/*
 * Extract a random image from the last 3 in a post gallery
 *
 * @param string $size the image size . default to thumbnail default WP size
 * @return array image data or false.
 */

if ( ! function_exists( 'get_rand_img_from_post_gallery' ) ){
    function get_rand_img_from_post_gallery($size = 'thumbnail') {
        global $post;
        $retarray = array();
        $images = get_children(array(
            'post_parent'    => $post->ID,
            'post_type'      => 'attachment',
            'numberposts'    => -1, // show all
            'post_status'    => null,
            'post_mime_type' => 'image',
            'orderby'                => 'menu_order',
            'order'                  => 'DESC'
        ));
        if (is_array($images) && count($images)>0){
            //preserve associative array keys: php > 5.0.2 only!!!
            $last_three_images= array_slice($images,0,3,true);
            $random = $last_three_images[array_rand($last_three_images,1)];
            $retarray['id'] = $random->ID;
            $retarray['imgtag'] = wp_get_attachment_image($random->ID,$size);
            $retarray['post-link'] = get_permalink($random->post_parent);
            $retarray['title'] = apply_filters('the_title',$random->post_title);
            return $retarray;
        }else{
            //no images found
            return false;
        }
    }
}