backend/src/routes/public.js

import express from 'express';
import githubService from '../services/githubService.js';
import memoryStorageService from '../services/memoryStorageService.js';
import screenshotService from '../services/screenshotService.js';

const router = express.Router();

// 选择存储服务
const getStorageService = () => {
  // 如果GitHub Token未配置，使用内存存储
  if (!process.env.GITHUB_TOKEN) {
    return memoryStorageService;
  }
  return githubService;
};

// 生成HTML页面来显示PPT幻灯片
const generateSlideHTML = (pptData, slideIndex, title) => {
  const slide = pptData.slides[slideIndex];
  const theme = pptData.theme || {};
  
  // 优化的PPT尺寸计算函数 - 确保长宽比一致性
  const calculatePptDimensions = (slide) => {
    if (!slide.elements || slide.elements.length === 0) {
      // 如果没有元素，使用标准PPT 16:9 比例
      return { width: 1280, height: 720 };
    }
    
    let maxRight = 0;
    let maxBottom = 0;
    let minLeft = Infinity;
    let minTop = Infinity;
    
    slide.elements.forEach(element => {
      const left = element.left || 0;
      const top = element.top || 0;
      const width = element.width || 0;
      const height = element.height || 0;
      
      // 计算元素的边界
      const elementRight = left + width;
      const elementBottom = top + height;
      
      maxRight = Math.max(maxRight, elementRight);
      maxBottom = Math.max(maxBottom, elementBottom);
      minLeft = Math.min(minLeft, left);
      minTop = Math.min(minTop, top);
    });
    
    // 确保有最小边距
    const padding = 40;
    const contentWidth = maxRight - Math.max(0, minLeft);
    const contentHeight = maxBottom - Math.max(0, minTop);
    
    // 计算最终尺寸，保持合理的长宽比
    let finalWidth = Math.max(contentWidth + padding * 2, 800);
    let finalHeight = Math.max(contentHeight + padding * 2, 600);
    
    // 确保长宽比合理（介于4:3到16:9之间）
    const aspectRatio = finalWidth / finalHeight;
    const minRatio = 4/3; // 1.33
    const maxRatio = 16/9; // 1.78
    
    if (aspectRatio < minRatio) {
      // 太高了，调整宽度
      finalWidth = finalHeight * minRatio;
    } else if (aspectRatio > maxRatio) {
      // 太宽了，调整高度
      finalHeight = finalWidth / maxRatio;
    }
    
    const result = { 
      width: Math.round(finalWidth), 
      height: Math.round(finalHeight) 
    };
    
    console.log(`PPT dimensions calculated: ${result.width}x${result.height} (aspect ratio: ${(result.width/result.height).toFixed(2)})`);
    
    return result;
  };
  
  const pptDimensions = calculatePptDimensions(slide);
  
  // 渲染幻灯片元素
  const renderElements = (elements) => {
    if (!elements || elements.length === 0) return '';
    
    return elements.map(element => {
      const style = `
        position: absolute;
        left: ${element.left}px;
        top: ${element.top}px;
        width: ${element.width}px;
        height: ${element.height}px;
        transform: rotate(${element.rotate || 0}deg);
        z-index: ${element.zIndex || 1};
      `;
      
      switch (element.type) {
        case 'text':
          return `
            <div style="${style} 
              font-size: ${element.fontSize || 14}px;
              font-family: ${element.fontName || 'Arial'};
              color: ${element.defaultColor || '#000'};
              font-weight: ${element.bold ? 'bold' : 'normal'};
              font-style: ${element.italic ? 'italic' : 'normal'};
              text-decoration: ${element.underline ? 'underline' : 'none'};
              text-align: ${element.align || 'left'};
              line-height: ${element.lineHeight || 1.2};
              padding: 10px;
              word-wrap: break-word;
              overflow: hidden;
            ">
              ${element.content || ''}
            </div>
          `;
        case 'image':
          return `
            <div style="${style}">
              <img src="${element.src}" alt="" style="width: 100%; height: 100%; object-fit: ${element.objectFit || 'contain'};" />
            </div>
          `;
        case 'shape':
          const shapeStyle = element.fill ? `background-color: ${element.fill};` : '';
          const borderStyle = element.outline ? `border: ${element.outline.width || 1}px ${element.outline.style || 'solid'} ${element.outline.color || '#000'};` : '';
          return `
            <div style="${style} ${shapeStyle} ${borderStyle}"></div>
          `;
        default:
          return `<div style="${style}"></div>`;
      }
    }).join('');
  };

