<?php

/**
 * Provides view and edit forms at GridField-specific URLs.  
 * These can be placed into pop-ups by an appropriate front-end.
 * Usually added to a grid field alongside of {@link GridFieldEditButton}
 * which takes care of linking the individual rows to their edit view.
 * 
 * The URLs provided will be off the following form:
 *  - <FormURL>/field/<GridFieldName>/item/<RecordID>
 *  - <FormURL>/field/<GridFieldName>/item/<RecordID>/edit
 */
class GridFieldDetailForm implements GridField_URLHandler {

	/**
	 * @var String
	 */
	protected $template = 'GridFieldDetailForm';

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

	/**
	 * @var Validator The form validator used for both add and edit fields.
	 */
	protected $validator;

	/**
	 * @var String
	 */
	protected $itemRequestClass;

	/**
	 * @var function With two parameters: $form and $component
	 */
	protected $itemEditFormCallback;

	function getURLHandlers($gridField) {
		return array(
			'item/$ID' => 'handleItem',
			'autocomplete' => 'handleAutocomplete',
		);
	}
	
	/**
	 * Create a popup component. The two arguments will specify how the popup form's HTML and
	 * behaviour is created.  The given controller will be customised, putting the edit form into the
	 * template with the given name.
	 *
	 * The arguments are experimental API's to support partial content to be passed back to whatever
	 * controller who wants to display the getCMSFields
	 * 
	 * @param string $name The name of the edit form to place into the pop-up form
	 */
	public function __construct($name = 'DetailForm') {
		$this->name = $name;
	}
	
	/**
	 *
	 * @param type $gridField
	 * @param type $request
	 * @return GridFieldDetailForm_ItemRequest 
	 */
	public function handleItem($gridField, $request) {
		$controller = $gridField->getForm()->Controller();

		if(is_numeric($request->param('ID'))) {
			$record = $gridField->getList()->byId($request->param("ID"));
		} else {
			$record = Object::create($gridField->getModelClass());	
		}

		$class = $this->getItemRequestClass();

		$handler = Object::create($class, $gridField, $this, $record, $controller, $this->name);
		$handler->setTemplate($this->template);

		return $handler->handleRequest($request, DataModel::inst());
	}

	/**
	 * @param String
	 */
	function setTemplate($template) {
		$this->template = $template;
		return $this;
	}

	/**
	 * @return String
	 */
	function getTemplate() {
		return $this->template;
	}

	/**
	 * @param String
	 */
	function setName($name) {
		$this->name = $name;
		return $this;
	}

	/**
	 * @return String
	 */
	function getName() {
		return $this->name;
	}

	/**
	 * @param Validator $validator
	 */
	public function setValidator(Validator $validator) {
		$this->validator = $validator;
		return $this;
	}

	/**
	 * @return Validator
	 */
	public function getValidator() {
		return $this->validator;
	}

	/**
	 * @param String
	 */
	public function setItemRequestClass($class) {
		$this->itemRequestClass = $class;
		return $this;
	}

	/**
	 * @return String
	 */
	public function getItemRequestClass() {
		if($this->itemRequestClass) {
			return $this->itemRequestClass;
		} else if(ClassInfo::exists(get_class($this) . "_ItemRequest")) {
			return get_class($this) . "_ItemRequest";
		} else {
			return 'GridFieldItemRequest_ItemRequest';
		}
	}

	/**
	 * @param Closure $cb Make changes on the edit form after constructing it.
	 */
	public function setItemEditFormCallback(Closure $cb) {
		$this->itemEditFormCallback = $cb;
	}

	/**
	 * @return Closure
	 */
	public function getItemEditFormCallback() {
		return $this->itemEditFormCallback;
	}
}

class GridFieldDetailForm_ItemRequest extends RequestHandler {
	
	/**
	 *
	 * @var GridField 
	 */
	protected $gridField;
	
	/**
	 *
	 * @var GridField_URLHandler
	 */
	protected $component;
	
	/**
	 *
	 * @var DataObject
	 */
	protected $record;

	/**
	 *
	 * @var Controller
	 */
	protected $popupController;
	
	/**
	 *
	 * @var string
	 */
	protected $popupFormName;
	
	/**
	 * @var String
	 */
	protected $template = 'GridFieldItemEditView';

	static $url_handlers = array(
		'$Action!' => '$Action',
		'' => 'edit',
	);
	
