import express from 'express';
import { authenticateToken } from '../middleware/auth.js';
import persistentImageLinkService from '../services/persistentImageLinkService.js';
import githubService from '../services/githubService.js';

const router = express.Router();

// 添加路由级别的日志中间件
router.use((req, res, next) => {
  console.log(`Persistent Images Router - ${req.method} ${req.path}`);
  next();
});

/**
 * 获取或创建PPT页面的持久化链接
 * POST /api/persistent-images/create
 */
router.post('/create', authenticateToken, async (req, res, next) => {
  try {
    const userId = req.user.userId;
    const {
      pptId,
      pageIndex,
      slideId,
      slideData,
      options = {}
    } = req.body;

    // 验证必需参数 - 需要slideId或pageIndex其中之一
    if (!pptId || (slideId === undefined && pageIndex === undefined)) {
      return res.status(400).json({
        error: 'Missing required parameters: pptId and (slideId or pageIndex)'
      });
    }

    // 优先使用slideId，如果不存在则使用pageIndex
    const uniqueId = slideId || pageIndex;
    
    console.log(`🔗 Creating/getting persistent link for PPT ${pptId}, uniqueId ${uniqueId}`);

    // 获取或创建持久化链接
    const result = await persistentImageLinkService.getOrCreatePersistentLink(
      userId,
      pptId,
      uniqueId,
      slideData,
      options
    );

    res.json({
      success: true,
      message: 'Persistent link created/retrieved successfully',
      ...result
    });
  } catch (error) {
    console.error('❌ Failed to create persistent link:', error);
    next(error);
  }
});

/**
 * 批量创建PPT所有页面的持久化链接
 * POST /api/persistent-images/create-all
 */
router.post('/create-all', authenticateToken, async (req, res, next) => {
  try {
    const userId = req.user.userId;
    const {
      pptId,
      slides,
      options = {}
    } = req.body;

    // 验证必需参数
    if (!pptId || !slides || !Array.isArray(slides)) {
      return res.status(400).json({
        error: 'Missing required parameters: pptId, slides (array)'
      });
    }

    console.log(`🔗 Creating persistent links for ${slides.length} pages of PPT ${pptId}`);

    // 批量创建持久化链接
    const results = await persistentImageLinkService.updateAllPersistentLinks(
      userId,
      pptId,
      slides,
      options
    );

    // 统计结果
    const successCount = results.filter(r => r.success).length;
    const failureCount = results.length - successCount;

    console.log(`✅ Created ${successCount} persistent links, ${failureCount} failed`);

    // 转换结果格式以匹配前端期望的数据结构
    const links = results.filter(r => r.success).map(result => ({
      linkId: result.linkId,
      url: result.url,
      publicUrl: result.publicUrl,
      pageIndex: result.pageIndex,
      slideId: result.slideId,
      lastUpdated: result.lastUpdated
    }));

    res.json({
      success: true,
      message: `Created ${successCount} persistent links successfully`,
      totalPages: slides.length,
      successCount,
      failureCount,
      links,
      results
    });
  } catch (error) {
    console.error('❌ Failed to create persistent links:', error);
    next(error);
  }
});

/**
 * 更新PPT页面图片
 * PUT /api/persistent-images/:linkId
 */
router.put('/:linkId', authenticateToken, async (req, res, next) => {
  try {
    const { linkId } = req.params;
    const {
      slideData,
      options = {}
    } = req.body;

    // 验证必需参数
    if (!slideData) {
      return res.status(400).json({
        error: 'Missing required parameter: slideData'
      });
    }

    console.log(`🔄 Updating image for persistent link: ${linkId}`);

    // 更新图片
    await persistentImageLinkService.updatePageImage(linkId, slideData, options);

    res.json({
      success: true,
      message: 'Image updated successfully',
      linkId,
      url: `/api/persistent-images/${linkId}`
    });
  } catch (error) {
    console.error(`❌ Failed to update persistent link ${req.params.linkId}:`, error);
    next(error);
  }
});

/**
 * 更新持久化链接的图片内容（通过图片数据）
 * POST /api/persistent-images/update-image
 */
router.post('/update-image', authenticateToken, async (req, res, next) => {
  try {
    const {
      linkId,
      imageData,
      format = 'jpeg'
    } = req.body;

    // 验证必需参数
    if (!linkId || !imageData) {
      return res.status(400).json({
        error: 'Missing required parameters: linkId, imageData'
      });
    }

    console.log(`🔄 Updating image content for persistent link: ${linkId}`);

    // 将base64图片数据转换为Buffer
    let imageBuffer;
    try {
      // 移除data:image/jpeg;base64,前缀（如果存在）
      const base64Data = imageData.replace(/^data:image\/[a-z]+;base64,/, '');
      imageBuffer = Buffer.from(base64Data, 'base64');
    } catch (error) {
      return res.status(400).json({
        error: 'Invalid image data format'
      });
    }

