backend/src/app.js

import express from 'express';
import cors from 'cors';
import helmet from 'helmet';
import rateLimit from 'express-rate-limit';
import dotenv from 'dotenv';
import path from 'path';
import { fileURLToPath } from 'url';
import axios from 'axios';
import fs from 'fs/promises'; // 添加ES模块fs导入

const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);

// 首先加载环境变量 - 必须在导入服务之前
dotenv.config({ path: path.join(__dirname, '../../.env') });

// 验证环境变量是否正确加载
console.log('=== Environment Variables Check ===');
console.log('GITHUB_TOKEN configured:', !!process.env.GITHUB_TOKEN);
console.log('GITHUB_TOKEN length:', process.env.GITHUB_TOKEN ? process.env.GITHUB_TOKEN.length : 0);
console.log('GITHUB_REPOS configured:', !!process.env.GITHUB_REPOS);
console.log('GITHUB_REPOS value:', process.env.GITHUB_REPOS);

// 现在导入需要环境变量的模块
import authRoutes from './routes/auth.js';
import pptRoutes from './routes/ppt.js';
import publicRoutes from './routes/public.js';
import imagesRoutes from './routes/images.js';
import persistentImagesRoutes from './routes/persistentImages.js';
import persistentLinksRoutes from './routes/persistentLinks.js';
import exportRoutes from './routes/export.js';
import { authenticateToken } from './middleware/auth.js';
import { errorHandler } from './middleware/errorHandler.js';

// 导入新的服务
import huggingfaceStorageService from './services/huggingfaceStorageService.js';
import backupSchedulerService from './services/backupSchedulerService.js';
import persistentImageLinkService from './services/persistentImageLinkService.js';
import autoBackupService from './services/autoBackupService.js';
import githubService from './services/githubService.js';

const app = express();
const PORT = process.env.PORT || 7861; // 修改为7861端口

// 设置trust proxy用于Huggingface Space
app.set('trust proxy', true);

// 安全中间件
app.use(helmet({
  contentSecurityPolicy: false, // 为了兼容前端静态文件
}));

// 修复限流配置 - 针对Huggingface Space生产环境
const limiter = rateLimit({
  windowMs: 15 * 60 * 1000, // 15分钟
  max: 100, // 每个IP每15分钟最多100个请求
  message: 'Too many requests from this IP, please try again later.',
  trustProxy: true, // 与Express trust proxy设置保持一致
  validate: {
    trustProxy: false // 禁用trust proxy验证以避免生产环境警告
  },
  standardHeaders: true,
  legacyHeaders: false
});

// 应用限流中间件
app.use('/api', limiter);

// CORS配置
app.use(cors({
  origin: process.env.FRONTEND_URL || '*',
  credentials: true
}));

app.use(express.json({ limit: '50mb' }));
app.use(express.urlencoded({ extended: true, limit: '50mb' }));

// 提供前端静态文件 - 修复路径配置，避免与API路由冲突
const frontendDistPath = path.join(__dirname, '../../frontend/dist');
console.log('Frontend dist path:', frontendDistPath);

// API路由 - 必须在静态文件服务之前注册
console.log('Registering API routes...');

// 认证相关路由（不需要认证）
app.use('/api/auth', authRoutes);

// 公共访问路由（不需要认证）
app.use('/api/public', publicRoutes);

// 添加测试路由来验证 PPT 路由是否工作（不需要认证）
app.get('/api/ppt/test', (req, res) => {
  res.json({ message: 'PPT routes are working', timestamp: new Date().toISOString() });
});

// PPT管理路由（需要认证）
app.use('/api/ppt', (req, res, next) => {
  console.log(`PPT route accessed: ${req.method} ${req.path}`);
  next();
}, authenticateToken, pptRoutes);

// 图片管理路由（部分需要认证）
app.use('/api/images', imagesRoutes);

// 持久化图片链接路由
app.use('/api/persistent-images', persistentImagesRoutes);

// 持久化链接管理路由（需要认证）
app.use('/api/persistent-links', persistentLinksRoutes);

// 添加 /api/persistent/ 路由来处理前端生成的永久链接格式
app.get('/api/persistent/:pptId/:slideId', async (req, res) => {
  try {
    const { pptId, slideId } = req.params;
    console.log(`🔗 Accessing persistent link: pptId=${pptId}, slideId=${slideId}`);
    
