<?php

namespace app\utils;

use app\models\QAndASetting;

class BaiduChat
{
    const ACCESS_TOKEN_API_URL = 'https://aip.baidubce.com/oauth/2.0/token';

    const CHAR_API_URL = 'https://aip.baidubce.com/rpc/2.0/ai_custom/v1/wenxinworkshop/chat/completions';

    // 获取access_token
    public static function getAccessToken()
    {
        $exists = cache()->exists('baidu_chat_access_token');
        if ($exists) {
            return cache()->get('baidu_chat_access_token');
        }

        $setting = QAndASetting::find()->where(['store_id' => get_store_id()])->one();

        if (!$setting) {
            throw new \Exception('请先配置百度千帆');
        }

        if ($setting->appid == '' || $setting->key == '') {
            throw new \Exception('请先配置百度千帆');
        }

        $res = http_post(static::ACCESS_TOKEN_API_URL, [
            'headers' => [
                'Content-Type' => 'application/json'
            ],
            'query' => [
                'grant_type' => 'client_credentials',
                'client_id' => $setting->appid,
                'client_secret' => $setting->key,
            ],
        ]);

        if ($res->getStatusCode() != 200) {
            throw new \Exception('Error: ' . $res->getStatusCode() . ' ' . $res->getReasonPhrase());
        }

        $data = json_decode((string)$res->getBody(), true);

        if (isset($data['error'])) {
            throw new \Exception('Error: ' . $data['error'] . ' ' . $data['error_description']);
        }

        cache()->set('baidu_chat_access_token', $data['access_token'], $data['expires_in'] - 60);

        return $data['access_token'];
    }

    /**
     * 发送消息
     * @param string $question 对话内容
     * @param string $system 模型设定，例如: 你是一个画家
     * @return void 
     * @throws \GuzzleHttp\Exception\GuzzleException 
     * @throws \Exception 
     * @author Syan mzsongyan@gmail.com
     * @date 2023-10-18
     */
    public static function send(string $question, string $system = '')
    {
        $body = [
            'messages' => [
                [
                    'role' => 'user',
                    'content' => $question,
                ],
            ],
            'temperature' => 0.6,
        ];

        if (!empty($system)) {
            $body['system'] = $system;
        }

        $res = http_post(static::CHAR_API_URL, [
            'body' => json_encode($body),
            'query' => [
                'access_token' => static::getAccessToken(),
            ],
            'headers' => [
                'Content-Type' => 'application/json',
            ],
        ]);

        if ($res->getStatusCode() != 200) {
            throw new \Exception('Error: ' . $res->getStatusCode() . ' ' . $res->getReasonPhrase());
        }

        $data = json_decode((string)$res->getBody(), true);

        if (isset($data['error_code'])) {
            throw new \Exception('Error: ' . $data['error_code'] . ' ' . $data['error_msg']);
        }

        return $data;
    }
}