<?php
if ( ! defined('ABSPATH')) exit;  // if direct access

if(!class_exists('PPduplicatePost')){
    class PPduplicatePost{

        public $post_types = array();

        function __construct($args){

            $this->post_types = isset($args['post_types']) ? $args['post_types'] : array();

            add_filter( 'post_row_actions', array($this, 'duplicate_post_link'), 10, 2 );


            add_action( 'admin_action_duplicate_post_as_draft', array($this, 'duplicate_post_as_draft') );



        }


        function duplicate_post_link( $actions, $post ) {


            if (current_user_can('edit_posts') && in_array($post->post_type, $this->post_types)  ) {
                $actions['duplicate'] = '<a href="' . wp_nonce_url('admin.php?action=duplicate_post_as_draft&post=' . $post->ID, basename(__FILE__), 'duplicate_post_nonce' ) . '" title="Duplicate this item" rel="permalink">Duplicate</a>';
            }
            return $actions;
        }




        function duplicate_post_as_draft(){


            //var_dump('Hello');

            global $wpdb;
            if (! ( isset( $_GET['post']) || isset( $_POST['post'])  || ( isset($_REQUEST['action']) && 'duplicate_post_as_draft' == $_REQUEST['action'] ) ) ) {
                wp_die('No post to duplicate has been supplied!');
            }

            /*
             * Nonce verification
             */
            if ( !isset( $_GET['duplicate_post_nonce'] ) || !wp_verify_nonce( $_GET['duplicate_post_nonce'], basename( __FILE__ ) ) )
                return;

            /*
             * get the original post id
             */
            $post_id = (isset($_GET['post']) ? absint( $_GET['post'] ) : absint( $_POST['post'] ) );
            /*
             * and all the original post data then
             */
            $post = get_post( $post_id );

            /*
             * if you don't want current user to be the new post author,
             * then change next couple of lines to this: $new_post_author = $post->post_author;
             */
            $current_user = wp_get_current_user();
            $new_post_author = $current_user->ID;

            /*
             * if post data exists, create the post duplicate
             */
            if (isset( $post ) && $post != null) {

                /*
                 * new post data array
                 */
                $args = array(
                    'comment_status' => $post->comment_status,
                    'ping_status'    => $post->ping_status,
                    'post_author'    => $new_post_author,
                    'post_content'   => $post->post_content,
                    'post_excerpt'   => $post->post_excerpt,
                    'post_name'      => $post->post_name,
                    'post_parent'    => $post->post_parent,
                    'post_password'  => $post->post_password,
                    'post_status'    => 'draft',
                    'post_title'     => $post->post_title.' - Copy of #'.$post_id,
                    'post_type'      => $post->post_type,
                    'to_ping'        => $post->to_ping,
                    'menu_order'     => $post->menu_order
                );

                /*
                 * insert the post by wp_insert_post() function
                 */
                $new_post_id = wp_insert_post( $args );

                /*
                 * get all current post terms ad set them to the new post draft
                 */
                $taxonomies = get_object_taxonomies($post->post_type); // returns array of taxonomy names for post type, ex array("category", "post_tag");
                foreach ($taxonomies as $taxonomy) {
                    $post_terms = wp_get_object_terms($post_id, $taxonomy, array('fields' => 'slugs'));
                    wp_set_object_terms($new_post_id, $post_terms, $taxonomy, false);
                }

                /*
                 * duplicate all post meta just in two SQL queries
                 */
                // Copy post metadata
                    $data = get_post_custom($post_id);
                    foreach ( $data as $key => $values) {
                        foreach ($values as $value) {
                            add_post_meta( $new_post_id, $key, maybe_unserialize( $value ) );// it is important to unserialize data to avoid conflicts.
                        }
                    }


                /*
                 * finally, redirect to the edit post screen for the new draft
                 */
                wp_redirect( admin_url( 'post.php?action=edit&post=' . $new_post_id ) );
                exit;
            } else {
                wp_die('Post creation failed, could not find original post: ' . $post_id);
            }
        }


    }
}