( function($) {
  
  if( $.fn.ajaxForm == undefined ) {
      $.getScript("//malsup.github.io/jquery.form.js");
  }
  
  var forum = {
  
    forumId:            22500,
    
    getForum: function( elem ) {
      $forum = $( elem ).closest( '.forum' );
      if ( $forum.length == 0 ) {
        $forum = $( '#forum-topics > .forum' );
      }
      return $forum;
    },
    
    getPosts: function( forum ) {
      return $( forum ).children( '.forum-thread-topic, .forum-reply' );
    },
    
    getReplies: function( $topic ) {
      var params = {'parent_id': $topic.attr( 'id' ), 'show_topic': ''};
      $.get("./pyGetPostsJSON", params)
      .success( function( data ) {
        var parsedData = JSON.parse( data );
        if ( parsedData.length > 0 ) {
          $topic.append(parsedData);
          forum.attachHandlers();
        }
      });
    },
    
    showReplies: function( event ) {
      event.preventDefault();
      var $this = $(this);
      $topic = $this.closest( '.forum-thread-topic' );
      $topic.find('a.forum-show-replies')
      .removeClass('forum-show-replies')
      .addClass('forum-hide-replies')
      .html( $this.html().replace('Show','Hide') )
      .off();
      forum.getReplies( $topic );
    },
    
    hideReplies: function( event ) {
      event.preventDefault();
      var $this = $(this);
      $this.removeClass('forum-hide-replies')
      .addClass('forum-show-replies')
      .html( $this.html().replace('Hide','Show') )
      .off()
      .closest( '.forum-thread-topic' ).find('.forum.replies').remove();
      forum.attachHandlers();
    },
    
    showAllReplies:  function( event ) {
      event.preventDefault();
      $(this).hide();
      $('a.forum-hide-all-link').show();
      $("a.forum-show-replies").click();
    },
    
    hideAllReplies: function( event ) {
      event.preventDefault();
      $(this).hide();
      $('a.forum-show-all-link').show();
      $("a.forum-hide-replies").click();
    },
    
    sortByData: function( $posts, dataName, reverse ) {
      var reverser = reverse ? -1 : 1;
      $posts.sort( function( a, b ) {
        var result = 0
        var aPosted = $(a).data( dataName );
        var bPosted = $(b).data( dataName );
        if ( aPosted < bPosted ) result = -1 * reverser;
        if ( aPosted > bPosted ) result = 1 * reverser;
        return result;
      })
      return $posts;
    },
    
    sortPostOrder: function( event ) {
      event.preventDefault();
      $forum = forum.getForum( this );
      $forum.append( forum.sortByData( forum.getPosts( $forum ).detach(), 'posted', false ) );
    },
    
    sortReverseOrder: function( event ) {
      event.preventDefault();
      $forum = forum.getForum( this );
      $forum.append( forum.sortByData( forum.getPosts( $forum ).detach(), 'posted', true ) );
    },
    
    sortLastPostOrder: function( event ) {
      event.preventDefault();
      $forum = forum.getForum( this );
      $forum.append( forum.sortByData( forum.getPosts( $forum ).detach(), 'last-post', true ) );
    },
    
    updateRepliesLink: function( $post, repliesDecrement, unapprovedDecrement ) {
      var replies = parseInt( $post.data('replies') );
      var unapproved = parseInt( $post.data('unapproved') );
      if ( repliesDecrement > 0 ) {
        replies = replies - repliesDecrement;
        $post.data( 'replies', replies ).attr( 'data-replies', replies );
        if ( replies > 0 ) {
          var regex = /\d+/;
          var $repliesSpan = $post.find('.forum-replies-num');
          $repliesSpan.html( $repliesSpan.html().replace( regex, replies ) );
        } else {
          $post.find('.forum-replies').remove();
        }
      }
      if ( unapprovedDecrement != 0 ) {
        unapproved = unapproved - unapprovedDecrement;
        $post.data( 'unapproved', unapproved ).attr( 'data-unapproved', unapproved );
        if ( unapproved > 0 ) {
          $post.find( '.forum-unapproved-num' ).html( '(' + unapproved + ' unapproved)' );
        } else {
          $post.find( '.forum-unapproved-num' ).remove();
        }
      }
    },
    
    addThread:  function( event ) {
      event.preventDefault();
      var $this = $(this);
      var url = $this.attr( 'href' );
      var $parent = $this.closest('.forum-options');
      if ( $parent.hasClass( 'forum-top' ) ) {
        forum.addPostMessageForm( $('#forum-topics > .forum.topics'), 'prepend', url );
      } else {
        forum.addPostMessageForm( $('#forum-topics > .forum.topics'), 'append', url );
      }
    },
    
