#!/usr/bin/env node
/**
 * html2pptx — HTML to editable PPTX export engine
 *
 * 用法: node bin/html2pptx.js <input.html> <output.pptx>
 *
 * 流程:
 * 1. 启动本地 HTTP 服务托管 HTML
 * 2. Chrome headless 打开页面
 * 3. 遍历 DOM 提取每页元素的位置/文字/样式
 * 4. pptxgenjs 生成 PPTX 文件
 */

const { chromium } = require('playwright');
const http = require('http');
const fs = require('fs');
const path = require('path');
const PptxGenJS = require('pptxgenjs');
const { execSync } = require('child_process');

const PORT = 8192;

// ====== CLI 参数解析 ======
const args = process.argv.slice(2);
if (args.length < 2) {
  console.error('用法: node bin/html2pptx.js <input.html> <output.pptx>');
  process.exit(1);
}
const inputPath = path.resolve(args[0]);
const outputPath = path.resolve(args[1]);

if (!fs.existsSync(inputPath)) {
  console.error(`文件不存在: ${inputPath}`);
  process.exit(1);
}

async function main() {
const server = http.createServer((req, res) => {
  const filePath = path.join(path.dirname(inputPath), req.url === '/' ? path.basename(inputPath) : req.url);
  if (fs.existsSync(filePath)) {
    const ext = path.extname(filePath);
    const mime = { '.html': 'text/html', '.css': 'text/css', '.js': 'application/javascript', '.png': 'image/png', '.jpg': 'image/jpeg', '.svg': 'image/svg+xml' };
    res.writeHead(200, { 'Content-Type': mime[ext] || 'text/plain' });
    res.end(fs.readFileSync(filePath));
  } else {
    res.writeHead(404);
    res.end('Not Found');
  }
});

await new Promise(resolve => server.listen(PORT, '127.0.0.1', resolve));
console.log(`HTTP 服务已启动: http://127.0.0.1:${PORT}/`);

// ====== 2. Chrome headless 打开页面 ======
const browser = await chromium.launch({ headless: true, channel: 'chrome' });
const page = await browser.newPage({ viewport: { width: 1280, height: 720 } });

try {
  await page.goto(`http://127.0.0.1:${PORT}/`, { waitUntil: 'networkidle' });
  console.log('页面加载完成');

  // ====== 3. 提取每页的 DOM 信息 ======
  const slidesData = await page.evaluate(() => {
    // 找 slide 容器：<section> 或 [data-slide] 或直接 .slide
    let slides = document.querySelectorAll('section[data-slide], .slide, section');
    if (slides.length === 0) {
      // 如果是横向翻页，可能在一页里
      slides = [document.body];
    }

    return Array.from(slides).map(slide => {
      const rect = slide.getBoundingClientRect();
      // 隐藏不可见的 slide
      if (rect.width === 0 || rect.height === 0) return null;

      const elements = [];
      const walker = document.createTreeWalker(slide, NodeFilter.SHOW_TEXT | NodeFilter.SHOW_ELEMENT, null, false);

      let node;
      while (node = walker.nextNode()) {
        if (node.nodeType === Node.TEXT_NODE) {
          const text = node.textContent.trim();
          if (!text) continue;
          const range = document.createRange();
          range.selectNodeContents(node);
          const textRect = range.getBoundingClientRect();
          if (textRect.width === 0 || textRect.height === 0) continue;

          const parent = node.parentElement;
          const style = parent ? window.getComputedStyle(parent) : null;

          elements.push({
            type: 'text',
            text: text,
            x: textRect.left - rect.left,
            y: textRect.top - rect.top,
            width: textRect.width,
            height: textRect.height,
            fontSize: style ? parseFloat(style.fontSize) : 14,
            fontFamily: style ? style.fontFamily : 'Arial',
            color: style ? style.color : '#000000',
            fontWeight: style ? style.fontWeight : 'normal',
            textAlign: style ? style.textAlign : 'left',
            bold: style ? (parseInt(style.fontWeight) >= 700 || style.fontWeight === 'bold') : false
          });
        }
      }

      // 获取 slide 背景色
      const bg = window.getComputedStyle(slide).backgroundColor;
      const bgColor = bg && bg !== 'rgba(0, 0, 0, 0)' && bg !== 'transparent' ? bg : '#FFFFFF';

      return {
        width: rect.width,
        height: rect.height,
        bgColor: bgColor,
        elements: elements
      };
    }).filter(Boolean);
  });

  console.log(`提取到 ${slidesData.length} 页幻灯片`);

  // ====== 4. pptxgenjs 生成 PPTX ======
  const pptx = new PptxGenJS();
  pptx.defineLayout({ name: 'CUSTOM', width: 10, height: 5.625 }); // 16:9
  pptx.layout = 'CUSTOM';

  for (const slideData of slidesData) {
    const slide = pptx.addSlide();
    
    // 背景色
    slide.background = { fill: slideData.bgColor };

    // 按 y 排序，从上到下
    slideData.elements.sort((a, b) => a.y - b.y || a.x - b.x);

    for (const el of slideData.elements) {
      if (el.type === 'text' && el.text.trim()) {
        // 缩放比例：HTML 像素 → PPT 英寸
        const scaleX = 10 / slideData.width;
        const scaleY = 5.625 / slideData.height;

        const x = el.x * scaleX;
        const y = el.y * scaleY;
        const w = Math.max(el.width * scaleX, 0.5);
        const h = Math.max(el.height * scaleY, 0.3);

        // 颜色格式转换: rgb(r,g,b) → hex
        let color = el.color;
        if (color.startsWith('rgb')) {
          const m = color.match(/\d+/g);
          if (m) color = '#' + m.slice(0, 3).map(c => parseInt(c).toString(16).padStart(2, '0')).join('');
        }

        try {
          slide.addText(el.text, {
            x: x,
            y: y,
            w: w,
            h: h,
            fontSize: Math.max(el.fontSize * scaleY, 8),
            fontFace: el.fontFamily ? el.fontFamily.split(',')[0].trim().replace(/['"]/g, '') : 'Arial',
            color: color,
            bold: el.bold,
            align: el.textAlign || 'left',
            valign: 'top',
            wrap: true,
            margin: 0
          });
        } catch (e) {
          // 跳过单个元素失败
        }
      }
    }
  }

  await pptx.writeFile({ fileName: outputPath });
  console.log(`\nPPTX 已导出: ${outputPath}`);

} catch (err) {
  console.error('导出失败:', err.message);
  process.exit(1);
} finally {
  await browser.close();
  server.close();
}
main().catch(err => { console.error('导出失败:', err.message); process.exit(1); });