<?php
/**
 *
 * @package framework
 * @subpackage forms
 *
 * @uses DBField::scaffoldFormField()
 * @uses DataObject::fieldLabels()
 */
class FormScaffolder extends Object {

	/**
	 * @var DataObject $obj The object defining the fields to be scaffolded
	 * through its metadata like $db, $searchable_fields, etc.
	 */
	protected $obj;

	/**
	 * @var boolean $tabbed Return fields in a tabset, with all main fields in the path "Root.Main",
	 * relation fields in "Root.<relationname>" (if {@link $includeRelations} is enabled).
	 */
	public $tabbed = false;

	/**
	 * @var boolean $ajaxSafe
	 */
	public $ajaxSafe = false;

	/**
	 * @var array $restrictFields Numeric array of a field name whitelist.
	 * If left blank, all fields from {@link DataObject->db()} will be included.
	 *
	 * @todo Implement restrictions for has_many and many_many relations.
	 */
	public $restrictFields;

	/**
	 * @var array $fieldClasses Optional mapping of fieldnames to subclasses of {@link FormField}.
	 * By default the scaffolder will determine the field instance by {@link DBField::scaffoldFormField()}.
	 *
	 * @todo Implement fieldClasses for has_many and many_many relations
	 */
	public $fieldClasses;

	/**
	 * @var boolean $includeRelations Include has_one, has_many and many_many relations
	 */
	public $includeRelations = false;

	/**
	 * @param DataObject $obj
	 * @param array $params
	 */
	public function __construct($obj) {
		$this->obj = $obj;
		parent::__construct();
	}

	/**
	 * Gets the form fields as defined through the metadata
	 * on {@link $obj} and the custom parameters passed to FormScaffolder.
	 * Depending on those parameters, the fields can be used in ajax-context,
	 * contain {@link TabSet}s etc.
	 *
	 * @return FieldList
	 */
	public function getFieldList() {
		$fields = new FieldList();

		// tabbed or untabbed
		if($this->tabbed) {
			$fields->push(new TabSet("Root", $mainTab = new Tab("Main")));
			$mainTab->setTitle(_t('SiteTree.TABMAIN', "Main"));
		}

		// Add logical fields directly specified in db config
		foreach($this->obj->config()->db as $fieldName => $fieldType) {
			// Skip restricted fields
			if($this->restrictFields && !in_array($fieldName, $this->restrictFields)) continue;

			// @todo Pass localized title
			if($this->fieldClasses && isset($this->fieldClasses[$fieldName])) {
				$fieldClass = $this->fieldClasses[$fieldName];
				$fieldObject = new $fieldClass($fieldName);
			} else {
				$fieldObject = $this
					->obj
					->dbObject($fieldName)
					->scaffoldFormField(null, $this->getParamsArray());
			}
			// Allow fields to opt-out of scaffolding
			if(!$fieldObject) {
				continue;
			}
			$fieldObject->setTitle($this->obj->fieldLabel($fieldName));
			if($this->tabbed) {
				$fields->addFieldToTab("Root.Main", $fieldObject);
			} else {
				$fields->push($fieldObject);
			}
		}

		// add has_one relation fields
		if($this->obj->hasOne()) {
			foreach($this->obj->hasOne() as $relationship => $component) {
				if($this->restrictFields && !in_array($relationship, $this->restrictFields)) continue;
				$fieldName = $component === 'DataObject'
					? $relationship // Polymorphic has_one field is composite, so don't refer to ID subfield
					: "{$relationship}ID";
				if($this->fieldClasses && isset($this->fieldClasses[$fieldName])) {
					$fieldClass = $this->fieldClasses[$fieldName];
					$hasOneField = new $fieldClass($fieldName);
				} else {
					$hasOneField = $this->obj->dbObject($fieldName)->scaffoldFormField(null, $this->getParamsArray());
				}
				if(empty($hasOneField)) continue; // Allow fields to opt out of scaffolding
				$hasOneField->setTitle($this->obj->fieldLabel($relationship));
				if($this->tabbed) {
					$fields->addFieldToTab("Root.Main", $hasOneField);
				} else {
					$fields->push($hasOneField);
				}
			}
		}

		// only add relational fields if an ID is present
		if($this->obj->ID) {
			// add has_many relation fields
			if($this->obj->hasMany()
					&& ($this->includeRelations === true || isset($this->includeRelations['has_many']))) {

				foreach($this->obj->hasMany() as $relationship => $component) {
					if($this->tabbed) {
						$relationTab = $fields->findOrMakeTab(
							"Root.$relationship",
							$this->obj->fieldLabel($relationship)
						);
					}
					$fieldClass = (isset($this->fieldClasses[$relationship]))
						? $this->fieldClasses[$relationship]
						: 'GridField';
					$grid = Object::create($fieldClass,
						$relationship,
						$this->obj->fieldLabel($relationship),
						$this->obj->$relationship(),
						GridFieldConfig_RelationEditor::create()
					);
					if($this->tabbed) {
						$fields->addFieldToTab("Root.$relationship", $grid);
					} else {
						$fields->push($grid);
					}
				}
			}

			if($this->obj->manyMany()
					&& ($this->includeRelations === true || isset($this->includeRelations['many_many']))) {

				foreach($this->obj->manyMany() as $relationship => $component) {
					if($this->tabbed) {
						$relationTab = $fields->findOrMakeTab(
							"Root.$relationship",
							$this->obj->fieldLabel($relationship)
						);
					}

					$fieldClass = (isset($this->fieldClasses[$relationship]))
						? $this->fieldClasses[$relationship]
						: 'GridField';

					$grid = Object::create($fieldClass,
						$relationship,
						$this->obj->fieldLabel($relationship),
						$this->obj->$relationship(),
						GridFieldConfig_RelationEditor::create()
					);
					if($this->tabbed) {
						$fields->addFieldToTab("Root.$relationship", $grid);
					} else {
						$fields->push($grid);
					}
				}
			}
		}

		return $fields;
	}

	/**
	 * Return an array suitable for passing on to {@link DBField->scaffoldFormField()}
	 * without tying this call to a FormScaffolder interface.
	 *
	 * @return array
	 */
	protected function getParamsArray() {
		return array(
			'tabbed' => $this->tabbed,
			'includeRelations' => $this->includeRelations,
			'restrictFields' => $this->restrictFields,
			'fieldClasses' => $this->fieldClasses,
			'ajaxSafe' => $this->ajaxSafe
		);
	}
}