    // 通过 pptId 和 slideId 查找对应的 linkId
    const linkInfo = await persistentImageLinkService.findLinkByPptAndSlide(pptId, slideId);
    
    if (!linkInfo) {
      console.log(`❌ No persistent link found for pptId=${pptId}, slideId=${slideId}`);
      return res.status(404).json({ error: 'Persistent link not found' });
    }
    
    // 检查图片是否存在，如果不存在则生成占位图片
    let imageResult;
    try {
      imageResult = await persistentImageLinkService.getPersistentImage(linkInfo.linkId);
    } catch (error) {
      if (error.message.includes('Image not available')) {
        console.log(`⚠️ Image not available for linkId=${linkInfo.linkId}, generating placeholder`);
        // 生成占位图片
        const placeholderBuffer = await persistentImageLinkService.generatePlaceholderImage({
          width: 1920,
          height: 1080,
          format: 'jpeg'
        });
        
        // 保存占位图片到文件系统
        const imagePath = path.join(persistentImageLinkService.linksDir, `${linkInfo.linkId}.jpeg`);
        await fs.writeFile(imagePath, placeholderBuffer);
        
        // 更新链接信息
        linkInfo.hasImage = true;
        linkInfo.imagePath = imagePath;
        linkInfo.format = 'jpeg';
        linkInfo.imageSize = placeholderBuffer.length;
        linkInfo.lastUpdated = new Date().toISOString();
        
        // 保存更新后的链接映射
        await persistentImageLinkService.saveLinkMap();
        
        imageResult = {
          success: true,
          data: placeholderBuffer,
          metadata: {
            linkId: linkInfo.linkId,
            format: 'jpeg',
            size: placeholderBuffer.length,
            createdAt: linkInfo.createdAt,
            lastUpdated: linkInfo.lastUpdated
          }
        };
      } else {
        throw error;
      }
    }
    
    if (!imageResult || !imageResult.success) {
      console.log(`❌ Failed to get image for linkId=${linkInfo.linkId}`);
      return res.status(404).json({ error: 'Image not found' });
    }
    
    // 设置正确的 Content-Type
    const format = imageResult.metadata?.format || linkInfo.format || 'jpeg';
    res.setHeader('Content-Type', `image/${format}`);
    res.setHeader('Cache-Control', 'public, max-age=31536000'); // 缓存1年
    
    console.log(`✅ Serving persistent image: linkId=${linkInfo.linkId}, format=${format}`);
    res.send(imageResult.data);
    
  } catch (error) {
    console.error('❌ Error serving persistent image:', error);
    res.status(500).json({ error: 'Internal server error', message: error.message });
  }
});

// 导出功能路由
app.use('/api/export', exportRoutes);

console.log('All API routes registered successfully');

// 添加调试中间件 - 处理未匹配的API路由
app.use('/api/*', (req, res) => {
  console.log(`Unmatched API route: ${req.method} ${req.path}`);
  res.status(404).json({ error: 'API route not found', path: req.path });
});

// 静态文件服务 - 在API路由之后
app.use((req, res, next) => {
  // 如果请求路径以 /api/ 开头，跳过静态文件服务
  if (req.path.startsWith('/api/')) {
    return next();
  }
  // 否则使用静态文件服务
  express.static(frontendDistPath)(req, res, next);
});

// 提供数据文件
app.use('/data', express.static(path.join(__dirname, '../../frontend/public/mocks')));

// 健康检查 - 需要在其他路由之前
app.get('/api/health', (req, res) => {
  res.json({ status: 'ok', timestamp: new Date().toISOString() });
});

// GitHub连接状态检查
app.get('/api/github/status', async (req, res) => {
  try {
    const { default: githubService } = await import('./services/githubService.js');
    const validation = await githubService.validateConnection();
    res.json({
      github: validation,
      environment: {
        tokenConfigured: !!process.env.GITHUB_TOKEN,
        tokenPreview: process.env.GITHUB_TOKEN ? `${process.env.GITHUB_TOKEN.substring(0, 8)}...` : 'Not set',
        reposConfigured: !!process.env.GITHUB_REPOS,
        reposList: process.env.GITHUB_REPOS ? process.env.GITHUB_REPOS.split(',') : [],
        nodeEnv: process.env.NODE_ENV
      }
    });
  } catch (error) {
    res.status(500).json({ 
      error: error.message,
      stack: error.stack
    });
  }
});

