const CompassApp = {
    StopTime:30, // seconds
    DarkTime:40, // seconds
  
    _stopInterval:0,
    _darkInterval:0,
  
    init : function() {
console.log("init");
      Bangle.on("touch", function() { compassApp.touch(); });
      Bangle.setLCDTimeout(0);
      this.touch();
    },
  
    touch : function() {
console.log("touch");
      if (this._stopInterval != 0) {
        clearInterval(this._stopInterval);
      }
      this._stopInterval = setInterval(function() { compassApp.stop(); }, this.StopTime * 1000);

      if (this._darkInterval != 0) {
        clearInterval(this._darkInterval);
      }
      this._darkInterval = setInterval(function() { compassApp.dark(); }, this.DarkTime * 1000);

      Bangle.on('mag', function(mag) { compassApp.update(mag); });
      Bangle.setCompassPower(1);
      Bangle.setLCDPower(1);
    },
  
    stop : function() {
console.log("stop");
      clearInterval(this._stopInterval);
      this._stopInterval = 0;
      Bangle.setCompassPower(0);
      this.drawOff();
    },
  
    dark : function() {
console.log("dark");
      clearInterval(this._darkInterval);
      this._darkInterval = 0;
      Bangle.setLCDPower(0);
    },

    update : function(mag) {
      if (this._stopInterval != 0) {
        this.drawOn(mag);
      }
    },
  
    drawOff : function() {
      g.clear();
      g.setFontVector(20);
      g.setColor(255,255,255);
      this.drawText("Power Saving\nTap for\ncompass");
      g.flip();
    },
  
    drawOn : function(mag) {
      var heading = mag.heading;
      
      var radius = Math.min(g.getWidth(), g.getHeight());
      var fullsize = radius * 0.47;
      var smallsize = radius * 0.43;
      var xc = g.getWidth()/2;
      var yc = g.getHeight()/2;
      
      g.setColor(0,0,0);
      g.clear();
      g.setColor(0,0,255);
      g.fillCircle(xc, yc, fullsize);
      g.setColor(0,0,0);
      g.fillCircle(xc, yc, smallsize);
      g.setColor(255,255,255);
      g.drawCircle(xc, yc, fullsize);
      
      var w=0.1;
      var h=0.2;
      g.setColor(255,0,0);
      this.fillTriangle(heading-180, fullsize, 0,1, 0+2*w,1-2*h, 0-2*w,1-2*h); 
      g.setColor(255,0,255);
      this.fillTriangle(heading-90, fullsize, 0,1, 0+w,1-h, 0-w,1-h); 
      this.fillTriangle(heading, fullsize, 0,1, 0+w,1-h, 0-w,1-h); 
      this.fillTriangle(heading+90, fullsize, 0,1, 0+w,1-h, 0-w,1-h); 
      
      w/=2;
      this.fillTriangle(heading-315, fullsize, 0,1, 0+w,1-h, 0-w,1-h); 
      this.fillTriangle(heading-225, fullsize, 0,1, 0+w,1-h, 0-w,1-h); 
      this.fillTriangle(heading-135, fullsize, 0,1, 0+w,1-h, 0-w,1-h); 
      this.fillTriangle(heading-45, fullsize, 0,1, 0+w,1-h, 0-w,1-h); 
      this.fillTriangle(heading+45, fullsize, 0,1, 0+w,1-h, 0-w,1-h); 
      this.fillTriangle(heading+135, fullsize, 0,1, 0+w,1-h, 0-w,1-h); 
      this.fillTriangle(heading+225, fullsize, 0,1, 0+w,1-h, 0-w,1-h); 
      this.fillTriangle(heading+315, fullsize, 0,1, 0+w,1-h, 0-w,1-h); 
      
      g.setFontVector(20);
      g.setColor(0,255,0);
      
      var text = "NORTH";
      if (this.nearest(heading, 22.5)) {
        text = "N-NW";
      } else if (this.nearest(heading, 45)) {
        text = "NW";
      } else if (this.nearest(heading, 67.5)) {
        text = "W-NW";
      } else if (this.nearest(heading, 90)) {
        text = "WEST";
      } else if (this.nearest(heading, 112.5)) {
        text = "W-SW";
      } else if (this.nearest(heading, 135)) {
        text = "SW";
      } else if (this.nearest(heading, 157.5)) {
        text = "S-SW";
      } else if (this.nearest(heading, 180)) {
        text = "SOUTH";
      } else if (this.nearest(heading, 202.5)) {
        text = "S-SE";
      } else if (this.nearest(heading, 225)) {
        text = "SE";
      } else if (this.nearest(heading, 247.5)) {
        text = "E-SE";
      } else if (this.nearest(heading, 270)) {
        text = "EAST";
      } else if (this.nearest(heading, 292.5)) {
        text = "E-NE";
      } else if (this.nearest(heading, 315)) {
        text = "NE";
      } else if (this.nearest(heading, 337.5)) {
        text = "N-NE";
      }
      this.drawText(text);
      g.flip();
    },

    drawText : function(str) {
      var split = str.split('\n');
      var lines = split.length;
      
      var yy = (g.getHeight() - g.getFontHeight() * lines)/2;
      for (var line in split) {
        var t = split[line];
        g.drawString(t, (g.getWidth() - g.stringWidth(t))/2, yy);
        yy += g.getFontHeight();
      }
    },
  
    fillTriangle : function(heading, radius, x1,y1, x2,y2, x3,y3) {
      var xc = g.getWidth()/2;
      var yc = g.getWidth()/2;
      var verts = [ radius*x1,radius*y1, radius*x2,radius*y2, radius*x3,radius*y3 ];
      console.log(verts);
      var rotated = g.transformVertices(verts, { x:xc, y:yc, scale:1, rotate:heading*3.1415/180 });
      g.fillPoly(rotated);
    },
  
    nearest : function(heading,angle) {
      return (heading > angle - 11.25) && (heading <= angle + 11.25);
    },

};

var compassApp = Object.create(CompassApp);
compassApp.init();