<?php

	class LinksEventHandler extends kCatDBEventHandler {
	
		/**
		 * Enter description here...
		 *
		 * @param kEvent $event
		 */
		function SetCustomQuery(&$event)
		{
			parent::SetCustomQuery($event);
	
			$object =& $event->getObject();
			if (substr($event->Special, 0, 10) == 'duplicates') {
				$object->removeFilter('category_filter');
	
				$grouping = $this->getGrouping($event);
				switch ($event->Special) {
					case 'duplicates':
						foreach ($grouping as $group_field) {
							$object->AddGroupByField($group_field);
						}
						$object->addFilter('has_dupes_filter', 'DupeCount > 1', AGGREGATE_FILTER, FLT_SYSTEM);
						break;
	
					case 'duplicates-sub':
						$main_object =& $this->Application->recallObject($event->Prefix.'.duplicates');
						foreach ($grouping as $field_index => $group_field) {
							$object->addFilter('dupe_filter_'.$field_index, '%1$s.`'.$group_field.'` = '.$this->Conn->qstr($main_object->GetDBField($group_field)) );
						}
						break;
				}
				$object->addFilter('primary_filter', TABLE_PREFIX.'CategoryItems.PrimaryCat = 1');
			}
	
		}
	
		/**
		 * Gets grouping fields
		 *
		 * @param kEvent $event
		 * @return Array
		 */
		function getGrouping(&$event)
		{
			// cut "sub" postfix from special
			$prefix_special = preg_replace('/(.*)-sub$/', '\\1', $event->getPrefixSpecial());
			$grouping = $this->Application->RecallVar($prefix_special.'_dupe_fields');
			if (!$grouping) {
				$grouping = '|Url|';
				$this->Application->StoreVar($prefix_special.'_dupe_fields', $grouping);
			}
			$grouping = explode('|', substr($grouping, 1, -1));
			return $grouping;
		}
	
		/**
		 * Set groping fields for link duplicate checker
		 *
		 * @param kEvent $event
		 */
		function OnSetGrouping(&$event)
		{
			$this->Application->LinkVar($event->getPrefixSpecial(true).'_dupe_fields', $event->getPrefixSpecial().'_dupe_fields');
		}
		
		/**
		 * Merge duplicate links together (only categories) & delete duplicates
		 *
		 * @param kEvent $event
		 */
		function OnMerge(&$event)
		{
			$grouping = $this->getGrouping($event);
			$ids = $this->StoreSelectedIDs($event);
			if (!$ids) return true;
			
			// check, that user has not selected multiple links from same group
			$primary_links = Array();
			
			$id_field = $this->Application->getUnitOption($event->Prefix, 'IDField');
			$table_name = $this->Application->getUnitOption($event->Prefix, 'TableName');
			$sql = 'SELECT *
					FROM '.$table_name.'
					WHERE '.$id_field.' IN ('.implode(',', $ids).')';
			$links = $this->Conn->Query($sql, $id_field);
			
			$groping_error = false;
			foreach ($links as $link_id => $link_data) {
				$group_key = '';
				foreach ($grouping as $grouping_field) {
					$group_key .= 'main_table.`'.$grouping_field.'` = '.$this->Conn->qstr($link_data[$grouping_field]).' AND ';
				}
				$group_key = preg_replace('/(.*) AND $/', '\\1', $group_key);
				
				if (isset($primary_links[$group_key])) {
					$groping_error = true;
					break;
				}
				else {
					$primary_links[$group_key] = $link_data['ResourceId'];
				}
			}
			
			if (!$groping_error) {
				$temp =& $this->Application->recallObject($event->getPrefixSpecial().'_TempHandler', 'kTempTablesHandler');
				
				$categories_sql = 'SELECT main_table.ResourceId, ci.CategoryId, main_table.'.$id_field.'
						FROM '.$table_name.' main_table
						LEFT JOIN '.TABLE_PREFIX.'CategoryItems ci ON main_table.ResourceId = ci.ItemResourceId
						WHERE %s';
				
				foreach ($primary_links as $group_key => $primary_resource_id) {
					$categories = Array();
					$group_links = Array();
					$group_categories = $this->Conn->Query(sprintf($categories_sql, $group_key));
					foreach ($group_categories as $category_data) {
						$group_links[ $category_data['ResourceId'] ] = $category_data[$id_field];
						$categories[$category_data['ResourceId'] == $primary_resource_id ? 'remove' : 'add'][] = $category_data['CategoryId'];
					}
					unset($group_links[$primary_resource_id]);
					$categories = array_unique( array_diff($categories['add'], $categories['remove']) );
					if ($categories) {
						// add link to other link categories
						$values_sql = '';
						foreach ($categories as $category_id) {
							$values_sql .= '('.$category_id.','.$primary_resource_id.',0),';
						}
						$values_sql = preg_replace('/(.*),$/', '\\1', $values_sql);
						$insert_sql = 'INSERT INTO '.TABLE_PREFIX.'CategoryItems (CategoryId,ItemResourceId,PrimaryCat) VALUES '.$values_sql;
						$this->Conn->Query($insert_sql);
					}
					
					// delete all links from group except primary
					$temp->DeleteItems($event->Prefix, $event->Special, array_values($group_links));
				}
				
				
			}
			else {
				$event->status = erFAIL;
				$event->redirect = false;
				$this->Application->SetVar($event->getPrefixSpecial().'_error', 1);
			}
			
		}
	
	}

?>