class GPS {
  parse(data) {
    this.data = data;
    this.index = 0;
    
    this.maxTimeDiff = 3600 * 6;
    this.maxDist = 3000;
    
    this.tracks = [];
    let t;
    while(t = gps.next()) {
      if (t.length > 1)
        this.tracks.push(new Track(t));
    }
    this.regions = this.getRegions();
  }
  next() {
    if(this.index >= this.data.length)
      return;
    let points = [];
    while(this.index < this.data.length - 1) {
      const cur = this.data[this.index];
      const nxt = this.data[this.index+1];
      
      cur.timeDiff = Date.parse(nxt.timestamp) / 1000 - Date.parse(cur.timestamp) / 1000;
      cur.distance = distance(cur, nxt);
      
      if(isNaN(cur.distance))
        cur.distance = 0;
      
      if(cur.speed <= 0) {
        cur.speed = cur.distance / cur.timeDiff * 3.6; // km/h
      }
      
      if(cur.timeDiff > this.maxTimeDiff || cur.distance > this.maxDist) {
        cur.distance = null;
        cur.timeDiff = null;
        cur.speed = null;
        break;
      }
      
      points.push(cur);
      this.index++;
    }
    if(this.index == this.data.length - 1) {
      this.data[this.index].distance = 0;
      this.data[this.index].timeDiff = 0;
      this.data[this.index].speed = 0;
    }
    points.push(this.data[this.index]);
    this.index++;
    
    return points;
  }
  getRegions() {
    var trips = [];
    var s = 0;
    for(let i=0; i<=this.tracks.length; i++) {
      while(i < this.tracks.length - 2) {
        const cur = this.tracks[i].info;
        const nxt = this.tracks[i+1].info;
        if((nxt.startTime - cur.endTime) > 3600 * 24 * 7 || distance(cur.center, nxt.center) > 100000) {
          break;
        }
        i++;
      }
      
      let trip = this.tracks.slice(s, i);
      let dist = trip.reduce((sum, p) => p.info.distance + sum, 0);
      if (dist > 30000) {
        trips.push({
          lat: median(trip.map(v => v.info.center.lat)),
          lng: median(trip.map(v => v.info.center.lng)),
          timestamp: median(trip.map(v => v.info.startTime)),
          distance: dist
        });
      }
      s = i;
    }
    return trips;
  }
  getInfo() {
    let i = {
      points: this.data.length,
      distance: this.tracks.reduce((sum, p) => p.info.distance + sum, 0),
      topSpeed: this.tracks.reduce((max, p) => p.info.topSpeed > max ? p.info.topSpeed : max, 0),
      ascend: this.tracks.reduce((sum, p) => p.info.ascend + sum, 0),
      descend: this.tracks.reduce((sum, p) => p.info.descend + sum, 0),
      movTime: this.tracks.reduce((sum, p) => p.info.movTime + sum, 0),
      totalTime: this.tracks.reduce((sum, p) => p.info.totalTime + sum, 0)
    };
    i.avgSpeed = i.distance / i.movTime * 3.6;
    return i;
  }
}
let trackId = 0;

class Track {
  constructor(data) {
    this.data = data;
    this.id = trackId++;
    
    this.deleted = this.clean();
    this.info = this.getInfo();
  }
  
  clean() {
    let last = this.data[this.data.length-2];
    let speed = last.speed, alt = last.alt;
    let res = [];
    for(let i=this.data.length-2; i>=0; i--) {
      let cur = this.data[i];
      let lst = this.data[i+1];
      if(Math.abs(cur.speed - lst.speed) / cur.timeDiff > 10 || Math.abs(cur.speed - speed) > 50) {
        res.push(this.data.splice(i, 1)[0]);
      } else
      speed = speed * 0.9 + cur.speed * 0.1;
      alt = alt * 0.9 + cur.alt * 0.1;
    }
    return res;
  }
  getInfo() {
    let i = {
      id: this.id,
      points: this.data.length,
      color: getRandomColor(this.data[0].timestamp),
      distance: this.data.reduce((sum, p) => p.distance + sum, 0),
      topSpeed: this.data.reduce((max, p) => p.speed > max ? p.speed : max, this.data[0].speed),
      ascend: 0,
      descend: 0,
      startTime: Date.parse(this.data[0].timestamp) / 1000,
      endTime: Date.parse(this.data[this.data.length-1].timestamp) / 1000,
      movTime: this.data.reduce((sum, p) => p.speed > 2 ? p.timeDiff + sum : sum, 0),
      minLat: this.data.reduce((min, p) => p.lat < min ? p.lat : min, this.data[0].lat),
      maxLat: this.data.reduce((max, p) => p.lat > max ? p.lat : max, this.data[0].lat),
      minLng: this.data.reduce((min, p) => p.lng < min ? p.lng : min, this.data[0].lng),
      maxLng: this.data.reduce((max, p) => p.lng > max ? p.lng : max, this.data[0].lng),
      
