<?php

/*
 * This file is part of the overtrue/wechat.
 *
 * (c) overtrue <i@overtrue.me>
 *
 * This source file is subject to the MIT license that is bundled
 * with this source code in the file LICENSE.
 */
namespace EasyWeChat\Kernel;

use EasyWeChat\Kernel\Contracts\MessageInterface;
use EasyWeChat\Kernel\Exceptions\BadRequestException;
use EasyWeChat\Kernel\Exceptions\InvalidArgumentException;
use EasyWeChat\Kernel\Messages\Message;
use EasyWeChat\Kernel\Messages\News;
use EasyWeChat\Kernel\Messages\NewsItem;
use EasyWeChat\Kernel\Messages\Raw as RawMessage;
use EasyWeChat\Kernel\Messages\Text;
use EasyWeChat\Kernel\Support\XML;
use EasyWeChat\Kernel\Traits\Observable;
use EasyWeChat\Kernel\Traits\ResponseCastable;
use Symfony\Component\HttpFoundation\Response;
/**
 * Class ServerGuard.
 *
 * 1. url 里的 signature 只是将 token+nonce+timestamp 得到的签名，只是用于验证当前请求的，在公众号环境下一直有
 * 2. 企业号消息发送时是没有的，因为固定为完全模式，所以 url 里不会存在 signature, 只有 msg_signature 用于解密消息的
 *
 * @author overtrue <i@overtrue.me>
 */
class ServerGuard
{
    use Observable;
    use ResponseCastable;
    /**
     * @var bool
     */
    protected $alwaysValidate = false;
    /**
     * Empty string.
     */
    const SUCCESS_EMPTY_RESPONSE = 'success';
    /**
     * @var array
     */
    const MESSAGE_TYPE_MAPPING = ['text' => Message::TEXT, 'image' => Message::IMAGE, 'voice' => Message::VOICE, 'video' => Message::VIDEO, 'shortvideo' => Message::SHORT_VIDEO, 'location' => Message::LOCATION, 'link' => Message::LINK, 'device_event' => Message::DEVICE_EVENT, 'device_text' => Message::DEVICE_TEXT, 'event' => Message::EVENT, 'file' => Message::FILE, 'miniprogrampage' => Message::MINIPROGRAM_PAGE];
    /**
     * @var \EasyWeChat\Kernel\ServiceContainer
     */
    protected $app;
    /**
     * Constructor.
     *
     * @codeCoverageIgnore
     *
     * @param \EasyWeChat\Kernel\ServiceContainer $app
     */
    public function __construct(ServiceContainer $app)
    {
        $this->app = $app;
        foreach ($this->app->extension->observers() as $observer) {
            call_user_func_array([$this, 'push'], $observer);
        }
    }
    /**
     * Handle and return response.
     *
     * @return Response
     *
     * @throws BadRequestException
     * @throws \EasyWeChat\Kernel\Exceptions\InvalidArgumentException
     * @throws \EasyWeChat\Kernel\Exceptions\InvalidConfigException
     */
    public function serve()
    {
        $this->app['logger']->debug('Request received:', ['method' => $this->app['request']->getMethod(), 'uri' => $this->app['request']->getUri(), 'content-type' => $this->app['request']->getContentType(), 'content' => $this->app['request']->getContent()]);
        $response = $this->validate()->resolve();
        $this->app['logger']->debug('Server response created:', ['content' => $response->getContent()]);
        return $response;
    }
    /**
     * @return $this
     *
     * @throws \EasyWeChat\Kernel\Exceptions\BadRequestException
     */
    public function validate()
    {
        if (!$this->alwaysValidate && !$this->isSafeMode()) {
            return $this;
        }
        if ($this->app['request']->get('signature') !== $this->signature([$this->getToken(), $this->app['request']->get('timestamp'), $this->app['request']->get('nonce')])) {
            throw new BadRequestException('Invalid request signature.', 400);
        }
        return $this;
    }
    /**
     * Force validate request.
     *
     * @return $this
     */
    public function forceValidate()
    {
        $this->alwaysValidate = true;
        return $this;
    }
    /**
     * Get request message.
     *
     * @return array|\EasyWeChat\Kernel\Support\Collection|object|string
     *
     * @throws BadRequestException
     * @throws \EasyWeChat\Kernel\Exceptions\InvalidArgumentException
     * @throws \EasyWeChat\Kernel\Exceptions\InvalidConfigException
     */
    public function getMessage()
    {
        $message = $this->parseMessage($this->app['request']->getContent(false));
        if (!is_array($message) || empty($message)) {
            throw new BadRequestException('No message received.');
        }
        if ($this->isSafeMode() && !empty($message['Encrypt'])) {
            $message = $this->decryptMessage($message);
            // Handle JSON format.
            $dataSet = json_decode($message, true);
            if ($dataSet && JSON_ERROR_NONE === json_last_error()) {
                return $dataSet;
            }
            $message = XML::parse($message);
        }
        return $this->detectAndCastResponseToType($message, $this->app->config->get('response_type'));
    }
    /**
     * Resolve server request and return the response.
