/*!
 * jQCloud
 * Copyright 2011 Luca Ongaro (http://www.lucaongaro.eu)
 * Copyright 2013 Daniel White (http://www.developerdan.com)
 * Copyright 2014 Damien "Mistic" Sorel (http://www.strangeplanet.fr)
 * Licensed under MIT (http://opensource.org/licenses/MIT)
 */

/*jshint -W055 *//* non standard constructor name */

(function($) {
  "use strict";

  /*
   * Plugin class
   */
  var jQCloud = function (element, word_array, options) {
    this.$element = $(element);

    this.word_array = word_array || [];
    this.options = options;

    this.sizeGenerator = null;
    this.colorGenerator = null;

    // Data used internally
    this.data = {
      placed_words: [],
      timeouts: {},
      namespace: null,
      step: null,
      angle: null,
      aspect_ratio: null,
      max_weight: null,
      min_weight: null,
      sizes: [],
      colors: []
    };

    this.initialize();
  };

  jQCloud.DEFAULTS = {
    width: 100,
    height: 100,
    center: { x: 0.5, y: 0.5 },
    steps: 10,
    delay: null,
    shape: 'elliptic',
    classPattern: 'w{n}',
    encodeURI: true,
    removeOverflowing: true,
    afterCloudRender: null,
    autoResize: false,
    colors: null,
    fontSize: null,
    template: null
  };

  jQCloud.prototype = {
    initialize: function() {
      // Set/Get dimensions
      if (this.options.width) {
        this.$element.width(this.options.width);
      }
      else {
        this.options.width = this.$element.width();
      }
      if (this.options.height) {
        this.$element.height(this.options.height);
      }
      else {
        this.options.height = this.$element.height();
      }

      // Default options value
      this.options = $.extend(true, {}, jQCloud.DEFAULTS, this.options);

      // Ensure delay
      if (this.options.delay === null) {
        this.options.delay = this.word_array.length > 50 ? 10 : 0;
      }

      // Backward compatibility
      if (this.options.center.x > 1) {
        this.options.center.x = this.options.center.x / this.options.width;
        this.options.center.y = this.options.center.y / this.options.height;
      }

      // Create colorGenerator function from options
      // Direct function
      if (typeof this.options.colors == 'function') {
        this.colorGenerator = this.options.colors;
      }
      // Array of sizes
      else if ($.isArray(this.options.colors)) {
        var cl = this.options.colors.length;
        if (cl > 0) {
          // Fill the sizes array to X items
          if (cl < this.options.steps) {
            for (var i=cl; i<this.options.steps; i++) {
              this.options.colors[i] = this.options.colors[cl-1];
            }
          }

          this.colorGenerator = function(weight) {
            return this.options.colors[this.options.steps - weight];
          };
        }
      }

      // Create sizeGenerator function from options
      // Direct function
      if (typeof this.options.fontSize == 'function') {
        this.sizeGenerator = this.options.fontSize;
      }
      // Object with 'from' and 'to'
      else if ($.isPlainObject(this.options.fontSize)) {
        this.sizeGenerator = function(width, height, weight) {
          var max = width * this.options.fontSize.from,
              min = width * this.options.fontSize.to;
          return Math.round(min + (max - min) * 1.0 / (this.options.steps-1) * (weight - 1)) + 'px';
        };
      }
      // Array of sizes
      else if ($.isArray(this.options.fontSize)) {
        var sl = this.options.fontSize.length;
        if (sl > 0) {
          // Fill the sizes array to X items
          if (sl < this.options.steps) {
            for (var j=sl; j<this.options.steps; j++) {
              this.options.fontSize[j] = this.options.fontSize[sl-1];
            }
          }

          this.sizeGenerator = function(width, height, weight) {
            return this.options.fontSize[this.options.steps - weight];
          };
        }
      }

      this.data.angle = Math.random() * 6.28;
      this.data.step = (this.options.shape === 'rectangular') ? 18.0 : 2.0;
      this.data.aspect_ratio = this.options.width / this.options.height;
      this.clearTimeouts();

      // Namespace word ids to avoid collisions between multiple clouds
      this.data.namespace = (this.$element.attr('id') || Math.floor((Math.random()*1000000)).toString(36)) + '_word_';

      this.$element.addClass('jqcloud');

      // Container's CSS position cannot be 'static'
      if (this.$element.css('position') === 'static') {
        this.$element.css('position', 'relative');
      }

      // Delay execution so that the browser can render the page before the computatively intensive word cloud drawing
      this.createTimeout($.proxy(this.drawWordCloud, this), 10);

      // Attach window resize event
      if (this.options.autoResize) {
        $(window).on('resize', throttle(this.resize, 50, this));
      }
    },

    // Helper function to keep track of timeouts so they can be destroyed
    createTimeout: function(callback, time) {
      var timeout = setTimeout($.proxy(function(){
        delete this.data.timeouts[timeout];
        callback();
      }, this), time);
      this.data.timeouts[timeout] = true;
    },

