/*
 * Shape Shifter
 * http://www.kennethcachia.com/shape-shifter
 * A canvas experiment
 */

'use strict';

var S = {
  init: function () {
    var action = window.location.href,
        i = action.indexOf('?a=');

    S.Drawing.init('.canvas');
    S.ShapeBuilder.init();
    S.UI.init();
    document.body.classList.add('body--ready');

    if (i !== -1) {
      S.UI.simulate(decodeURI(action).substring(i + 3));
    } else {
      S.UI.simulate('zhou|chuan|yu|love you|#countdown 3|| suprise');
    }

    S.Drawing.loop(function () {
      S.Shape.render();
    });
  }
};


window.addEventListener('load', function () {
  S.init();
});


S.Drawing = (function () {
  var canvas,
      context,
      renderFn,
      requestFrame = window.requestAnimationFrame       ||
                     window.webkitRequestAnimationFrame ||
                     window.mozRequestAnimationFrame    ||
                     window.oRequestAnimationFrame      ||
                     window.msRequestAnimationFrame     ||
                     function (callback) {
                        window.setTimeout(callback, 1000 / 60);
                      };

  return {
    init: function (el) {
      canvas = document.querySelector(el);
      context = canvas.getContext('2d');
      this.adjustCanvas();

      window.addEventListener('resize', function () {
        S.Drawing.adjustCanvas();
      });
    },

    loop: function (fn) {
      renderFn = !renderFn ? fn : renderFn;
      this.clearFrame();
      renderFn();
      requestFrame.call(window, this.loop.bind(this));
    },

    adjustCanvas: function () {
      canvas.width = window.innerWidth;
      canvas.height = window.innerHeight;
    },

    clearFrame: function () {
      context.clearRect(0, 0, canvas.width, canvas.height);
    },

    getArea: function () {
      return { w: canvas.width, h: canvas.height };
    },

    drawCircle: function (p, c) {
      context.fillStyle = c.render();
      context.beginPath();
      context.arc(p.x, p.y, p.z, 0, 2 * Math.PI, true);
      context.closePath();
      context.fill();
    }
  };
}());


S.Point = function (args) {
  this.x = args.x;
  this.y = args.y;
  this.z = args.z;
  this.a = args.a;
  this.h = args.h;
};


S.Color = function (r, g, b, a) {
  this.r = r;
  this.g = g;
  this.b = b;
  this.a = a;
};

S.Color.prototype = {
  render: function () {
    return 'rgba(' + this.r + ',' + this.g + ',' + this.b + ',' + this.a + ')';
  }
};


S.UI = (function () {
  var input = document.querySelector('.ui-input'),
      ui = document.querySelector('.ui'),
      help = document.querySelector('.help'),
      commands = document.querySelector('.commands'),
      overlay = document.querySelector('.overlay'),
      canvas = document.querySelector('.canvas'),
      interval,
      isTouch = ('ontouchstart' in window || navigator.msMaxTouchPoints),
      currentAction,
      resizeTimer,
      time,
      maxShapeSize = 30,
      firstAction = true,
      sequence = [],
      cmd = '#';

  function formatTime(date) {
    var h = date.getHours(),
        m = date.getMinutes();

    m = m < 10 ? '0' + m : m;
    return h + ':' + m;
  }

  function getValue(value) {
    return value && value.split(' ')[1];
  }

  function getAction(value) {
    value = value && value.split(' ')[0];
    return value && value[0] === cmd && value.substring(1);
  }

  function timedAction(fn, delay, max, reverse) {
    clearInterval(interval);
    currentAction = reverse ? max : 1;
    fn(currentAction);

    if (!max || (!reverse && currentAction < max) || (reverse && currentAction > 0)) {
      interval = setInterval(function () {
        currentAction = reverse ? currentAction - 1 : currentAction + 1;
        fn(currentAction);

        if ((!reverse && max && currentAction === max) || (reverse && currentAction === 0)) {
          clearInterval(interval);
        }
      }, delay);
    }
  }

  function reset(destroy) {
    clearInterval(interval);
    sequence = [];
    time = null;

    if (destroy) {
      S.Shape.switchShape(S.ShapeBuilder.letter(''));
    }
  }

  function performAction(value) {
    var action,
        current;

    overlay.classList.remove('overlay--visible');
    sequence = typeof(value) === 'object' ? value : sequence.concat(value.split('|'));
    input.value = '';
    checkInputWidth();

    timedAction(function () {
      current = sequence.shift();
      action = getAction(current);
      value = getValue(current);

      switch (action) {
      case 'countdown':
        value = parseInt(value, 10) || 10;
        value = value > 0 ? value : 10;

        timedAction(function (index) {
          if (index === 0) {
            if (sequence.length === 0) {
              S.Shape.switchShape(S.ShapeBuilder.letter(''));
            } else {
              performAction(sequence);
            }
          } else {
            S.Shape.switchShape(S.ShapeBuilder.letter(index), true);
          }
        }, 1000, value, true);
        break;

      case 'rectangle':
        value = value && value.split('x');
        value = (value && value.length === 2) ? value : [maxShapeSize, maxShapeSize / 2];