// 添加GitHub测试路由
app.get('/api/github/test', async (req, res) => {
  try {
    console.log('=== GitHub Connection Test ===');
    console.log('GITHUB_TOKEN exists:', !!process.env.GITHUB_TOKEN);
    console.log('GITHUB_REPOS:', process.env.GITHUB_REPOS);
    
    const { default: githubService } = await import('./services/githubService.js');
    
    // 测试基本配置
    const config = {
      hasToken: !!githubService.token,
      useMemoryStorage: githubService.useMemoryStorage,
      repositories: githubService.repositories,
      apiUrl: githubService.apiUrl
    };
    
    console.log('GitHub Service Config:', config);
    
    // 如果有token，测试连接
    let connectionTest = null;
    if (githubService.token) {
      console.log('Testing GitHub API connection...');
      connectionTest = await githubService.validateConnection();
      console.log('Connection test result:', connectionTest);
    }
    
    res.json({
      timestamp: new Date().toISOString(),
      config,
      connectionTest,
      environment: {
        tokenLength: process.env.GITHUB_TOKEN ? process.env.GITHUB_TOKEN.length : 0,
        nodeEnv: process.env.NODE_ENV
      }
    });
    
  } catch (error) {
    console.error('GitHub test error:', error);
    res.status(500).json({ 
      error: error.message,
      stack: process.env.NODE_ENV === 'development' ? error.stack : undefined
    });
  }
});

// 添加GitHub调试路由
app.get('/api/debug/github', async (req, res) => {
  try {
    console.log('=== GitHub Debug Information ===');
    
    const { default: githubService } = await import('./services/githubService.js');
    
    const debugInfo = {
      timestamp: new Date().toISOString(),
      environment: {
        tokenConfigured: !!process.env.GITHUB_TOKEN,
        tokenLength: process.env.GITHUB_TOKEN ? process.env.GITHUB_TOKEN.length : 0,
        reposConfigured: !!process.env.GITHUB_REPOS,
        reposList: process.env.GITHUB_REPOS ? process.env.GITHUB_REPOS.split(',') : [],
        nodeEnv: process.env.NODE_ENV
      },
      service: {
        hasToken: !!githubService.token,
        repositoriesCount: githubService.repositories?.length || 0,
        repositories: githubService.repositories || [],
        apiUrl: githubService.apiUrl
      }
    };
    
    // 测试连接
    try {
      const connectionTest = await githubService.validateConnection();
      debugInfo.connectionTest = connectionTest;
    } catch (connError) {
      debugInfo.connectionError = connError.message;
    }
    
    console.log('Debug info:', debugInfo);
    res.json(debugInfo);
    
  } catch (error) {
    console.error('Debug route error:', error);
    res.status(500).json({ 
      error: error.message,
      stack: process.env.NODE_ENV === 'development' ? error.stack : undefined
    });
  }
});

// 添加PPT调试路由
app.get('/api/debug/ppt/:userId', async (req, res) => {
  try {
    const { userId } = req.params;
    console.log(`=== PPT Debug for User: ${userId} ===`);
    
    const { default: githubService } = await import('./services/githubService.js');
    
    const debugInfo = {
      timestamp: new Date().toISOString(),
      userId: userId,
      repositories: []
    };
    
    // Check if GitHub repositories are configured
    if (!githubService.repositories || githubService.repositories.length === 0) {
      return res.json({
        ...debugInfo,
        error: 'GitHub repositories not configured',
        details: 'No GitHub repositories available for PPT storage'
      });
    }
    
    // 检查每个仓库中用户的文件
    for (let i = 0; i < githubService.repositories.length; i++) {
      const repoInfo = {
        index: i,
        url: githubService.repositories[i],
        accessible: false,
        userDirectoryExists: false,
        files: []
      };
      
      try {
        const { owner, repo } = githubService.parseRepoUrl(githubService.repositories[i]);
        
        // 检查仓库是否可访问
        await axios.get(`https://api.github.com/repos/${owner}/${repo}`, {
          headers: {
            'Authorization': `token ${githubService.token}`,
            'Accept': 'application/vnd.github.v3+json'
          }
        });
        repoInfo.accessible = true;
        
