//= require jquery.ba-bbq

/* 
 * AJAX Pagination: Ajaxifying your pagination links
 * https://github.com/ronalchn/ajax_pagination
 * 
 * Copyright (c) 2012 Ronald Ping Man Chan
 * Distributed under the LGPL license
 */
if (History && History.enabled) {
  var ajaxPagination;
  $(document).ready(function () {
    ajaxPagination = new function() {
      this.pagination_loader_state = new Array(); // the page we are waiting for
      //this.pagination_stack = new Array(); // stack of request urls in history (to get state of url we came from)
      this.pagination_url = location.href; // url we came from, so we can see transitions of the url

      function display_pagination_loader(pagination_name) {
        if (this.pagination_loader_state[pagination_name] != undefined) return; // if already loading, don't reshow loader
        var paginated_section = $('#' + pagination_name + '_paginated_section');
        var paginated_content = paginated_section.children(".paginated_content").first(); // don't want to support multiple loader images
        var height = paginated_content.height();
        // setup loading look
        var img = document.createElement("IMG");
        img.src = "<%= asset_path "ajax-loader.gif" %>";
        var margin = Math.round(height>400?100:(height/4));
        $(img).css({'margin': margin + 'px', 'max-height': (height/2) + 'px'});
        var div = document.createElement("DIV");
        $(div).append(img);
        $(div).css({'position': 'absolute', 'left': 0, 'top': 0, 'width': '100%', 'height': '100%', 'text-align': 'center', 'opacity': 0.9});
        paginated_content.children().css({'opacity': 0.4});
        paginated_content.append(div);

        // scroll to top of paginated_section if it is not visible
        if ($('body').scrollTop() > paginated_section.offset().top) {
          $('body').scrollTop(paginated_section.offset().top);
        }
      }

      this.display_pagination_content = function(pagination_name,requesturl,content) {
        if (this.pagination_loader_state[pagination_name] == requesturl) {
          //pagination_content_state[pagination_name] = pagination_loader_state[pagination_name];
          delete this.pagination_loader_state[pagination_name]; // not waiting for page anymore
          $("#" + pagination_name + "_paginated_section").html(content);
        }
        // else content is stale
      };

      function swapPage(pagination_name,requesturl) { // swaps the page at pagination_name to that from requesturl
        display_pagination_loader.call(this,pagination_name);
        this.pagination_loader_state[pagination_name] = requesturl; // remember which page number we are waiting for
        $.ajax(requesturl,{dataType:'script',cache:true});
      }
      $('body').on("click", ".pagination a, .ajaxpagination a", function() {
        var pagination_name = /^(.*)_paginated_section$/.exec($(this).closest(".paginated_section").attr("id"))[1];
        if (pagination_name == null) return; // pagination not set up properly
        var requesturl = $.param.querystring(this.href,{pagination:pagination_name}); // by default, adds ?pagination=page
        swapPage.call(ajaxPagination,pagination_name,requesturl);
        ajaxPagination.pagination_url = this.href;
        History.pushState(null,document.title,this.href);
        return false;
      });

      History.Adapter.bind(window,'popstate',function(){ // popstate, but can work with hash changes as well
        var from = ajaxPagination.pagination_url, to = location.href; // from what state to what other state

        $(".paginated_section").each(function(){
          var pagination_name = /^(.*)_paginated_section$/.exec($(this).attr("id"))[1];
          if (pagination_name == null) return; // pagination not set up properly

          // if data-reload is not defined, the use default reload test
          if ($(this).data('reload') === undefined) {
            // if ?pagination_name=ABC, where ABC is the same for both urls, then don't need to reload
            if ($.deparam.querystring(from)[pagination_name] === $.deparam.querystring(to)[pagination_name]) return;
          }
          else { // otherwise parse json and perform tests
            var reload = $(this).data('reload');
            if (!(reload instanceof Array)) reload = new Array(reload);
            var changed = false;
            for (i=0;i<reload.length;i++) {
              if (reload[i].query !== undefined) {
                if ($.deparam.querystring(from)[reload[i].query] !== $.deparam.querystring(to)[reload[i].query]) changed = true;
              }
              if (reload[i].urlregex !== undefined) {
                var index = 0;
                if (reload[i].regexindex !== undefined) index = reload[i].regexindex;
                var regex = new RegExp(reload[i].urlregex);
                var frommatch = regex.exec(from), tomatch = regex.exec(to);
                if (frommatch != null && frommatch.length>=index) frommatch = frommatch[index];
                if (tomatch != null && tomatch.length>=index) tomatch = tomatch[index];
                if (frommatch !== tomatch) changed = true;
              }
              if (changed) break;
            }
            if (!changed) return; // otherwise it has changed, and we must reload
          }
          var requesturl = $.param.querystring(location.href,{pagination:pagination_name}); // by default, adds ?pagination=page
          swapPage.call(ajaxPagination,pagination_name,requesturl);
        });

        ajaxPagination.pagination_url = location.href; // update url (new url recognised)
      });

      //History.Adapter.trigger(window,"popstate"); // update stuff on page load
    };
  });
}