// ddaccordion.js

var ddaccordion = {
  contentclassname:{}, //object to store corresponding contentclass name based on headerclass
  
  expandone: function(headerclass, selected) { //PUBLIC function to expand a particular header
    this.toggleone(headerclass, selected, "expand")
  },
  
  collapseone: function(headerclass, selected) { //PUBLIC function to collapse a particular header
    this.toggleone(headerclass, selected, "collapse")
  },
  
  expandall: function(headerclass) { //PUBLIC function to expand all headers based on their shared CSS classname
    var $headers = $('.' + headerclass)
    $('.' + this.contentclassname[headerclass] + ':hidden').each(function() {
                                                                   $headers.eq(parseInt($(this).attr('contentindex'))).click()
                                                                 })
  },
  
  collapseall: function(headerclass) { //PUBLIC function to collapse all headers based on their shared CSS classname
    var $headers = $('.' + headerclass)
    $('.' + this.contentclassname[headerclass] + ':visible').each(function() {
                                                                    $headers.eq(parseInt($(this).attr('contentindex'))).click()
                                                                  })
  },
  
  toggleone: function(headerclass, selected, optstate) { //PUBLIC function to expand/ collapse a particular header
    var $targetHeader = $('.' + headerclass).eq(selected)
    var $subcontent = $('.' + this.contentclassname[headerclass]).eq(selected)
    
    if (typeof optstate == "undefined" || optstate == "expand" && $subcontent.is(":hidden") || optstate == "collapse" && $subcontent.is(":visible"))
      $targetHeader.click()
  },
  
  expandit: function($targetHeader, $targetContent, config) {
    $targetContent.slideDown(config.animatespeed)
    this.transformHeader($targetHeader, config, "expand")
  },
  
  collapseit: function($targetHeader, $targetContent, config) {
    $targetContent.slideUp(config.animatespeed)
    this.transformHeader($targetHeader, config, "collapse")
  },
  
  transformHeader: function($targetHeader, config, state) {
    $targetHeader.addClass((state == "expand") ? config.cssclass.expand:
                                                 config.cssclass.collapse) //alternate btw "expand" and "collapse" CSS classes
    .removeClass((state == "expand") ? config.cssclass.collapse:
                                       config.cssclass.expand)
    
    if (config.htmlsetting.location == 'src') { //Change header image (assuming header is an image)?
      $targetHeader = ($targetHeader.is("img")) ? $targetHeader:
                                                  $targetHeader.find('img').eq(0) //Set target to either header itself, or first image within header
      $targetHeader.attr('src', (state == "expand") ? config.htmlsetting.expand:
                                                      config.htmlsetting.collapse) //change header image
    } else if (config.htmlsetting.location == "prefix") //if change "prefix" HTML, locate dynamically added ".accordprefix" span tag and change it
      $targetHeader.find('.accordprefix').html((state == "expand") ? config.htmlsetting.expand:
                                                                     config.htmlsetting.collapse)
     else if (config.htmlsetting.location == "suffix")
      $targetHeader.find('.accordsuffix').html((state == "expand") ? config.htmlsetting.expand:
                                                                     config.htmlsetting.collapse)
  },
  
  getCookie: function(Name) {
    var re = new RegExp(Name + "=[^;]+", "i") //construct RE to search for target name/value pair
    
    if (document.cookie.match(re)) //if cookie found
      return document.cookie.match(re)[0].split("=")[1] //return its value
    