  return `
    <!DOCTYPE html>
    <html lang="zh-CN">
    <head>
        <meta charset="UTF-8">
        <meta name="viewport" content="width=${pptDimensions.width}, height=${pptDimensions.height}, initial-scale=1.0, user-scalable=no">
        <title>${title} - 第${slideIndex + 1}页</title>
        <style>
            * {
                margin: 0 !important;
                padding: 0 !important;
                box-sizing: border-box !important;
            }
            
            html {
                width: 100vw !important;
                height: 100vh !important;
                overflow: hidden !important;
                background-color: #000 !important;
            }
            
            body {
                width: 100vw !important;
                height: 100vh !important;
                overflow: hidden !important;
                font-family: 'Microsoft YaHei', Arial, sans-serif !important;
                background-color: #000 !important;
                display: flex !important;
                align-items: center !important;
                justify-content: center !important;
            }
            
            .slide-container {
                width: ${pptDimensions.width}px !important;
                height: ${pptDimensions.height}px !important;
                background-color: ${slide.background?.color || theme.backgroundColor || '#ffffff'} !important;
                position: relative !important;
                overflow: hidden !important;
                box-shadow: 0 0 20px rgba(255,255,255,0.1) !important;
                transform-origin: center center !important;
            }
            
            ${slide.background?.type === 'image' ? `
            .slide-container::before {
                content: '';
                position: absolute;
                top: 0;
                left: 0;
                right: 0;
                bottom: 0;
                background-image: url('${slide.background.image}');
                background-size: ${slide.background.imageSize || 'cover'};
                background-position: center;
                background-repeat: no-repeat;
                z-index: 0;
            }
            ` : ''}
            
            /* 隐藏滚动条 */
            ::-webkit-scrollbar {
                display: none;
            }
            
            /* 截图模式样式 */
            .screenshot-mode {
                background-color: transparent !important;
            }
            
            .screenshot-mode body {
                background-color: transparent !important;
                width: ${pptDimensions.width}px !important;
                height: ${pptDimensions.height}px !important;
                display: block !important;
            }
            
            .screenshot-mode .slide-container {
                position: absolute !important;
                top: 0 !important;
                left: 0 !important;
                transform: none !important;
                box-shadow: none !important;
            }
        </style>
        <script>
            // 将PPT尺寸信息传递给JavaScript，用于截图服务
            window.PPT_DIMENSIONS = {
                width: ${pptDimensions.width},
                height: ${pptDimensions.height}
            };
            
            // 截图模式标识
            window.SCREENSHOT_MODE = window.location.search.includes('screenshot=true');
        </script>
    </head>
    <body${slide.background?.type === 'image' && slide.background?.image ? '' : ''}>
        <div class="slide-container" id="slideContainer">
            ${renderElements(slide.elements)}
        </div>
        
        <script>
            console.log('PPT页面加载完成');
            console.log('PPT尺寸:', window.PPT_DIMENSIONS);
            console.log('截图模式:', window.SCREENSHOT_MODE);
            
            // 根据模式应用不同的样式和行为
            if (window.SCREENSHOT_MODE) {
                // 截图模式：固定尺寸，无缩放
                document.documentElement.classList.add('screenshot-mode');
                document.body.style.cssText = \`
                    width: ${pptDimensions.width}px !important;
                    height: ${pptDimensions.height}px !important;
                    background: transparent !important;
                    overflow: hidden !important;
                    margin: 0 !important;
                    padding: 0 !important;
                    display: block !important;
                \`;
                
                const container = document.getElementById('slideContainer');
                if (container) {
                    container.style.cssText = \`
                        width: ${pptDimensions.width}px !important;
                        height: ${pptDimensions.height}px !important;
                        position: absolute !important;
                        top: 0 !important;
                        left: 0 !important;
                        transform: none !important;
                        box-shadow: none !important;
                        background-color: ${slide.background?.color || theme.backgroundColor || '#ffffff'} !important;
                    \`;
                }
                
                console.log('截图模式样式已应用');
            } else {
                // 网页浏览模式：响应式缩放，保持长宽比
                function resizeSlide() {
                    const container = document.getElementById('slideContainer');
                    const slideWidth = window.PPT_DIMENSIONS.width;
                    const slideHeight = window.PPT_DIMENSIONS.height;
                    
