How to shortcode ai1ec step 4

/**
     * view shortcode function
     *
     * Display requested calendar page.
     *
     * @return void
     **/
    function view_shortcode($atts)
    {

        global $ai1ec_view_helper,
               $ai1ec_settings,
               $ai1ec_events_helper;

        If($atts){
            extract( $atts );   }
        $this->process_request();

        // Set body class
        add_filter( 'body_class', array( &$this, 'body_class' ) );
        // Queue any styles, scripts
        $this->load_css();
        $this->load_js();

      $post_ids = array_filter( explode( ',', $this->request['ai1ec_post_ids'] ), 'is_numeric' );
        // Define arguments for specific calendar sub-view (month, agenda, etc.)
        $args = array(
            'active_event' => $this->request['ai1ec_active_event'],
          'post_ids'     => $post_ids,
        );

        // Find out which view of the calendar page was requested
        switch( $this->request['action'] )
        {
            case 'ai1ec_month':
                $args['month_offset'] = $this->request['ai1ec_month_offset'];
                $view = $this->get_month_view( $args );
                break;

            case 'ai1ec_week':
                $args['week_offset'] = $this->request['ai1ec_week_offset'];
                $view = $this->get_week_view( $args );
                break;

            case 'ai1ec_agenda':
                $args['page_offset'] = $this->request['ai1ec_page_offset'];
                $view = $this->get_agenda_view( $args );
                break;
        }

      if( $ai1ec_settings->show_create_event_button && current_user_can( 'edit_ai1ec_events' ) )
        $create_event_url = admin_url( 'post-new.php?post_type=' . AI1EC_POST_TYPE );
      else
        $create_event_url = false;

      // Validate preselected category/tag/post IDs
      $cat_ids  = join( ',', array_filter( explode( ',', $this->request['ai1ec_cat_ids'] ), 'is_numeric' ) );
      $tag_ids  = join( ',', array_filter( explode( ',', $this->request['ai1ec_tag_ids'] ), 'is_numeric' ) );
      $post_ids = join( ',', $post_ids );

        If($cat_ids){
                $cat_ids  = cat_ids . join( ',', array_filter( explode( ',', $cat ), 'is_numeric' ) );
            }
            else
            {
                $cat_ids  = join( ',', array_filter( explode( ',', $cat ), 'is_numeric' ) );
            }

        If($tag_ids){
                $tag_ids  = tag_ids . join( ',', array_filter( explode( ',', $tag ), 'is_numeric' ) );
            }
            else
            {
                $tag_ids  = join( ',', array_filter( explode( ',', $tag ), 'is_numeric' ) );
            }

      $categories = get_terms( 'events_categories', array( 'orderby' => 'name' ) );
    foreach( $categories as &$cat ) {
      $cat->color = $ai1ec_events_helper->get_category_color_square( $cat->term_id );
    }
        // Define new arguments for overall calendar view
        $args = array(
            'view'                    => $view,
            'create_event_url'        => $create_event_url,
            'categories'              => $categories,
            'tags'                    => get_terms( 'events_tags', array( 'orderby' => 'name' ) ),
            'selected_cat_ids'        => $cat_ids,
            'selected_tag_ids'        => $tag_ids,
            'selected_post_ids'       => $post_ids,
            'show_subscribe_buttons'  => ! $ai1ec_settings->turn_off_subscription_buttons
        );
        // Feed month view into generic calendar view
        echo apply_filters( 'ai1ec_view', $ai1ec_view_helper->get_view( 'calendar.php', $args ), $args );
    }