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 || {};
  
  // 精确计算PPT内容的真实尺寸 - 基于填满画布的图像元素推断
  const calculatePptDimensions = (slide) => {
    console.log('开始计算PPT尺寸，当前slide元素数量:', slide.elements?.length || 0);
    
    // 1. 优先使用PPT数据中的viewportSize和viewportRatio（编辑器的真实尺寸）
    if (pptData.viewportSize && pptData.viewportRatio) {
      const result = {
        width: Math.ceil(pptData.viewportSize),
        height: Math.ceil(pptData.viewportSize * pptData.viewportRatio)
      };
      console.log(`使用编辑器真实尺寸: ${result.width}x${result.height} (viewportSize: ${pptData.viewportSize}, viewportRatio: ${pptData.viewportRatio})`);
      return result;
    }
    
    // 2. 使用PPT数据中的预设尺寸
    if (pptData.slideSize && pptData.slideSize.width && pptData.slideSize.height) {
      const result = {
        width: Math.ceil(pptData.slideSize.width),
        height: Math.ceil(pptData.slideSize.height)
      };
      console.log(`使用PPT预设尺寸: ${result.width}x${result.height}`);
      return result;
    }
    
    // 3. 如果PPT数据中有width和height
    if (pptData.width && pptData.height) {
      const result = {
        width: Math.ceil(pptData.width),
        height: Math.ceil(pptData.height)
      };
      console.log(`使用PPT根级尺寸: ${result.width}x${result.height}`);
      return result;
    }
    
    // 4. 使用slide级别的尺寸设置
    if (slide.width && slide.height) {
      const result = {
        width: Math.ceil(slide.width),
        height: Math.ceil(slide.height)
      };
      console.log(`使用slide尺寸: ${result.width}x${result.height}`);
      return result;
    }
    
    // 5. 基于填满画布的图像元素精确推断PPT尺寸
    if (slide.elements && slide.elements.length > 0) {
      // 寻找可能填满画布的图像元素（left=0, top=0 或接近0，且尺寸较大）
      const candidateImages = slide.elements.filter(element => 
        element.type === 'image' && 
        Math.abs(element.left || 0) <= 10 &&  // 允许小偏差
        Math.abs(element.top || 0) <= 10 &&   // 允许小偏差
        (element.width || 0) >= 800 &&        // 宽度至少800
        (element.height || 0) >= 400          // 高度至少400
      );
      
      if (candidateImages.length > 0) {
        // 使用面积最大的图像作为画布尺寸参考
        const referenceImage = candidateImages.reduce((max, current) => {
          const maxArea = (max.width || 0) * (max.height || 0);
          const currentArea = (current.width || 0) * (current.height || 0);
          return currentArea > maxArea ? current : max;
        });
        
        const result = {
          width: Math.ceil(referenceImage.width || 1000),
          height: Math.ceil(referenceImage.height || 562)
        };
        
        console.log(`基于填满画布的图像推断PPT尺寸: ${result.width}x${result.height} (参考图像: ${referenceImage.id})`);
        console.log(`参考图像信息: left=${referenceImage.left}, top=${referenceImage.top}, width=${referenceImage.width}, height=${referenceImage.height}`);
        
        return result;
      }
      
      // 如果没有找到填满画布的图像，回退到边界计算
      let maxRight = 0;
      let maxBottom = 0;
      let minLeft = Infinity;
      let minTop = Infinity;
      
      // 计算所有元素的实际边界
      slide.elements.forEach(element => {
        const left = element.left || 0;
        const top = element.top || 0;
        const width = element.width || 0;
        const height = element.height || 0;
        
        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);
        
        console.log(`元素 ${element.id}: type=${element.type}, left=${left}, top=${top}, width=${width}, height=${height}, right=${elementRight}, bottom=${elementBottom}`);
      });
      
      // 重置无限值
      if (minLeft === Infinity) minLeft = 0;
      if (minTop === Infinity) minTop = 0;
      
      console.log(`元素边界: minLeft=${minLeft}, minTop=${minTop}, maxRight=${maxRight}, maxBottom=${maxBottom}`);
      
      // 根据实际元素分布确定画布尺寸
      const canvasLeft = Math.min(0, minLeft);
      const canvasTop = Math.min(0, minTop);
      const canvasRight = Math.max(maxRight, 1000); // 最小宽度1000（基于GitHub数据）
      const canvasBottom = Math.max(maxBottom, 562);  // 最小高度562（基于GitHub数据）
      
      // 计算最终的画布尺寸
      let finalWidth = canvasRight - canvasLeft;
      let finalHeight = canvasBottom - canvasTop;
      
      // 基于从GitHub仓库观察到的实际比例进行智能调整
      const currentRatio = finalWidth / finalHeight;
      console.log(`当前计算比例: ${currentRatio.toFixed(3)}`);
      
      // 从GitHub数据分析：1000x562.5 ≈ 1.78 (接近16:9的1.77)
      const targetRatio = 1000 / 562.5; // ≈ 1.778
      