    // Destroy all timeouts
    clearTimeouts: function() {
      $.each(this.data.timeouts, function(key){
        clearTimeout(key);
      });
      this.data.timeouts = {};
    },

    // Pairwise overlap detection
    overlapping: function(a, b) {
      if (Math.abs(2.0*a.left + a.width - 2.0*b.left - b.width) < a.width + b.width) {
        if (Math.abs(2.0*a.top + a.height - 2.0*b.top - b.height) < a.height + b.height) {
          return true;
        }
      }
      return false;
    },

    // Helper function to test if an element overlaps others
    hitTest: function(elem) {
      // Check elements for overlap one by one, stop and return false as soon as an overlap is found
      for(var i=0, l=this.data.placed_words.length; i<l; i++) {
        if (this.overlapping(elem, this.data.placed_words[i])) {
          return true;
        }
      }
      return false;
    },

    // Initialize the drawing of the whole cloud
    drawWordCloud: function() {
      var i, l;

      this.$element.children('[id^="' + this.data.namespace + '"]').remove();

      if (this.word_array.length === 0) {
        return;
      }

      // Make sure every weight is a number before sorting
      for (i=0, l=this.word_array.length; i<l; i++) {
        this.word_array[i].weight = parseFloat(this.word_array[i].weight, 10);
      }

      // Sort word_array from the word with the highest weight to the one with the lowest
      this.word_array.sort(function(a, b) {
        return b.weight - a.weight;
      });

      // Kepp trace of bounds
      this.data.max_weight = this.word_array[0].weight;
      this.data.min_weight = this.word_array[this.word_array.length - 1].weight;

      // Generate colors
      this.data.colors = [];
      if (this.colorGenerator) {
        for (i=0; i<this.options.steps; i++) {
          this.data.colors.push(this.colorGenerator(i+1));
        }
      }

      // Generate font sizes
      this.data.sizes = [];
      if (this.sizeGenerator) {
        for (i=0; i<this.options.steps; i++) {
          this.data.sizes.push(this.sizeGenerator(this.options.width, this.options.height, i+1));
        }
      }

      // Iterate drawOneWord on every word, immediately or with delay
      if (this.options.delay > 0){
        this.drawOneWordDelayed();
      }
      else {
        for (i=0, l=this.word_array.length; i<l; i++) {
          this.drawOneWord(i, this.word_array[i]);
        }

        if (typeof this.options.afterCloudRender === 'function') {
          this.options.afterCloudRender.call(this.$element);
        }
      }
    },

    // Function to draw a word, by moving it in spiral until it finds a suitable empty place
    drawOneWord: function(index, word) {
      var word_id = this.data.namespace + index,
          word_selector = '#' + word_id,

          // option.shape == 'elliptic'
          angle = this.data.angle,
          radius = 0.0,

          // option.shape == 'rectangular'
          steps_in_direction = 0.0,
          quarter_turns = 0.0,

          weight = Math.floor(this.options.steps / 2),
          word_span,
          word_size,
          word_style;

      // Create word attr object
      word.attr = $.extend({}, word.html, { id: word_id });

      // Linearly map the original weight to a discrete scale from 1 to 10
      // Only if weights are different
      if (this.data.max_weight != this.data.min_weight) {
        weight = Math.round((word.weight - this.data.min_weight) * 1.0 * (this.options.steps-1) / (this.data.max_weight - this.data.min_weight)) + 1;
      }
      word_span = $('<span>').attr(word.attr);

      // Apply class
      if (this.options.classPattern) {
        word_span.addClass(this.options.classPattern.replace('{n}', weight));
      }

      // Apply color
      if (this.data.colors.length) {
        word_span.css('color', this.data.colors[weight-1]);
      }

      // Apply size
      if (this.data.sizes.length) {
        word_span.css('font-size', this.data.sizes[weight-1]);
      }

      //Render using template function if provided.
      if (this.options.template) {
        word_span.html(this.options.template(word));
      } else if (word.link) {
        // Append link if word.link attribute was set
        // If link is a string, then use it as the link href
        if (typeof word.link === 'string') {
          word.link = { href: word.link };
        }

        if (this.options.encodeURI) {
          word.link.href = encodeURI(word.link.href).replace(/'/g, '%27');
        }

        word_span.append($('<a>').attr(word.link).text(word.text));
      }
      else {
        word_span.text(word.text);
      }

      // Bind handlers to words
      if (word.handlers) {
        word_span.on(word.handlers);
      }

      this.$element.append(word_span);

      word_size = {
        width: word_span.outerWidth(),
        height: word_span.outerHeight()
      };
      word_size.left = this.options.center.x*this.options.width - word_size.width / 2.0;
      word_size.top = this.options.center.y*this.options.height - word_size.height / 2.0;

