import express from 'express';
import { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js';
import { StreamableHTTPServerTransport } from '@modelcontextprotocol/sdk/server/streamableHttp.js';
import { z } from 'zod';
import path from 'path';
import fs from 'fs';
import { fileURLToPath } from 'url';

const __dirname = path.dirname(fileURLToPath(import.meta.url));
const PORT = parseInt(process.env.PORT || '7860');
const BASE_URL = (process.env.SPACE_URL || `http://localhost:${PORT}`).replace(/\/$/, '');
const DOWNLOADS_DIR = path.join(__dirname, 'downloads');

if (!fs.existsSync(DOWNLOADS_DIR)) fs.mkdirSync(DOWNLOADS_DIR, { recursive: true });

// ── Lazy imports ──────────────────────────────────────────────
async function getPdfLib() {
  const pdfLib = await import('pdf-lib');
  const fontkit = await import('@pdf-lib/fontkit');
  return { pdfLib, fontkit: fontkit.default };
}
async function getPdfMake() { return (await import('pdfmake')).default; }
async function getPuppeteer() { return (await import('puppeteer')).default; }
async function getPdfParse() { return (await import('pdf-parse')).default; }

function savePath(filename) {
  const safe = filename.endsWith('.pdf') ? filename : `${filename}.pdf`;
  return path.join(DOWNLOADS_DIR, safe);
}
function dlUrl(filename) {
  const safe = filename.endsWith('.pdf') ? filename : `${filename}.pdf`;
  return `${BASE_URL}/download/${safe}`;
}
async function fetchBytes(urlOrPath) {
  if (urlOrPath.startsWith('http')) {
    const fetch = (await import('node-fetch')).default;
    const r = await fetch(urlOrPath);
    return Buffer.from(await r.arrayBuffer());
  }
  return fs.readFileSync(urlOrPath);
}
function hexToRgb(hex) {
  return {
    r: parseInt(hex.slice(1,3),16)/255,
    g: parseInt(hex.slice(3,5),16)/255,
    b: parseInt(hex.slice(5,7),16)/255
  };
}
function getPdfMakeFonts() {
  const fontsDir = path.join(__dirname, 'fonts');
  if (!fs.existsSync(fontsDir)) return {};
  const n = path.join(fontsDir, 'Roboto-Regular.ttf');
  if (!fs.existsSync(n)) return {};
  return { Roboto: {
    normal: n,
    bold: path.join(fontsDir, 'Roboto-Bold.ttf'),
    italics: path.join(fontsDir, 'Roboto-Italic.ttf'),
    bolditalics: path.join(fontsDir, 'Roboto-BoldItalic.ttf'),
  }};
}

// ── Express ───────────────────────────────────────────────────
const app = express();
app.use(express.json({ limit: '50mb' }));
app.use('/download', express.static(DOWNLOADS_DIR));
app.use((req, res, next) => {
  res.setHeader('Access-Control-Allow-Origin', '*');
  res.setHeader('Access-Control-Allow-Methods', 'GET, POST, OPTIONS, DELETE');
  res.setHeader('Access-Control-Allow-Headers', 'Content-Type, Authorization, mcp-session-id');
  if (req.method === 'OPTIONS') { res.sendStatus(200); return; }
  next();
});

app.get('/', (req, res) => res.json({ name: 'PDF MCP Server', tools: 40, mcp: `${BASE_URL}/mcp` }));
app.get('/files', (req, res) => {
  const files = fs.readdirSync(DOWNLOADS_DIR).map(f => ({
    name: f, url: `${BASE_URL}/download/${f}`,
    size: `${(fs.statSync(path.join(DOWNLOADS_DIR,f)).size/1024).toFixed(1)}KB`
  }));
  res.json({ count: files.length, files });
});

// ── MCP ───────────────────────────────────────────────────────
app.all('/mcp', async (req, res) => {
  console.log(`[MCP] ${req.method}`);
  const server = new McpServer({ name: 'pdf-mcp-server', version: '1.0.0' });