        // 检查用户目录
        try {
          const userDirResponse = await axios.get(
            `https://api.github.com/repos/${owner}/${repo}/contents/users/${userId}`,
            {
              headers: {
                'Authorization': `token ${githubService.token}`,
                'Accept': 'application/vnd.github.v3+json'
              }
            }
          );
          
          repoInfo.userDirectoryExists = true;
          repoInfo.files = userDirResponse.data
            .filter(item => item.type === 'file' && item.name.endsWith('.json'))
            .map(file => ({
              name: file.name,
              size: file.size,
              sha: file.sha
            }));
        } catch (userDirError) {
          repoInfo.userDirectoryError = userDirError.response?.status === 404 ? 'Directory not found' : userDirError.message;
        }
        
      } catch (repoError) {
        repoInfo.error = repoError.message;
      }
      
      debugInfo.repositories.push(repoInfo);
    }
    
    console.log('PPT Debug info:', debugInfo);
    res.json(debugInfo);
    
  } catch (error) {
    console.error('PPT Debug route error:', error);
    res.status(500).json({ 
      error: error.message,
      stack: process.env.NODE_ENV === 'development' ? error.stack : undefined
    });
  }
});

// 添加仓库初始化端点
app.post('/api/github/initialize', async (req, res) => {
  try {
    console.log('=== Manual Repository Initialization ===');
    
    const { default: githubService } = await import('./services/githubService.js');
    
    if (githubService.useMemoryStorage) {
      return res.status(400).json({ 
        error: 'Cannot initialize repository: using memory storage mode',
        reason: 'GitHub token not configured'
      });
    }
    
    const { repoIndex = 0 } = req.body;
    console.log(`Initializing repository at index: ${repoIndex}`);
    
    const result = await githubService.initializeRepository(repoIndex);
    
    if (result.success) {
      res.json({
        success: true,
        message: 'Repository initialized successfully',
        commit: result.commit,
        timestamp: new Date().toISOString()
      });
    } else {
      res.status(500).json({
        success: false,
        error: result.error,
        reason: result.reason
      });
    }
    
  } catch (error) {
    console.error('Repository initialization error:', error);
    res.status(500).json({ 
      error: error.message,
      stack: process.env.NODE_ENV === 'development' ? error.stack : undefined
    });
  }
});

// 添加GitHub权限详细检查路由
app.get('/api/debug/github-permissions', async (req, res) => {
  try {
    console.log('=== GitHub Token Permissions Check ===');
    
    const { default: githubService } = await import('./services/githubService.js');
    
    if (!githubService.token) {
      return res.status(400).json({ error: 'No GitHub token configured' });
    }
    
    const debugInfo = {
      timestamp: new Date().toISOString(),
      tokenInfo: {},
      repositoryTests: []
    };
    
    // 1. 检查token基本信息和权限
    try {
      const userResponse = await axios.get('https://api.github.com/user', {
        headers: {
          'Authorization': `token ${githubService.token}`,
          'Accept': 'application/vnd.github.v3+json'
        }
      });
      
      debugInfo.tokenInfo = {
        login: userResponse.data.login,
        id: userResponse.data.id,
        type: userResponse.data.type,
        company: userResponse.data.company,
        publicRepos: userResponse.data.public_repos,
        privateRepos: userResponse.data.total_private_repos,
        tokenScopes: userResponse.headers['x-oauth-scopes'] || 'Unknown'
      };
      
      console.log('Token info:', debugInfo.tokenInfo);
      
    } catch (tokenError) {
      debugInfo.tokenError = {
        status: tokenError.response?.status,
        message: tokenError.message
      };
    }
    
    // Check if GitHub repositories are configured
    if (!githubService.repositories || githubService.repositories.length === 0) {
      debugInfo.repositoryError = 'GitHub repositories not configured';
      return res.json(debugInfo);
    }
    
    // 2. 检查每个仓库的详细状态
    for (let i = 0; i < githubService.repositories.length; i++) {
      const repoUrl = githubService.repositories[i];
      const repoTest = {
        index: i,
        url: repoUrl,
        tests: {}
      };
      
      try {
        const { owner, repo } = githubService.parseRepoUrl(repoUrl);
        repoTest.owner = owner;
        repoTest.repo = repo;
        
