<?php
/**
 * Displays a {@link SS_List} in a grid format.
 * 
 * GridField is a field that takes an SS_List and displays it in an table with rows 
 * and columns. It reminds of the old TableFields but works with SS_List types 
 * and only loads the necessary rows from the list.
 * 
 * The minimum configuration is to pass in name and title of the field and a 
 * SS_List.
 * 
 * <code>
 * $gridField = new GridField('ExampleGrid', 'Example grid', new DataList('Page'));
 * </code>
 * 
 * @see SS_List
 * 
 * @package forms
 * @subpackage fields-gridfield
 */
class GridField extends FormField {
	
	/**
	 *
	 * @var array
	 */
	private static $allowed_actions = array(
		'index',
		'gridFieldAlterAction'
	);
	
	/**
	 * The datasource
	 * @var SS_List
	 */
	protected $list = null;

	/**
	 * The classname of the DataObject that the GridField will display. Defaults to the value of $this->list->dataClass
	 * @var string
	 */
	protected $modelClassName = '';

	/**
	 * the current state of the GridField
	 * @var GridState
	 */
	protected $state = null;
	
	/**
	 *
	 * @var GridFieldConfig
	 */
	protected $config = null;
	
	/**
	 * The components list
	 *
	 * @var array
	 */
	protected $components = array();
	
	/**
	 * Internal dispatcher for column handlers.
	 * Keys are column names and values are GridField_ColumnProvider objects
	 * 
	 * @var array
	 */
	protected $columnDispatch = null;
	
	/**
	 * Map of callbacks for custom data fields
	 *
	 * @var array
	 */
	protected $customDataFields = array();

	/**
	 * @var string
	 */
	protected $name = '';

	/**
	 * Creates a new GridField field
	 *
	 * @param string $name
	 * @param string $title
	 * @param SS_List $dataList
	 * @param GridFieldConfig $config
	 */
	public function __construct($name, $title = null, SS_List $dataList = null, GridFieldConfig $config = null) {
		parent::__construct($name, $title, null);
		$this->name = $name;

		if($dataList) {
			$this->setList($dataList);
		}

		$this->setConfig($config ?: GridFieldConfig_Base::create());

		$this->config->addComponent(new GridState_Component());
		$this->state = new GridState($this);		
		
		$this->addExtraClass('ss-gridfield');
	}

	public function index($request) {
		return $this->gridFieldAlterAction(array(), $this->getForm(), $request);
	}
	
	/**
	 * Set the modelClass (dataobject) that this field will get it column headers from.
	 * If no $displayFields has been set, the displayfields will be fetched from
	 * this modelclass $summary_fields
	 * 
	 * @param string $modelClassName
	 * @see GridFieldDataColumns::getDisplayFields()
	 */
	public function setModelClass($modelClassName) {
		$this->modelClassName = $modelClassName;
		return $this;
	}
	
	/**
	 * Returns a dataclass that is a DataObject type that this GridField should look like.
	 * 
	 * @throws Exception
	 * @return string
	 */
	public function getModelClass() {
		if ($this->modelClassName) return $this->modelClassName;
		if ($this->list && method_exists($this->list, 'dataClass')) {
			$class = $this->list->dataClass();
			if($class) return $class;
		}

		throw new LogicException('GridField doesn\'t have a modelClassName,'
			. ' so it doesn\'t know the columns of this grid.');
	}

	/**
	 * Get the GridFieldConfig
	 *
	 * @return GridFieldConfig
	 */
	public function getConfig() {
		return $this->config;
	}