                    // 窗口尺寸
                    const windowWidth = window.innerWidth;
                    const windowHeight = window.innerHeight;
                    
                    // 计算缩放比例，保持宽高比
                    const scaleX = (windowWidth - 40) / slideWidth; // 留20px边距
                    const scaleY = (windowHeight - 40) / slideHeight;
                    const scale = Math.min(scaleX, scaleY, 1); // 最大不超过1倍
                    
                    // 应用缩放
                    container.style.transform = \`scale(\${scale})\`;
                    
                    console.log(\`响应式缩放应用: \${scale.toFixed(3)}x (窗口: \${windowWidth}x\${windowHeight}, PPT: \${slideWidth}x\${slideHeight})\`);
                }
                
                // 页面加载时调整大小
                window.addEventListener('load', resizeSlide);
                
                // 窗口大小改变时重新调整
                window.addEventListener('resize', resizeSlide);
                
                // 立即执行一次
                resizeSlide();
            }
        </script>
    </body>
    </html>
  `;
};

// 公开访问PPT页面 - 返回HTML页面
router.get('/view/:userId/:pptId/:slideIndex?', async (req, res, next) => {
  try {
    const { userId, pptId, slideIndex = 0 } = req.params;
    const querySlideIndex = req.query.slide ? parseInt(req.query.slide) : parseInt(slideIndex);
    const fileName = `${pptId}.json`;
    const storageService = getStorageService();

    let pptData = null;
    
    // 如果是GitHub服务，尝试所有仓库
    if (storageService === githubService && storageService.repositories) {
      for (let i = 0; i < storageService.repositories.length; i++) {
        try {
          const result = await storageService.getFile(userId, fileName, i);
          if (result) {
            pptData = result.content;
            break;
          }
        } catch (error) {
          continue;
        }
      }
    } else {
      // 内存存储服务
      const result = await storageService.getFile(userId, fileName);
      if (result) {
        pptData = result.content;
      }
    }

    if (!pptData) {
      return res.status(404).send(`
        <!DOCTYPE html>
        <html lang="zh-CN">
        <head>
            <meta charset="UTF-8">
            <meta name="viewport" content="width=device-width, initial-scale=1.0">
            <title>PPT未找到</title>
            <style>
                body { font-family: Arial, sans-serif; text-align: center; padding: 50px; }
                .error { color: #e74c3c; font-size: 18px; }
            </style>
        </head>
        <body>
            <div class="error">
                <h2>PPT未找到</h2>
                <p>请检查链接是否正确</p>
            </div>
        </body>
        </html>
      `);
    }

    const slideIdx = querySlideIndex;
    if (slideIdx >= pptData.slides.length || slideIdx < 0) {
      return res.status(404).send(`
        <!DOCTYPE html>
        <html lang="zh-CN">
        <head>
            <meta charset="UTF-8">
            <meta name="viewport" content="width=device-width, initial-scale=1.0">
            <title>幻灯片未找到</title>
            <style>
                body { font-family: Arial, sans-serif; text-align: center; padding: 50px; }
                .error { color: #e74c3c; font-size: 18px; }
            </style>
        </head>
        <body>
            <div class="error">
                <h2>幻灯片未找到</h2>
                <p>请检查幻灯片索引是否正确</p>
            </div>
        </body>
        </html>
      `);
    }

    // 返回HTML页面
    const htmlContent = generateSlideHTML(pptData, slideIdx, pptData.title);
    res.setHeader('Content-Type', 'text/html; charset=utf-8');
    res.send(htmlContent);
  } catch (error) {
    next(error);
  }
});

// API接口：获取PPT数据和指定幻灯片（JSON格式）
router.get('/api-view/:userId/:pptId/:slideIndex?', async (req, res, next) => {
  try {
    const { userId, pptId, slideIndex = 0 } = req.params;
    const fileName = `${pptId}.json`;
    const storageService = getStorageService();

    let pptData = null;
    