    // 直接更新持久化链接的图片内容
    const result = await persistentImageLinkService.updateImageContent(linkId, imageBuffer, format);

    if (!result.success) {
      return res.status(404).json({
        error: 'Persistent link not found',
        linkId
      });
    }

    res.json({
      success: true,
      message: 'Image content updated successfully',
      linkId,
      url: `/api/persistent-images/${linkId}`,
      size: imageBuffer.length,
      format
    });
  } catch (error) {
    console.error(`❌ Failed to update image content for link ${req.body.linkId}:`, error);
    next(error);
  }
});

/**
 * 获取用户的所有持久化链接
 * GET /api/persistent-images/user/list
 */
router.get('/user/list', authenticateToken, async (req, res, next) => {
  try {
    const userId = req.user.userId;
    const { pptId } = req.query;

    console.log(`📋 Getting persistent links for user ${userId}${pptId ? `, PPT ${pptId}` : ''}`);

    const userLinks = persistentImageLinkService.getUserPersistentLinks(userId, pptId);

    res.json({
      success: true,
      userId,
      pptId: pptId || null,
      linkCount: userLinks.length,
      links: userLinks
    });
  } catch (error) {
    console.error(`❌ Failed to get user persistent links:`, error);
    next(error);
  }
});

/**
 * 获取服务统计信息
 * GET /api/persistent-images/stats
 */
router.get('/stats', authenticateToken, async (req, res, next) => {
  try {
    console.log('📊 Getting persistent image service stats');

    const stats = persistentImageLinkService.getStats();

    res.json({
      success: true,
      stats
    });
  } catch (error) {
    console.error('❌ Failed to get persistent image stats:', error);
    next(error);
  }
});

/**
 * 获取持久化链接的图片 (通过 pptId 和 slideId)
 * GET /api/persistent-images/:pptId/:slideId
 */
router.get('/:pptId/:slideId', async (req, res, next) => {
  try {
    const { pptId, slideId } = req.params;
    const { download } = req.query;

    // 验证pptId格式 (应该是UUID格式)
    const uuidRegex = /^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/i;
    if (!uuidRegex.test(pptId)) {
      return next(); // 不是UUID格式，继续到下一个路由
    }

    // 验证slideId格式 (不应该包含文件扩展名)
    if (slideId.includes('.')) {
      return next(); // 包含文件扩展名，可能是静态文件请求
    }

    console.log(`🖼️ Getting persistent image by pptId: ${pptId}, slideId: ${slideId}`);

    // 通过 pptId 和 slideId 查找对应的链接
    const linkInfo = await persistentImageLinkService.findLinkByPptAndSlide(pptId, slideId);
    
    if (!linkInfo) {
      return res.status(404).json({
        error: 'Persistent image not found for the specified PPT and slide',
        pptId,
        slideId
      });
    }

    // 获取图片
    const imageResult = await persistentImageLinkService.getPersistentImage(linkInfo.linkId);
    
    if (!imageResult.success) {
      return res.status(404).json({
        error: 'Persistent image not found',
        pptId,
        slideId,
        linkId: linkInfo.linkId
      });
    }

    const { data: imageBuffer, metadata } = imageResult;

    // 设置响应头
    const contentType = metadata.format === 'jpg' ? 'image/jpeg' : `image/${metadata.format}`;
    res.set({
      'Content-Type': contentType,
      'Content-Length': metadata.size,
      'Cache-Control': 'public, max-age=3600', // 缓存1小时
      'ETag': `"${linkInfo.linkId}"`,
      'Last-Modified': new Date(metadata.lastUpdated).toUTCString()
    });

    // 如果是下载请求，设置下载头
    if (download) {
      const fileName = `persistent-slide-${pptId}-${slideId}.${metadata.format}`;
      res.set('Content-Disposition', `attachment; filename="${fileName}"`);
    }

    // 检查条件请求
    const ifNoneMatch = req.get('If-None-Match');
    if (ifNoneMatch === `"${linkInfo.linkId}"`) {
      return res.status(304).end();
    }

    res.send(imageBuffer);
  } catch (error) {
    console.error(`❌ Failed to get persistent image ${req.params.pptId}/${req.params.slideId}:`, error);
    if (error.message.includes('not found')) {
      return res.status(404).json({
        error: 'Persistent image not found',
        pptId: req.params.pptId,
        slideId: req.params.slideId
      });
    }
    next(error);
  }
});

/**
 * 获取持久化链接的图片 (通过 pptId 或 linkId)
 * GET /api/persistent-images/:id
 */
router.get('/:id', async (req, res, next) => {
  try {
    const { id } = req.params;
    const { download } = req.query;

    console.log(`🖼️ Getting persistent image: ${id}`);

    // 检查是否是PPT ID格式（通常比linkId短，且可能包含特殊字符）
    // 如果是PPT ID，返回该PPT的第一页图片
    let imageResult;
    let isLinkId = false;
    
    try {
      // 首先尝试作为linkId获取图片
      imageResult = await persistentImageLinkService.getPersistentImage(id);
      isLinkId = true;
    } catch (error) {
      // 如果作为linkId失败，尝试作为PPT ID获取第一页图片
      console.log(`⚠️ Not found as linkId, trying as PPT ID: ${id}`);
      
