self.importScripts("satellite.js");

norad = ""
groundStations = []
TLE = []
Orbits = []

onmessage = function(e) {
    norad = e.data[0]
    TLE = e.data[1]
    getStations()
    getOrbit()
}

setInterval(function(){ 
    getStations()
}, 20000);

setInterval(function(){ 
    var satrec = self.satellite_js.twoline2satrec(TLE[1],TLE[2]);
    var gmst = self.satellite_js.gstime(new Date());
    var positionAndVelocity = self.satellite_js.propagate(satrec, new Date());
    var positionEci = positionAndVelocity.position
    var positionGd    = self.satellite_js.eciToGeodetic(positionEci, gmst)
    var curLat = degress(positionGd.latitude)
    var curLng = degress(positionGd.longitude)
    if (groundStations[1] == undefined){
        groundStations.push([])
    }
    
    postMessage([norad,TLE[0],[curLat,curLng],groundStations[0],groundStations[1],Orbits])
    
    
}, 1000);

function getStations(){
var xhttp = new XMLHttpRequest();
  xhttp.onreadystatechange = function() {
    if (this.readyState == 4 && this.status == 200) {
     groundStations = JSON.parse(this.responseText);
    }
  };
  xhttp.open("GET", "/stations_from_sat/"+norad, true);
  xhttp.send();
}

function degress (radians) {
  return radians * 180 / Math.PI;
};

function getOrbit(){
    var satrec = self.satellite_js.twoline2satrec(TLE[1],TLE[2]); 
    gmst = self.satellite_js.gstime(new Date());
    while(Orbits.length < 300){
    gmst = gmst+0.00833333333
    if (gmst > 6.28318530718){
        return
    }
    positionAndVelocity = self.satellite_js.propagate(satrec, (new Date() / 1000/60));
    positionEci = positionAndVelocity.position
    positionGd    = self.satellite_js.eciToGeodetic(positionEci, gmst)
    Orbits.push([degress(positionGd.latitude),degress(positionGd.longitude)])
    }
}