      // 如果比例接近观察到的标准比例，调整为精确比例
      if (Math.abs(currentRatio - targetRatio) < 0.2) {
        if (finalWidth > finalHeight * targetRatio) {
          finalHeight = finalWidth / targetRatio;
        } else {
          finalWidth = finalHeight * targetRatio;
        }
        console.log(`调整为GitHub观察到的标准比例: ${targetRatio.toFixed(3)}`);
      }
      // 如果比例接近16:9，调整为标准16:9
      else if (Math.abs(currentRatio - 16/9) < 0.1) {
        if (finalWidth > finalHeight * 16/9) {
          finalHeight = finalWidth / (16/9);
        } else {
          finalWidth = finalHeight * (16/9);
        }
        console.log(`调整为16:9比例`);
      }
      // 如果比例接近4:3，调整为标准4:3
      else if (Math.abs(currentRatio - 4/3) < 0.1) {
        if (finalWidth > finalHeight * 4/3) {
          finalHeight = finalWidth / (4/3);
        } else {
          finalWidth = finalHeight * (4/3);
        }
        console.log(`调整为4:3比例`);
      }
      
      // 确保尺寸为偶数（避免半像素问题）
      finalWidth = Math.ceil(finalWidth / 2) * 2;
      finalHeight = Math.ceil(finalHeight / 2) * 2;
      
      const result = { width: finalWidth, height: finalHeight };
      console.log(`根据元素边界计算最终尺寸: ${result.width}x${result.height}, 比例: ${(result.width/result.height).toFixed(3)}`);
      
      return result;
    }
    
    // 6. 如果没有元素，使用从GitHub数据分析得出的标准尺寸
    const result = { width: 1000, height: 562 }; // 基于GitHub仓库中观察到的实际数据
    console.log(`使用GitHub数据分析的默认尺寸: ${result.width}x${result.height} (1000x562, 比例≈1.78)`);
    return result;
  };
  
  const pptDimensions = calculatePptDimensions(slide);
  
  // 渲染幻灯片元素 - 使用原始像素值，完全保真
  const renderElements = (elements) => {
    if (!elements || elements.length === 0) return '';
    
    return elements.map(element => {
      const style = `
        position: absolute;
        left: ${element.left || 0}px;
        top: ${element.top || 0}px;
        width: ${element.width || 0}px;
        height: ${element.height || 0}px;
        transform: rotate(${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;
              box-sizing: border-box;
            ">
              ${element.content || ''}
            </div>
          `;
        case 'image':
          return `
            <div style="${style}">
              <img src="${element.src}" alt="" style="width: 100%; height: 100%; object-fit: ${element.objectFit || 'cover'}; display: block;" />
            </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} ${borderStyle} box-sizing: border-box;"></div>
          `;
        default:
          return `<div style="${style}"></div>`;
      }
    }).join('');
  };

  return `
    <!DOCTYPE html>
    <html lang="zh-CN">
    <head>
        <meta charset="UTF-8">
        <meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=no">
        <title>${title} - 第${slideIndex + 1}页</title>
        <style>
            /* 完全重置所有默认样式 */
            *, *::before, *::after {
                margin: 0 !important;
                padding: 0 !important;
                border: 0 !important;
                outline: 0 !important;
                box-sizing: border-box !important;
            }
            
            /* HTML - 填满整个窗口，黑色背景 */
            html {
                width: 100vw !important;
                height: 100vh !important;
                background: #000000 !important;
                overflow: hidden !important;
                position: fixed !important;
                top: 0 !important;
                left: 0 !important;
            }
            
            /* Body - 填满整个窗口，黑色背景，居中显示PPT */
            body {
                width: 100vw !important;
                height: 100vh !important;
                background: #000000 !important;
                overflow: hidden !important;
                font-family: 'Microsoft YaHei', Arial, sans-serif !important;
                position: fixed !important;
                top: 0 !important;
                left: 0 !important;
                display: flex !important;
                align-items: center !important;
                justify-content: center !important;
            }
            
            /* PPT容器 - 使用PPT原始尺寸 */
            .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;
                transform-origin: center center !important;
                /* 缩放将通过JavaScript动态设置 */
            }
            
            /* 背景图片处理 */
            ${slide.background?.type === 'image' ? `
            .slide-container::before {
                content: '';
                position: absolute !important;
                top: 0 !important;
                left: 0 !important;
                width: 100% !important;
                height: 100% !important;
                background-image: url('${slide.background.image}') !important;
                background-size: cover !important;
                background-position: center !important;
                background-repeat: no-repeat !important;
                z-index: 0 !important;
            }
            ` : ''}
            
            /* 隐藏所有滚动条 */
            ::-webkit-scrollbar {
                display: none !important;
            }
            
            html {
                scrollbar-width: none !important;
                -ms-overflow-style: none !important;
            }
            
            /* 禁用用户交互 */
            * {
                -webkit-user-select: none !important;
                -moz-user-select: none !important;
                -ms-user-select: none !important;
                user-select: none !important;
                -webkit-user-drag: none !important;
                -khtml-user-drag: none !important;
                -moz-user-drag: none !important;
                -o-user-drag: none !important;
                user-drag: none !important;
            }
            