  // ═══════════════════════════════════════════════
  // GROUP 1: pdfmake — Creation + Tables (10 tools)
  // ═══════════════════════════════════════════════

  server.tool('create_pdf',
    'নতুন PDF তৈরি করে। title, content array (text/heading/list blocks), pageSize, pageOrientation দিয়ে সম্পূর্ণ PDF বানায়। Download link return করে।',
    { filename: z.string(), title: z.string().optional(), content: z.array(z.object({ type: z.string(), value: z.any(), style: z.any().optional() })), pageSize: z.string().optional(), pageOrientation: z.string().optional() },
    async ({ filename, title, content, pageSize, pageOrientation }) => {
      const PdfPrinter = await getPdfMake();
      const fonts = getPdfMakeFonts();
      const printer = new PdfPrinter(fonts);
      const blocks = (content||[]).map(b => {
        if (b.type==='heading') return { text: b.value, fontSize:16, bold:true, margin:[0,10,0,5] };
        if (b.type==='list') return { ul: Array.isArray(b.value)?b.value:[b.value], margin:[0,4,0,4] };
        return { text: b.value||b, margin:[0,2,0,2] };
      });
      const docDef = {
        pageSize: pageSize||'A4', pageOrientation: pageOrientation||'portrait',
        content: [
          title ? { text:title, fontSize:20, bold:true, alignment:'center', margin:[0,0,0,20] } : null,
          ...blocks
        ].filter(Boolean)
      };
      const out = savePath(filename);
      await new Promise((res2,rej) => {
        const doc = printer.createPdfKitDocument(docDef);
        const st = fs.createWriteStream(out);
        doc.pipe(st); doc.end();
        st.on('finish', res2); st.on('error', rej);
      });
      return { content: [{ type:'text', text:`✅ PDF তৈরি!\n🔗 ${dlUrl(filename)}` }] };
    }
  );

  server.tool('create_pdf_with_table',
    'Complex table সহ PDF তৈরি করে। headers, rows, colspan, colors সহ পূর্ণ table support। Invoice, report, schedule সব কাজে ব্যবহারযোগ্য।',
    { filename: z.string(), title: z.string().optional(), tables: z.array(z.object({ headers: z.array(z.string()), rows: z.array(z.array(z.any())), widths: z.array(z.string()).optional(), headerColor: z.string().optional() })), headerText: z.string().optional(), footerText: z.string().optional() },
    async ({ filename, title, tables, headerText, footerText }) => {
      const PdfPrinter = await getPdfMake();
      const printer = new PdfPrinter(getPdfMakeFonts());
      const tblBlocks = (tables||[]).map(t => ({
        table: {
          headerRows:1,
          widths: t.widths||t.headers.map(()=>'*'),
          body: [
            t.headers.map(h=>({ text:h, bold:true, fillColor:t.headerColor||'#4472C4', color:'#FFF', alignment:'center', margin:[4,6,4,6] })),
            ...t.rows.map((row,ri)=>row.map(cell=>({ text:String(cell), fillColor:ri%2===0?'#F2F2F2':'#FFF', margin:[4,4,4,4] })))
          ]
        }, layout:'lightHorizontalLines', margin:[0,10,0,10]
      }));
      const docDef = {
        pageSize:'A4', defaultStyle:{ fontSize:10 },
        content: [
          title ? { text:title, fontSize:18, bold:true, alignment:'center', margin:[0,0,0,10] } : null,
          headerText ? { text:headerText, margin:[0,0,0,10] } : null,
          ...tblBlocks,
          footerText ? { text:footerText, margin:[0,10,0,0] } : null,
        ].filter(Boolean)
      };
      const out = savePath(filename);
      await new Promise((res2,rej) => {
        const doc = printer.createPdfKitDocument(docDef);
        const st = fs.createWriteStream(out);
        doc.pipe(st); doc.end();
        st.on('finish',res2); st.on('error',rej);
      });
      return { content: [{ type:'text', text:`✅ Table PDF তৈরি!\n🔗 ${dlUrl(filename)}` }] };
    }
  );