        // 测试1: 基本仓库访问
        try {
          const repoResponse = await axios.get(`https://api.github.com/repos/${owner}/${repo}`, {
            headers: {
              'Authorization': `token ${githubService.token}`,
              'Accept': 'application/vnd.github.v3+json'
            }
          });
          
          repoTest.tests.basicAccess = {
            success: true,
            repoExists: true,
            private: repoResponse.data.private,
            permissions: repoResponse.data.permissions,
            defaultBranch: repoResponse.data.default_branch,
            size: repoResponse.data.size
          };
          
        } catch (repoError) {
          repoTest.tests.basicAccess = {
            success: false,
            status: repoError.response?.status,
            message: repoError.message,
            details: repoError.response?.data
          };
          
          // 如果是404，检查是否是权限问题还是仓库不存在
          if (repoError.response?.status === 404) {
            // 尝试不使用认证访问（如果是公开仓库应该能访问）
            try {
              await axios.get(`https://api.github.com/repos/${owner}/${repo}`);
              repoTest.tests.basicAccess.possibleCause = 'Repository exists but token lacks permission';
            } catch (publicError) {
              if (publicError.response?.status === 404) {
                repoTest.tests.basicAccess.possibleCause = 'Repository does not exist';
              }
            }
          }
        }
        
        // 测试2: 检查是否能列出用户的仓库
        try {
          const userReposResponse = await axios.get(`https://api.github.com/users/${owner}/repos?per_page=100`, {
            headers: {
              'Authorization': `token ${githubService.token}`,
              'Accept': 'application/vnd.github.v3+json'
            }
          });
          
          const hasRepo = userReposResponse.data.some(r => r.name === repo);
          repoTest.tests.userReposList = {
            success: true,
            totalRepos: userReposResponse.data.length,
            targetRepoFound: hasRepo,
            repoNames: userReposResponse.data.slice(0, 10).map(r => ({ name: r.name, private: r.private }))
          };
          
        } catch (userReposError) {
          repoTest.tests.userReposList = {
            success: false,
            status: userReposError.response?.status,
            message: userReposError.message
          };
        }
        
      } catch (parseError) {
        repoTest.parseError = parseError.message;
      }
      
      debugInfo.repositoryTests.push(repoTest);
    }
    
    // 3. 提供修复建议
    const suggestions = [];
    
    if (debugInfo.tokenError) {
      suggestions.push('Token authentication failed - check if GITHUB_TOKEN is valid');
    }
    
    debugInfo.repositoryTests.forEach((repoTest, index) => {
      if (!repoTest.tests.basicAccess?.success) {
        if (repoTest.tests.basicAccess?.status === 404) {
          if (repoTest.tests.basicAccess?.possibleCause === 'Repository does not exist') {
            suggestions.push(`Repository ${repoTest.url} does not exist - please create it on GitHub`);
          } else {
            suggestions.push(`Repository ${repoTest.url} exists but token lacks permission - check token scopes`);
          }
        } else if (repoTest.tests.basicAccess?.status === 403) {
          suggestions.push(`Permission denied for ${repoTest.url} - check if token has 'repo' scope`);
        }
      }
    });
    
    debugInfo.suggestions = suggestions;
    
    console.log('GitHub permissions debug completed');
    res.json(debugInfo);
    
  } catch (error) {
    console.error('GitHub permissions check error:', error);
    res.status(500).json({ 
      error: error.message,
      stack: process.env.NODE_ENV === 'development' ? error.stack : undefined
    });
  }
});

// 添加大文件处理调试端点
app.get('/api/debug/large-files/:userId', async (req, res) => {
  try {
    const { userId } = req.params;
    console.log(`=== Large Files Debug for User: ${userId} ===`);
    
    const { default: githubService } = await import('./services/githubService.js');
    
    const debugInfo = {
      timestamp: new Date().toISOString(),
      userId: userId,
      fileAnalysis: []
    };
    
