/**
 * @author Ryan Johnson <http://syntacticx.com/>
 * @copyright 2008 PersonalGrid Corporation <http://personalgrid.com/>
 * @package LivePipe UI
 * @license MIT
 * @url http://livepipe.net/control/tabs
 * @require prototype.js, livepipe.js
 */

/*global window, document, Prototype, $, $A, $H, $break, Class, Element, Event, Control */

if(typeof(Prototype) == "undefined") {
  throw "Control.Tabs requires Prototype to be loaded.";
}
if(typeof(Object.Event) == "undefined") {
  throw "Control.Tabs requires Object.Event to be loaded.";
}

Control.Tabs = Class.create({
  initialize: function(tab_list_container, options) {
      if(!$(tab_list_container)) {
          throw "Control.Tabs could not find the element: " + tab_list_container; }
      this.activeContainer = false;
      this.activeLink = false;
      this.containers = $H({});
      this.links = [];
      //Control.Tabs.instances.push(this);
      this.options = {
          beforeChange: Prototype.emptyFunction,
          afterChange: Prototype.emptyFunction,
          hover: false,
          linkSelector: 'li a',
          setClassOnContainer: false,
          activeClassName: 'active',
          defaultTab: 'first',
          autoLinkExternal: true,
          targetRegExp: /#(.+)$/,
          showFunction: Element.show,
          hideFunction: Element.hide
      };
      Object.extend(this.options,options || {});
      (typeof(this.options.linkSelector == 'string') ? 
          $(tab_list_container).select(this.options.linkSelector) : 
          this.options.linkSelector($(tab_list_container))
      ).findAll(function(link){
          return (/^#/).exec((Prototype.Browser.WebKit ? decodeURIComponent(link.href) : link.href).replace(window.location.href.split('#')[0],''));
      }).each(function(link){
          this.addTab(link);
      }.bind(this));
      this.containers.values().each(Element.hide);
      if(this.options.defaultTab == 'first') {
          this.setActiveTab(this.links.first());
      } else if(this.options.defaultTab == 'last') {
          this.setActiveTab(this.links.last());
      } else {
          this.setActiveTab(this.options.defaultTab); }
      var targets = this.options.targetRegExp.exec(window.location);
      if(targets && targets[1]){
          targets[1].split(',').each(function(target){
              this.setActiveTab(this.links.find(function(link){
                  return link.key == target;
              }));
          }.bind(this));
      }
      if(this.options.autoLinkExternal){
          $A(document.getElementsByTagName('a')).each(function(a){
              if(!this.links.include(a)){
                  var clean_href = a.href.replace(window.location.href.split('#')[0],'');
                  if(clean_href.substring(0,1) == '#'){
                      if(this.containers.keys().include(clean_href.substring(1))){
                          $(a).observe('click',function(event,clean_href){
                              this.setActiveTab(clean_href.substring(1));
                          }.bindAsEventListener(this,clean_href));
                      }
                  }
              }
          }.bind(this));
      }
  },
  addTab: function(link) {
    this.links.push(link);
    link.key = link.getAttribute('href').replace(window.location.href.split('#')[0],'').split('#').last().replace(/#/,'');
    var container = $(link.key);
    if(!container) {
      throw "Control.Tabs: #" + link.key + " was not found on the page.";
    }
    this.containers.set(link.key,container);
    link[this.options.hover ? 'onmouseover' : 'onclick'] = function(link) {
      if(window.event) {
        Event.stop(window.event);
      }
      this.setActiveTab(link);
      return false;
    }.bind(this,link);
  },
  setActiveTab: function(link) {
    if(!link && typeof(link) == 'undefined') {
      return;
    }
    if(typeof(link) == 'string') {
      this.setActiveTab(this.links.find(function(_link) {
        return _link.key == link;
      }));
    } else if(typeof(link) == 'number') {
      this.setActiveTab(this.links[link]);
    } else {
      if(this.notify('beforeChange',this.activeContainer,this.containers.get(link.key)) === false) {
        return;
      }
      if(this.activeContainer) {
        this.options.hideFunction(this.activeContainer);
      }
      this.links.each(function(item) {
        (this.options.setClassOnContainer ? $(item.parentNode) : item).removeClassName(this.options.activeClassName);
      }.bind(this));
      (this.options.setClassOnContainer ? $(link.parentNode) : link).addClassName(this.options.activeClassName);
      this.activeContainer = this.containers.get(link.key);
      this.activeLink = link;
      this.options.showFunction(this.containers.get(link.key));
      this.notify('afterChange',this.containers.get(link.key));
    }
  },
  next: function() {
    this.links.each(function(link, i) {
      if(this.activeLink == link && this.links[i + 1]) {
        this.setActiveTab(this.links[i + 1]);
        throw $break;
      }
    }.bind(this));
  },
  previous: function() {
    this.links.each(function(link,i){
      if(this.activeLink == link && this.links[i - 1]){
        this.setActiveTab(this.links[i - 1]);
        throw $break;
      }
    }.bind(this));
  },
  first: function() {
    this.setActiveTab(this.links.first());
  },
  last: function() {
    this.setActiveTab(this.links.last());
  }
});
Object.Event.extend(Control.Tabs);