  server.tool('create_invoice',
    'Professional invoice/bill PDF তৈরি করে। company, client info, items (quantity×price), tax, total সহ। BDT currency support।',
    { filename:z.string(), invoiceNumber:z.string().optional(), date:z.string().optional(), company:z.object({ name:z.string(), address:z.string().optional(), phone:z.string().optional(), email:z.string().optional() }), client:z.object({ name:z.string(), address:z.string().optional(), phone:z.string().optional() }), items:z.array(z.object({ description:z.string(), quantity:z.number(), unitPrice:z.number() })), taxRate:z.number().optional(), currency:z.string().optional(), notes:z.string().optional() },
    async ({ filename, invoiceNumber, date, company, client, items, taxRate=0, currency='BDT ৳', notes }) => {
      const PdfPrinter = await getPdfMake();
      const printer = new PdfPrinter(getPdfMakeFonts());
      const subtotal = items.reduce((s,i)=>s+i.quantity*i.unitPrice,0);
      const tax = subtotal*taxRate/100;
      const total = subtotal+tax;
      const docDef = {
        pageSize:'A4', defaultStyle:{fontSize:10},
        content:[
          { columns:[ { text:company.name, fontSize:22, bold:true, color:'#2C3E50' }, { text:`INVOICE\n#${invoiceNumber||'INV-001'}`, alignment:'right', fontSize:16, bold:true, color:'#E74C3C' } ] },
          { text:company.address||'', color:'#666', margin:[0,4,0,0] },
          { text:`${company.phone||''} | ${company.email||''}`, color:'#666', margin:[0,2,0,20] },
          { columns:[ [{ text:'BILL TO:', bold:true, margin:[0,10,0,5] }, { text:client.name, bold:true }, { text:client.address||'' }, { text:client.phone||'' }], [{ text:`Date: ${date||new Date().toLocaleDateString()}`, alignment:'right', margin:[0,10,0,5] }] ] },
          { margin:[0,20,0,0], table:{ headerRows:1, widths:['*','auto','auto','auto'], body:[
            [{ text:'Description', bold:true, fillColor:'#2C3E50', color:'#FFF', margin:[4,6,4,6] },{ text:'Qty', bold:true, fillColor:'#2C3E50', color:'#FFF', margin:[4,6,4,6] },{ text:'Unit Price', bold:true, fillColor:'#2C3E50', color:'#FFF', margin:[4,6,4,6] },{ text:'Amount', bold:true, fillColor:'#2C3E50', color:'#FFF', margin:[4,6,4,6] }],
            ...items.map((item,i)=>[ { text:item.description, fillColor:i%2===0?'#F8F9FA':'white', margin:[4,4,4,4] }, { text:String(item.quantity), alignment:'center', fillColor:i%2===0?'#F8F9FA':'white', margin:[4,4,4,4] }, { text:`${currency} ${item.unitPrice.toFixed(2)}`, alignment:'right', fillColor:i%2===0?'#F8F9FA':'white', margin:[4,4,4,4] }, { text:`${currency} ${(item.quantity*item.unitPrice).toFixed(2)}`, alignment:'right', fillColor:i%2===0?'#F8F9FA':'white', margin:[4,4,4,4] } ])
          ] }, layout:'lightHorizontalLines' },
          { columns:[ {text:''}, { width:200, table:{ widths:['*','auto'], body:[ [{ text:'Subtotal:', bold:true },{ text:`${currency} ${subtotal.toFixed(2)}`, alignment:'right' }], taxRate>0?[{ text:`Tax (${taxRate}%):`, bold:true },{ text:`${currency} ${tax.toFixed(2)}`, alignment:'right' }]:null, [{ text:'TOTAL:', bold:true, fontSize:14, color:'#E74C3C' },{ text:`${currency} ${total.toFixed(2)}`, bold:true, fontSize:14, color:'#E74C3C', alignment:'right' }] ].filter(Boolean) }, layout:'noBorders', margin:[0,20,0,0] } ] },
          notes ? { text:`Notes: ${notes}`, color:'#666', margin:[0,20,0,0], italics:true } : null,
        ].filter(Boolean)
      };
      const out = savePath(filename);
      await new Promise((res2,rej) => { const doc = printer.createPdfKitDocument(docDef); const st=fs.createWriteStream(out); doc.pipe(st); doc.end(); st.on('finish',res2); st.on('error',rej); });
      return { content:[{ type:'text', text:`✅ Invoice তৈরি!\n💰 Total: ${currency} ${total.toFixed(2)}\n🔗 ${dlUrl(filename)}` }] };
    }
  );

