<?php
// +----------------------------------------------------------------------
// | ThinkPHP [ WE CAN DO IT JUST THINK ]
// +----------------------------------------------------------------------
// | Copyright (c) 2006~2023 http://thinkphp.cn All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
// +----------------------------------------------------------------------
// | Author: liu21st <liu21st@gmail.com>
// +----------------------------------------------------------------------
declare(strict_types=1);

namespace think;

use ReflectionClass;
use ReflectionMethod;

/**
 * 事件管理类
 * @package think
 */
class Event
{
 /**
 * 监听者
 * @var array
 */
 protected $listener = [];

 /**
 * 事件别名
 * @var array
 */
 protected $bind = [
 'AppInit' => event\AppInit::class,
 'HttpRun' => event\HttpRun::class,
 'HttpEnd' => event\HttpEnd::class,
 'RouteLoaded' => event\RouteLoaded::class,
 'LogWrite' => event\LogWrite::class,
 'LogRecord' => event\LogRecord::class,
 ];

 /**
 * 应用对象
 * @var App
 */
 protected $app;

 public function __construct(App $app)
 {
 $this->app = $app;
 }

 /**
 * 批量注册事件监听
 * @access public
 * @param array $events 事件定义
 * @return $this
 */
 public function listenEvents(array $events)
 {
 foreach ($events as $event => $listeners) {
 if (isset($this->bind[$event])) {
 $event = $this->bind[$event];
 }

 $this->listener[$event] = array_merge($this->listener[$event] ?? [], $listeners);
 }

 return $this;
 }

 /**
 * 注册事件监听
 * @access public
 * @param string $event 事件名称
 * @param mixed $listener 监听操作(或者类名)
 * @param bool $first 是否优先执行
 * @return $this
 */
 public function listen(string $event, $listener, bool $first = false)
 {
 if (isset($this->bind[$event])) {
 $event = $this->bind[$event];
 }

 if ($first && isset($this->listener[$event])) {
 array_unshift($this->listener[$event], $listener);
 } else {
 $this->listener[$event][] = $listener;
 }

 return $this;
 }

 /**
 * 是否存在事件监听
 * @access public
 * @param string $event 事件名称
 * @return bool
 */
 public function hasListener(string $event): bool
 {
 if (isset($this->bind[$event])) {
 $event = $this->bind[$event];
 }

 return isset($this->listener[$event]);
 }

 /**
 * 移除事件监听
 * @access public
 * @param string $event 事件名称
 * @return void
 */
 public function remove(string $event): void
 {
 if (isset($this->bind[$event])) {
 $event = $this->bind[$event];
 }

 unset($this->listener[$event]);
 }

 /**
 * 指定事件别名标识 便于调用
 * @access public
 * @param array $events 事件别名
 * @return $this
 */
 public function bind(array $events)
 {
 $this->bind = array_merge($this->bind, $events);

 return $this;
 }

 /**
 * 注册事件订阅者
 * @access public
 * @param mixed $subscriber 订阅者
 * @return $this
 */
 public function subscribe($subscriber)
 {
 $subscribers = (array) $subscriber;

 foreach ($subscribers as $subscriber) {
 if (is_string($subscriber)) {
 $subscriber = $this->app->make($subscriber);
 }

 if (method_exists($subscriber, 'subscribe')) {
 // 手动订阅
 $subscriber->subscribe($this);
 } else {
 // 智能订阅
 $this->observe($subscriber);
 }
 }

 return $this;
 }

 /**
 * 自动注册事件观察者
 * @access public
 * @param string|object $observer 观察者
 * @param null|string $prefix 事件名前缀
 * @return $this
 */
 public function observe($observer, string $prefix = '')
 {
 if (is_string($observer)) {
 $observer = $this->app->make($observer);
 }

 $reflect = new ReflectionClass($observer);
 $methods = $reflect->getMethods(ReflectionMethod::IS_PUBLIC);

 if (empty($prefix) && $reflect->hasProperty('eventPrefix')) {
 $reflectProperty = $reflect->getProperty('eventPrefix');
 $reflectProperty->setAccessible(true);
 $prefix = $reflectProperty->getValue($observer);
 }

 foreach ($methods as $method) {
 $name = $method->getName();
 if (str_starts_with($name, 'on')) {
 $this->listen($prefix . substr($name, 2), [$observer, $name]);
 }
 }

 return $this;
 }

 /**
 * 触发事件
 * @access public
 * @param string|object $event 事件名称
 * @param mixed $params 传入参数
 * @param bool $once 只获取一个有效返回值
 * @return mixed
 */
 public function trigger($event, $params = null, bool $once = false)
 {
 if (is_object($event)) {
 $params = $event;
 $event = $event::class;
 }

 if (isset($this->bind[$event])) {
 $event = $this->bind[$event];
 }

 $result = [];
 $listeners = $this->listener[$event] ?? [];

 if (str_contains($event, '.')) {
 [$prefix, $event] = explode('.', $event, 2);
 if (isset($this->listener[$prefix . '.*'])) {
 $listeners = array_merge($listeners, $this->listener[$prefix . '.*']);
 }
 }

 $listeners = array_unique($listeners, SORT_REGULAR);

 foreach ($listeners as $key => $listener) {
 $result[$key] = $this->dispatch($listener, $params);

 if (false === $result[$key] || (!is_null($result[$key]) && $once)) {
 break;
 }
 }

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

 /**
 * 触发事件(只获取一个有效返回值)
 * @param $event
 * @param null $params
 * @return mixed
 */
 public function until($event, $params = null)
 {
 return $this->trigger($event, $params, true);
 }

 /**
 * 执行事件调度
 * @access protected
 * @param mixed $event 事件方法
 * @param mixed $params 参数
 * @return mixed
 */
 protected function dispatch($event, $params = null)
 {
 if (!is_string($event)) {
 $call = $event;
 } elseif (str_contains($event, '::')) {
 $call = $event;
 } else {
 $obj = $this->app->make($event);
 $call = [$obj, 'handle'];
 }

 return $this->app->invoke($call, [$params]);
 }
}