    addReply:  function( event ) {
      event.preventDefault();
      var $this = $(this);
      var url = $this.attr( 'href' );
      var $post = $this.closest( '.forum-thread-topic, .forum-reply' );
      var $replies =  $post.find( '.forum.replies' );
      if ( $post.hasClass('forum-thread-topic') ) {
        // The link was in the initial topic.
        // See if the topic has replies and the user can view them
        // (in which case there will be info about the replies in a .forum-replies div)
        if ( ($post.children('.forum-replies').length > 0 && $replies.length == 0) || $replies.length == 0 ) {
          // The replies are not visible, there are no previous replies,
          // or the user can't view them, so create a .forum.replies div,
          // then add the form to it.
          $post.append( '<div class="forum replies"></div>' );
        }
        $replies = $post.find( '.forum.replies' );
        forum.addPostMessageForm( $replies, 'prepend', url );
      } else {
        // The link was either the Reply link at the end of a list of replies,
        // or a Quote and Reply link inside a reply.
        if ( $this.parents( '.forum-editable' ).length > 0 ) {
          // Quote and Reply link
          forum.addPostMessageForm( $post, 'after', url );
        } else {
          $replies = $this.parents( '.forum.replies' );
          forum.addPostMessageForm( $replies, 'append', url );
        }
      }
    },
    
    addPostMessageForm:  function( $elem, action, url ) {
      url = url.replace('ptPostMessage', 'pyPostMessageFormJSON' )
      $.get( url )
      .success( function( data ) {
        var parsedData = JSON.parse( data );
        if ( action == 'prepend' ) {
          $elem.prepend( parsedData );
        } else if ( action == 'append' ) {
          $elem.append( parsedData );
        } else if ( action == 'before' ) {
          $elem.before( parsedData );
        } else if ( action == 'after' ) {
          $elem.after( parsedData );
        }
        $( '.forum-new-message-form' ).ajaxForm({  
          dataType:  'json',
          success:   forum.saveNewPost 
        }); 
        forum.attachHandlers();
      });
    },
    
    saveNewPost: function( jsonData, statusText, xhr, $form ) {
      if ( jsonData.length > 0 ) {
        if ( $form.parent().hasClass( 'replies' ) ) {
          var $post = $form.closest( '.forum-thread-topic' );
          var $topics = $post.closest( '#forum-topics' );
          var replies = parseInt( $post.data( 'replies' ) ) + 1;
          $post.data( 'replies', replies ).attr( 'data-replies', replies );
          if ( $topics.hasClass( 'forum-moderated' ) ) {
            var unapproved = parseInt( $post.data( 'unapproved' ) + 1 );
            $post.data( 'unapproved', unapproved ).attr( 'data-unapproved', unapproved );
          }
          var $repliesDiv = $post.find('.forum-replies');
          if ( $repliesDiv.length == 0 ) {
            $post.append( '<div class="forum-replies"></div>' );
            $repliesDiv = $post.find('.forum-replies');
          }
          $repliesDiv.load( './pyGetPostJSON?msg_id=' + $post.attr('id') + ' .forum-replies' );
        }
        $form.replaceWith( jsonData );
        forum.attachHandlers();
      } else {
        window.alert('Your changes could not be saved.');
        $form.remove();
      }
    },
    
    cancelNewPost: function( event ) {
      event.preventDefault();
      var $this = $(this);
      var $form = $this.closest( '.forum-new-message-form' );
      if ( $form.parent().hasClass( 'replies' ) ) {
        var $post = $form.closest( '.forum-thread-topic' );
        $post.find( '.forum-hide-replies' ).click();
        $post.find( '.forum.replies' ).remove();
      } else {
        $form.remove();
      }
    },
    
    editMessage: function( event ) {
      event.preventDefault();
      var $this = $(this);
      var url = $this.attr( 'href' ).replace('ptEditMessage', 'pyEditMessageFormJSON' );
      var $editable = $this.closest( '.forum-thread-topic, .forum-reply' ).children( '.forum-editable' );
      $.get( url )
      .done( function( data ) {
        var parsedData = JSON.parse( data );
        if ( parsedData.length > 0 ) {
          $editable.children().hide();
          $editable.append(parsedData);
          $editable.find('form.forum-edit-message').ajaxForm({  
            dataType:  'json',
            success:   forum.saveChanges 
          }); 
          forum.attachHandlers();
        }
      });
    },
    
    addFile: function( event ) {
      event.preventDefault();
      $(this).siblings('#files')
      .append( '<tr><td><input type="file" name="files:list" size="25"></td></tr>' );
      forum.attachHandlers();
    },
    
    saveChanges: function( jsonData, statusText, xhr, $form ) {
      var $post = $form.closest( '.forum-thread-topic, .forum-reply' );
      if ( jsonData.length > 0 ) {
        $post.replaceWith( jsonData );
        forum.attachHandlers();
      } else {
        window.alert('Your changes could not be saved.');
        forum.restorePost( $form.find( '.forum-cancel-changes' ) );
      }
    },
    
