_volts = vlt;
    m.ideal_amps = amp;
    m.amp_hours = hr;
    m.charge_percent = chp;
    m.charge_amps = cha;
    return m;
  },
  apply_load : func(load,dt) {
    if (me.switch.getValue()) {
      var amphrs_used = load * dt / 3600.0;
      var percent_used = amphrs_used / me.amp_hours;
      me.charge_percent -= percent_used;
      if ( me.charge_percent < 0.0 ) {
          me.charge_percent = 0.0;
      } elsif ( me.charge_percent > 1.0 ) {
        me.charge_percent = 1.0;
      }
      var output =me.amp_hours * me.charge_percent;
      return output;
    }else {
      return 0;
    }
  },

  get_output_volts : func {
    if (me.switch.getValue()) {
      var x = 1.0 - me.charge_percent;
      var tmp = -(3.0 * x - 1.0);
      var factor = (tmp*tmp*tmp*tmp*tmp + 32) / 32;
      var output =me.ideal_volts * factor;
      return output;
    } else {
      return 0;
    }
  },

  get_output_amps : func {
    if (me.switch.getValue()) {
      var x = 1.0 - me.charge_percent;
      var tmp = -(3.0 * x - 1.0);
      var factor = (tmp*tmp*tmp*tmp*tmp + 32) / 32;
      var output =me.ideal_amps * factor;
      return output;
    } else {
      return 0;
    }
  }
};

# var alternator = Alternator.new(num,switch,rpm_source,rpm_threshold,volts,amps);
Alternator = {
  new : func (num,switch,src,thr,vlt,amp){
    m = { parents : [Alternator] };
    m.switch =  props.globals.getNode(switch,1);
    m.switch.setBoolValue(0);
    m.meter =  props.globals.getNode("systems/electrical/gen-load["~num~"]",1);
    m.meter.setDoubleValue(0);
    m.gen_output =  props.globals.getNode("engines/engine["~num~"]/amp-v",1);
    m.gen_output.setDoubleValue(0);
    m.meter.setDoubleValue(0);
    m.rpm_source =  props.globals.getNode(src,1);
    m.rpm_threshold = thr;
    m.ideal_volts = vlt;
    m.ideal_amps = amp;
    return m;
  },

  apply_load : func(load) {
    var cur_volt=me.gen_output.getValue();
    var cur_amp=me.meter.getValue();
    if (cur_volt >1) {
      var factor=1/cur_volt;
      gout = (load * factor);
      if (gout>1) {
        gout=1;
      }
    } else {
      gout=0;
    }
    if (cur_amp > gout) {
      me.meter.setValue(cur_amp - 0.01);
    }
    if (cur_amp < gout) {
      me.meter.setValue(cur_amp + 0.01);
    }
  },

  get_output_volts : func {
    var out = 0;
    if (me.switch.getBoolValue()) {
      var factor = me.rpm_source.getValue() / me.rpm_threshold;
      if ( factor > 1.0 ) {
        factor = 1.0;
      }
      var out = (me.ideal_volts * factor);
    }
    me.gen_output.setValue(out);
    return out;
  },

  get_output_amps : func {
    var ampout =0;
    if(me.switch.getBoolValue()) {
      var factor = me.rpm_source.getValue() / me.rpm_threshold;
      if ( factor > 1.0 ) {
        factor = 1.0;
      }
      ampout = me.ideal_amps * factor;
    }
    return ampout;
  }
};

var battery = Battery.new("/controls/electric/battery-switch",24,30,34,1.0,7.0);
var alternator1 = Alternator.new(0,"controls/electric/engine[0]/generator","/engines/engine[0]/rpm",100.0,28.0,60.0);

#####################################
setlistener("/sim/signals/fdm-initialized", func {
  BattVolts.setDoubleValue(0);
  init_switches();
  settimer(update_electrical,5);
  print("Electrical System ... ok");
});

init_switches = func() {
  var tprop=props.globals.getNode("controls/electric/ammeter-switch",1);
  tprop.setBoolValue(1);
  tprop=props.globals.getNode("controls/lighting/instrument-lights",1);
  tprop.setBoolValue(0);

  setprop("controls/lighting/instrument-lights-norm",0.8);
  setprop("controls/lighting/instruments-norm",0.8);

  append(switch_list,"controls/engines/engine/starter");
  append(output_list,"starter");
  append(watt_list,10.0);

  append(switch_list,"controls/anti-ice/pitot-heat");
  append(output_list,"pitot-heat");
  append(watt_list,0.5);

  append(switch_list,"controls/lighting/landing-lights");
  append(output_list,"landing-lights");
  append(watt_list,1.0);