    // 如果是GitHub服务，尝试所有仓库
    if (storageService === githubService && storageService.repositories) {
      for (let i = 0; i < storageService.repositories.length; i++) {
        try {
          const result = await storageService.getFile(userId, fileName, i);
          if (result) {
            pptData = result.content;
            break;
          }
        } catch (error) {
          continue;
        }
      }
    } else {
      // 内存存储服务
      const result = await storageService.getFile(userId, fileName);
      if (result) {
        pptData = result.content;
      }
    }

    if (!pptData) {
      return res.status(404).json({ error: 'PPT not found' });
    }

    const slideIdx = parseInt(slideIndex);
    if (slideIdx >= pptData.slides.length || slideIdx < 0) {
      return res.status(404).json({ error: 'Slide not found' });
    }

    // 返回PPT数据和指定幻灯片
    res.json({
      id: pptData.id,
      title: pptData.title,
      theme: pptData.theme,
      currentSlide: pptData.slides[slideIdx],
      slideIndex: slideIdx,
      totalSlides: pptData.slides.length,
      isPublicView: true
    });
  } catch (error) {
    next(error);
  }
});

// 获取完整PPT数据（只读模式）
router.get('/ppt/:userId/:pptId', async (req, res, next) => {
  try {
    const { userId, pptId } = req.params;
    const fileName = `${pptId}.json`;
    const storageService = getStorageService();

    let pptData = null;
    
    // 如果是GitHub服务，尝试所有仓库
    if (storageService === githubService && storageService.repositories) {
      for (let i = 0; i < storageService.repositories.length; i++) {
        try {
          const result = await storageService.getFile(userId, fileName, i);
          if (result) {
            pptData = result.content;
            break;
          }
        } catch (error) {
          continue;
        }
      }
    } else {
      // 内存存储服务
      const result = await storageService.getFile(userId, fileName);
      if (result) {
        pptData = result.content;
      }
    }

    if (!pptData) {
      return res.status(404).json({ error: 'PPT not found' });
    }

    // 返回只读版本的PPT数据
    res.json({
      ...pptData,
      isPublicView: true,
      readOnly: true
    });
  } catch (error) {
    next(error);
  }
});

// 生成PPT分享链接
router.post('/generate-share-link', async (req, res, next) => {
  try {
    const { userId, pptId, slideIndex = 0 } = req.body;

    if (!userId || !pptId) {
      return res.status(400).json({ error: 'User ID and PPT ID are required' });
    }

    console.log(`Generating share link for PPT: ${pptId}, User: ${userId}`);

    // 验证PPT是否存在
    const fileName = `${pptId}.json`;
    const storageService = getStorageService();
    let pptExists = false;
    let pptData = null;
    
    console.log(`Using storage service: ${storageService === githubService ? 'GitHub' : 'Memory'}`);
    
    // 如果是GitHub服务，尝试所有仓库
    if (storageService === githubService && storageService.repositories) {
      console.log(`Checking ${storageService.repositories.length} GitHub repositories...`);
      
      for (let i = 0; i < storageService.repositories.length; i++) {
        try {
          console.log(`Checking repository ${i}: ${storageService.repositories[i]}`);
          const result = await storageService.getFile(userId, fileName, i);
          if (result) {
            pptExists = true;
            pptData = result.content;
            console.log(`PPT found in repository ${i}`);
            break;
          }
        } catch (error) {
          console.log(`PPT not found in repository ${i}: ${error.message}`);
          continue;
        }
      }
    } else {
      // 内存存储服务
      console.log('Checking memory storage...');
      try {
        const result = await storageService.getFile(userId, fileName);
        if (result) {
          pptExists = true;
          pptData = result.content;
          console.log('PPT found in memory storage');
        }
      } catch (error) {
        console.log(`PPT not found in memory storage: ${error.message}`);
      }
    }

    if (!pptExists) {
      console.log('PPT not found in any storage location');
      
      // 额外尝试：如果GitHub失败，检查memory storage作为fallback
      if (storageService === githubService) {
        console.log('GitHub lookup failed, trying memory storage fallback...');
        try {
          const memoryResult = await memoryStorageService.getFile(userId, fileName);
          if (memoryResult) {
            pptExists = true;
            pptData = memoryResult.content;
            console.log('PPT found in memory storage fallback');
          }
        } catch (memoryError) {
          console.log(`Memory storage fallback also failed: ${memoryError.message}`);
        }
      }
    }

    if (!pptExists) {
      return res.status(404).json({ 
        error: 'PPT not found',
        details: `PPT ${pptId} not found for user ${userId}`,
        searchedLocations: storageService === githubService ? 'GitHub repositories and memory storage' : 'Memory storage only'
      });
    }