      // 查找该PPT的第一页链接
      const links = [];
      for (const [linkId, linkInfo] of persistentImageLinkService.persistentLinks) {
        if (linkInfo.pptId === id && linkInfo.hasImage) {
          links.push({ linkId, pageIndex: linkInfo.pageIndex || 0 });
        }
      }
      
      if (links.length === 0) {
        return res.status(404).json({
          error: 'No persistent images found for PPT',
          pptId: id
        });
      }
      
      // 按页面索引排序，取第一页
      links.sort((a, b) => a.pageIndex - b.pageIndex);
      const firstPageLinkId = links[0].linkId;
      
      imageResult = await persistentImageLinkService.getPersistentImage(firstPageLinkId);
    }
    
    if (!imageResult.success) {
      return res.status(404).json({
        error: 'Persistent image not found',
        id
      });
    }

    const { data: imageBuffer, metadata } = imageResult;

    // 设置响应头
    const contentType = metadata.format === 'jpg' ? 'image/jpeg' : `image/${metadata.format}`;
    res.set({
      'Content-Type': contentType,
      'Content-Length': metadata.size,
      'Cache-Control': 'public, max-age=3600', // 缓存1小时
      'ETag': `"${id}"`,
      'Last-Modified': new Date(metadata.lastUpdated).toUTCString()
    });

    // 如果是下载请求，设置下载头
    if (download) {
      const fileName = isLinkId ? `persistent-slide-${id}.${metadata.format}` : `persistent-ppt-${id}.${metadata.format}`;
      res.set('Content-Disposition', `attachment; filename="${fileName}"`);
    }

    // 检查条件请求
    const ifNoneMatch = req.get('If-None-Match');
    if (ifNoneMatch === `"${id}"`) {
      return res.status(304).end();
    }

    res.send(imageBuffer);
  } catch (error) {
    console.error(`❌ Failed to get persistent image ${req.params.id}:`, error);
    if (error.message.includes('not found')) {
      return res.status(404).json({
        error: 'Persistent image not found',
        id: req.params.id
      });
    }
    next(error);
  }
});

/**
 * 删除持久化链接
 * DELETE /api/persistent-images/:linkId
 */
router.delete('/:linkId', authenticateToken, async (req, res, next) => {
  try {
    const { linkId } = req.params;

    console.log(`🗑️ Deleting persistent link: ${linkId}`);

    // 删除持久化链接
    const deleteResult = await persistentImageLinkService.deletePersistentLink(linkId);

    if (deleteResult) {
      res.json({
        success: true,
        message: 'Persistent link deleted successfully',
        linkId
      });
    } else {
      res.status(404).json({
        error: 'Persistent link not found',
        linkId
      });
    }
  } catch (error) {
    console.error(`❌ Failed to delete persistent link ${req.params.linkId}:`, error);
    next(error);
  }
});

/**
 * 从PPT数据同步创建持久化链接
 * POST /api/persistent-images/sync-from-ppt
 */
router.post('/sync-from-ppt', authenticateToken, async (req, res, next) => {
  try {
    const userId = req.user.userId;
    const { pptId } = req.body;

    // 验证必需参数
    if (!pptId) {
      return res.status(400).json({
        error: 'Missing required parameter: pptId'
      });
    }

    console.log(`🔄 Syncing persistent links from PPT data: ${pptId}`);

    // 从GitHub服务获取PPT数据
    const pptData = await githubService.getPPT(userId, pptId);
    
    if (!pptData || !pptData.slides) {
      return res.status(404).json({
        error: 'PPT not found or has no slides',
        pptId
      });
    }

    // 创建持久化链接（不生成图片，只创建链接）
    const results = [];
    for (let pageIndex = 0; pageIndex < pptData.slides.length; pageIndex++) {
      try {
        const result = await persistentImageLinkService.getOrCreatePersistentLink(
          userId,
          pptId,
          pageIndex,
          null, // 不提供slideData，只创建链接
          {}
        );
        
        results.push({
          pageIndex,
          success: true,
          ...result
        });
      } catch (error) {
        console.error(`❌ Failed to sync persistent link for page ${pageIndex}:`, error);
        results.push({
          pageIndex,
          success: false,
          error: error.message
        });
      }
    }

    const successCount = results.filter(r => r.success).length;
    const failureCount = results.length - successCount;

    console.log(`✅ Synced ${successCount} persistent links, ${failureCount} failed`);

    res.json({
      success: true,
      message: `Synced ${successCount} persistent links from PPT data`,
      pptId,
      totalPages: pptData.slides.length,
      successCount,
      failureCount,
      results
    });
  } catch (error) {
    console.error('❌ Failed to sync persistent links from PPT:', error);
    next(error);
  }
});

export default router;