<?php
/**
 * User: Jobs Lin
 * Date: 2019/12/11
 * Time: 15:34
 */

interface Log
{
    public function write();
}

// 文件记录日志
class FileLog implements Log
{
    public function write(){
        echo 'file log write...';
    }
}

// 数据库记录日志
class DatabaseLog implements Log
{
    public function write(){
        echo 'database log write...';
    }
}

class User
{
    protected $log;
    public function __construct(Log $log)
    {
        $this->log = $log;
    }
    public function login()
    {
        // 登录成功，记录登录日志
        echo 'login success...';
        $this->log->write();
    }
}

class Ioc
{
    public $binding = [];

    public function bind($abstract, $concrete)
    {
        //这里为什么要返回一个closure呢？因为bind的时候还不需要创建User对象，所以采用closure等make的时候再创建FileLog;
        $this->binding[$abstract]['concrete'] = function ($ioc) use ($concrete) {
            return $ioc->build($concrete);
        };
    }

    public function make($abstract)
    {
        // 根据key获取binding的值
        $concrete = $this->binding[$abstract]['concrete'];
        return $concrete($this);
    }

    // 创建对象
    public function build($concrete) {
        $reflector = new ReflectionClass($concrete);
        $constructor = $reflector->getConstructor();
        if(is_null($constructor)) {
            return $reflector->newInstance();
        }else {
            $dependencies = $constructor->getParameters();
            $instances = $this->getDependencies($dependencies);
            return $reflector->newInstanceArgs($instances);
        }
    }

    // 获取参数的依赖
    protected function getDependencies($paramters) {
        $dependencies = [];
        foreach ($paramters as $paramter) {
            $dependencies[] = $this->make($paramter->getClass()->name);
        }
        return $dependencies;
    }

}

class UserFacade
{
    // 维护Ioc容器
    protected static $ioc;

    public static function setFacadeIoc($ioc)
    {
        static::$ioc = $ioc;
    }

    // 返回User在Ioc中的bind的key
    protected static function getFacadeAccessor()
    {
        return 'user';
    }

    // php 魔术方法，当静态方法被调用时会被触发
    public static function __callStatic($method, $args)
    {
        $instance = static::$ioc->make(static::getFacadeAccessor());
        return $instance->$method(...$args);
    }

}

//实例化IoC容器
$ioc = new Ioc();
$ioc->bind('Log','FileLog');
$ioc->bind('user','User');

$user = $ioc->make('User');
$user->login();

//外观模式实现
UserFacade::setFacadeIoc($ioc);
UserFacade::login();