    const baseUrl = process.env.PUBLIC_URL || req.get('host');
    const protocol = process.env.NODE_ENV === 'production' ? 'https' : req.protocol;
    
    const shareLinks = {
      // 单页分享链接
      slideUrl: `${protocol}://${baseUrl}/api/public/view/${userId}/${pptId}/${slideIndex}`,
      // 完整PPT分享链接
      pptUrl: `${protocol}://${baseUrl}/api/public/ppt/${userId}/${pptId}`,
      // 前端查看链接
      viewUrl: `${protocol}://${baseUrl}/public/${userId}/${pptId}/${slideIndex}`,
      // 新增：截图链接
      screenshotUrl: `${protocol}://${baseUrl}/api/public/screenshot/${userId}/${pptId}/${slideIndex}`,
      // 添加PPT信息
      pptInfo: {
        id: pptId,
        title: pptData?.title || 'Unknown Title',
        slideCount: pptData?.slides?.length || 0
      }
    };

    console.log('Share links generated successfully:', shareLinks);
    res.json(shareLinks);
  } catch (error) {
    console.error('Share link generation error:', error);
    next(error);
  }
});

// 截图功能 - 返回JPEG图片
router.get('/screenshot/:userId/:pptId/:slideIndex?', async (req, res, next) => {
  try {
    console.log('Screenshot request received:', req.params);
    
    const { userId, pptId, slideIndex = 0 } = req.params;
    const slideIdx = parseInt(slideIndex);
    const fileName = `${pptId}.json`;
    const storageService = getStorageService();

    console.log(`Generating screenshot for: ${userId}/${pptId}/${slideIdx}`);

    let pptData = null;
    
    // 获取PPT数据（复用现有逻辑）
    if (storageService === githubService && storageService.repositories) {
      console.log('Checking GitHub repositories...');
      for (let i = 0; i < storageService.repositories.length; i++) {
        try {
          const result = await storageService.getFile(userId, fileName, i);
          if (result) {
            pptData = result.content;
            console.log(`PPT data found in repository ${i}`);
            break;
          }
        } catch (error) {
          continue;
        }
      }
    } else {
      console.log('Checking memory storage...');
      const result = await storageService.getFile(userId, fileName);
      if (result) {
        pptData = result.content;
        console.log('PPT data found in memory storage');
      }
    }

    // 如果GitHub失败，尝试内存存储fallback
    if (!pptData && storageService === githubService) {
      console.log('Trying memory storage fallback...');
      try {
        const memoryResult = await memoryStorageService.getFile(userId, fileName);
        if (memoryResult) {
          pptData = memoryResult.content;
          console.log('PPT data found in memory storage fallback');
        }
      } catch (memoryError) {
        console.log('Memory storage fallback failed:', memoryError.message);
      }
    }

    if (!pptData) {
      console.log('PPT not found');
      return res.status(404).json({ error: 'PPT not found' });
    }

    if (slideIdx >= pptData.slides.length || slideIdx < 0) {
      console.log('Slide index out of bounds');
      return res.status(404).json({ error: 'Slide not found' });
    }

    console.log('Generating HTML content...');
    // 生成HTML内容（复用现有函数）
    const htmlContent = generateSlideHTML(pptData, slideIdx, pptData.title);
    
    console.log('Calling screenshot service...');
    // 生成截图
    const screenshot = await screenshotService.generateScreenshot(htmlContent);
    
    console.log('Screenshot generated, sending response...');
    
    // 返回图片
    res.setHeader('Content-Type', 'image/jpeg');
    res.setHeader('Cache-Control', 'public, max-age=60'); // 1分钟缓存，减少服务器压力
    res.setHeader('Content-Disposition', `inline; filename="${pptData.title}-${slideIdx + 1}.jpg"`);
    res.send(screenshot);
  } catch (error) {
    console.error('Screenshot route error:', error);
    console.error('Stack trace:', error.stack);
    
    // 返回一个简单的错误响应而不是抛出异常
    try {
      res.status(500).setHeader('Content-Type', 'application/json');
      res.json({ 
        error: 'Screenshot generation failed', 
        message: error.message,
        details: process.env.NODE_ENV === 'development' ? error.stack : undefined
      });
    } catch (responseError) {
      console.error('Error sending error response:', responseError);
      // 如果连错误响应都发送失败，调用next
      next(error);
    }
  }
});

export default router;