<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8" />
    <title>Honestly stolen from BlackSharkDen</title>
    <meta name="viewport" content="initial-scale=1,maximum-scale=1,user-scalable=no" />
    <script src="https://unpkg.com/maplibre-gl@2.4.0/dist/maplibre-gl.js"></script>
    <link href="https://unpkg.com/maplibre-gl@2.4.0/dist/maplibre-gl.css" rel="stylesheet" />
    <style>
      body { margin: 0; padding: 0; }
      #map { position: absolute; top: 0; bottom: 0; width: 100%; }
      #info {
      display: block;
      position: relative;
      margin: 0px auto;
      width: 50%;
      padding: 10px;
      border: none;
      border-radius: 3px;
      font-size: 12px;
      text-align: center;
      color: #222;
      background: #fff;
      }
    </style>
  </head>
  <body>
    <div id="map"></div>
    <pre id="info"></pre>
    <script>
      // const sleep = ms => new Promise(r => setTimeout(r, ms));
      var api_key = "rYNCGwdgATyHCjyDil7t";
      var serverURL = "http://homeplate.close-air.support:8888/";
      var map = new maplibregl.Map({
        center: [42, 42],
        container: "map",
        style: "https://api.maptiler.com/maps/topo-v2/style.json?key="+api_key,
        zoom: 7
      });

      map.on("load", () => { 

        myData = fetchData(serverURL);
        for (chip in myData)
        {
          //latest.push(myData[chip].UnitName);
          let UnitImage = myData[chip].UnitName+"-img";
          let UnitSource = myData[chip].UnitName+"-src";
          let UnitPoint = myData[chip].UnitName+"-point";
          let UnitLong = myData[chip].Longitude;
          let UnitLati = myData[chip].Latitude;
          let UnitCoalition = myData[chip].Coalition;

          map.loadImage(
            "/symbols/"+UnitCoalition+"/plane.png",
            (error, image) => {
              if (error) throw error;
              map.addImage(UnitImage, image);
              map.addSource(UnitSource, { "type": 'geojson', 'data': { 'type': 'FeatureCollection', 'features': [{ 'type': 'Feature', 'geometry': { 'type': 'Point', 'coordinates': [UnitLong, UnitLati] } }] } } );
              map.addLayer({
                'id': UnitPoint,
                'type': 'symbol',
                'source': UnitSource,
                'layout': {
                  'icon-image': UnitImage,
                  'icon-size': 0.25
                }
              }); // map.addLayer()
            }
          ); // map.loadImage()

        };// End for() loop

        // Deletion
        // await sleep(10000);
        // for (chip in myData)
        // {
        //   //latest.push(myData[chip].UnitName);
        //   let UnitImage = myData[chip].UnitName+"-img";
        //   let UnitSource = myData[chip].UnitName+"-src";
        //   let UnitPoint = myData[chip].UnitName+"-point";

        //   if (map.hasImage(UnitImage)) map.removeImage(UnitImage);
        //   if (map.getSource(UnitSource)) map.removeSource(UnitSource);
        //   if (map.getLayer(UnitPoint)) map.removeLayer(UnitPoint);
        // };

      }); // End map.on()


    // function wait(ms){
    //   var start = new Date().getTime();
    //   var end = start;
    //   while(end < start + ms) {
    //     end = new Date().getTime();
    //   };
    // };

      function MGRSString (Lat, Long) { 
        //if (Lat < -80) return 'Too far South' ; if (Lat > 84) return 'Too far North' ;
      
        var c = 1 + Math.floor ((Long+180)/6);
        var e = c*6 - 183 ;
        var k = Lat*Math.PI/180;
        var l = Long*Math.PI/180;
        var m = e*Math.PI/180;
        var n = Math.cos (k);
        var o = 0.006739496819936062*Math.pow (n,2);
        var p = 40680631590769/(6356752.314*Math.sqrt(1 + o));
        var q = Math.tan (k);
        var r = q*q;
        var s = (r*r*r) - Math.pow (q,6);
        var t = l - m;
        var u = 1.0 - r + o;
        var v = 5.0 - r + 9*o + 4.0*(o*o);
        var w = 5.0 - 18.0*r + (r*r) + 14.0*o - 58.0*r*o;
        var x = 61.0 - 58.0*r + (r*r) + 270.0*o - 330.0*r*o;
        var y = 61.0 - 479.0*r + 179.0*(r*r) - (r*r*r);
        var z = 1385.0 - 3111.0*r + 543.0*(r*r) - (r*r*r);
        var aa = p*n*t + (p/6.0*Math.pow (n,3)*u*Math.pow (t,3)) + (p/120.0*Math.pow (n,5)*w*Math.pow (t,5)) + (p/5040.0*Math.pow (n,7)*y*Math.pow (t,7));
        var ab = 6367449.14570093*(k - (0.00251882794504*Math.sin (2*k)) + (0.00000264354112*Math.sin (4*k)) - (0.00000000345262*Math.sin (6*k)) + (0.000000000004892*Math.sin (8*k))) + (q/2.0*p*Math.pow (n,2)*Math.pow (t,2)) + (q/24.0*p*Math.pow (n,4)*v*Math.pow (t,4)) + (q/720.0*p*Math.pow (n,6)*x*Math.pow (t,6)) + (q/40320.0*p*Math.pow (n,8)*z*Math.pow (t,8));
        aa = aa*0.9996 + 500000.0;
        ab = ab*0.9996; if (ab < 0.0) ab += 10000000.0;
        var ad = 'CDEFGHJKLMNPQRSTUVWXX'.charAt (Math.floor (Lat/8 + 10));
        var ae = Math.floor (aa/100000);
        var af = ['ABCDEFGH','JKLMNPQR','STUVWXYZ'][(c-1)%3].charAt (ae-1);
        var ag = Math.floor (ab/100000)%20;
        var ah = ['ABCDEFGHJKLMNPQRSTUV','FGHJKLMNPQRSTUVABCDE'][(c-1)%2].charAt (ag);
        function pad (val) {if (val < 10) {val = '0000' + val} else if (val < 100) {val = '000' + val} else if (val < 1000) {val = '00' + val} else if (val < 10000) {val = '0' + val};return val};
        aa = Math.floor (aa%100000); aa = pad (aa);
        ab = Math.floor (ab%100000); ab = pad (ab);
        return c + ad + ' ' + af + ah + ' ' + aa + ' ' + ab;
      };
      
      map.on('mousemove', function (e) {
        var coordinate = e.lngLat.wrap();
        document.getElementById('info').innerHTML = MGRSString(coordinate.lat, coordinate.lng);
      });

      function fetchData(url)
      {
          var xhr = new XMLHttpRequest();    
          var retval
          
          xhr.open("GET", url, false);
          xhr.send();
          
          return JSON.parse(xhr.responseText)
      }
      
    </script>
  </body>
</html>