<?php
// +----------------------------------------------------------------------
// | ThinkPHP [ WE CAN DO IT JUST THINK ]
// +----------------------------------------------------------------------
// | Copyright (c) 2006~2018 http://thinkphp.cn All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
// +----------------------------------------------------------------------
// | Author: liu21st <liu21st@gmail.com>
// +----------------------------------------------------------------------

namespace think;

class Hook
{
 /**
 * @var array 标签
 */
 private static $tags = [];

 /**
 * 动态添加行为扩展到某个标签
 * @access public
 * @param string $tag 标签名称
 * @param mixed $behavior 行为名称
 * @param bool $first 是否放到开头执行
 * @return void
 */
 public static function add($tag, $behavior, $first = false)
 {
 isset(self::$tags[$tag]) || self::$tags[$tag] = [];

 if (is_array($behavior) && !is_callable($behavior)) {
 if (!array_key_exists('_overlay', $behavior) || !$behavior['_overlay']) {
 unset($behavior['_overlay']);
 self::$tags[$tag] = array_merge(self::$tags[$tag], $behavior);
 } else {
 unset($behavior['_overlay']);
 self::$tags[$tag] = $behavior;
 }
 } elseif ($first) {
 array_unshift(self::$tags[$tag], $behavior);
 } else {
 self::$tags[$tag][] = $behavior;
 }
 }

 /**
 * 批量导入插件
 * @access public
 * @param array $tags 插件信息
 * @param boolean $recursive 是否递归合并
 * @return void
 */
 public static function import(array $tags, $recursive = true)
 {
 if ($recursive) {
 foreach ($tags as $tag => $behavior) {
 self::add($tag, $behavior);
 }
 } else {
 self::$tags = $tags + self::$tags;
 }
 }

 /**
 * 获取插件信息
 * @access public
 * @param string $tag 插件位置(留空获取全部)
 * @return array
 */
 public static function get($tag = '')
 {
 if (empty($tag)) {
 return self::$tags;
 }

 return array_key_exists($tag, self::$tags) ? self::$tags[$tag] : [];
 }

 /**
 * 监听标签的行为
 * @access public
 * @param string $tag 标签名称
 * @param mixed $params 传入参数
 * @param mixed $extra 额外参数
 * @param bool $once 只获取一个有效返回值
 * @return mixed
 */
 public static function listen($tag, &$params = null, $extra = null, $once = false)
 {
 $results = [];

 foreach (static::get($tag) as $key => $name) {
 $results[$key] = self::exec($name, $tag, $params, $extra);

 // 如果返回 false,或者仅获取一个有效返回则中断行为执行
 if (false === $results[$key] || (!is_null($results[$key]) && $once)) {
 break;
 }
 }

 return $once ? end($results) : $results;
 }

 /**
 * 执行某个行为
 * @access public
 * @param mixed $class 要执行的行为
 * @param string $tag 方法名(标签名)
 * @param mixed $params 传人的参数
 * @param mixed $extra 额外参数
 * @return mixed
 */
 public static function exec($class, $tag = '', &$params = null, $extra = null)
 {
 App::$debug && Debug::remark('behavior_start', 'time');

 $method = Loader::parseName($tag, 1, false);

 if ($class instanceof \Closure) {
 $result = call_user_func_array($class, [ & $params, $extra]);
 $class = 'Closure';
 } elseif (is_array($class)) {
 list($class, $method) = $class;

 $result = (new $class())->$method($params, $extra);
 $class = $class . '->' . $method;
 } elseif (is_object($class)) {
 $result = $class->$method($params, $extra);
 $class = get_class($class);
 } elseif (strpos($class, '::')) {
 $result = call_user_func_array($class, [ & $params, $extra]);
 } else {
 $obj = new $class();
 $method = ($tag && is_callable([$obj, $method])) ? $method : 'run';
 $result = $obj->$method($params, $extra);
 }

 if (App::$debug) {
 Debug::remark('behavior_end', 'time');
 Log::record('[ BEHAVIOR ] Run ' . $class . ' @' . $tag . ' [ RunTime:' . Debug::getRangeTime('behavior_start', 'behavior_end') . 's ]', 'info');
 }

 return $result;
 }

}