<?php

namespace SilverStripe\Forms;

use SilverStripe\ORM\ArrayList;
use SilverStripe\View\ArrayData;

/**
 * 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
 */
class ListboxField extends MultiSelectField {

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

	/**
	 * @var array
	 */
	protected $disabledItems = 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|null $value You can pass an array of values or a single value like a drop down to be selected
	 * @param int $size Optional size of the select element
	 */
	public function __construct($name, $title = '', $source = array(), $value = null, $size = null) {
		if($size) {
			$this->setSize($size);
		}

		parent::__construct($name, $title, $source, $value);
	}

	/**
	 * Returns a <select> tag containing all the appropriate <option> tags
	 *
	 * @param array $properties
	 * @return string
	 */
	public function Field($properties = array()) {
		$properties = array_merge($properties, array(
			'Options' => $this->getOptions(),
		));

		return FormField::Field($properties);
	}

	/**
	 * Gets the list of options to render in this formfield
	 *
	 * @return ArrayList
	 */
	public function getOptions() {
		// Loop through and figure out which values were selected.
		$options = array();
		$selectedValue = $this->getValueArray();
		foreach($this->getSource() as $itemValue => $title) {
			$itemSelected = in_array($itemValue, $selectedValue)
				|| in_array($itemValue, $this->getDefaultItems());
			$itemDisabled = $this->isDisabled()
				|| in_array($itemValue, $this->getDisabledItems());
			$options[] = new ArrayData(array(
				'Title' => $title,
				'Value' => $itemValue,
				'Selected' => $itemSelected,
				'Disabled' => $itemDisabled,
			));
		}

		$options = new ArrayList($options);
		$this->extend('updateGetOptions', $options);
		return $options;
	}

	public function getAttributes() {
		return array_merge(
			parent::getAttributes(),
			array(
				'multiple' => 'true',
				'size' => $this->getSize(),
				'name' => $this->getName() . '[]'
			)
		);
	}

	/**
	 * Get the size of this dropdown in rows.
	 *
	 * @return integer
	 */
	public function getSize() {
		return $this->size;
	}

	/**
	 * Sets the size of this dropdown in rows.
	 *
	 * @param int $size The height in rows (e.g. 3)
	 * @return $this Self reference
	 */
	public function setSize($size) {
		$this->size = $size;
		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
	 * @return $this Self reference
	 */
	public function setDisabledItems($items) {
		$this->disabledItems = $items;
		return $this;
	}

	/**
	 * @return array
	 */
	public function getDisabledItems() {
		return $this->disabledItems;
	}

}