// Generated by CoffeeScript 1.10.0
(function() {
  var closest, drag, get_closest, height, lines_data, lines_layer, perpendicular, points_data, points_layer, redraw, result_layer, svg, width;

  get_closest = function(A, B, P) {
    var C, a_to_b, a_to_p, atb2, atp_dot_atb, maxx, maxy, minx, miny, ref, ref1, t;
    a_to_p = [P.x - A.x, P.y - A.y];
    a_to_b = [B.x - A.x, B.y - A.y];
    atb2 = a_to_b[0] * a_to_b[0] + a_to_b[1] * a_to_b[1];
    atp_dot_atb = a_to_p[0] * a_to_b[0] + a_to_p[1] * a_to_b[1];
    t = atp_dot_atb / atb2;
    C = {
      x: A.x + a_to_b[0] * t,
      y: A.y + a_to_b[1] * t
    };
    minx = Math.min(A.x, B.x);
    maxx = Math.max(A.x, B.x);
    miny = Math.min(A.y, B.y);
    maxy = Math.max(A.y, B.y);
    if ((minx <= (ref = C.x) && ref <= maxx) && (miny <= (ref1 = C.y) && ref1 <= maxy)) {
      return C;
    } else {
      return null;
    }
  };

  points_data = [
    {
      x: -200,
      y: 200
    }, {
      x: 200,
      y: -200
    }, {
      x: 200,
      y: 200
    }
  ];

  lines_data = [
    {
      start: points_data[0],
      end: points_data[1]
    }
  ];

  svg = d3.select('svg');

  width = svg.node().getBoundingClientRect().width;

  height = svg.node().getBoundingClientRect().height;

  svg.attr({
    viewBox: (-width / 2) + " " + (-height / 2) + " " + width + " " + height
  });

  drag = d3.behavior.drag().origin(function(d) {
    return d;
  });

  drag.on('drag', function(d) {
    d.x = d3.event.x;
    d.y = d3.event.y;
    return redraw();
  });

  lines_layer = svg.append('g');

  points_layer = svg.append('g');

  result_layer = svg.append('g');

  closest = result_layer.append('circle').attr({
    "class": 'closest',
    r: 4
  });

  perpendicular = lines_layer.append('line').attr({
    "class": 'perpendicular'
  });

  redraw = function() {
    var closest_data, lines, points;
    lines = lines_layer.selectAll('.line').data(lines_data);
    lines.enter().append('line').attr({
      "class": 'line'
    });
    lines.attr({
      x1: function(l) {
        return l.start.x;
      },
      y1: function(l) {
        return l.start.y;
      },
      x2: function(l) {
        return l.end.x;
      },
      y2: function(l) {
        return l.end.y;
      }
    });
    points = points_layer.selectAll('.point').data(points_data);
    points.enter().append('circle').call(drag).attr({
      "class": 'point',
      r: 8
    });
    points.attr({
      cx: function(p) {
        return p.x;
      },
      cy: function(p) {
        return p.y;
      }
    });
    closest_data = get_closest(points_data[0], points_data[1], points_data[2]);
    closest.attr({
      cx: closest_data != null ? closest_data.x : 0,
      cy: closest_data != null ? closest_data.y : 0,
      display: closest_data != null ? 'inline' : 'none'
    });
    return perpendicular.attr({
      x1: points_data[2].x,
      y1: points_data[2].y,
      x2: closest_data != null ? closest_data.x : 0,
      y2: closest_data != null ? closest_data.y : 0,
      display: closest_data != null ? 'inline' : 'none'
    });
  };

  redraw();

}).call(this);