const fastify = require('fastify')({ 
  logger: true,
  bodyLimit: 100 * 1024 * 1024 // 設置為 100MB
});
const { PDFDocument, PDFName, StandardFonts, PDFString, PDFPermissionFlag } = require('pdf-lib');
const cors = require('@fastify/cors');

// 更詳細的 CORS 設置
fastify.register(cors, {
  origin: ['*', 'null'],
  methods: ['GET', 'POST', 'OPTIONS'],
  allowedHeaders: ['Content-Type']
});

// 處理 PDF 生成請求
fastify.post('/generate-pdf', {
  bodyLimit: 100 * 1024 * 1024, // 100MB
}, async (request, reply) => {
  try {
    const { frames, settings } = request.body;
    
    // 檢查 frames 是否為有效數組
    if (!Array.isArray(frames) || frames.length === 0) {
      throw new Error('No frames provided or frames is not an array');
    }

    // 創建 PDF 文件
    const pdfDoc = await PDFDocument.create();
    
    // 設置 PDF 元數據
    if (settings.title) pdfDoc.setTitle(settings.title);
    if (settings.author) pdfDoc.setAuthor(settings.author);
    if (settings.subject) pdfDoc.setSubject(settings.subject);
    if (settings.keywords) pdfDoc.setKeywords(Array.isArray(settings.keywords) ? settings.keywords : []);
    if (settings.creator) pdfDoc.setCreator(settings.creator);
    if (settings.producer) pdfDoc.setProducer(settings.producer);
    if (settings.language) pdfDoc.setLanguage(settings.language);
    
    // 設置日期
    pdfDoc.setCreationDate(settings.creationDate ? new Date(settings.creationDate) : new Date());
    pdfDoc.setModificationDate(settings.modificationDate ? new Date(settings.modificationDate) : new Date());

    // 根據品質設定調整圖片品質
    const qualitySettings = {
      low: { scale: 1 },
      medium: { scale: 2 },
      high: { scale: 3 }
    };
    const quality = qualitySettings[settings.quality || 'medium'];

    // 處理每個 Frame
    for (const frame of frames) {
      if (!frame.imageBase64) {
        fastify.log.warn(`No image data for frame: ${frame.name}`);
        continue;
      }

      try {
        // 解碼 base64 圖片數據
        const imageBuffer = Buffer.from(frame.imageBase64, 'base64');
        
        // 嵌入圖片到 PDF
        const image = await pdfDoc.embedPng(imageBuffer);
        
        // 獲取圖片尺寸
        const { width, height } = image.scale(1);
        
        // 添加新頁面
        const page = pdfDoc.addPage([width, height]);
        
        // 繪製圖片
        page.drawImage(image, {
          x: 0,
          y: 0,
          width,
          height,
        });

      } catch (error) {
        fastify.log.error(`Error processing frame ${frame.name}: ${error.message}`);
        continue;
      }
    }

    // 檢查是否有頁面被添加
    if (pdfDoc.getPageCount() === 0) {
      throw new Error('No valid frames were processed');
    }

    // 處理加密設置
    if (settings.encryption?.enabled) {
      // 定義權限映射
      const permissionsMap = {
        printing: PDFPermissionFlag.Print,
        modifying: PDFPermissionFlag.ModifyDocument,
        copying: PDFPermissionFlag.Extract,
        annotating: PDFPermissionFlag.Modify,
      };

      // 收集啟用的權限
      const permissions = [];
      if (settings.encryption.permissions?.printing) permissions.push(permissionsMap.printing);
      if (settings.encryption.permissions?.modifying) permissions.push(permissionsMap.modifying);
      if (settings.encryption.permissions?.copying) permissions.push(permissionsMap.copying);
      if (settings.encryption.permissions?.annotating) permissions.push(permissionsMap.annotating);

      // 應用加密設置
      await pdfDoc.encrypt({
        userPassword: settings.encryption.userPassword || undefined,
        ownerPassword: settings.encryption.ownerPassword || undefined,
        permissions: permissions
      });
    }

    // 生成 PDF
    const pdfBytes = await pdfDoc.save();

    // 設置響應頭
    reply.header('Content-Type', 'application/pdf');
    reply.header('Content-Disposition', `attachment; filename=${settings.filename || 'figma-export.pdf'}`);

    return reply.send(Buffer.from(pdfBytes));

  } catch (error) {
    fastify.log.error(error);
    reply.code(500).send({ 
      error: 'Failed to generate PDF',
      message: error.message 
    });
  }
});

// 啟動服務器
const start = async () => {
  try {
    await fastify.listen({ port: 3000, host: '0.0.0.0' });
    console.log('Server running at http://localhost:3000');
  } catch (err) {
    fastify.log.error(err);
    process.exit(1);
  }
};

start();