    // 检查用户的所有PPT文件
    const pptList = await githubService.getUserPPTList(userId);
    
    for (const ppt of pptList) {
      const fileInfo = {
        pptId: ppt.name,
        title: ppt.title,
        fileName: `${ppt.name}.json`,
        analysis: {}
      };
      
      try {
        // 获取文件内容
        const result = await githubService.getFile(userId, `${ppt.name}.json`, ppt.repoIndex || 0);
        
        if (result && result.content) {
          const content = result.content;
          const jsonString = JSON.stringify(content);
          const fileSize = Buffer.byteLength(jsonString, 'utf8');
          
          fileInfo.analysis = {
            fileSize: fileSize,
            fileSizeKB: (fileSize / 1024).toFixed(2),
            slidesCount: content.slides?.length || 0,
            isChunked: !!content.isChunked,
            chunkedInfo: content.isChunked ? {
              totalChunks: content.totalChunks,
              totalSlides: content.totalSlides
            } : null,
            wasReassembled: !!result.isReassembled,
            metadata: content.metadata || 'No metadata',
            status: fileSize > 1024 * 1024 ? 'LARGE' : fileSize > 800 * 1024 ? 'MEDIUM' : 'NORMAL'
          };
          
          // 分析每个slide的大小
          if (content.slides && content.slides.length > 0) {
            const slideSizes = content.slides.map((slide, index) => {
              const slideJson = JSON.stringify(slide);
              const slideSize = Buffer.byteLength(slideJson, 'utf8');
              return {
                index: index,
                size: slideSize,
                sizeKB: (slideSize / 1024).toFixed(2),
                elementsCount: slide.elements?.length || 0
              };
            });
            
            // 找出最大的slides
            const largestSlides = slideSizes
              .sort((a, b) => b.size - a.size)
              .slice(0, 3);
            
            fileInfo.analysis.slideSummary = {
              averageSlideSize: (fileSize / content.slides.length).toFixed(0),
              largestSlides: largestSlides
            };
          }
        } else {
          fileInfo.analysis = { error: 'Could not read file content' };
        }
        
      } catch (error) {
        fileInfo.analysis = { 
          error: error.message,
          errorType: error.name
        };
      }
      
      debugInfo.fileAnalysis.push(fileInfo);
    }
    
    // 添加统计摘要
    debugInfo.summary = {
      totalFiles: debugInfo.fileAnalysis.length,
      largeFiles: debugInfo.fileAnalysis.filter(f => f.analysis.status === 'LARGE').length,
      chunkedFiles: debugInfo.fileAnalysis.filter(f => f.analysis.isChunked).length,
      errors: debugInfo.fileAnalysis.filter(f => f.analysis.error).length
    };
    
    console.log('Large files debug completed');
    res.json(debugInfo);
    
  } catch (error) {
    console.error('Large files debug error:', error);
    res.status(500).json({ 
      error: error.message,
      stack: process.env.NODE_ENV === 'development' ? error.stack : undefined
    });
  }
});

// 添加分块文件修复端点
app.post('/api/debug/fix-chunked-file/:userId/:pptId', async (req, res) => {
  try {
    const { userId, pptId } = req.params;
    console.log(`=== Fixing Chunked File: ${userId}/${pptId} ===`);
    
    const { default: githubService } = await import('./services/githubService.js');
    const fileName = `${pptId}.json`;
    
    const result = {
      timestamp: new Date().toISOString(),
      userId,
      pptId,
      fileName,
      status: 'unknown',
      details: {},
      actions: []
    };
    
    // Check if GitHub repositories are configured
    if (!githubService.repositories || githubService.repositories.length === 0) {
      return res.status(500).json({
        ...result,
        status: 'error',
        error: 'GitHub repositories not configured'
      });
    }
    
    // 1. 检查主文件是否存在
    let mainFile = null;
    let mainFileRepo = -1;
    
    for (let i = 0; i < githubService.repositories.length; i++) {
      try {
        const fileResult = await githubService.getFile(userId, fileName, i);
        if (fileResult) {
          mainFile = fileResult;
          mainFileRepo = i;
          result.details.mainFileFound = true;
          result.details.mainFileRepo = i;
          result.actions.push(`Main file found in repository ${i}`);
          break;
        }
      } catch (error) {
        continue;
      }
    }
    
    if (!mainFile) {
      result.status = 'error';
      result.details.error = 'Main file not found in any repository';
      return res.json(result);
    }
    
    const content = mainFile.content;
    
