<?php
/**
 * This component provides a checkbox which when checked enables drag-and-drop re-ordering of elements displayed in a {@link GridField}
 *
 * @package forms
 */
class GridFieldSortableRows implements GridField_HTMLProvider, GridField_ActionProvider, GridField_DataManipulator {
	protected $sortColumn;
	
	/**
	 * @param String $sortColumn Column that should be used to update the sort information
	 */
	public function __construct($sortColumn) {
		$this->sortColumn = $sortColumn;
	}
	
	/**
	 * Returns a map where the keys are fragment names and the values are pieces of HTML to add to these fragments.
	 * @param GridField $gridField Grid Field Reference
	 * @return Array Map where the keys are fragment names and the values are pieces of HTML to add to these fragments.
	 */
	public function getHTMLFragments($gridField) {
		$state = $gridField->State->GridFieldSortableRows;
		if(!is_bool($state->sortableToggle)) {
			$state->sortableToggle = false;
		}
		
		
		//Sort order toggle
		$sortOrderToggle = Object::create(
			'GridField_FormAction',
			$gridField,
			'sortablerows-toggle',
			_t('GridFieldSortableRows.ALLOW_DRAG_DROP', '_Allow drag and drop re-ordering'),
			'saveGridRowSort',
			null
		)->addExtraClass('sortablerows-toggle');
		
		
		//Disable Pagenator
		$disablePagenator = Object::create(
			'GridField_FormAction',
			$gridField,
			'sortablerows-disablepagenator',
			_t('GridFieldSortableRows.DISABLE_PAGINATOR', '_Disable Pagenator'),
			'sortableRowsDisablePaginator',
			null
		)->addExtraClass('sortablerows-disablepagenator');
		
		
		$data = array('SortableToggle' => $sortOrderToggle,
					'PagenatorToggle' => $disablePagenator,
					'Checked' => ($state->sortableToggle == true ? ' checked = "checked"':''));
		
		$forTemplate = new ArrayData($data);
		
		
		//Inject Requirements
		Requirements::css('SortableGridField/css/GridFieldSortableRows.css');
		Requirements::javascript('SortableGridField/javascript/GridFieldSortableRows.js');
		
		
		$args = array('Colspan' => count($gridField->getColumns()));
		
		return array('header' => $forTemplate->renderWith('GridFieldSortableRows', $args));
	}
	
	/**
	 * Manipulate the datalist as needed by this grid modifier.
	 * @param GridField $gridField Grid Field Reference
	 * @param SS_List $dataList Data List to adjust
	 * @return DataList Modified Data List
	 */
	public function getManipulatedData(GridField $gridField, SS_List $dataList) {
		$state = $gridField->State->GridFieldSortableHeader;
		if ($state && !empty($state->SortColumn)) {
			return $dataList;
		}
		
		return $dataList->sort($this->sortColumn);
	}
	
	/**
	 * Return a list of the actions handled by this action provider.
	 * @param GridField $gridField Grid Field Reference
	 * @return Array Array with action identifier strings.
	 */
	public function getActions($gridField) {
		return array('saveGridRowSort', 'sortableRowsDisablePaginator');
	}
	
	/**
	 * Handle an action on the given grid field.
	 * @param GridField $gridField Grid Field Reference
	 * @param String $actionName Action identifier, see {@link getActions()}.
	 * @param Array $arguments Arguments relevant for this
	 * @param Array $data All form data
	 */
	public function handleAction(GridField $gridField, $actionName, $arguments, $data) {
		$state = $gridField->State->GridFieldSortableRows;
		if (!is_bool($state->sortableToggle)) {
			$state->sortableToggle = false;
		} else if ($state->sortableToggle == true) {
			if ($gridField->getConfig()->getComponentsByType('GridFieldPaginator')) {
				$gridField->getConfig()->removeComponentsByType('GridFieldPaginator');
				$gridField->getConfig()->addComponent(new GridFieldFooter());
			}
			
			$gridField->getConfig()->removeComponentsByType('GridFieldFilterHeader');
			$gridField->getConfig()->removeComponentsByType('GridFieldSortableHeader');
		}
		
		
		if ($actionName == 'savegridrowsort') {
			return $this->saveGridRowSort($gridField, $data);
		}
	}
	
	/**
	 * Handles saving of the row sort order
	 * @param GridField $gridField Grid Field Reference
	 * @param Array $data Data submitted in the request
	 */
	private function saveGridRowSort(GridField $gridField, $data) {
		if (empty($data['Items'])) {
			user_error('No items to sort', E_USER_ERROR);
		}
		
		$className = $gridField->getModelClass();
		$owner = $gridField->Form->getRecord();
		$items = $gridField->getList();
		$many_many = ($items instanceof ManyManyList);
		$sortColumn = $this->sortColumn;
		
		
		if ($many_many) {
			list($parentClass, $componentClass, $parentField, $componentField, $table) = $owner->many_many($gridField->getName());
		}
		
		
		$data['Items'] = explode(',', $data['Items']);
		for($sort = 0;$sort<count($data['Items']);$sort++) {
			$id = intval($data['Items'][$sort]);
			if ($many_many) {
				DB::query('UPDATE "' . $table
						. '" SET "' . $sortColumn.'" = ' . ($sort+1)
						. ' WHERE "' . $componentField . '" = ' . $id . ' AND "' . $parentField . '" = ' . $owner->ID);
			} else {
				$obj = $items->byID($data['Items'][$sort]);
				$obj->$sortColumn = $sort+1;
				$obj->write();
			}
		}
	}
}
?>