	/**
	 *
	 * @param GridFIeld $gridField
	 * @param GridField_URLHandler $component
	 * @param DataObject $record
	 * @param Controller $popupController
	 * @param string $popupFormName 
	 */
	public function __construct($gridField, $component, $record, $popupController, $popupFormName) {
		$this->gridField = $gridField;
		$this->component = $component;
		$this->record = $record;
		$this->popupController = $popupController;
		$this->popupFormName = $popupFormName;
		parent::__construct();
	}

	public function Link($action = null) {
		return Controller::join_links($this->gridField->Link('item'), $this->record->ID ? $this->record->ID : 'new', $action);
	}

	public function view($request) {
		if(!$this->record->canView()) {
			$this->httpError(403);
		}

		$controller = $this->getToplevelController();

		$form = $this->ItemEditForm($this->gridField, $request);
		$form->makeReadonly();

		$data = new ArrayData(array(
			'Backlink'     => $controller->Link(),
			'ItemEditForm' => $form
		));
		$return = $data->renderWith($this->template);

		if($request->isAjax()) {
			return $return;
		} else {
			return $controller->customise(array('Content' => $return));
		}
	}

	function edit($request) {
		$controller = $this->getToplevelController();
		$form = $this->ItemEditForm($this->gridField, $request);

		$return = $this->customise(array(
			'Backlink' => $controller->hasMethod('Backlink') ? $controller->Backlink() : $controller->Link(),
			'ItemEditForm' => $form,
		))->renderWith($this->template);

		if($request->isAjax()) {
			return $return;	
		} else {
			// If not requested by ajax, we need to render it within the controller context+template
			return $controller->customise(array(
				// TODO CMS coupling
				'Content' => $return,
			));	
		}
	}

	/**
	 * Builds an item edit form.  The arguments to getCMSFields() are the popupController and
	 * popupFormName, however this is an experimental API and may change.
	 * 
	 * @todo In the future, we will probably need to come up with a tigher object representing a partially
	 * complete controller with gaps for extra functionality.  This, for example, would be a better way
	 * of letting Security/login put its log-in form inside a UI specified elsewhere.
	 * 
	 * @return Form 
	 */
	function ItemEditForm() {
		if (empty($this->record)) {
			$controller = Controller::curr();
			$noActionURL = $controller->removeAction($_REQUEST['url']);
			$controller->getResponse()->removeHeader('Location');   //clear the existing redirect
			return $controller->redirect($noActionURL, 302);
		}

		$actions = new FieldList();
		if($this->record->ID !== 0) {
			$actions->push(FormAction::create('doSave', _t('GridFieldDetailForm.Save', 'Save'))
				->setUseButtonTag(true)->addExtraClass('ss-ui-action-constructive')->setAttribute('data-icon', 'accept'));
			$actions->push(FormAction::create('doDelete', _t('GridFieldDetailForm.Delete', 'Delete'))
				->addExtraClass('ss-ui-action-destructive'));
		}else{ // adding new record
			//Change the Save label to 'Create'
			$actions->push(FormAction::create('doSave', _t('GridFieldDetailForm.Create', 'Create'))
				->setUseButtonTag(true)->addExtraClass('ss-ui-action-constructive')->setAttribute('data-icon', 'add'));
				
			// Add a Cancel link which is a button-like link and link back to one level up.
			$curmbs = $this->Breadcrumbs();
			if($curmbs && $curmbs->count()>=2){
				$one_level_up = $curmbs->offsetGet($curmbs->count()-2);
				$text = "
				<a class=\"crumb ss-ui-button ss-ui-action-destructive cms-panel-link ui-corner-all\" href=\"".$one_level_up->Link."\">
					Cancel
				</a>";
				$actions->push(new LiteralField('cancelbutton', $text));
			}
		}
		$form = new Form(
			$this,
			'ItemEditForm',
			$this->record->getCMSFields(),
			$actions,
			$this->component->getValidator()
		);
		$form->loadDataFrom($this->record);