        S.Shape.switchShape(S.ShapeBuilder.rectangle(Math.min(maxShapeSize, parseInt(value[0], 10)), Math.min(maxShapeSize, parseInt(value[1], 10))));
        break;

      case 'circle':
        value = parseInt(value, 10) || maxShapeSize;
        value = Math.min(value, maxShapeSize);
        S.Shape.switchShape(S.ShapeBuilder.circle(value));
        break;

      case 'time':
        var t = formatTime(new Date());

        if (sequence.length > 0) {
          S.Shape.switchShape(S.ShapeBuilder.letter(t));
        } else {
          timedAction(function () {
            t = formatTime(new Date());
            if (t !== time) {
              time = t;
              S.Shape.switchShape(S.ShapeBuilder.letter(time));
            }
          }, 1000);
        }
        break;

      case 'icon':
        S.ShapeBuilder.imageFile('font-awesome/' + value + '.png', function (obj) {
          S.Shape.switchShape(obj);
        });
        break;

      default:
        S.Shape.switchShape(S.ShapeBuilder.letter(current[0] === cmd ? 'What?' : current));
      }
    }, 2000, sequence.length);
  }

  function checkInputWidth() {
    if (input.value.length > 18) {
      ui.classList.add('ui--wide');
    } else {
      ui.classList.remove('ui--wide');
    }

    if (firstAction && input.value.length > 0) {
      ui.classList.add('ui--enter');
    } else {
      ui.classList.remove('ui--enter');
    }
  }

  function bindEvents() {
    document.body.addEventListener('keydown', function (e) {
      input.focus();

      if (e.keyCode === 13) {
        firstAction = false;
        reset();
        performAction(input.value);
      }
    });

    window.addEventListener('resize', function () {
      clearTimeout(resizeTimer);
      resizeTimer = setTimeout(function () {
        S.Shape.shuffleIdle();
        reset(true);
      }, 500);
    });

    input.addEventListener('input', checkInputWidth);
    input.addEventListener('change', checkInputWidth);
    input.addEventListener('focus', checkInputWidth);

    help.addEventListener('click', function () {
      overlay.classList.toggle('overlay--visible');

      if (overlay.classList.contains('overlay--visible')) {
        reset(true);
      }
    });

    commands.addEventListener('click', function (e) {
      var el,
          info,
          demo,
          url;

      if (e.target.classList.contains('commands-item')) {
        el = e.target;
      } else {
        el = e.target.parentNode.classList.contains('commands-item') ? e.target.parentNode : e.target.parentNode.parentNode;
      }

      info = el && el.querySelector('.commands-item-info');
      demo = el && info.getAttribute('data-demo');
      url = el && info.getAttribute('data-url');

      if (info) {
        overlay.classList.remove('overlay--visible');

        if (demo) {
          input.value = demo;

          if (isTouch) {
            reset();
            performAction(input.value);
          } else {
            input.focus();
          }
        } else if (url) {
          window.location = url;
        }
      }
    });

    canvas.addEventListener('click', function () {
      overlay.classList.remove('overlay--visible');
    });
  }

  return {
    init: function () {
      bindEvents();
      input.focus();

      if (isTouch) {
        document.body.classList.add('touch');
      }

      S.UI.Tabs.init();
    },

    simulate: function (action) {
      performAction(action);
    }
  };
}());


S.UI.Tabs = (function () {
  var labels = document.querySelector('.tabs-labels'),
      triggers = document.querySelectorAll('.tabs-label'),
      panels = document.querySelectorAll('.tabs-panel');

  function activate(i) {
    triggers[i].classList.add('tabs-label--active');
    panels[i].classList.add('tabs-panel--active');
  }

  function bindEvents() {
    labels.addEventListener('click', function (e) {
      var el = e.target,
          index;

      if (el.classList.contains('tabs-label')) {
        for (var t = 0; t < triggers.length; t++) {
          triggers[t].classList.remove('tabs-label--active');
          panels[t].classList.remove('tabs-panel--active');

          if (el === triggers[t]) {
            index = t;
          }
        }

        activate(index);
      }
    });
  }

  return {
    init: function () {
      activate(0);
      bindEvents();
    }
  };
}());