  server.tool('create_report',
    'বিস্তারিত report PDF তৈরি করে। Cover page, sections with headings, data tables, page numbers সহ professional format।',
    { filename:z.string(), title:z.string(), subtitle:z.string().optional(), author:z.string().optional(), date:z.string().optional(), sections:z.array(z.object({ heading:z.string(), body:z.string() })), includePageNumbers:z.boolean().optional() },
    async ({ filename, title, subtitle, author, date, sections }) => {
      const PdfPrinter = await getPdfMake();
      const printer = new PdfPrinter(getPdfMakeFonts());
      const content = [
        { text:title, fontSize:24, bold:true, alignment:'center', margin:[0,50,0,10] },
        subtitle ? { text:subtitle, fontSize:14, alignment:'center', color:'#666', margin:[0,0,0,5] } : null,
        author ? { text:`By: ${author}`, alignment:'center', color:'#666', margin:[0,0,0,5] } : null,
        { text:date||new Date().toLocaleDateString(), alignment:'center', color:'#666', margin:[0,0,0,30] },
        { text:'', pageBreak:'after' },
        ...(sections||[]).flatMap(s => [
          { text:s.heading, fontSize:14, bold:true, margin:[0,15,0,5], color:'#2C3E50' },
          { text:s.body, margin:[0,0,0,10] }
        ])
      ].filter(Boolean);
      const docDef = { pageSize:'A4', content, defaultStyle:{ fontSize:11 }, footer:(pg,total) => ({ text:`Page ${pg} of ${total}`, alignment:'center', fontSize:9, color:'#999', margin:[0,10,0,0] }) };
      const out = savePath(filename);
      await new Promise((res2,rej) => { const doc=printer.createPdfKitDocument(docDef); const st=fs.createWriteStream(out); doc.pipe(st); doc.end(); st.on('finish',res2); st.on('error',rej); });
      return { content:[{ type:'text', text:`✅ Report তৈরি! (${sections.length} sections)\n🔗 ${dlUrl(filename)}` }] };
    }
  );

  server.tool('create_certificate',
    'সুন্দর certificate PDF তৈরি করে। Decorative border, recipient name, achievement, issuer signature সহ।',
    { filename:z.string(), recipientName:z.string(), title:z.string().optional(), description:z.string().optional(), issuerName:z.string(), issuerTitle:z.string().optional(), date:z.string().optional(), certificateId:z.string().optional() },
    async ({ filename, recipientName, title, description, issuerName, issuerTitle, date, certificateId }) => {
      const PdfPrinter = await getPdfMake();
      const printer = new PdfPrinter(getPdfMakeFonts());
      const docDef = {
        pageSize:'A4', pageOrientation:'landscape',
        content:[
          { text:title||'Certificate of Achievement', fontSize:28, bold:true, alignment:'center', color:'#2C3E50', margin:[0,60,0,20] },
          { text:'This is to certify that', fontSize:14, alignment:'center', color:'#555', margin:[0,0,0,10] },
          { text:recipientName, fontSize:34, bold:true, alignment:'center', color:'#C9A227', margin:[0,5,0,10] },
          { text:description||'has successfully completed the requirements', fontSize:12, alignment:'center', margin:[0,10,0,40] },
          { columns:[ { text:`${issuerName}\n${issuerTitle||''}`, alignment:'center', bold:true }, { text:date||new Date().toLocaleDateString(), alignment:'center' } ] },
          certificateId ? { text:`Certificate ID: ${certificateId}`, fontSize:8, color:'#999', alignment:'center', margin:[0,20,0,0] } : null,
        ].filter(Boolean)
      };
      const out = savePath(filename);
      await new Promise((res2,rej) => { const doc=printer.createPdfKitDocument(docDef); const st=fs.createWriteStream(out); doc.pipe(st); doc.end(); st.on('finish',res2); st.on('error',rej); });
      return { content:[{ type:'text', text:`✅ Certificate তৈরি! Recipient: ${recipientName}\n🔗 ${dlUrl(filename)}` }] };
    }
  );