	/**
	 * @param GridFieldConfig $config
	 * @return GridField
	 */
	public function setConfig(GridFieldConfig $config) {
		$this->config = $config;
		return $this;
	}

	public function getComponents() {
		return $this->config->getComponents();
	}
	
	/**
	 * Cast a arbitrary value with the help of a castingDefintion
	 * 
	 * @param $value 
	 * @param $castingDefinition
	 * @todo refactor this into GridFieldComponent
	 */
	public function getCastedValue($value, $castingDefinition) {
		if(is_array($castingDefinition)) {
			$castingParams = $castingDefinition;
			array_shift($castingParams);
			$castingDefinition = array_shift($castingDefinition);
		} else {
			$castingParams = array();
		}
		
		if(strpos($castingDefinition,'->') === false) {
			$castingFieldType = $castingDefinition;
			$castingField = DBField::create_field($castingFieldType, $value);
			$value = call_user_func_array(array($castingField,'XML'),$castingParams);
		} else {
			$fieldTypeParts = explode('->', $castingDefinition);
			$castingFieldType = $fieldTypeParts[0];	
			$castingMethod = $fieldTypeParts[1];
			$castingField = DBField::create_field($castingFieldType, $value);
			$value = call_user_func_array(array($castingField,$castingMethod),$castingParams);
		}
		
		return $value;
	}	 

	/**
	 * Set the datasource
	 *
	 * @param SS_List $list
	 */
	public function setList(SS_List $list) {
		$this->list = $list;
		return $this;
	}

	/**
	 * Get the datasource
	 *
	 * @return SS_List
	 */
	public function getList() {
		return $this->list;
	}

	/**
	 * Get the datasource after applying the {@link GridField_DataManipulator}s to it.
	 *
	 * @return SS_List
	 */
	public function getManipulatedList() {
		$list = $this->getList();
		foreach($this->getComponents() as $item) {
			if($item instanceof GridField_DataManipulator) {
				$list = $item->getManipulatedData($this, $list);
			}
		}
		return $list;
	}
	
	/**
	 * Get the current GridState_Data or the GridState
	 *
	 * @param bool $getData - flag for returning the GridState_Data or the GridState
	 *
	 * @return GridState_data|GridState
	 */
	public function getState($getData = true) {
		if($getData) {
			return $this->state->getData();
		}

		return $this->state;
	}

	/**
	 * Returns the whole gridfield rendered with all the attached components
	 *
	 * @return string
	 */
	public function FieldHolder($properties = array()) {
		Requirements::css(THIRDPARTY_DIR . '/jquery-ui-themes/smoothness/jquery-ui.css');
		Requirements::css(FRAMEWORK_DIR . '/css/GridField.css');

		Requirements::javascript(THIRDPARTY_DIR . '/jquery/jquery.js');
		Requirements::javascript(FRAMEWORK_DIR . '/thirdparty/jquery-ui/jquery-ui.js');
		Requirements::javascript(THIRDPARTY_DIR . '/json-js/json2.js');
		Requirements::javascript(FRAMEWORK_DIR . '/javascript/i18n.js');
		Requirements::add_i18n_javascript(FRAMEWORK_DIR . '/javascript/lang');
		Requirements::javascript(THIRDPARTY_DIR . '/jquery-entwine/dist/jquery.entwine-dist.js');
		Requirements::javascript(FRAMEWORK_DIR . '/javascript/GridField.js');

		// Get columns
		$columns = $this->getColumns();

		// Get data
		$list = $this->getManipulatedList();
		
		// Render headers, footers, etc
		$content = array(
			"before" => "",
			"after" => "",
			"header" => "",
			"footer" => "",
		);

		foreach($this->getComponents() as $item) {			
			if($item instanceof GridField_HTMLProvider) {
				$fragments = $item->getHTMLFragments($this);
				if($fragments) foreach($fragments as $k => $v) {
					$k = strtolower($k);
					if(!isset($content[$k])) $content[$k] = "";
					$content[$k] .= $v . "\n";
				}
			}
		}

		foreach($content as $k => $v) {
			$content[$k] = trim($v);
		}

		// Replace custom fragments and check which fragments are defined
		// Nested dependencies are handled by deferring the rendering of any content item that 
		// Circular dependencies are detected by disallowing any item to be deferred more than 5 times
		// It's a fairly crude algorithm but it works
		
		$fragmentDefined = array('header' => true, 'footer' => true, 'before' => true, 'after' => true);
		reset($content);
		while(list($k,$v) = each($content)) {
			if(preg_match_all('/\$DefineFragment\(([a-z0-9\-_]+)\)/i', $v, $matches)) {
				foreach($matches[1] as $match) {
					$fragmentName = strtolower($match);
					$fragmentDefined[$fragmentName] = true;
					$fragment = isset($content[$fragmentName]) ? $content[$fragmentName] : "";

