var Class = {
  create: function() {
    return function() {
      this.initialize.apply(this, arguments);
    }
  }
}

Object.extend = function(destination, source) {
  for (var property in source) {
    destination[property] = source[property];
  }
  return destination;
}

var $break    = new Object();
var $continue = new Object();

var Enumerable = {
  each: function(iterator) {
    var index = 0;
    try {
      this._each(function(value) {
        try {
          iterator(value, index++);
        } catch (e) {
          if (e != $continue) throw e;
        }
      });
    } catch (e) {
      if (e != $break) throw e;
    }
    return this;
  },

  findAll: function(iterator) {
    var results = [];
    this.each(function(value, index) {
      if (iterator(value, index))
        results.push(value);
    });
    return results;
  },

  include: function(object) {
    var found = false;
    this.each(function(value) {
      if (value == object) {
        found = true;
        throw $break;
      }
    });
    return found;
  },

  inspect: function() {
    return '#<Enumerable:' + this.toArray().inspect() + '>';
  }
}

Object.extend(Enumerable, {
  map:     Enumerable.collect,
  find:    Enumerable.detect,
  select:  Enumerable.findAll,
  member:  Enumerable.include,
  entries: Enumerable.toArray
});

var $A = Array.from = function(iterable) {
  if (!iterable) return [];
  if (iterable.toArray) {
    return iterable.toArray();
  } else {
    var results = [];
    for (var i = 0, length = iterable.length; i < length; i++)
      results.push(iterable[i]);
    return results;
  }
}

Object.extend(Array.prototype, Enumerable);

Object.extend(Array.prototype, {
  _each: function(iterator) {
    for (var i = 0, length = this.length; i < length; i++)
      iterator(this[i]);
  },

  without: function() {
    var values = $A(arguments);
    return this.select(function(value) {
      return !values.include(value);
    });
  },

  inspect: function() {
    return '[' + this.map(Object.inspect).join(', ') + ']';
  }
});

var Hash = function(obj) {
  Object.extend(this, obj || {});
};

Object.extend(Hash, {
  toQueryString: function(obj) {
    var parts = [];

	  this.prototype._each.call(obj, function(pair) {
      if (!pair.key) return;

      if (pair.value == undefined) pair[1] = '';
      parts.push(pair.map(encodeURIComponent).join('='));
	  });

    return parts.join('&');
  }
});

function $(element) {
  if (typeof element == 'string')
    element = document.getElementById(element);
  return Element.extend(element);
}

/*--------------------------------------------------------------------------*/

if (!window.Element)
  var Element = new Object();

Element.extend = function(element) {
  element._extended = true;
  return element;
};

//----------------------------------------------------------------------------------------------------------------------------

Element.Methods = {
  classNames: function(element) {
    return new Element.ClassNames(element);
  },

  addClassName: function(element, className) {
    if (!(element = $(element))) return;
    Element.classNames(element).add(className);
    return element;
  },

  removeClassName: function(element, className) {
    if (!(element = $(element))) return;
    Element.classNames(element).remove(className);
    return element;
  }
};

Object.extend(Element, Element.Methods);

/*--------------------------------------------------------------------------*/

Element.ClassNames = Class.create();
Element.ClassNames.prototype = {
  initialize: function(element) {
    this.element = $(element);
  },

  _each: function(iterator) {
    this.element.className.split(/\s+/).select(function(name) {
      return name.length > 0;
    })._each(iterator);
  },

  set: function(className) {
    this.element.className = className;
  },

  add: function(classNameToAdd) {
    if (this.include(classNameToAdd)) return;
    this.set($A(this).concat(classNameToAdd).join(' '));
  },

  remove: function(classNameToRemove) {
    if (!this.include(classNameToRemove)) return;
    this.set($A(this).without(classNameToRemove).join(' '));
  },

  toString: function() {
    return $A(this).join(' ');
  }
};

Object.extend(Element.ClassNames.prototype, Enumerable);
var Selector = Class.create();
Selector.prototype = {
  toString: function() {
    return this.expression;
  }
}

Object.extend(Selector, {
  findChildElements: function(element, expressions) {
    return expressions.map(function(expression) {
      return expression.match(/[^\s"]+(?:"[^"]*"[^\s"]+)*/g).inject([null], function(results, expr) {
        var selector = new Selector(expr);
        return results.inject([], function(elements, result) {
          return elements.concat(selector.findElements(result || element));
        });
      });
    }).flatten();
  }
});