  server.tool('create_resume',
    'Professional CV/Resume PDF তৈরি করে। Contact info, summary, experience, education, skills sections সহ ATS-friendly format।',
    { filename:z.string(), personalInfo:z.object({ name:z.string(), email:z.string().optional(), phone:z.string().optional(), address:z.string().optional(), linkedin:z.string().optional(), github:z.string().optional() }), summary:z.string().optional(), experience:z.array(z.object({ company:z.string(), position:z.string(), duration:z.string(), description:z.string().optional() })).optional(), education:z.array(z.object({ institution:z.string(), degree:z.string(), year:z.string() })).optional(), skills:z.array(z.object({ category:z.string(), items:z.array(z.string()) })).optional() },
    async ({ filename, personalInfo, summary, experience, education, skills }) => {
      const PdfPrinter = await getPdfMake();
      const printer = new PdfPrinter(getPdfMakeFonts());
      const p = personalInfo;
      const content = [
        { text:p.name, fontSize:24, bold:true, alignment:'center' },
        { text:[p.email,p.phone,p.address].filter(Boolean).join(' | '), alignment:'center', color:'#555', margin:[0,4,0,15] },
        summary ? [{ text:'SUMMARY', fontSize:12, bold:true, margin:[0,8,0,4], decoration:'underline' }, { text:summary, margin:[0,0,0,10] }] : null,
        (experience||[]).length>0 ? { text:'EXPERIENCE', fontSize:12, bold:true, margin:[0,8,0,4], decoration:'underline' } : null,
        ...(experience||[]).map(e=>[
          { columns:[{ text:e.position, bold:true },{ text:e.duration, alignment:'right', color:'#555' }] },
          { text:e.company, color:'#2980B9' },
          e.description ? { text:e.description, margin:[0,4,0,8] } : null
        ]).flat().filter(Boolean),
        (education||[]).length>0 ? { text:'EDUCATION', fontSize:12, bold:true, margin:[0,8,0,4], decoration:'underline' } : null,
        ...(education||[]).map(e=>[ { text:e.degree, bold:true }, { text:`${e.institution} — ${e.year}`, color:'#555', margin:[0,2,0,8] } ]).flat(),
        (skills||[]).length>0 ? { text:'SKILLS', fontSize:12, bold:true, margin:[0,8,0,4], decoration:'underline' } : null,
        ...(skills||[]).map(s=>({ text:`${s.category}: ${s.items.join(', ')}`, margin:[0,2,0,4] })),
      ].flat().filter(Boolean);
      const docDef = { pageSize:'A4', content, defaultStyle:{ fontSize:11 } };
      const out = savePath(filename);
      await new Promise((res2,rej) => { const doc=printer.createPdfKitDocument(docDef); const st=fs.createWriteStream(out); doc.pipe(st); doc.end(); st.on('finish',res2); st.on('error',rej); });
      return { content:[{ type:'text', text:`✅ Resume তৈরি! ${p.name}\n🔗 ${dlUrl(filename)}` }] };
    }
  );

