<?php
/**
 * Base class for all fields that contain other fields.
 *
 * Implements sequentialisation - so that when we're saving / loading data, we 
 * can populate a tabbed form properly. All of the children are stored in 
 * $this->children
 *
 * @package forms
 * @subpackage fields-structural
 */
class CompositeField extends FormField {
	
	/**
	 * @var FieldList
	 */
	protected $children;
	
	/**
	 * Set to true when this field is a readonly field
	 */
	protected $readonly;
	
	/**
	 * @var $columnCount int Toggle different css-rendering for multiple columns 
	 * ("onecolumn", "twocolumns", "threecolumns"). The content is determined
	 * by the $children-array, so wrap all items you want to have grouped in a
	 * column inside a CompositeField.
	 * Caution: Please make sure that this variable actually matches the 
	 * count of your $children.
	 */
	protected $columnCount = null;

	/**
	 * @var String custom HTML tag to render with, e.g. to produce a <fieldset>.
	 */
	protected $tag = 'div';
	
	/**
	 * @var String Optional description for this set of fields.
	 * If the {@link $tag} property is set to use a 'fieldset', this will be
	 * rendered as a <legend> tag, otherwise its a 'title' attribute.
	 */
	protected $legend;

	public function __construct($children = null) {
		if($children instanceof FieldList) {
			$this->children = $children;
		} elseif(is_array($children)) {
			$this->children = new FieldList($children); 
		} else {
			$children = is_array(func_get_args()) ? func_get_args() : array();
			$this->children = new FieldList($children); 
		}
		$this->children->setContainerField($this);
		
		// Skipping FormField::__construct(), but we have to make sure this
		// doesn't count as a broken constructor
		$this->brokenOnConstruct = false;
		Object::__construct();
	}

	/**
	 * Returns all the sub-fields, suitable for <% loop FieldList %>
	 *
	 * @return FieldList
	 */
	public function FieldList() {
		return $this->children;
	}

	public function setID($id) {
		$this->id = $id;
		return $this;
	}

	/**
	 * Accessor method for $this->children
	 *
	 * @return FieldList
	 */
	public function getChildren() {
		return $this->children;
	}
	
	/**
	 * @param FieldList $children
	 */
	public function setChildren($children) {
		$this->children = $children;
		return $this;
	}

	/** 
	 * @param string 
	 */
	public function setTag($tag) {
		$this->tag = $tag;
		
		return $this;
	}

	/**
	 * @return string 
	 */
	public function getTag() {
		return $this->tag;
	}

	/** 
	 * @param string 
	 */
	public function setLegend($legend) {
		$this->legend = $legend;
		return $this;
	}

	/**
	 * @return string 
	 */
	public function getLegend() {
		return $this->legend;
	}

	public function extraClasses() {
		$classes = array('field', 'CompositeField', parent::extraClasses());
		if($this->columnCount) $classes[] = 'multicolumn';
		
		return implode(' ', $classes);
	}

	public function getAttributes() {
		return array_merge(
			parent::getAttributes(),
			array(
				'tabindex' => null, 
				'type' => null, 
				'value' => null, 
				'type' => null,
				'title' => ($this->tag == 'fieldset') ? null : $this->legend
			)
		);
	}

	/**
	 * Add all of the non-composite fields contained within this field to the 
	 * list.
	 *
	 * Sequentialisation is used when connecting the form to its data source
	 */
	public function collateDataFields(&$list, $saveableOnly = false) {
		foreach($this->children as $field) {
			if(is_object($field)) {
				if($field->isComposite()) $field->collateDataFields($list, $saveableOnly);
				if($saveableOnly) {
					$isIncluded =  ($field->hasData() && !$field->isReadonly() && !$field->isDisabled());
				} else {
					$isIncluded =  ($field->hasData());
				}
				if($isIncluded) {
					$name = $field->getName();
					if($name) {
						$formName = (isset($this->form)) ? $this->form->FormName() : '(unknown form)';
						if(isset($list[$name])) {
							user_error("collateDataFields() I noticed that a field called '$name' appears twice in"
								. " your form: '{$formName}'.  One is a '{$field->class}' and the other is a"
								. " '{$list[$name]->class}'", E_USER_ERROR);
						}
						$list[$name] = $field;
					}
				}
			}
		}
	}

	public function setForm($form) {
		foreach($this->children as $f) 
			if(is_object($f)) $f->setForm($form);
			
		parent::setForm($form);
		
		return $this;
	}
	
	public function setColumnCount($columnCount) {
		$this->columnCount = $columnCount;
		return $this;
	}
	
	public function getColumnCount() {
		return $this->columnCount;
	}
	
	public function isComposite() {
		return true; 
	}

	public function hasData() {
		return false; 
	}

	public function fieldByName($name) {
		return $this->children->fieldByName($name);
	}
	
