<?php
/**
 * Multi-line listbox field, created from a <select> tag.
 * 
 * <b>Usage</b>
 * 
 * <code>
 * new ListboxField(
 *    $name = "pickanumber",
 *    $title = "Pick a number",
 *    $source = array(
 *       "1" => "one",
 *       "2" => "two",
 *       "3" => "three"
 *    ),
 *    $value = 1
 * )
 * </code> 
 * 
 * @see DropdownField for a simple <select> field with a single element.
 * @see CheckboxSetField for multiple selections through checkboxes.
 * @see OptionsetField for single selections via radiobuttons.
 * @see TreeDropdownField for a rich and customizeable UI that can visualize a tree of selectable elements
 * 
 * @package forms
 * @subpackage fields-basic
 */
class ListboxField extends DropdownField {

	/**
	 * The size of the field in rows.
	 * @var int
	 */
	protected $size;

	/**
	 * Should the user be able to select multiple
	 * items on this dropdown field?
	 * 
	 * @var boolean
	 */
	protected $multiple = false;

	/**
	 * @var Array
	 */
	protected $disabledItems = array();

	/**
	 * @var Array
	 */
	protected $defaultItems = array();
	
	/**
	 * Creates a new dropdown field.
	 * 
	 * @param string $name The field name
	 * @param string $title The field title
	 * @param array $source An map of the dropdown items
	 * @param string|array $value You can pass an array of values or a single value like a drop down to be selected
	 * @param int $size Optional size of the select element
	 * @param form The parent form
	 */
	function __construct($name, $title = '', $source = array(), $value = '', $size = null, $multiple = false) {
		if($size) $this->size = $size;
		if($multiple) $this->multiple = $multiple;
		parent::__construct($name, $title, $source, $value);
	}
	
	/**
	 * Returns a <select> tag containing all the appropriate <option> tags
	 */
	function Field($properties = array()) {
		if($this->multiple) $this->name .= '[]';
		$options = array();
		
		// We have an array of values
		if(is_array($this->value)){
			// Loop through and figure out which values were selected.
			foreach($this->getSource() as $value => $title) {
				$options[] = new ArrayData(array(
					'Title' => $title,
					'Value' => $value,
					'Selected' => (in_array($value, $this->value) || in_array($value, $this->defaultItems)),
					'Disabled' => $this->disabled || in_array($value, $this->disabledItems),
				));
			}
		} else {
			// Listbox was based a singlular value, so treat it like a dropdown.
			foreach($this->getSource() as $value => $title) {
				$options[] = new ArrayData(array(
					'Title' => $title,
					'Value' => $value,
					'Selected' => ($value == $this->value || in_array($value, $this->defaultItems)),
					'Disabled' => $this->disabled || in_array($value, $this->disabledItems),
				));
			}
		}
		$properties = array_merge($properties, array('Options' => new ArrayList($options)));
		return $this->customise($properties)->renderWith($this->getTemplate());
	}

	function getAttributes() {
		return array_merge(
			parent::getAttributes(),
			array(
				'multiple' => $this->multiple,
				'size' => $this->size
			)
		);
	}
	
	/** 
	 * Sets the size of this dropdown in rows.
	 * @param int $size The height in rows (e.g. 3)
	 */
	function setSize($size) {
		$this->size = $size;
		return $this;
	}
	
	/** 
	 * Sets this field to have a muliple select attribute
	 * @param boolean $bool
	 */
	function setMultiple($bool) {
		$this->multiple = $bool;
		return $this;
	}
	
	function setSource($source) {
		if($source) {
			$hasCommas = array_filter(array_keys($source), create_function('$key', 'return strpos($key, ",") !== FALSE;'));
			if($hasCommas) {
				throw new InvalidArgumentException('No commas allowed in $source keys');
			}
		}
		
		parent::setSource($source);

		return $this;
	}

	/**
	 * Return the CheckboxSetField value as a string 
	 * selected item keys.
	 * 
	 * @return string
	 */
	function dataValue() {
		if($this->value && is_array($this->value) && $this->multiple) {
			$filtered = array();
			foreach($this->value as $item) {
				if($item) {
					$filtered[] = str_replace(",", "{comma}", $item);
				}
			}
			return implode(',', $filtered);
		} else {
			return parent::dataValue();
		}
	}
	
	/**
	 * Save the current value of this field into a DataObject.
	 * If the field it is saving to is a has_many or many_many relationship,
	 * it is saved by setByIDList(), otherwise it creates a comma separated
	 * list for a standard DB text/varchar field.
	 *
	 * @param DataObject $record The record to save into
	 */
	function saveInto(DataObject $record) {
		if($this->multiple) {
			$fieldname = $this->name;
			if($fieldname && $record && ($record->has_many($fieldname) || $record->many_many($fieldname))) {
				$idList = (is_array($this->value)) ? array_values($this->value) : array();
				if(!$record->ID) $record->write(); // record needs to have an ID in order to set relationships
				$record->$fieldname()->setByIDList($idList);
			} elseif($fieldname && $record) {
				if($this->value) {
					$this->value = str_replace(',', '{comma}', $this->value);
					$record->$fieldname = implode(",", $this->value);
				} else {
					$record->$fieldname = null;
				}
			}	
		} else {
			parent::saveInto($record);
		}
	}

	/**
	 * Load a value into this CheckboxSetField
	 */
	function setValue($val, $obj = null) {
		// If we're not passed a value directly, 
		// we can look for it in a relation method on the object passed as a second arg
		if(!$val && $obj && $obj instanceof DataObject && $obj->hasMethod($this->name)) {
			$funcName = $this->name;
			$val = array_values($obj->$funcName()->getIDList());
		}

		if($val) {
			if(!$this->multiple && is_array($val)) {
				throw new InvalidArgumentException('No array values allowed with multiple=false');
			}

			if($this->multiple) {
				$parts = (is_array($val)) ? $val : preg_split("/ *, */", trim($val));
				if(ArrayLib::is_associative($parts)) {
					throw new InvalidArgumentException('No associative arrays allowed multiple=true');
				}

				// Doesn't check against unknown values in order to allow for less rigid data handling.
				// They're silently ignored and overwritten the next time the field is saved.
				parent::setValue($parts);
			} else {
				if(!in_array($val, array_keys($this->source))) {
					throw new InvalidArgumentException(sprintf(
						'Invalid value "%s" for multiple=false', 
						Convert::raw2xml($val)
					));
				}

				parent::setValue($val);
			}
		} else {
			parent::setValue($val);
		}
		
		return $this;
	}

	/**
	 * Mark certain elements as disabled,
	 * regardless of the {@link setDisabled()} settings.
	 * 
	 * @param array $items Collection of array keys, as defined in the $source array
	 */
	function setDisabledItems($items) {
		$this->disabledItems = $items;
		return $this;
	}
	
	/**
	 * @return Array
	 */
	function getDisabledItems() {
		return $this->disabledItems;
	}

	/**
	 * Default selections, regardless of the {@link setValue()} settings.
	 * Note: Items marked as disabled through {@link setDisabledItems()} can still be
	 * selected by default through this method.
	 * 
	 * @param Array $items Collection of array keys, as defined in the $source array
	 */
	function setDefaultItems($items) {
		$this->defaultItems = $items;
		return $this;
	}
	
	/**
	 * @return Array
	 */
	function getDefaultItems() {
		return $this->defaultItems;
	}
	
}