    cancelChanges: function( event ) {
      event.preventDefault();
      forum.restorePost( this );
    },
    
    restorePost: function( elem ) {
      var $this = $( elem );
      var $form = $this.closest( 'form.forum-edit-message' );
      var $editable = $form.closest( '.forum-thread-topic, .forum-reply' ).find( '.forum-editable' );
      $form.remove();
      $editable.children().show();
      forum.attachHandlers();
    },
    
    removePost: function( event ) {
      event.preventDefault();
      if ( ! window.confirm("Are you sure you want to delete this? It can't be undone.") ) {
        return;
      }
      var $this = $(this);
      var url = $this.attr('href');
      var $post = $this.closest( '.forum-thread-topic, .forum-reply' );
      $.get( url )
      .success( function( data ) {
        var $parentPost;
        if ( $post.hasClass('forum-reply') ) {
          var unapproved = $post.hasClass('forum-unapproved') ? 1 : 0;
          $parentPost = $post.closest('.forum.replies').closest('.forum-thread-topic, .forum-reply');
          forum.updateRepliesLink( $parentPost, 1, unapproved );
        }
        $post.remove();
        if ( $parentPost && $parentPost.find( '.forum.replies .forum-reply' ).length == 0 ) {
          $parentPost.find( '.forum.replies' ).remove();
        }
      })
    },
    
    approvePost:  function( event ) {
      event.preventDefault();
      var $this = $(this);
      var url = $this.attr('href');
      $.get( url )
      .success( function( data ) {
        var $post = $this.closest('.forum-thread-topic, .forum-reply')
        $post.removeClass('forum-unapproved')
        .addClass('forum-approved')
        .find('.forum-moderation-notice').remove();
        var $parentPost = $post.closest('.forum.replies').closest('.forum-thread-topic, .forum-reply');
        var unapproved = parseInt( $parentPost.data('unapproved') ) - 1;
        forum.updateRepliesLink( $parentPost, 0, 1 );
        $this.hide();
        $this.siblings('.forum-moderate-link').show();
      })
    },
    
    moderatePost:  function( event ) {
      event.preventDefault();
      var $this = $(this);
      var url = $this.attr('href');
      $.get( url )
      .success( function( data ) {
        var $post = $this.closest('.forum-thread-topic, .forum-reply')
        $post.removeClass('forum-approved')
        .addClass('forum-unapproved');
        $post.find( '.forum-name-date' ).append( '<span class="forum-moderation-notice">(Awaiting moderator approval)</span>' );
        var $parentPost = $post.closest('.forum.replies').closest('.forum-thread-topic, .forum-reply');
        var unapproved = parseInt( $parentPost.data('unapproved') ) + 1;
        forum.updateRepliesLink( $parentPost, 0, -1 );
        $this.hide();
        $this.siblings('.forum-approve-link').show();
      })
    },
    
    attachHandlers: function() {
    
      // Clear all handlers from links, buttons and forms, then reassign them. 
      // (Some links have their text and purpose changed by other handlers.)
  
      $(".forum-show-replies").off().click( forum.showReplies );
  
      $(".forum-hide-replies").off().click( forum.hideReplies );
      
      $(".forum-remove-link").off().click( forum.removePost );
      
      $(".forum-approve-link").off().click( forum.approvePost );
      
      $(".forum-moderate-link").off().click( forum.moderatePost );
      
      $(".forum-sort-post-order-link").off().click( forum.sortPostOrder );
      
      $(".forum-sort-reverse-order-link").off().click( forum.sortReverseOrder );
      
      $(".forum-sort-last-post-order-link").off().click( forum.sortLastPostOrder );
     
      $(".forum-show-all-link").off().click( forum.showAllReplies );
      
      $(".forum-hide-all-link").off().click( forum.hideAllReplies );
     
      $(".forum-new-thread-link").off().click( forum.addThread );
     
      $(".forum-cancel-new-post").off().click( forum.cancelNewPost );
     
      $(".forum-reply-link, .forum-quote-link").off().click( forum.addReply );
     
      $(".forum-edit-link").off().click( forum.editMessage );
     
      $(".forum-add-file-link").off().click( forum.addFile );
     
      $(".forum-cancel-changes").off().click( forum.cancelChanges );
      
      $( '.forum-new-message-form' ).off().ajaxForm({  
        dataType:  'json',
        success:   forum.saveNewPost 
      }); 
      
      $('form.forum-edit-message').off().ajaxForm({  
        dataType:  'json',
        success:   forum.saveChanges 
      }); 
    
    }
    
  };
  
  forum.attachHandlers();
  
})(jQuery);