            /* 禁用缩放 */
            body {
                zoom: 1 !important;
                -webkit-text-size-adjust: 100% !important;
                -ms-text-size-adjust: 100% !important;
            }
        </style>
    </head>
    <body>
        <div class="slide-container" id="slideContainer">
            ${renderElements(slide.elements)}
        </div>
        
        <script>
            // PPT尺寸信息
            window.PPT_DIMENSIONS = {
                width: ${pptDimensions.width},
                height: ${pptDimensions.height}
            };
            
            console.log('PPT页面初始化 - 原始尺寸整体缩放模式:', window.PPT_DIMENSIONS);
            
            // 计算整体缩放比例，让PPT适应窗口大小
            function calculateScale() {
                const windowWidth = window.innerWidth;
                const windowHeight = window.innerHeight;
                const pptWidth = ${pptDimensions.width};
                const pptHeight = ${pptDimensions.height};
                
                // 计算缩放比例，保持PPT长宽比
                const scaleX = windowWidth / pptWidth;
                const scaleY = windowHeight / pptHeight;
                
                // 使用较小的缩放比例，确保PPT完全可见（会有黑边）
                const scale = Math.min(scaleX, scaleY);
                
                return Math.min(scale, 1); // 最大不超过1（不放大）
            }
            
            // 应用缩放变换
            function scalePPTToFitWindow() {
                const container = document.getElementById('slideContainer');
                if (!container) return;
                
                const scale = calculateScale();
                
                // 应用缩放变换
                container.style.transform = \`scale(\${scale})\`;
                
                console.log(\`PPT整体缩放: \${scale.toFixed(3)}x (窗口: \${window.innerWidth}x\${window.innerHeight}, PPT: \${${pptDimensions.width}}x\${${pptDimensions.height}})\`);
            }
            
            // 页面加载完成后初始化
            window.addEventListener('load', function() {
                const html = document.documentElement;
                const body = document.body;
                const container = document.getElementById('slideContainer');
                
                console.log('页面加载完成，开始整体缩放布局');
                
                // 确保页面元素填满窗口
                html.style.width = '100vw';
                html.style.height = '100vh';
                html.style.background = '#000000';
                html.style.overflow = 'hidden';
                html.style.margin = '0';
                html.style.padding = '0';
                
                body.style.width = '100vw';
                body.style.height = '100vh';
                body.style.background = '#000000';
                body.style.overflow = 'hidden';
                body.style.margin = '0';
                body.style.padding = '0';
                body.style.display = 'flex';
                body.style.alignItems = 'center';
                body.style.justifyContent = 'center';
                
                // 确保PPT容器使用原始尺寸
                if (container) {
                    container.style.width = '${pptDimensions.width}px';
                    container.style.height = '${pptDimensions.height}px';
                    container.style.transformOrigin = 'center center';
                }
                
                // 执行整体缩放
                scalePPTToFitWindow();
                
                // 禁用各种用户交互
                document.addEventListener('wheel', function(e) {
                    if (e.ctrlKey) e.preventDefault();
                }, { passive: false });
                
                document.addEventListener('keydown', function(e) {
                    if ((e.ctrlKey && (e.key === '+' || e.key === '-' || e.key === '0')) || e.key === 'F11') {
                        e.preventDefault();
                    }
                }, false);
                
                document.addEventListener('contextmenu', function(e) {
                    e.preventDefault();
                }, false);
                
                // 禁用触摸缩放
                let lastTouchEnd = 0;
                document.addEventListener('touchend', function(e) {
                    const now = new Date().getTime();
                    if (now - lastTouchEnd <= 300) {
                        e.preventDefault();
                    }
                    lastTouchEnd = now;
                }, false);
                
                document.addEventListener('touchstart', function(e) {
                    if (e.touches.length > 1) {
                        e.preventDefault();
                    }
                }, { passive: false });
                
                console.log('原始尺寸PPT页面初始化完成');
                
                // 验证最终效果
                setTimeout(() => {
                    const actualScale = container.style.transform.match(/scale\\(([^)]+)\\)/);
                    const scaleValue = actualScale ? parseFloat(actualScale[1]) : 1;
                    
                    console.log(\`✅ PPT以原始尺寸(\${${pptDimensions.width}}x\${${pptDimensions.height}})显示，整体缩放: \${scaleValue.toFixed(3)}x\`);
                    console.log('🎯 显示效果与编辑器完全一致，周围黑边正常');
                }, 200);
            });
            
            // 监听窗口大小变化，实时调整缩放
            window.addEventListener('resize', function() {
                console.log('窗口大小变化，重新计算整体缩放');
                scalePPTToFitWindow();
            });
            
            // 监听屏幕方向变化（移动设备）
            window.addEventListener('orientationchange', function() {
                console.log('屏幕方向变化，重新计算整体缩放');
                setTimeout(scalePPTToFitWindow, 100);
            });
        </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;