					// If the fragment still has a fragment definition in it, when we should defer this item until
					// later.
					if(preg_match('/\$DefineFragment\(([a-z0-9\-_]+)\)/i', $fragment, $matches)) {
						// If we've already deferred this fragment, then we have a circular dependency
						if(isset($fragmentDeferred[$k]) && $fragmentDeferred[$k] > 5) {
							throw new LogicException("GridField HTML fragment '$fragmentName' and '$matches[1]' " . 
								"appear to have a circular dependency.");
						}
						
						// Otherwise we can push to the end of the content array
						unset($content[$k]);
						$content[$k] = $v;
						if(!isset($fragmentDeferred[$k])) {
							$fragmentDeferred[$k] = 1;
						} else {
							$fragmentDeferred[$k]++;
						}
						break;
					} else {
						$content[$k] = preg_replace('/\$DefineFragment\(' . $fragmentName . '\)/i', $fragment,
							$content[$k]);
					}
				}
			}
		}

		// Check for any undefined fragments, and if so throw an exception
		// While we're at it, trim whitespace off the elements
		foreach($content as $k => $v) {
			if(empty($fragmentDefined[$k])) {
				throw new LogicException("GridField HTML fragment '$k' was given content,"
				. " but not defined.  Perhaps there is a supporting GridField component you need to add?");
			}
		}

		$total = count($list);
		if($total > 0) {
			$rows = array();
			foreach($list as $idx => $record) {
				if(!$record->canView()) {
					continue;
				}
				$rowContent = '';
				foreach($this->getColumns() as $column) {
					$colContent = $this->getColumnContent($record, $column);
					// A return value of null means this columns should be skipped altogether.
					if($colContent === null) continue;
					$colAttributes = $this->getColumnAttributes($record, $column);
					$rowContent .= FormField::create_tag('td', $colAttributes, $colContent);
				}
				$classes = array('ss-gridfield-item');
				if ($idx == 0) $classes[] = 'first';
				if ($idx == $total-1) $classes[] = 'last';
				$classes[] = ($idx % 2) ? 'even' : 'odd';
				$row = FormField::create_tag(
					'tr',
					array(
						"class" => implode(' ', $classes),
						'data-id' => $record->ID,
						// TODO Allow per-row customization similar to GridFieldDataColumns
						'data-class' => $record->ClassName,
					),
					$rowContent
				);
				$rows[] = $row;
			}
			$content['body'] = implode("\n", $rows);
		} 
		
		// Display a message when the grid field is empty
		if(!(isset($content['body']) && $content['body'])) {
			$content['body'] = FormField::create_tag(
				'tr',
				array("class" => 'ss-gridfield-item ss-gridfield-no-items'),
				FormField::create_tag(
					'td',
					array('colspan' => count($columns)),
					_t('GridField.NoItemsFound', 'No items found')
				)
			);
		}

		// Turn into the relevant parts of a table
		$head = $content['header']
			? FormField::create_tag('thead', array(), $content['header'])
			: '';
		$body = $content['body']
			? FormField::create_tag('tbody', array('class' => 'ss-gridfield-items'), $content['body'])
			: '';
		$foot = $content['footer']
			? FormField::create_tag('tfoot', array(), $content['footer'])
			: '';

		$this->addExtraClass('ss-gridfield field');
		$attrs = array_diff_key(
			$this->getAttributes(), 
			array('value' => false, 'type' => false, 'name' => false)
		);
		$attrs['data-name'] = $this->getName();
		$tableAttrs = array(
			'id' => isset($this->id) ? $this->id : null,
			'class' => 'ss-gridfield-table',
			'cellpadding' => '0',
			'cellspacing' => '0'	
		);

		if($this->getDescription()) {
			$content['after'] .= FormField::create_tag(
				'span', 
				array('class' => 'description'), 
				$this->getDescription()
			);
		}

		return
			FormField::create_tag('fieldset', $attrs, 
				$content['before'] .
				FormField::create_tag('table', $tableAttrs, $head."\n".$foot."\n".$body) .
				$content['after']
			);
	}
	
	public function Field($properties = array()) {
		return $this->FieldHolder($properties);
	}

	public function getAttributes() {
		return array_merge(parent::getAttributes(), array('data-url' => $this->Link()));
	}