    };
    for(let n=1; n<this.data.length; n++) {
      const cur = this.data[n].alt;
      const lst = this.data[n-1].alt;
      if(cur > lst)
        i.ascend  += cur - lst;
      else
        i.descend += lst - cur;
    }
    i.totalAscend = i.ascend - i.descend;
    i.avgSpeed = i.distance / i.movTime * 3.6;
    i.center = this.data[parseInt(this.data.length/2)];
    i.totalTime = i.endTime - i.startTime;
    
    return i;
  }
  
}

function getRandomColor(str) {
  let arr = str.split('');
  let i = Math.abs(arr.reduce(
    (hashCode, currentVal) =>
      (hashCode = currentVal.charCodeAt(0) + (hashCode << 6) + (hashCode << 16) - hashCode),
    0
  ));
  return "hsl(" + (i * 2 % 360) + ", " + (i * 3 % 60 + 40) + "%, " + (i * 5 % 40 + 30) + "%)";
}
function distance (a, b) {
 
  // Convert degrees to radians
  var lat1 = a.lat * Math.PI / 180.0;
  var lon1 = a.lng * Math.PI / 180.0;
 
  var lat2 = b.lat * Math.PI / 180.0;
  var lon2 = b.lng * Math.PI / 180.0;
 
  // radius of earth in metres
  var r = 6378100;
 
  // P
  var rho1 = r * Math.cos(lat1);
  var z1 = r * Math.sin(lat1);
  var x1 = rho1 * Math.cos(lon1);
  var y1 = rho1 * Math.sin(lon1);
 
  // Q
  var rho2 = r * Math.cos(lat2);
  var z2 = r * Math.sin(lat2);
  var x2 = rho2 * Math.cos(lon2);
  var y2 = rho2 * Math.sin(lon2);
 
  // Dot product
  var dot = (x1 * x2 + y1 * y2 + z1 * z2);
  var cos_theta = dot / (r * r);
 
  var theta = Math.acos(cos_theta);
 
  // Distance in Metres
  return r * theta;
}

function timeFormat (sec, x = "time") {
  let d = new Date(sec*1000);
  let t = new Date(null,null,null,null,null,sec).toTimeString().match(/\d{2}:\d{2}:\d{2}/)[0];
  
  switch(x) {
    case "time":
      if(sec < 3600*24)
        return t;
      else
        return Math.floor(sec/3600/24) + "d " + t;
    case "datetime":
      return d.toLocaleDateString('de-DE', {
        year: "numeric",
        month: "2-digit",
        day: "2-digit",
        hour: "2-digit",
        minute: "2-digit",
        second: "2-digit",
      });
    case "date":
      return d.toLocaleDateString('de-DE', {
        year: "numeric",
        month: "2-digit",
        day: "2-digit"
      }); 
    case "short":
      return d.toLocaleDateString('de-DE', {
        year: "numeric",
        month: "2-digit"
      }); 
  }
}
function median(values) {

  values.sort( function(a,b) {return a - b;} );

  var half = Math.floor(values.length/2);

  return values[half];
}
function avg (v) {
  return v.reduce((a,b) => a+b, 0)/v.length;
}

function smoothOut (vector, variance) {
  var t_avg = avg(vector)*variance;
  var ret = Array(vector.length);
  for (var i = 0; i < vector.length; i++) {
    (function () {
      var prev = i>0 ? ret[i-1] : vector[i];
      var next = i<vector.length ? vector[i] : vector[i-1];
      ret[i] = avg([t_avg, avg([prev, vector[i], next])]);
    })();
  }
  return ret;
}