      // Save a reference to the style property, for better performance
      word_style = word_span[0].style;
      word_style.position = 'absolute';
      word_style.left = word_size.left + 'px';
      word_style.top = word_size.top + 'px';

      while(this.hitTest(word_size)) {
        // option shape is 'rectangular' so move the word in a rectangular spiral
        if (this.options.shape === 'rectangular') {
          steps_in_direction++;

          if (steps_in_direction * this.data.step > (1 + Math.floor(quarter_turns / 2.0)) * this.data.step * ((quarter_turns % 4 % 2) === 0 ? 1 : this.data.aspect_ratio)) {
            steps_in_direction = 0.0;
            quarter_turns++;
          }

          switch(quarter_turns % 4) {
            case 1:
              word_size.left += this.data.step * this.data.aspect_ratio + Math.random() * 2.0;
              break;
            case 2:
              word_size.top -= this.data.step + Math.random() * 2.0;
              break;
            case 3:
              word_size.left -= this.data.step * this.data.aspect_ratio + Math.random() * 2.0;
              break;
            case 0:
              word_size.top += this.data.step + Math.random() * 2.0;
              break;
          }
        }
        // Default settings: elliptic spiral shape
        else {
          radius += this.data.step;
          angle += (index % 2 === 0 ? 1 : -1) * this.data.step;

          word_size.left = this.options.center.x*this.options.width - (word_size.width / 2.0) + (radius*Math.cos(angle)) * this.data.aspect_ratio;
          word_size.top = this.options.center.y*this.options.height + radius*Math.sin(angle) - (word_size.height / 2.0);
        }
        word_style.left = word_size.left + 'px';
        word_style.top = word_size.top + 'px';
      }

      // Don't render word if part of it would be outside the container
      if (this.options.removeOverflowing && (
          word_size.left < 0 || word_size.top < 0 ||
          (word_size.left + word_size.width) > this.options.width ||
          (word_size.top + word_size.height) > this.options.height
        )
      ) {
        word_span.remove();
        return;
      }

      // Save position for further usage
      this.data.placed_words.push(word_size);

      if (typeof word.afterWordRender === 'function') {
        word.afterWordRender.call(word_span);
      }
    },

    // Draw one word then recall the function after a delay
    drawOneWordDelayed: function(index) {
      index = index || 0;

      // if not visible then do not attempt to draw
      if (!this.$element.is(':visible')) {
        this.createTimeout($.proxy(function(){
          this.drawOneWordDelayed(index);
        }, this), 10);

        return;
      }

      if (index < this.word_array.length) {
        this.drawOneWord(index, this.word_array[index]);

        this.createTimeout($.proxy(function(){
          this.drawOneWordDelayed(index + 1);
        }, this), this.options.delay);
      }
      else {
        if (typeof this.options.afterCloudRender == 'function') {
          this.options.afterCloudRender.call(this.$element);
        }
      }
    },

    // Destroy any data and objects added by the plugin
    destroy: function() {
      this.clearTimeouts();
      this.$element.removeClass('jqcloud');
      this.$element.removeData('jqcloud');
      this.$element.children('[id^="' + this.data.namespace + '"]').remove();
    },

    // Update the list of words
    update: function(word_array) {
      this.word_array = word_array;
      this.data.placed_words = [];

      this.clearTimeouts();
      this.drawWordCloud();
    },
    
    resize: function() {
      var new_size = {
        width: this.$element.width(),
        height: this.$element.height()
      };

      if (new_size.width != this.options.width || new_size.height != this.options.height) {
        this.options.width = new_size.width;
        this.options.height = new_size.height;
        this.data.aspect_ratio = this.options.width / this.options.height;

        this.update(this.word_array);
      }
    }
  };

  /*
   * Apply throttling to a callback
   * @param callback {function}
   * @param delay {int} milliseconds
   * @param context {object|null}
   * @return {function}
   */
  function throttle(callback, delay, context) {
    var state = {
      pid: null,
      last: 0
    };

    return function() {
      var elapsed = new Date().getTime() - state.last,
          args = arguments,
          that = this;

      function exec() {
        state.last = new Date().getTime();
        return callback.apply(context || that, Array.prototype.slice.call(args));
      }

      if (elapsed > delay) {
        return exec();
      }
      else {
        clearTimeout(state.pid);
        state.pid = setTimeout(exec, delay - elapsed);
      }
    };
  }

  /*
   * jQuery plugin
   */
  $.fn.jQCloud = function(word_array, option) {
    var args = arguments;

    return this.each(function () {
      var $this = $(this),
          data = $this.data('jqcloud');

      if (!data && word_array === 'destroy') {
        // Don't even try to initialize when called with 'destroy'
        return;
      }
      if (!data) {
        var options = typeof option === 'object' ? option : {};
        $this.data('jqcloud', (data = new jQCloud(this, word_array, options)));
      }
      else if (typeof word_array === 'string') {
        data[word_array].apply(data, Array.prototype.slice.call(args, 1));
      }
    });
  };

  $.fn.jQCloud.defaults = {
    set: function(options) {
      $.extend(true, jQCloud.DEFAULTS, options);
    },
    get: function(key) {
      var options = jQCloud.DEFAULTS;
      if (key) {
        options = options[key];
      }
      return $.extend(true, {}, options);
    }
  };
})(jQuery);