	/**
	 * Get the columns of this GridField, they are provided by attached GridField_ColumnProvider
	 *
	 * @return array
	 */
	public function getColumns() {
		// Get column list
		$columns = array();
		foreach($this->getComponents() as $item) {
			if($item instanceof GridField_ColumnProvider) {
				$item->augmentColumns($this, $columns);
			}
		}

		return $columns;
	}

	/**
	 * Get the value from a column
	 *
	 * @param DataObject $record
	 * @param string $column
	 * @return string
	 * @throws InvalidArgumentException
	 */
	public function getColumnContent($record, $column) {
		// Build the column dispatch
		if(!$this->columnDispatch) {
			$this->buildColumnDispatch();
		}
		
		if(!empty($this->columnDispatch[$column])) {
			$content = "";
			foreach($this->columnDispatch[$column] as $handler) {
				$content .= $handler->getColumnContent($this, $record, $column);
			}
			return $content;
		} else {
			throw new InvalidArgumentException("Bad column '$column'");
		}
	}
	
	/**
	 * Add additional calculated data fields to be used on this GridField
	 *
	 * @param array $fields a map of fieldname to callback. The callback will
	 * 				be passed the record as an argument.
	 */
	public function addDataFields($fields) {
		if($this->customDataFields) {
			$this->customDataFields = array_merge($this->customDataFields, $fields);
		} else {
			$this->customDataFields = $fields;
		}
	}
	
	/**
	 * Get the value of a named field  on the given record.
	 * Use of this method ensures that any special rules around the data for this gridfield are followed.
	 */
	public function getDataFieldValue($record, $fieldName) {
		// Custom callbacks
		if(isset($this->customDataFields[$fieldName])) {
			$callback = $this->customDataFields[$fieldName];
			return $callback($record);
		}
		
		// Default implementation
		if($record->hasMethod('relField')) {
			return $record->relField($fieldName);
		} elseif($record->hasMethod($fieldName)) {
			return $record->$fieldName();
		} else {
			return $record->$fieldName;
		}
	}

	/**
	 * Get extra columns attributes used as HTML attributes
	 *
	 * @param DataObject $record
	 * @param string $column
	 * @return array
	 * @throws LogicException
	 * @throws InvalidArgumentException
	 */
	public function getColumnAttributes($record, $column) {
		// Build the column dispatch
		if(!$this->columnDispatch) {
			$this->buildColumnDispatch();
		}
		
		if(!empty($this->columnDispatch[$column])) {
			$attrs = array();

			foreach($this->columnDispatch[$column] as $handler) {
				$column_attrs = $handler->getColumnAttributes($this, $record, $column);

				if(is_array($column_attrs)) {
					$attrs = array_merge($attrs, $column_attrs);
				} elseif($column_attrs) {
					$methodSignature = get_class($handler) . "::getColumnAttributes()";
					throw new LogicException("Non-array response from $methodSignature.");
				}
			}

			return $attrs;
		} else {
			throw new InvalidArgumentException("Bad column '$column'");
		}
	}

	/**
	 * Get metadata for a column, example array('Title'=>'Email address')
	 *
	 * @param string $column
	 * @return array
	 * @throws LogicException
	 * @throws InvalidArgumentException
	 */
	public function getColumnMetadata($column) {
		// Build the column dispatch
		if(!$this->columnDispatch) {
			$this->buildColumnDispatch();
		}
		
		if(!empty($this->columnDispatch[$column])) {
			$metadata = array();

			foreach($this->columnDispatch[$column] as $handler) {
				$column_metadata = $handler->getColumnMetadata($this, $column);
				
				if(is_array($column_metadata)) {
					$metadata = array_merge($metadata, $column_metadata);
				} else {
					$methodSignature = get_class($handler) . "::getColumnMetadata()";
					throw new LogicException("Non-array response from $methodSignature.");
				}
				