    // 2. 检查是否是分块文件
    if (!content.isChunked) {
      result.status = 'normal';
      result.details.isChunked = false;
      result.details.slideCount = content.slides?.length || 0;
      result.actions.push('File is not chunked, no action needed');
      return res.json(result);
    }
    
    // 3. 分析分块文件状态
    result.details.isChunked = true;
    result.details.totalChunks = content.totalChunks;
    result.details.totalSlides = content.totalSlides;
    result.details.mainFileSlides = content.slides?.length || 0;
    
    // 4. 检查所有chunk文件
    const chunkStatus = [];
    let totalFoundSlides = content.slides?.length || 0;
    
    for (let i = 1; i < content.totalChunks; i++) {
      const chunkFileName = fileName.replace('.json', `_chunk_${i}.json`);
      const chunkInfo = {
        index: i,
        fileName: chunkFileName,
        found: false,
        slides: 0,
        error: null
      };
      
      try {
        const repoUrl = githubService.repositories[mainFileRepo];
        const { owner, repo } = githubService.parseRepoUrl(repoUrl);
        const path = `users/${userId}/${chunkFileName}`;

        const response = await axios.get(
          `${githubService.apiUrl}/repos/${owner}/${repo}/contents/${path}`,
          {
            headers: {
              'Authorization': `token ${githubService.token}`,
              'Accept': 'application/vnd.github.v3+json'
            },
            timeout: 30000
          }
        );

        const chunkContent = Buffer.from(response.data.content, 'base64').toString('utf8');
        const chunkData = JSON.parse(chunkContent);
        
        chunkInfo.found = true;
        chunkInfo.slides = chunkData.slides?.length || 0;
        totalFoundSlides += chunkInfo.slides;
        
        result.actions.push(`Chunk ${i} found: ${chunkInfo.slides} slides`);
      } catch (error) {
        chunkInfo.error = error.message;
        result.actions.push(`Chunk ${i} missing or error: ${error.message}`);
      }
      
      chunkStatus.push(chunkInfo);
    }
    
    result.details.chunks = chunkStatus;
    result.details.totalFoundSlides = totalFoundSlides;
    result.details.missingSlides = content.totalSlides - totalFoundSlides;
    
    // 5. 判断状态和建议修复方案
    const missingChunks = chunkStatus.filter(chunk => !chunk.found);
    
    if (missingChunks.length === 0 && totalFoundSlides === content.totalSlides) {
      result.status = 'healthy';
      result.actions.push('All chunks found, file should load correctly');
    } else if (missingChunks.length > 0) {
      result.status = 'incomplete';
      result.details.missingChunks = missingChunks.map(c => c.index);
      result.actions.push(`Missing chunks: ${missingChunks.map(c => c.index).join(', ')}`);
      
      // 提供修复建议
      if (totalFoundSlides >= content.totalSlides * 0.8) {
        result.actions.push('Recommendation: Reassemble available slides into single file');
        result.details.recommendation = 'reassemble';
      } else {
        result.actions.push('Recommendation: File may be corrupted, consider restoration from backup');
        result.details.recommendation = 'restore';
      }
    } else {
      result.status = 'mismatch';
      result.actions.push('Slide count mismatch detected');
    }
    
    console.log('Chunked file analysis completed:', result);
    res.json(result);
    
  } catch (error) {
    console.error('Chunked file fix error:', error);
    res.status(500).json({ 
      error: error.message,
      stack: process.env.NODE_ENV === 'development' ? error.stack : undefined
    });
  }
});

// 添加分块文件重组端点
app.post('/api/debug/reassemble-chunked-file/:userId/:pptId', async (req, res) => {
  try {
    const { userId, pptId } = req.params;
    console.log(`=== Reassembling Chunked File: ${userId}/${pptId} ===`);
    
    const { default: githubService } = await import('./services/githubService.js');
    const fileName = `${pptId}.json`;
    
    // 强制重新组装文件
    const result = await githubService.getFile(userId, fileName, 0);
    
    if (!result) {
      return res.status(404).json({ error: 'File not found' });
    }
    
    if (result.isReassembled) {
      res.json({
        success: true,
        message: 'File reassembled successfully',
        slideCount: result.content.slides?.length || 0,
        wasChunked: !!result.content.reassembledInfo,
        reassembledInfo: result.content.reassembledInfo
      });
    } else {
      res.json({
        success: true,
        message: 'File was not chunked',
        slideCount: result.content.slides?.length || 0,
        wasChunked: false
      });
    }
    