  server.tool('create_letter',
    'Formal letter/application PDF তৈরি করে। Sender, recipient, subject, body, closing সহ official letterhead format।',
    { filename:z.string(), senderName:z.string(), senderAddress:z.string().optional(), recipientName:z.string(), recipientOrg:z.string().optional(), recipientAddress:z.string().optional(), date:z.string().optional(), subject:z.string(), body:z.string(), closing:z.string().optional() },
    async ({ filename, senderName, senderAddress, recipientName, recipientOrg, recipientAddress, date, subject, body, closing='Sincerely' }) => {
      const PdfPrinter = await getPdfMake();
      const printer = new PdfPrinter(getPdfMakeFonts());
      const docDef = {
        pageSize:'A4',
        content:[
          { text:senderName, bold:true, fontSize:14 },
          senderAddress ? { text:senderAddress, color:'#555' } : null,
          { text:date||new Date().toLocaleDateString(), margin:[0,10,0,15] },
          { text:recipientName, bold:true },
          recipientOrg ? { text:recipientOrg } : null,
          recipientAddress ? { text:recipientAddress, margin:[0,0,0,15] } : null,
          { text:`Subject: ${subject}`, bold:true, margin:[0,10,0,15] },
          { text:'Dear '+recipientName+',', margin:[0,0,0,10] },
          ...body.split('\n').map(p=>({ text:p, margin:[0,0,0,8] })),
          { text:closing+',', margin:[0,20,0,5] },
          { text:senderName, bold:true },
        ].filter(Boolean),
        defaultStyle:{ fontSize:11 }
      };
      const out = savePath(filename);
      await new Promise((res2,rej) => { const doc=printer.createPdfKitDocument(docDef); const st=fs.createWriteStream(out); doc.pipe(st); doc.end(); st.on('finish',res2); st.on('error',rej); });
      return { content:[{ type:'text', text:`✅ Letter তৈরি!\n🔗 ${dlUrl(filename)}` }] };
    }
  );

  server.tool('create_booklet',
    'Multi-section booklet/brochure PDF তৈরি করে। Cover page, chapters, page numbers সহ। Manual, catalog, magazine format।',
    { filename:z.string(), title:z.string(), subtitle:z.string().optional(), chapters:z.array(z.object({ title:z.string(), content:z.string() })), pageSize:z.string().optional() },
    async ({ filename, title, subtitle, chapters, pageSize }) => {
      const PdfPrinter = await getPdfMake();
      const printer = new PdfPrinter(getPdfMakeFonts());
      const content = [
        { text:title, fontSize:28, bold:true, alignment:'center', margin:[0,80,0,10] },
        subtitle ? { text:subtitle, fontSize:14, alignment:'center', color:'#666' } : null,
        { text:'', pageBreak:'after' },
        ...(chapters||[]).flatMap((c,i)=>[
          { text:`${i+1}. ${c.title}`, fontSize:16, bold:true, margin:[0,20,0,10], color:'#2C3E50', pageBreak:i>0?'before':undefined },
          { text:c.content, margin:[0,0,0,10] }
        ])
      ].filter(Boolean);
      const docDef = { pageSize:pageSize||'A4', content, defaultStyle:{ fontSize:11 }, footer:(pg,total)=>({ text:`${pg} / ${total}`, alignment:'center', fontSize:9, color:'#999' }) };
      const out = savePath(filename);
      await new Promise((res2,rej) => { const doc=printer.createPdfKitDocument(docDef); const st=fs.createWriteStream(out); doc.pipe(st); doc.end(); st.on('finish',res2); st.on('error',rej); });
      return { content:[{ type:'text', text:`✅ Booklet তৈরি! (${chapters.length} chapters)\n🔗 ${dlUrl(filename)}` }] };
    }
  );

  server.tool('html_to_pdf',
    'HTML string থেকে pixel-perfect PDF তৈরি করে। CSS styling, custom fonts সহ। Complex dashboard, styled reports সব কাজে।',
    { filename:z.string(), html:z.string(), pageSize:z.string().optional(), orientation:z.string().optional(), printBackground:z.boolean().optional() },
    async ({ filename, html, pageSize, orientation, printBackground }) => {
      const puppeteer = await getPuppeteer();
      const browser = await puppeteer.launch({ args:['--no-sandbox','--disable-setuid-sandbox'] });
      const page = await browser.newPage();
      await page.setContent(html, { waitUntil:'networkidle0' });
      const out = savePath(filename);
      await page.pdf({ path:out, format:pageSize||'A4', landscape:orientation==='landscape', printBackground:printBackground!==false, margin:{top:'20px',bottom:'20px',left:'20px',right:'20px'} });
      await browser.close();
      return { content:[{ type:'text', text:`✅ HTML → PDF!\n🔗 ${dlUrl(filename)}` }] };
    }
  );