# append(switch_list,"controls/lighting/instrument-lights");
# append(output_list,"instrument-lights");
# append(watt_list,0.2);

  append(switch_list,"controls/lighting/beacon-state/state");
  append(output_list,"beacon");
  append(watt_list,0.5);

  append(switch_list,"controls/lighting/nav-lights");
  append(output_list,"nav-lights");
  append(watt_list,0.5);

  append(switch_list,"controls/lighting/strobe-state/state");
  append(output_list,"strobe");
  append(watt_list,0.5);

  append(switch_list,"controls/engines/engine/fuel-pump");
  append(output_list,"fuel-pump");
  append(watt_list,0.5);

  append(switch_list,"controls/electric/avionics-switch");
  append(output_list,"adf");
  append(watt_list,0.2);

  append(switch_list,"controls/electric/avionics-switch");
  append(output_list,"dme");
  append(watt_list,0.2);

# append(switch_list,"controls/electric/avionics-switch");
# append(output_list,"gps");
# append(watt_list,0.5);

  append(switch_list,"controls/electric/avionics-switch");
  append(output_list,"DG");
  append(watt_list,0.2);

  append(switch_list,"controls/electric/avionics-switch");
  append(output_list,"transponder");
  append(watt_list,0.2);

# append(switch_list,"controls/electric/avionics-switch");
# append(output_list,"mk-viii");
# append(watt_list,0.2);

# append(switch_list,"controls/electric/avionics-switch");
# append(output_list,"tacan");
# append(watt_list,0.2);

  append(switch_list,"controls/electric/avionics-switch");
  append(output_list,"turn-coordinator");
  append(watt_list,0.2);

  append(switch_list,"controls/electric/avionics-switch");
  append(output_list,"comm[0]");
  append(watt_list,0.2);

# append(switch_list,"controls/electric/avionics-switch");
# append(output_list,"comm[1]");
# append(watt_list,0.2);

  append(switch_list,"controls/electric/avionics-switch");
  append(output_list,"nav[0]");
  append(watt_list,0.2);

# append(switch_list,"controls/electric/avionics-switch");
# append(output_list,"nav[1]");
# append(watt_list,0.2);

  append(switch_list,"controls/electric/avionics-switch");
  append(output_list,"autopilot");
  append(watt_list,0.2);

  append(switch_list,"controls/electric/avionics-switch");
  append(output_list,"kns80");
  append(watt_list,0.2);

  for(var i=0; i<size(switch_list); i+=1) {
    var tmp = props.globals.getNode(switch_list[i],1);
    tmp.setBoolValue(0);
  }
  setprop("controls/electric/avionics-switch",1);
}

update_virtual_bus = func( dt ) {
  var PWR = getprop("systems/electrical/serviceable");
  var battery_volts = battery.get_output_volts();
  BattVolts.setValue(battery_volts);
  var alternator1_volts = alternator1.get_output_volts();
  var external_volts = 24.0;

  load = 0.0;
  bus_volts = 0.0;
  power_source = nil;

  bus_volts = battery_volts;
  power_source = "battery";

  if (alternator1_volts > bus_volts) {
    bus_volts = alternator1_volts;
    power_source = "alternator1";
  }

  if ( EXT.getBoolValue() and ( external_volts > bus_volts) ) {
    bus_volts = external_volts;
  }

  bus_volts *=PWR;

  load += electrical_bus(bus_volts);

  ammeter = 0.0;

  if ( power_source == "battery" ) {
      ammeter = -load;
  } else {
    ammeter = battery.charge_amps;
  }

  if ( power_source == "battery" ) {
    battery.apply_load( load, dt );
  } elsif ( bus_volts > battery_volts ) {
    battery.apply_load( -battery.charge_amps, dt );
  }

  ammeter_ave = 0.8 * ammeter_ave + 0.2 * ammeter;

  Amps.setValue(ammeter_ave);
  Volts.setValue(bus_volts);
  alternator1.apply_load(load);

  return load;
}

electrical_bus = func(bv) {
  var bus_volts = bv;
  var load = 0.0;
  var srvc = 0.0;

  for(var i=0; i<size(switch_list); i+=1) {
    var srvc = getprop(switch_list[i]);
    load = load + srvc * watt_list[i];
    setprop(outPut~output_list[i],bus_volts * srvc);
  }

  var DIMMER = bus_volts * getprop("controls/lighting/instrument-lights-norm");
  var INSTR_SWTCH = getprop("controls/lighting/instrument-lights");
  DIMMER=DIMMER*INSTR_SWTCH;

  setprop(outPut~"instrument-lights",DIMMER);
  setprop(outPut~"instrument-lights-norm",DIMMER * 0.0357);

  return load;
}

update_electrical = func {
  var scnd = getprop("sim/time/delta-sec");
  update_virtual_bus( scnd );
  settimer(update_electrical, 0);
}