	/**
	 * Add a new child field to the end of the set.
	 * 
	 * @param FormField
	 */
	public function push(FormField $field) {
		$this->children->push($field);
	}
	
	/**
	 * @uses FieldList->insertBefore()
	 */
	public function insertBefore($field, $insertBefore) {
		$ret = $this->children->insertBefore($field, $insertBefore);
		$this->sequentialSet = null;
		return $ret;
	}

	public function insertAfter($field, $insertAfter) {
		$ret = $this->children->insertAfter($field, $insertAfter);
		$this->sequentialSet = null;
		return $ret;
	}

	/**
	 * Remove a field from this CompositeField by Name.
	 * The field could also be inside a CompositeField.
	 * 
	 * @param string $fieldName The name of the field
	 * @param boolean $dataFieldOnly If this is true, then a field will only
	 * be removed if it's a data field.  Dataless fields, such as tabs, will
	 * be left as-is.
	 */
	public function removeByName($fieldName, $dataFieldOnly = false) {
		$this->children->removeByName($fieldName, $dataFieldOnly);
	}

	public function replaceField($fieldName, $newField) {
		return $this->children->replaceField($fieldName, $newField);
	}

	public function rootFieldList() {
		if(is_object($this->containerFieldList)) return $this->containerFieldList->rootFieldList();
		else return $this->children;
	}
	
	/**
	 * Return a readonly version of this field. Keeps the composition but returns readonly
	 * versions of all the child {@link FormField} objects.
	 *
	 * @return CompositeField
	 */
	public function performReadonlyTransformation() {
		$newChildren = new FieldList();
		$clone = clone $this;
		if($clone->getChildren()) foreach($clone->getChildren() as $idx => $child) {
			if(is_object($child)) $child = $child->transform(new ReadonlyTransformation());
			$newChildren->push($child, $idx);
		}

		$clone->children = $newChildren;
		$clone->readonly = true;
		$clone->addExtraClass($this->extraClass());
		$clone->setDescription($this->getDescription());

		return $clone;
	}

	/**
	 * Return a disabled version of this field. Keeps the composition but returns disabled
	 * versions of all the child {@link FormField} objects.
	 *
	 * @return CompositeField
	 */
	public function performDisabledTransformation() {
		$newChildren = new FieldList();
		$clone = clone $this;
		if($clone->getChildren()) foreach($clone->getChildren() as $idx => $child) {
			if(is_object($child)) $child = $child->transform(new DisabledTransformation());
			$newChildren->push($child, $idx);
		}

		$clone->children = $newChildren;
		$clone->readonly = true;
		$clone->addExtraClass($this->extraClass());
		$clone->setDescription($this->getDescription());
		foreach($this->attributes as $k => $v) {
			$clone->setAttribute($k, $v);
		}

		return $clone;
	}

	public function IsReadonly() {
		return $this->readonly;
	}
	
	/**
	 * Find the numerical position of a field within
	 * the children collection. Doesn't work recursively.
	 * 
	 * @param string|FormField
	 * @return int Position in children collection (first position starts with 0). Returns FALSE if the field can't
	 *             be found.
	 */
	public function fieldPosition($field) {
		if(is_string($field)) $field = $this->fieldByName($field);
		if(!$field) return false;
		
		$i = 0;
		foreach($this->children as $child) {
			if($child->getName() == $field->getName()) return $i;
			$i++;
		}
		
		return false;
	}
	
	/**
	 * Transform the named field into a readonly feld.
	 * 
	 * @param string|FormField
	 */
	public function makeFieldReadonly($field) {
		$fieldName = ($field instanceof FormField) ? $field->getName() : $field;
		
		// Iterate on items, looking for the applicable field
		foreach($this->children as $i => $item) {
			if($item->isComposite()) {
				$item->makeFieldReadonly($fieldName);
			} else {
				// Once it's found, use FormField::transform to turn the field into a readonly version of itself.
				if($item->getName() == $fieldName) {
					$this->children->replaceField($fieldName, $item->transform(new ReadonlyTransformation()));

					// Clear an internal cache
					$this->sequentialSet = null;

					// A true results indicates that the field was foudn
					return true;
				}
			}
		}
		return false;
	}

	public function debug() {
		$result = "$this->class ($this->name) <ul>";
		foreach($this->children as $child) {
			$result .= "<li>" . Debug::text($child) . "&nbsp;</li>";
		}
		$result .= "</ul>";
		return $result;
	}

	public function validate($validator) {
		$valid = true;
		foreach($this->children as $idx => $child){
			$valid = ($child && $child->validate($validator) && $valid);
		}
		return $valid;
	}

}