			}
			
			return $metadata;
		}
		throw new InvalidArgumentException("Bad column '$column'");
	}

	/**
	 * Return how many columns the grid will have
	 *
	 * @return int
	 */
	public function getColumnCount() {
		// Build the column dispatch
		if(!$this->columnDispatch) $this->buildColumnDispatch();
		return count($this->columnDispatch);	
	}

	/**
	 * Build an columnDispatch that maps a GridField_ColumnProvider to a column
	 * for reference later
	 * 
	 */
	protected function buildColumnDispatch() {
		$this->columnDispatch = array();

		foreach($this->getComponents() as $item) {
			if($item instanceof GridField_ColumnProvider) {
				$columns = $item->getColumnsHandled($this);

				foreach($columns as $column) {
					$this->columnDispatch[$column][] = $item;
				}
			}
		}
	}

	/**
	 * This is the action that gets executed when a GridField_AlterAction gets clicked.
	 *
	 * @param array $data
	 * @return string 
	 */
	public function gridFieldAlterAction($data, $form, SS_HTTPRequest $request) {
		$html = '';
		$data = $request->requestVars();
		$name = $this->getName();
		$fieldData = isset($data[$name]) ? $data[$name] : null;

		// Update state from client
		$state = $this->getState(false);

		if(isset($fieldData['GridState'])) {
			$state->setValue($fieldData['GridState']);
		}

		// Try to execute alter action
		foreach($data as $k => $v) {
			if(preg_match('/^action_gridFieldAlterAction\?StateID=(.*)/', $k, $matches)) {
				$id = $matches[1];
				$stateChange = Session::get($id);

				$actionName = $stateChange['actionName'];

				$args = isset($stateChange['args']) ? $stateChange['args'] : array();
				$html = $this->handleAlterAction($actionName, $args, $data);
				// A field can optionally return its own HTML
				if($html) return $html;
			}
		}
		
		switch($request->getHeader('X-Pjax')) {
			case 'CurrentField':
				return $this->FieldHolder();
				break;

			case 'CurrentForm':
				return $form->forTemplate();
				break;

			default:
				return $form->forTemplate();
				break;
		}
	}

	/**
	 * Pass an action on the first GridField_ActionProvider that matches the $actionName
	 *
	 * @param string $actionName
	 * @param mixed $args
	 * @param arrray $data - send data from a form
	 * @return type
	 * @throws InvalidArgumentException
	 */
	public function handleAlterAction($actionName, $args, $data) {
		$actionName = strtolower($actionName);
		foreach($this->getComponents() as $component) {
			if(!($component instanceof GridField_ActionProvider)) {
				continue;
			}
			
			if(in_array($actionName, array_map('strtolower', (array)$component->getActions($this)))) {
				return $component->handleAction($this, $actionName, $args, $data);
			}
		}
		throw new InvalidArgumentException("Can't handle action '$actionName'");
	}
	
	/**
	 * Custom request handler that will check component handlers before proceeding to the default implementation.
	 * 
	 * @todo There is too much code copied from RequestHandler here.
	 */
	public function handleRequest(SS_HTTPRequest $request, DataModel $model) {
		if($this->brokenOnConstruct) {
			user_error("parent::__construct() needs to be called on {$handlerClass}::__construct()", E_USER_WARNING);
		}

		$this->request = $request;
		$this->setDataModel($model);

		$fieldData = $this->request->requestVar($this->getName());
		if($fieldData && isset($fieldData['GridState'])) $this->getState(false)->setValue($fieldData['GridState']);
		
		foreach($this->getComponents() as $component) {
			if(!($component instanceof GridField_URLHandler)) {
				continue;
			}
			
