<?php

/**
 * Some additional introspection tools that are used often by the fulltext search code
 */
class SearchIntrospection {

	protected static $ancestry = array();

	/**
	 * Check if class is subclass of (a) the class in $of, or (b) any of the classes in the array $of
	 * @static
	 * @param  $class
	 * @param  $of
	 * @return bool
	 */
	static function is_subclass_of ($class, $of) {
		$ancestry = isset(self::$ancestry[$class]) ? self::$ancestry[$class] : (self::$ancestry[$class] = ClassInfo::ancestry($class));
		return is_array($of) ? (bool)array_intersect($of, $ancestry) : array_key_exists($of, $ancestry);
	}

	protected static $hierarchy = array();

	/**
	 * Get all the classes involved in a DataObject hierarchy - both super and optionally subclasses
	 *
	 * @static
	 * @param String $class - The class to query
	 * @param bool $includeSubclasses - True to return subclasses as well as super classes
	 * @param bool $dataOnly - True to only return classes that have tables
	 * @return Array - Integer keys, String values as classes sorted by depth (most super first)
	 */
	static function hierarchy ($class, $includeSubclasses = true, $dataOnly = false) {
		$key = "$class!" . ($includeSubclasses ? 'sc' : 'an') . '!' . ($dataOnly ? 'do' : 'al');
		
		if (!isset(self::$hierarchy[$key])) {
			$classes = array_values(ClassInfo::ancestry($class));
			if ($includeSubclasses) $classes = array_unique(array_merge($classes, array_values(ClassInfo::subclassesFor($class))));

			$idx = array_search('DataObject', $classes);
			if ($idx !== false) array_splice($classes, 0, $idx+1);

			if ($dataOnly) foreach($classes as $i => $class) {
				if (!DataObject::has_own_table($class)) unset($classes[$i]);
			}

			self::$hierarchy[$key] = $classes;
		}

		return self::$hierarchy[$key];
	}

	/**
	 * Add classes to list, keeping only the parent when parent & child are both in list after add
	 */
	static function add_unique_by_ancestor(&$list, $class) {
		// If class already has parent in list, just ignore
		if (self::is_subclass_of($class, $list)) return;

		// Strip out any subclasses of $class already in the list
		$children = ClassInfo::subclassesFor($class);
		$list = array_diff($list, $children);

		// Then add the class in
		$list[] = $class;
	}

	/**
	 * Does this class, it's parent (or optionally one of it's children) have the passed extension attached?
	 */
	static function has_extension($class, $extension, $includeSubclasses = true) {
		foreach (self::hierarchy($class, $includeSubclasses) as $relatedclass) {
			if (Object::has_extension($relatedclass, $extension)) return true;
		}
		return false;
	}

}