/**
 * @param  {Float32Array} positions coordinates of line points written
 * like this: [x1, y1, z1, x2, y2, z2, ...]
 * @param  {Float32Array} colors of line points written like this:
 * [x1, y1, z1, x2, y2, z2, ...]
 * @param  {Float32Array} sizes of line points written like this:
 * [size1, size2, ...]
 */
function wideLine(positions, colors, sizes) {
  var vertexShader = [
    "attribute float size;",
    "attribute vec3 customColor;",
    "varying vec3 vColor;",
    "void main() {",
    "vColor = customColor;",
    "vec4 mvPosition = modelViewMatrix * vec4(position, 1.0);",
    "gl_PointSize = size * (300.0 / length(mvPosition.xyz));",
    "gl_Position = projectionMatrix * mvPosition;",
    "}"
  ].join("\n");

  var fragmentShader = [
    "varying vec3 vColor;",
    "void main() {",
    "gl_FragColor = vec4(vColor, 1.0);",
    "}"
  ].join("\n");

  var shaderMaterial = new THREE.ShaderMaterial( {
    vertexShader: vertexShader,
    fragmentShader: fragmentShader
  });

  this.linkGeometry = new THREE.BufferGeometry();

  this.linkGeometry.addAttribute('position', new THREE.BufferAttribute(positions, 3));
  this.linkGeometry.addAttribute('customColor', new THREE.BufferAttribute(colors, 3));
  this.linkGeometry.addAttribute('size', new THREE.BufferAttribute(sizes, 1));

  this.particleMesh = new THREE.PointCloud(this.linkGeometry, shaderMaterial);
  this.particleMesh.dynamic = false;
  this.particleMesh.frustrumCulled = true;
  this.hide();
}

wideLine.prototype.getMesh = function() {
  return this.particleMesh;
};

wideLine.prototype.hide = function() {
  this.linkGeometry.setDrawRange(0, 0);
}

wideLine.prototype.show = function(lBound, uBound) {
  this.linkGeometry.setDrawRange(lBound, uBound);
};
/**
 * draws a set of labeled curves with desired thickness and color
 * is able to hide all curves or show certain curves
 * curves don't have to have unique names
 * @param  {Object[]} data — array of objects, e.g.
 * {
    "name": "TUR",
    "points": splinePoints, //array of THREE.Vector3 points corresponding to a curve
    "color": "#00ffff",
    "size": 0.35, //curve thickness
  }
 */
function wideCurves(data) {
  this.bounds = {};
  var count = 0;
  for (var i = 0; i < data.length; i++) {
    count += data[i].points.length;
  }
  var positions = new Float32Array(count * 3);
  var colors = new Float32Array(count * 3);
  var sizes = new Float32Array(count);
  var offset = 0;
  var name = '';
  var lBound = 0;
  var uBound = 0;
  var writeToBounds = false;

  for (var i = 0; i < data.length; i ++) {
    var points = data[i].points,
      color = new THREE.Color(data[i].color),
      pointsNum = data[i].points.length;

    for (var j = 0; j < pointsNum; j++) {
      positions[offset + j*3] = points[j].x;
      positions[offset + j*3 + 1] = points[j].y;
      positions[offset + j*3 + 2] = points[j].z;
      colors[offset + j*3] = color.r;
      colors[offset + j*3+1] = color.g;
      colors[offset + j*3+2] = color.b;
      sizes[offset/3 + j] = data[i].size;
    }

    if (data[i].name != name) {
      if (lBound != 0 || uBound != 0) {
        this.bounds[name] = [lBound, uBound];
        writeToBounds = false;
      }
      name = data[i].name;
      lBound = offset/3;
      uBound = offset /3 + pointsNum;
      writeToBounds = true;
    } else {
      uBound += pointsNum;
    }

    offset += pointsNum*3;
  }

  if (writeToBounds) {
    this.bounds[name] = [lBound, uBound];
  }

  this.curves = new wideLine(positions, colors, sizes);
  this.uBound = count;
  this.hide();
}

wideCurves.prototype.getMesh = function() {
  return this.curves.getMesh();
}

wideCurves.prototype.hide = function() {
  this.curves.hide();
}

wideCurves.prototype.show = function(name) {
  if (typeof(name) != "undefined") {
    var bounds = this.bounds[name];
    var lBound = bounds[0], uBound = bounds[1];
    this.curves.show(lBound, uBound);
  } else {
    this.curves.show(0, this.uBound);
  }
};