使用Google服务账号实现Google Drive API无缝集成与文件访问

// backend-service.js (Node.js example)
const { GoogleAuth } = require('google-auth-library');
const path = require('path');

// 您的服务账号密钥文件路径
// 在生产环境中，推荐使用环境变量或Secrets Manager来管理密钥内容，而不是直接读取文件
const KEYFILE_PATH = path.join(__dirname, 'path/to/your-service-account-key.json');

async function getServiceAccountAccessToken() {
  try {
    const auth = new GoogleAuth({
      keyFile: KEYFILE_PATH,
      scopes: ['https://www.googleapis.com/auth/drive.readonly'], // 仅读取Google Drive文件
    });

    const client = await auth.getClient();
    const accessTokenResponse = await client.getAccessToken();
    return accessTokenResponse.token; // 返回访问令牌
  } catch (error) {
    console.error('Error getting service account access token:', error);
    throw new Error('Failed to obtain access token from Google Service Account.');
  }
}

// 示例：如何在一个Express后端路由中使用
// const express = require('express');
// const app = express();

// app.get('/api/google-drive-token', async (req, res) => {
//   try {
//     const accessToken = await getServiceAccountAccessToken();
//     res.json({ accessToken });
//   } catch (error) {
//     res.status(500).json({ error: error.message });
//   }
// });

// app.listen(3000, () => console.log('Backend listening on port 3000'));

// Wix Velo code example
import { fetch } from 'wix-fetch';

// 假设您的后端服务部署在 'https://your-backend-domain.com'
const BACKEND_TOKEN_ENDPOINT = 'https://your-backend-domain.com/api/google-drive-token';
const GOOGLE_DRIVE_API_URL = 'https://www.googleapis.com/drive/v3/files';

/**
 * 从后端服务获取Google Drive访问令牌
 * @returns {Promise<string>} 访问令牌
 */
async function getAccessTokenFromBackend() {
  try {
    const response = await fetch(BACKEND_TOKEN_ENDPOINT, { method: 'GET' });
    if (!response.ok) {
      throw new Error(`Failed to get access token from backend: ${response.statusText}`);
    }
    const data = await response.json();
    return data.accessToken;
  } catch (error) {
    console.error('Error fetching access token from backend:', error);
    throw error;
  }
}

/**
 * 从Google Drive获取图片文件列表
 * @returns {Promise<Array>} 图片文件列表
 */
async function fetchPhotosFromGoogleDrive() {
  const fields = 'files(id,name,mimeType,thumbnailLink)';
  let accessToken;
  try {
    accessToken = await getAccessTokenFromBackend();
  } catch (error) {
    console.error("无法获取访问令牌，停止获取图片。", error);
    throw error;
  }

  try {
    const response = await fetch(`${GOOGLE_DRIVE_API_URL}?fields=${fields}&q='YOUR_FOLDER_ID'+in+parents+and+mimeType+contains+'image'`, {
      method: 'GET',
      headers: {
        'Authorization': `Bearer ${accessToken}`
      }
    });
    const data = await response.json();

    if (!response.ok) {
      // 检查Google Drive API返回的错误信息
      const errorDetails = data.error ? data.error.message : 'Unknown error';
      throw new Error(`Failed to fetch photos from Google Drive: ${errorDetails}`);
    }

    if (!data.files) {
      return []; // 没有找到文件
    }

    // 过滤出图片文件（如果API查询参数已经足够，这一步可能不是必需的）
    const imageFiles = data.files.filter(file => file.mimeType.startsWith('image/'));
    return imageFiles;

  } catch (error) {
    console.error('Error fetching photos from Google Drive:', error);
    throw new Error('Failed to retrieve photo data from Google Drive.');
  }
}

/**
 * 更新Wix图库展示图片
 */
async function displayPhotos() {
  const myGallery = $w('#myGallery'); // 假设您有一个ID为'myGallery'的Wix图库组件

  try {
    const photos = await fetchPhotosFromGoogleDrive();

    const galleryItems = photos.map(photo => ({
      type: 'image',
      src: photo.thumbnailLink, // 使用缩略图链接
      title: photo.name,
      description: photo.name // 可选：添加描述
    }));

    myGallery.items = galleryItems;
    console.log('Photos successfully loaded and displayed.');
  } catch (error) {
    console.error('Error fetching and displaying photos:', error);
    // 可以在此处向用户显示错误信息
  }
}

// 在Wix页面加载完成后调用
$w.onReady(function () {
  displayPhotos();
});