		// TODO Coupling with CMS
		$toplevelController = $this->getToplevelController();
		if($toplevelController && $toplevelController instanceof LeftAndMain) {
			// Always show with base template (full width, no other panels), 
			// regardless of overloaded CMS controller templates.
			// TODO Allow customization, e.g. to display an edit form alongside a search form from the CMS controller
			$form->setTemplate('LeftAndMain_EditForm');
			$form->addExtraClass('cms-content cms-edit-form center ss-tabset');
			$form->setAttribute('data-pjax-fragment', 'CurrentForm Content');
			if($form->Fields()->hasTabset()) $form->Fields()->findOrMakeTab('Root')->setTemplate('CMSTabSet');
			// TODO Link back to controller action (and edited root record) rather than index,
			// which requires more URL knowledge than the current link to this field gives us.
			// The current root record is held in session only, 
			// e.g. page/edit/show/6/ vs. page/edit/EditForm/field/MyGridField/....
			$form->Backlink = $toplevelController->hasMethod('Backlink') ? $toplevelController->Backlink() : $toplevelController->Link();
		}

		$cb = $this->component->getItemEditFormCallback();
		if($cb) $cb($form, $this);

		return $form;
	}

	/**
	 * Traverse up nested requests until we reach the first that's not a GridFieldDetailForm_ItemRequest.
	 * The opposite of {@link Controller::curr()}, required because
	 * Controller::$controller_stack is not directly accessible.
	 * 
	 * @return Controller
	 */
	protected function getToplevelController() {
		$c = $this->popupController;
		while($c && $c instanceof GridFieldDetailForm_ItemRequest) {
			$c = $c->getController();
		}
		return $c;
	}

	function doSave($data, $form) {
		$new_record = $this->record->ID == 0;

		try {
			$form->saveInto($this->record);
			$this->record->write();
			$this->gridField->getList()->add($this->record);
		} catch(ValidationException $e) {
			$form->sessionMessage($e->getResult()->message(), 'bad');
			return Controller::curr()->redirectBack();
		}

		// TODO Save this item into the given relationship

		$message = sprintf(
			_t('GridFieldDetailForm.Saved', 'Saved %s %s'),
			$this->record->singular_name(),
			'<a href="' . $this->Link('edit') . '">"' . htmlspecialchars($this->record->Title, ENT_QUOTES) . '"</a>'
		);
		
		$form->sessionMessage($message, 'good');

		return Controller::curr()->redirect($this->Link());
	}

	function doDelete($data, $form) {
		try {
			$toDelete = $this->record;
			if (!$toDelete->canDelete()) {
				throw new ValidationException(_t('GridFieldDetailForm.DeletePermissionsFailure',"No delete permissions"),0);
			}

			$toDelete->delete();
		} catch(ValidationException $e) {
			$form->sessionMessage($e->getResult()->message(), 'bad');
			return Controller::curr()->redirectBack();
		}

		$message = sprintf(
			_t('GridFieldDetailForm.Deleted', 'Deleted %s %s'),
			$this->record->singular_name(),
			'<a href="' . $this->Link('edit') . '">"' . htmlspecialchars($this->record->Title, ENT_QUOTES) . '"</a>'
		);

		$form->sessionMessage($message, 'good');

		//when an item is deleted, redirect to the revelant admin section without the action parameter
		$controller = Controller::curr();
		$noActionURL = $controller->removeAction($data['url']);
		$controller->getRequest()->addHeader('X-Pjax', 'Content'); // Force a content refresh

		return $controller->redirect($noActionURL, 302); //redirect back to admin section
	}

	/**
	 * @param String
	 */
	function setTemplate($template) {
		$this->template = $template;
		return $this;
	}

	/**
	 * @return String
	 */
	function getTemplate() {
		return $this->template;
	}

	/**
	 * @return Controller
	 */
	function getController() {
		return $this->popupController;
	}

	/**
	 * @return GridField
	 */
	function getGridField() {
		return $this->gridField;
	}

	/**
	 * CMS-specific functionality: Passes through navigation breadcrumbs
	 * to the template, and includes the currently edited record (if any).
	 * see {@link LeftAndMain->Breadcrumbs()} for details.
	 * 
	 * @param boolean $unlinked 
	 * @return ArrayData
	 */
	function Breadcrumbs($unlinked = false) {
		if(!$this->popupController->hasMethod('Breadcrumbs')) return;

		$items = $this->popupController->Breadcrumbs($unlinked);
		if($this->record && $this->record->ID) {
			$items->push(new ArrayData(array(
				'Title' => $this->record->Title,
				'Link' => $this->Link()
			)));	
		} else {
			$items->push(new ArrayData(array(
				'Title' => sprintf(_t('GridField.NewRecord', 'New %s'), $this->record->singular_name()),
				'Link' => false
			)));	
		}
		
		return $items;
	}
}