     *
     * @return \Symfony\Component\HttpFoundation\Response
     *
     * @throws \EasyWeChat\Kernel\Exceptions\BadRequestException
     * @throws \EasyWeChat\Kernel\Exceptions\InvalidArgumentException
     * @throws \EasyWeChat\Kernel\Exceptions\InvalidConfigException
     */
    protected function resolve()
    {
        $result = $this->handleRequest();
        if ($this->shouldReturnRawResponse()) {
            $response = new Response($result['response']);
        } else {
            $response = new Response($this->buildResponse($result['to'], $result['from'], $result['response']), 200, ['Content-Type' => 'application/xml']);
        }
        // $this->app->events->dispatch(new Events\ServerGuardResponseCreated($response));
        return $response;
    }
    /**
     * @return string|null
     */
    protected function getToken()
    {
        return $this->app['config']['token'];
    }
    /**
     * @param                                                   $to
     * @param                                                   $from
     * @param \EasyWeChat\Kernel\Contracts\MessageInterface|string|int $message
     *
     * @return string
     *
     * @throws \EasyWeChat\Kernel\Exceptions\InvalidArgumentException
     */
    public function buildResponse($to, $from, $message)
    {
        if (empty($message) || self::SUCCESS_EMPTY_RESPONSE === $message) {
            return self::SUCCESS_EMPTY_RESPONSE;
        }
        if ($message instanceof RawMessage) {
            return $message->get('content', self::SUCCESS_EMPTY_RESPONSE);
        }
        if (is_string($message) || is_numeric($message)) {
            $message = new Text((string) $message);
        }
        if (is_array($message) && reset($message) instanceof NewsItem) {
            $message = new News($message);
        }
        if (!$message instanceof Message) {
            throw new InvalidArgumentException(sprintf('Invalid Messages type "%s".', gettype($message)));
        }
        return $this->buildReply($to, $from, $message);
    }
    /**
     * Handle request.
     *
     * @return array
     *
     * @throws \EasyWeChat\Kernel\Exceptions\BadRequestException
     * @throws \EasyWeChat\Kernel\Exceptions\InvalidArgumentException
     * @throws \EasyWeChat\Kernel\Exceptions\InvalidConfigException
     */
    protected function handleRequest()
    {
        $castedMessage = $this->getMessage();
        $messageArray = $this->detectAndCastResponseToType($castedMessage, 'array');
        $response = $this->dispatch(self::MESSAGE_TYPE_MAPPING[!empty($messageArray['MsgType']) ? $messageArray['MsgType'] : (isset($messageArray['msg_type']) ? $messageArray['msg_type'] : 'text')], $castedMessage);
        return ['to' => !empty($messageArray['FromUserName']) ? $messageArray['FromUserName'] : '', 'from' => !empty($messageArray['ToUserName']) ? $messageArray['ToUserName'] : '', 'response' => $response];
    }
    /**
     * Build reply XML.
     *
     * @param                                        $to
     * @param                                        $from
     * @param \EasyWeChat\Kernel\Contracts\MessageInterface $message
     *
     * @return string
     */
    protected function buildReply($to, $from, MessageInterface $message)
    {
        $prepends = ['ToUserName' => $to, 'FromUserName' => $from, 'CreateTime' => time(), 'MsgType' => $message->getType()];
        $response = $message->transformToXml($prepends);
        if ($this->isSafeMode()) {
            $this->app['logger']->debug('Messages safe mode is enabled.');
            $response = $this->app['encryptor']->encrypt($response);
        }
        return $response;
    }
    /**
     * @param array $params
     *
     * @return string
     */
    protected function signature(array $params)
    {
        sort($params, SORT_STRING);
        return sha1(implode($params));
    }
    /**
     * Parse message array from raw php input.
     *
     * @param $content
     *
     * @return array
     *
     * @throws \EasyWeChat\Kernel\Exceptions\BadRequestException
     */
    protected function parseMessage($content)
    {
        try {
            if (0 === stripos($content, '<')) {
                $content = XML::parse($content);
            } else {
                // Handle JSON format.
                $dataSet = json_decode($content, true);
                if ($dataSet && JSON_ERROR_NONE === json_last_error()) {
                    $content = $dataSet;
                }
            }
            return (array) $content;
        } catch (\Exception $e) {
            throw new BadRequestException(sprintf('Invalid message content:(%s) %s', $e->getCode(), $e->getMessage()), $e->getCode());
        }
    }
    /**
     * Check the request message safe mode.
     *
     * @return bool
     */
    protected function isSafeMode()
    {
        return $this->app['request']->get('signature') && 'aes' === $this->app['request']->get('encrypt_type');
    }
    /**
     * @return bool
     */
    protected function shouldReturnRawResponse()
    {
        return false;
    }
    /**
     * @param array $message
     *
     * @return mixed
     */
    protected function decryptMessage(array $message)
    {
        return $message = $this->app['encryptor']->decrypt($message['Encrypt'], $this->app['request']->get('msg_signature'), $this->app['request']->get('nonce'), $this->app['request']->get('timestamp'));
    }
}
