<?php
	/*	
	*	Goodlayers Revision
	*	---------------------------------------------------------------------
	*	File which store the revision
	*	---------------------------------------------------------------------
	*/
	
	if( !class_exists('gdlr_fw2_revision') ){
		
		class gdlr_fw2_revision{
			
			// static function for field registration
			private static $revision_fields = array();
			
			static function add_field( $field ){
				self::$revision_fields[] = $field;
			}	

			// starting revision object
			private $num_revision;
			
			function __construct( $num_revision = 10 ){
				
				$this->num_revision = $num_revision;
				add_filter('wp_revisions_to_keep', array(&$this, 'filter_function_name'), 10, 2);
				
				add_action('init', array(&$this, 'add_revision_action'));
			}
			function add_revision_action(){
				add_filter('wp_save_post_revision_post_has_changed', array(&$this, 'check_revision_field_changes'), 10, 3);
				add_action('_wp_put_post_revision', array(&$this, 'update_revision_meta_field'));
				add_action('wp_restore_post_revision', array(&$this, 'restore_revision_meta_filed'), 10, 2);
				
				// for preview revision
				add_filter('_wp_post_revision_fields', array(&$this, 'add_preview_revision_fields'));
				foreach( self::$revision_fields as $revision_field ){
					if( !empty($revision_field['callback']) ){
						add_filter('_wp_post_revision_field_' . $revision_field['meta_key'], $revision_field['callback']);
					}
				}
			}
			
			// define the number of revision user can stored
			function filter_function_name( $num, $post ) {
				return $this->num_revision;
			}

			// check if there are any changes to meta fields
			function check_revision_field_changes( $post_has_changed, $last_revision, $post ){
				foreach( self::$revision_fields as $revision_field ){
					if( get_post_meta($post->ID, $revision_field['meta_key'], true) != get_post_meta($last_revision->ID, $revision_field['meta_key'], true) ){
						$post_has_changed = true;
					}
				}
				
				return $post_has_changed;
			}
			
			// update meta field when revision is updated
			function update_revision_meta_field( $revision_id ){
				$post_parent = wp_is_post_revision($revision_id);
				
				foreach( self::$revision_fields as $revision_field ){
					$meta_value = get_post_meta($post_parent, $revision_field['meta_key'], true);
					if( !empty($meta_value) ){
						add_metadata('post', $revision_id, $revision_field['meta_key'], $meta_value);
					}
				}
			}
			
			// restore meta field when revision is restored
			function restore_revision_meta_filed( $post_id, $revision_id ){
				foreach( self::$revision_fields as $revision_field ){
					$revision_data = get_post_meta($revision_id, $revision_field['meta_key'], true);
					if( !empty($revision_data) ){
						update_post_meta($post_id, $revision_field['meta_key'], $revision_data);
					}
				}
			}
			
			// for previewing the revision
			function add_preview_revision_fields( $fields ){
				foreach( self::$revision_fields as $revision_field ){
					$fields[$revision_field['meta_key']] = $revision_field['meta_name'];
				}
				return $fields;
			}
			
		} // gdlr_revision

	} // class_exists
	
	if( !function_exists('gdlr_fw2_decode_preventslashes') ){
		function gdlr_fw2_decode_preventslashes($value){
			$value = str_replace('|gq6|', '\\\\\\"', $value);
			$value = str_replace('|gq5|', '\\\\\"', $value);
			$value = str_replace('|gq4|', '\\\\"', $value);
			$value = str_replace('|gq3|', '\\\"', $value);
			$value = str_replace('|gq2|', '\\"', $value);
			$value = str_replace('|gq"|', '\"', $value);
			$value = str_replace('|g2t|', '\\\t', $value);
			$value = str_replace('|g1t|', '\t', $value);			
			$value = str_replace('|g2n|', '\\\n', $value);
			$value = str_replace('|g1n|', '\n', $value);
			return $value;
		}
	}	
	
	if( !function_exists('gdlr_convert_fw2_revision_data') ){
		function gdlr_convert_fw2_revision_data( $data ){
			if( is_array($data) ){ $data = $data[0]; }
			
			$data_val = gdlr_fw2_decode_preventslashes($data);
			$data_array = json_decode($data_val, true);
			
			if( !empty($data_array) ){
				return $data_val;
			}
			return '';
		}
	}
	
	if( class_exists('gdlr_fw2_revision') ){
		gdlr_fw2_revision::add_field(array(
			'meta_key'=>'gdlr-lms-content-settings', 
			'meta_name'=>esc_html__('Course Content', 'gdlr_translate'),
			'callback'=>'gdlr_convert_fw2_revision_data'
		));
		gdlr_fw2_revision::add_field(array(
			'meta_key'=>'above-sidebar', 
			'meta_name'=>esc_html__('Above Sidebar', 'gdlr_translate'),
			'callback'=>'gdlr_convert_fw2_revision_data'
		));
		gdlr_fw2_revision::add_field(array(
			'meta_key'=>'below-sidebar', 
			'meta_name'=>esc_html__('Below Sidebar', 'gdlr_translate'),
			'callback'=>'gdlr_convert_fw2_revision_data'
		));
		gdlr_fw2_revision::add_field(array(
			'meta_key'=>'content-with-sidebar', 
			'meta_name'=>esc_html__('Content With Sidebar', 'gdlr_translate'),
			'callback'=>'gdlr_convert_fw2_revision_data'
		));
		gdlr_fw2_revision::add_field(array(
			'meta_key'=>'post-option', 
			'meta_name'=>esc_html__('Post Option', 'gdlr_translate'),
			'callback'=>'gdlr_convert_fw2_revision_data'
		));
		new gdlr_fw2_revision();
	}