  server.tool('markdown_to_pdf',
    'Markdown text থেকে styled PDF তৈরি করে। Headings, bold, italic, lists, code blocks, tables সব support করে।',
    { filename:z.string(), markdown:z.string(), pageSize:z.string().optional() },
    async ({ filename, markdown, pageSize }) => {
      const puppeteer = await getPuppeteer();
      let html = markdown
        .replace(/^### (.+)$/gm,'<h3>$1</h3>')
        .replace(/^## (.+)$/gm,'<h2>$1</h2>')
        .replace(/^# (.+)$/gm,'<h1>$1</h1>')
        .replace(/\*\*(.+?)\*\*/g,'<strong>$1</strong>')
        .replace(/\*(.+?)\*/g,'<em>$1</em>')
        .replace(/`(.+?)`/g,'<code>$1</code>')
        .replace(/^\- (.+)$/gm,'<li>$1</li>')
        .replace(/\n\n/g,'</p><p>');
      const fullHtml = `<html><head><style>body{font-family:Arial,sans-serif;max-width:800px;margin:40px auto;line-height:1.6;}h1,h2,h3{color:#2C3E50;}code{background:#f4f4f4;padding:2px 6px;border-radius:3px;}li{margin:4px 0;}</style></head><body><p>${html}</p></body></html>`;
      const browser = await puppeteer.launch({ args:['--no-sandbox','--disable-setuid-sandbox'] });
      const page = await browser.newPage();
      await page.setContent(fullHtml,{waitUntil:'networkidle0'});
      const out = savePath(filename);
      await page.pdf({ path:out, format:pageSize||'A4', printBackground:true, margin:{top:'30px',bottom:'30px',left:'40px',right:'40px'} });
      await browser.close();
      return { content:[{ type:'text', text:`✅ Markdown → PDF!\n🔗 ${dlUrl(filename)}` }] };
    }
  );

  // ════════════════════════════════════════════════
  // GROUP 2: pdf-lib — Edit + Merge + Security (15)
  // ════════════════════════════════════════════════

  server.tool('merge_pdfs',
    'একাধিক PDF ফাইল একটিতে merge করে। URL বা path থেকে PDF নিয়ে order অনুযায়ী combine করে।',
    { filename:z.string(), pdfUrls:z.array(z.string()) },
    async ({ filename, pdfUrls }) => {
      const { pdfLib } = await getPdfLib();
      const merged = await pdfLib.PDFDocument.create();
      for (const url of pdfUrls) {
        const bytes = await fetchBytes(url);
        const doc = await pdfLib.PDFDocument.load(bytes);
        const pages = await merged.copyPages(doc, doc.getPageIndices());
        pages.forEach(p => merged.addPage(p));
      }
      const bytes = await merged.save();
      fs.writeFileSync(savePath(filename), bytes);
      return { content:[{ type:'text', text:`✅ ${pdfUrls.length}টি PDF merge হয়েছে!\n🔗 ${dlUrl(filename)}` }] };
    }
  );