  } catch (error) {
    console.error('File reassembly error:', error);
    res.status(500).json({ 
      error: error.message,
      details: error.stack
    });
  }
});

// 添加路由注册日志
console.log('Importing route modules...');
console.log('Auth routes imported:', !!authRoutes);
console.log('PPT routes imported:', !!pptRoutes);
console.log('Public routes imported:', !!publicRoutes);

// 这些路由已经在前面注册过了，删除重复的注册

// 前端路由处理 - 修复ES模块兼容性
app.get('*', (req, res) => {
  const indexPath = path.join(frontendDistPath, 'index.html');
  console.log(`Serving frontend route: ${req.path}, index.html path: ${indexPath}`);
  
  // 使用ES模块的fs检查文件是否存在
  if (fs.existsSync(indexPath)) {
    res.sendFile(indexPath);
  } else {
    console.error('index.html not found at:', indexPath);
    res.status(404).send(`
      <h1>前端文件未找到</h1>
      <p>index.html路径: ${indexPath}</p>
      <p>请确保前端已正确构建</p>
      <a href="/test">访问API测试页面</a>
    `);
  }
});

// 错误处理中间件
app.use(errorHandler);

// 初始化服务
async function initializeServices() {
  console.log('🚀 Initializing services...');
  
  let servicesInitialized = 0;
  let totalServices = 5;
  
  // 初始化GitHub服务
  try {
    await githubService.initialize();
    servicesInitialized++;
  } catch (error) {
    console.error('❌ Failed to initialize GitHubService:', error);
    console.log('⚠️ Continuing without GitHubService...');
  }
  
  // 初始化Huggingface存储服务
  try {
    await huggingfaceStorageService.initialize();
    servicesInitialized++;
  } catch (error) {
    console.error('❌ Failed to initialize HuggingfaceStorageService:', error);
    console.log('⚠️ Continuing without HuggingfaceStorageService...');
  }
  
  // 初始化备份调度服务
  try {
    await backupSchedulerService.initialize();
    servicesInitialized++;
  } catch (error) {
    console.error('❌ Failed to initialize BackupSchedulerService:', error);
    console.log('⚠️ Continuing without BackupSchedulerService...');
  }
  
  // 初始化持久化图片链接服务
  try {
    await persistentImageLinkService.initialize();
    servicesInitialized++;
  } catch (error) {
    console.error('❌ Failed to initialize PersistentImageLinkService:', error);
    console.log('⚠️ Continuing without PersistentImageLinkService...');
  }
  
  // 初始化自动备份服务
  try {
    await autoBackupService.initialize();
    servicesInitialized++;
  } catch (error) {
    console.error('❌ Failed to initialize AutoBackupService:', error);
    console.log('⚠️ Continuing without AutoBackupService...');
  }
  
  console.log(`✅ ${servicesInitialized}/${totalServices} services initialized successfully`);
  
  if (servicesInitialized === 0) {
    console.error('❌ No services could be initialized. Exiting...');
    process.exit(1);
  }
}

// 启动服务器
async function startServer() {
  await initializeServices();
  
  app.listen(PORT, '0.0.0.0', () => {
    console.log(`Server is running on port ${PORT}`);
    console.log(`Environment: ${process.env.NODE_ENV || 'development'}`);
    console.log(`💾 Huggingface storage service ready`);
    console.log(`⏰ Backup scheduler service ready`);
    console.log(`🔗 Persistent image link service ready`);
    console.log(`🔄 Auto backup service ready (every 8 hours)`);
  });
}

// 启动服务器
startServer().catch(error => {
  console.error('❌ Failed to start server:', error);
  process.exit(1);
});

// 优雅关闭处理
process.on('SIGTERM', async () => {
  console.log('🛑 Received SIGTERM, shutting down gracefully...');
  await backupSchedulerService.cleanup();
  await autoBackupService.cleanup();
  process.exit(0);
});

process.on('SIGINT', async () => {
  console.log('🛑 Received SIGINT, shutting down gracefully...');
  await backupSchedulerService.cleanup();
  await autoBackupService.cleanup();
  process.exit(0);
});