    return null
  },
  
  setCookie: function(name, value) {
    document.cookie = name + "=" + value
  },
  
  init: function(config) {
    document.write('<style type="text/css">\n')
    document.write('.' + config.contentclass + '{display: none}\n') //generate CSS to hide contents
    document.write('<\/style>')
    $(document).ready(function() {
                        ddaccordion.contentclassname[config.headerclass] = config.contentclass //remember contentclass name based on headerclass
                        config.cssclass = {
                          collapse: config.toggleclass[0],
                          expand: config.toggleclass[1]
                        } //store expand and contract CSS classes as object properties
                        config.htmlsetting = {
                          location: config.togglehtml[0],
                          collapse: config.togglehtml[1],
                          expand: config.togglehtml[2]
                        } //store HTML settings as object properties
                        var lastexpanded = {} //object to hold reference to last expanded header and content (jquery objects)
                        var expandedindices = (config.persiststate) ? ddaccordion.getCookie(config.headerclass):
                                                                      config.defaultexpanded
                        expandedindices = (typeof expandedindices == 'string') ? expandedindices.replace(/c/ig, '').split(','):
                                                                                 config.defaultexpanded //test for valid cookie ('string'), otherwise (null, or 1st page load), default to defaultexpanded setting
                        var $subcontents = $('.' + config["contentclass"])
                        
                        if (config["collapseprev"] && expandedindices.length > 1)
                          expandedindices = [expandedindices.pop()] //return last array element as an array (for sake of jQuery.inArray())
                        
                        $('.' + config["headerclass"]).each(function(index) { //loop through all headers
                                                              if (/(prefix)|(suffix)/i.test(config.htmlsetting.location) && $(this).html() != "") { //add a SPAN element to header depending on user setting and if header is a container tag
                                                                $('<span class="accordprefix"></span>').prependTo(this)
                                                                $('<span class="accordsuffix"></span>').appendTo(this)
                                                              }
                                                              
                                                              $(this).attr('headerindex', index + 'h') //store position of this header relative to its peers
                                                              $subcontents.eq(index).attr('contentindex', index + 'c') //store position of this content relative to its peers
                                                              var $subcontent = $subcontents.eq(index)
                                                              
                                                              if (jQuery.inArray(index, expandedindices) != -1) { //check for headers that should be expanded automatically
                                                                if (config.animatedefault == false)
                                                                  $subcontent.show()
                                                                
                                                                ddaccordion.expandit($(this), $subcontent, config)
                                                                lastexpanded = {
                                                                  $header: $(this),
                                                                  $content: $subcontent
                                                                }
                                                              }  //end check
                                                               else {
                                                                $subcontent.hide()
                                                                ddaccordion.transformHeader($(this), config, "collapse")
                                                              }
                                                            })
                        $('.' + config["headerclass"]).click(function() { //assign behavior when headers are clicked on
                                                               var $subcontent = $subcontents.eq(parseInt($(this).attr('headerindex'))) //get subcontent that should be expanded/collapsed
                                                               
                                                               if ($subcontent.css('display') == "none") {
                                                                 ddaccordion.expandit($(this), $subcontent, config)
                                                                 
                                                                 if (config["collapseprev"] && lastexpanded.$header && $(this).get(0) != lastexpanded.$header.get(0)) //collapse previous content?
                                                                   ddaccordion.collapseit(lastexpanded.$header, lastexpanded.$content, config)
                                                                 
                                                                 lastexpanded = {
                                                                   $header: $(this),
                                                                   $content: $subcontent
                                                                 }
                                                               } else
                                                                 ddaccordion.collapseit($(this), $subcontent, config)
                                                               
                                                               return false
                                                             })
                        $(window).bind('unload', function() { //clean up and persist on page unload
                                                   $('.' + config["headerclass"]).unbind('click')
                                                   var expandedindices = []
                                                   $('.' + config["contentclass"] + ":visible").each(function(index) { //get indices of expanded headers
                                                                                                       expandedindices.push($(this).attr('contentindex'))
                                                                                                     })
                                                   
                                                   if (config.persiststate == true) { //persist state?
                                                     expandedindices = (expandedindices.length == 0) ? '-1c':
                                                                                                       expandedindices //No contents expanded, indicate that with dummy '-1c' value?
                                                     ddaccordion.setCookie(config.headerclass, expandedindices)
                                                   }
                                                 })
    })
  }
}