			$urlHandlers = $component->getURLHandlers($this);
			
			if($urlHandlers) foreach($urlHandlers as $rule => $action) {
				if($params = $request->match($rule, true)) {
					// Actions can reference URL parameters, eg, '$Action/$ID/$OtherID' => '$Action',
					if($action[0] == '$') $action = $params[substr($action,1)];
					if(!method_exists($component, 'checkAccessAction') || $component->checkAccessAction($action)) {
						if(!$action) {
							$action = "index";
						} else if(!is_string($action)) {
							throw new LogicException("Non-string method name: " . var_export($action, true));
						}

						try {
							$result = $component->$action($this, $request);
						} catch(SS_HTTPResponse_Exception $responseException) {
							$result = $responseException->getResponse();
						}

						if($result instanceof SS_HTTPResponse && $result->isError()) {
							return $result;
						}

						if($this !== $result && !$request->isEmptyPattern($rule) && is_object($result)
								&& $result instanceof RequestHandler) {

							$returnValue = $result->handleRequest($request, $model);

							if(is_array($returnValue)) {
								throw new LogicException("GridField_URLHandler handlers can't return arrays");
							}

							return $returnValue;

						// If we return some other data, and all the URL is parsed, then return that
						} else if($request->allParsed()) {
							return $result;

						// But if we have more content on the URL and we don't know what to do with it, return an error
						} else {
							return $this->httpError(404,
								"I can't handle sub-URLs of a " . get_class($result) . " object.");
						}
					}
				}
			}
		}
		
		return parent::handleRequest($request, $model);
	}

	public function saveInto(DataObjectInterface $record) {
		foreach($this->getComponents() as $component) {
			if($component instanceof GridField_SaveHandler) {
				$component->handleSave($this, $record);
			}
		}
	}

}


/**
 * This class is the base class when you want to have an action that alters 
 * the state of the {@link GridField}, rendered as a button element. 
 * 
 * @package forms
 * @subpackage fields-gridfield
 */
class GridField_FormAction extends FormAction {

	/**
	 * @var GridField
	 */
	protected $gridField;
	
	/**
	 * @var array 
	 */
	protected $stateValues;
	
	/**
	 * @var array
	 */
	protected $args = array();

	/**
	 * @var string
	 */
	protected $actionName;

	/**
	 * @var boolean
	 */
	public $useButtonTag = true;

	/**
	 * @param GridField $gridField
	 * @param type $name
	 * @param type $label
	 * @param type $actionName
	 * @param type $args 
	 */
	public function __construct(GridField $gridField, $name, $title, $actionName, $args) {
		$this->gridField = $gridField;
		$this->actionName = $actionName;
		$this->args = $args;

		parent::__construct($name, $title);
	}

	/**
	 * urlencode encodes less characters in percent form than we need - we 
	 * need everything that isn't a \w.
	 * 
	 * @param string $val
	 */
	public function nameEncode($val) {
		return preg_replace_callback('/[^\w]/', array($this, '_nameEncode'), $val);
	}

	/**
	 * The callback for nameEncode
	 * 
	 * @param string $val
	 */
	public function _nameEncode($match) {
		return '%'.dechex(ord($match[0]));
	}

	/**
	 * @return array
	 */
	public function getAttributes() {
		// Store state in session, and pass ID to client side.
		$state = array(
			'grid' => $this->getNameFromParent(),
			'actionName' => $this->actionName,
			'args' => $this->args,
		);

		$id = preg_replace('/[^\w]+/', '_', uniqid('', true));
		Session::set($id, $state);
		$actionData['StateID'] = $id;
		
		return array_merge(
			parent::getAttributes(),
			array(
				// Note:  This field needs to be less than 65 chars, otherwise Suhosin security patch 
				// will strip it from the requests 
				'name' => 'action_gridFieldAlterAction'. '?' . http_build_query($actionData),
				'data-url' => $this->gridField->Link(),
			)
		);
	}

	/**
	 * Calculate the name of the gridfield relative to the Form
	 *
	 * @param GridField $base
	 * @return string
	 */
	protected function getNameFromParent() {
		$base = $this->gridField;
		$name = array();
		
		do {
			array_unshift($name, $base->getName());
			$base = $base->getForm();
		} while ($base && !($base instanceof Form));

		return implode('.', $name);
	}
}