S.Dot = function (x, y) {
  this.p = new S.Point({
    x: x,
    y: y,
    z: 5,
    a: 1,
    h: 0
  });

  this.e = 0.07;
  this.s = true;

  this.c = new S.Color(255, 255, 255, this.p.a);

  this.t = this.clone();
  this.q = [];
};

S.Dot.prototype = {
  clone: function () {
    return new S.Point({
      x: this.x,
      y: this.y,
      z: this.z,
      a: this.a,
      h: this.h
    });
  },

  _draw: function () {
    this.c.a = this.p.a;
    S.Drawing.drawCircle(this.p, this.c);
  },

  _moveTowards: function (n) {
    var details = this.distanceTo(n, true),
        dx = details[0],
        dy = details[1],
        d = details[2],
        e = this.e * d;

    if (this.p.h === -1) {
      this.p.x = n.x;
      this.p.y = n.y;
      return true;
    }

    if (d > 1) {
      this.p.x -= ((dx / d) * e);
      this.p.y -= ((dy / d) * e);
    } else {
      if (this.p.h > 0) {
        this.p.h--;
      } else {
        return true;
      }
    }

    return false;
  },

  _update: function () {
    var p,
        d;

    if (this._moveTowards(this.t)) {
      p = this.q.shift();

      if (p) {
        this.t.x = p.x || this.p.x;
        this.t.y = p.y || this.p.y;
        this.t.z = p.z || this.p.z;
        this.t.a = p.a || this.p.a;
        this.p.h = p.h || 0;
      } else {
        if (this.s) {
          this.p.x -= Math.sin(Math.random() * 3.142);
          this.p.y -= Math.sin(Math.random() * 3.142);
        } else {
          this.move(new S.Point({
            x: this.p.x + (Math.random() * 50) - 25,
            y: this.p.y + (Math.random() * 50) - 25,
          }));
        }
      }
    }

    d = this.p.a - this.t.a;
    this.p.a = Math.max(0.1, this.p.a - (d * 0.05));
    d = this.p.z - this.t.z;
    this.p.z = Math.max(1, this.p.z - (d * 0.05));
  },

  distanceTo: function (n, details) {
    var dx = this.p.x - n.x,
        dy = this.p.y - n.y,
        d = Math.sqrt(dx * dx + dy * dy);

    return details ? [dx, dy, d] : d;
  },

  move: function (p, avoidStatic) {
    if (!avoidStatic || (avoidStatic && this.distanceTo(p) > 1)) {
      this.q.push(p);
    }
  },

  render: function () {
    this._update();
    this._draw();
  }
};


S.ShapeBuilder = (function () {
  var gap = 13,
      shapeCanvas = document.createElement('canvas'),
      shapeContext = shapeCanvas.getContext('2d'),
      fontSize = 500,
      fontFamily = 'Avenir, Helvetica Neue, Helvetica, Arial, sans-serif';

  function fit() {
    shapeCanvas.width = Math.floor(window.innerWidth / gap) * gap;
    shapeCanvas.height = Math.floor(window.innerHeight / gap) * gap;
    shapeContext.fillStyle = 'red';
    shapeContext.textBaseline = 'middle';
    shapeContext.textAlign = 'center';
  }

  function processCanvas() {
    var pixels = shapeContext.getImageData(0, 0, shapeCanvas.width, shapeCanvas.height).data,
        dots = [],
        x = 0,
        y = 0,
        fx = shapeCanvas.width,
        fy = shapeCanvas.height,
        w = 0,
        h = 0;

    for (var p = 0; p < pixels.length; p += (4 * gap)) {
      if (pixels[p + 3] > 0) {
        dots.push(new S.Point({
          x: x,
          y: y
        }));

        w = x > w ? x : w;
        h = y > h ? y : h;
        fx = x < fx ? x : fx;
        fy = y < fy ? y : fy;
      }

      x += gap;

      if (x >= shapeCanvas.width) {
        x = 0;
        y += gap;
        p += gap * 4 * shapeCanvas.width;
      }
    }

    return { dots: dots, w: w + fx, h: h + fy };
  }

  function setFontSize(s) {
    shapeContext.font = 'bold ' + s + 'px ' + fontFamily;
  }

