<?php

/**
 * A button which allows objects to be created with a specified classname(s)
 */
class GridFieldAddClassesButton extends Object implements GridField_HTMLProvider, GridField_URLHandler {

	private static $allowed_actions = array(
		'handleAdd'
	);
	
	/**
	 * Name of fragment to insert into
	 * 
	 * @var string
	 */
	protected $targetFragment;

	/**
	 * Button title
	 *
	 * @var string
	 */
	protected $buttonName;

	/**
	 * Additonal CSS classes for the button
	 *
	 * @var string
	 */
	protected $buttonClass = null;

	/**
	 * Class names
	 *
	 * @var array
	 */
	protected $modelClasses = null;

	/**
	 * @param array $classes Class or list of classes to create.
	 * If you enter more than one class, each click of the "add" button will create one of each
	 * @param string $targetFragment The fragment to render the button into
	 */
	public function __construct($classes, $targetFragment = 'buttons-before-left') {
		parent::__construct();
		$this->setClasses($classes);
		$this->setFragment($targetFragment);
	}

	/**
	 * Change the button name
	 *
	 * @param string $name
	 * @return $this
	 */
	public function setButtonName($name) {
		$this->buttonName = $name;
		return $this;
	}

	/**
	 * Get the button name
	 *
	 * @return string
	 */
	public function getButtonName() {
		return $this->buttonName;
	}

	/**
	 * Gets the fragment name this button is rendered into.
	 *
	 * @return string
	 */
	public function getFragment() {
		return $this->targetFragment;
	}

	/**
	 * Sets the fragment name this button is rendered into.
	 *
	 * @param string $fragment
	 * @return GridFieldAddNewInlineButton $this
	 */
	public function setFragment($fragment) {
		$this->targetFragment = $fragment;
		return $this;
	}

	/**
	 * Get extra button class
	 *
	 * @return string
	 */
	public function getButtonClass() {
		return $this->buttonClass;
	}

	/**
	 * Sets extra CSS classes for this button
	 *
	 * @param string $buttonClass
	 * @return $this
	 */
	public function setButtonClass($buttonClass) {
		$this->buttonClass = $buttonClass;
		return $this;
	}


	/**
	 * Get the classes of the objects to create
	 *
	 * @return array
	 */
	public function getClasses() {
		return $this->modelClasses;
	}

	/**
	 * Gets the list of classes which can be created, with checks for permissions.
	 * Will fallback to the default model class for the given DataGrid
	 *
	 * @param DataGrid $grid
	 * @return array
	 */
	public function getClassesCreate($grid) {
		// Get explicit or fallback class list
		$classes = $this->modelClasses;
		if(empty($classes) && $grid) {
			$classes = array($grid->getModelClass());
		}

		// Filter out classes without permission
		return array_filter($classes, function($class) {
			return singleton($class)->canCreate();
		});
	}

	/**
	 * Specify the classes to create
	 *
	 * @param array $classes
	 */
	public function setClasses($classes) {
		if(!is_array($classes)) {
			$classes = $classes ? array($classes) : array();
		}
		$this->modelClasses = $classes;
	}

	public function getHTMLFragments($grid) {
		// Check create permission
		$singleton = singleton($grid->getModelClass());
		if(!$singleton->canCreate()) {
			return array();
		}

		// Get button name
		$buttonName = $this->getButtonName();
		if(!$buttonName) {
			// provide a default button name, can be changed by calling {@link setButtonName()} on this component
			$objectName = $singleton->i18n_singular_name();
			$buttonName = _t('GridField.Add', 'Add {name}', array('name' => $objectName));
		}

		$data = new ArrayData(array(
			'Title' => $this->getButtonName(),
			'ButtonClass' => $this->getButtonClass(),
			'Link' => Controller::join_links($grid->Link(), $this->getAction())
		));

		return array(
			$this->getFragment() => $data->renderWith(__CLASS__)
		);
	}

	/**
	 * Get the action suburl for this component
	 *
	 * @return type
	 */
	protected function getAction() {
		$classes = implode('-', $this->getClasses());
		return Controller::join_links('add-classes', $classes);
	}

	/**
	 * {@inheritDoc}
	 */
	public function getURLHandlers($grid) {
		return array(
			$this->getAction() => 'handleAdd'
		);
	}

	/**
	 * Handles adding a new instance of a selected class.
	 *
	 * @param GridField $grid
	 * @param SS_HTTPRequest $request
	 */
	public function handleAdd($grid, $request) {
		$classes = $this->getClassesCreate($grid);

		if(empty($classes)) {
			throw new SS_HTTPResponse_Exception(400);
		}

		// Add item to gridfield
		$list = $grid->getList();
		foreach($classes as $class) {
			$item = $class::create();
			$item->write();
			$list->add($item);
		}

		// Return directly to the gridfield again
		return $grid
			->getForm()
			->getController()
			->redirectBack();
	}
}