  function isNumber(n) {
    return !isNaN(parseFloat(n)) && isFinite(n);
  }

  return {
    init: function () {
      fit();
      window.addEventListener('resize', fit);
    },

    imageFile: function (url, callback) {
      var image = new Image(),
          a = S.Drawing.getArea();

      image.onload = function () {
        shapeContext.clearRect(0, 0, shapeCanvas.width, shapeCanvas.height);
        shapeContext.drawImage(this, 0, 0, a.h * 0.6, a.h * 0.6);
        callback(processCanvas());
      };

      image.onerror = function () {
        callback(S.ShapeBuilder.letter('What?'));
      };

      image.src = url;
    },

    circle: function (d) {
      var r = Math.max(0, d) / 2;
      shapeContext.clearRect(0, 0, shapeCanvas.width, shapeCanvas.height);
      shapeContext.beginPath();
      shapeContext.arc(r * gap, r * gap, r * gap, 0, 2 * Math.PI, false);
      shapeContext.fill();
      shapeContext.closePath();

      return processCanvas();
    },

    letter: function (l) {
      var s = 0;

      setFontSize(fontSize);
      s = Math.min(fontSize,
                  (shapeCanvas.width / shapeContext.measureText(l).width) * 0.8 * fontSize, 
                  (shapeCanvas.height / fontSize) * (isNumber(l) ? 1 : 0.45) * fontSize);
      setFontSize(s);

      shapeContext.clearRect(0, 0, shapeCanvas.width, shapeCanvas.height);
      shapeContext.fillText(l, shapeCanvas.width / 2, shapeCanvas.height / 2);

      return processCanvas();
    },

    rectangle: function (w, h) {
      var dots = [],
          width = gap * w,
          height = gap * h;

      for (var y = 0; y < height; y += gap) {
        for (var x = 0; x < width; x += gap) {
          dots.push(new S.Point({
            x: x,
            y: y,
          }));
        }
      }

      return { dots: dots, w: width, h: height };
    }
  };
}());


S.Shape = (function () {
  var dots = [],
      width = 0,
      height = 0,
      cx = 0,
      cy = 0;

  function compensate() {
    var a = S.Drawing.getArea();

    cx = a.w / 2 - width / 2;
    cy = a.h / 2 - height / 2;
  }

  return {
    shuffleIdle: function () {
      var a = S.Drawing.getArea();

      for (var d = 0; d < dots.length; d++) {
        if (!dots[d].s) 

      }
    },

    switchShape: function (n, fast) {
      var size,
          a = S.Drawing.getArea(),
          d = 0,
          i = 0;

      width = n.w;
      height = n.h;

      compensate();

      if (n.dots.length > dots.length) {
        size = n.dots.length - dots.length;
        for (d = 1; d <= size; d++) {
          dots.push(new S.Dot(a.w / 2, a.h / 2));
        }
      }

      d = 0;

      while (n.dots.length > 0) {
        i = Math.floor(Math.random() * n.dots.length);
        dots[d].e = fast ? 0.25 : (dots[d].s ? 0.14 : 0.11);

        if (dots[d].s) {
          dots[d].move(new S.Point({
            z: Math.random() * 20 + 10,
            a: Math.random(),
            h: 18
          }));
        } else {
          dots[d].move(new S.Point({
            z: Math.random() * 5 + 5,
            h: fast ? 18 : 30
          }));
        }

        dots[d].s = true;
        dots[d].move(new S.Point({
          x: n.dots[i].x + cx,
          y: n.dots[i].y + cy,
          a: 1,
          z: 5,
          h: 0
        }));

        n.dots = n.dots.slice(0, i).concat(n.dots.slice(i + 1));
        d++;
      }

      for (i = d; i < dots.length; i++) {
        if (dots[i].s) {
          dots[i].move(new S.Point({
            z: Math.random() * 20 + 10,
            a: Math.random(),
            h: 20
          }));

          dots[i].s = false;
          dots[i].e = 0.04;
          dots[i].move(new S.Point({ 
            x: Math.random() * a.w,
            y: Math.random() * a.h,
            a: 0.3, //.4
            z: Math.random() * 4,
            h: 0
          }));
        }
      }
    },

    render: function () {
      for (var d = 0; d < dots.length; d++) {
        dots[d].render();
      }
    }
  };
}());

{
          dots[d].move({
            x: Math.random() * a.w,
            y: Math.random() * a.h
          });
        }