  server.tool('split_pdf',
    'PDF থেকে নির্দিষ্ট page ranges আলাদা করে। ranges না দিলে প্রতিটি page আলাদা PDF হয়।',
    { pdfUrl:z.string(), outputPrefix:z.string(), ranges:z.array(z.object({ start:z.number(), end:z.number(), name:z.string().optional() })).optional() },
    async ({ pdfUrl, outputPrefix, ranges }) => {
      const { pdfLib } = await getPdfLib();
      const src = await pdfLib.PDFDocument.load(await fetchBytes(pdfUrl));
      const total = src.getPageCount();
      const results = [];
      const rng = ranges||[];
      if (rng.length===0) {
        for (let i=0;i<total;i++) {
          const d = await pdfLib.PDFDocument.create();
          const [p] = await d.copyPages(src,[i]);
          d.addPage(p);
          const fname = `${outputPrefix}_page${i+1}`;
          fs.writeFileSync(savePath(fname), await d.save());
          results.push(dlUrl(fname));
        }
      } else {
        for (const r of rng) {
          const d = await pdfLib.PDFDocument.create();
          const idx = [];
          for (let i=(r.start||1)-1;i<Math.min(r.end||total,total);i++) idx.push(i);
          const pages = await d.copyPages(src,idx);
          pages.forEach(p=>d.addPage(p));
          const fname = r.name||`${outputPrefix}_${r.start}-${r.end}`;
          fs.writeFileSync(savePath(fname), await d.save());
          results.push(dlUrl(fname));
        }
      }
      return { content:[{ type:'text', text:`✅ ${results.length}টি ফাইল তৈরি:\n${results.map((r,i)=>`${i+1}. ${r}`).join('\n')}` }] };
    }
  );

  server.tool('extract_pages',
    'PDF থেকে নির্দিষ্ট page নম্বর গুলো বের করে নতুন PDF তৈরি করে।',
    { pdfUrl:z.string(), filename:z.string(), pages:z.array(z.number()) },
    async ({ pdfUrl, filename, pages }) => {
      const { pdfLib } = await getPdfLib();
      const src = await pdfLib.PDFDocument.load(await fetchBytes(pdfUrl));
      const d = await pdfLib.PDFDocument.create();
      const ps = await d.copyPages(src, pages.map(p=>p-1));
      ps.forEach(p=>d.addPage(p));
      fs.writeFileSync(savePath(filename), await d.save());
      return { content:[{ type:'text', text:`✅ ${pages.length}টি page extract হয়েছে!\n🔗 ${dlUrl(filename)}` }] };
    }
  );

  server.tool('rotate_pages',
    'PDF-এর page rotate করে। 90, 180, 270 degree। সব page বা নির্দিষ্ট page।',
    { pdfUrl:z.string(), filename:z.string(), rotation:z.number(), pages:z.array(z.number()).optional() },
    async ({ pdfUrl, filename, rotation, pages }) => {
      const { pdfLib } = await getPdfLib();
      const doc = await pdfLib.PDFDocument.load(await fetchBytes(pdfUrl));
      const idx = pages?.length>0 ? pages.map(p=>p-1) : doc.getPageIndices();
      idx.forEach(i => doc.getPage(i).setRotation(pdfLib.degrees(rotation)));
      fs.writeFileSync(savePath(filename), await doc.save());
      return { content:[{ type:'text', text:`✅ ${idx.length}টি page ${rotation}° rotate হয়েছে!\n🔗 ${dlUrl(filename)}` }] };
    }
  );

  server.tool('add_watermark',
    'PDF-এর প্রতিটি page-এ text watermark যোগ করে। Opacity, color, rotation, font size customize করা যায়।',
    { pdfUrl:z.string(), filename:z.string(), text:z.string(), opacity:z.number().optional(), fontSize:z.number().optional(), color:z.string().optional(), rotation:z.number().optional() },
    async ({ pdfUrl, filename, text, opacity=0.3, fontSize=48, color='#FF0000', rotation=-45 }) => {
      const { pdfLib } = await getPdfLib();
      const doc = await pdfLib.PDFDocument.load(await fetchBytes(pdfUrl));
      const font = await doc.embedFont(pdfLib.StandardFonts.HelveticaBold);
      const c = hexToRgb(color);
      for (const page of doc.getPages()) {
        const { width, height } = page.getSize();
        page.drawText(text, { x:width/4, y:height/2, size:fontSize, font, color:pdfLib.rgb(c.r,c.g,c.b), opacity, rotate:pdfLib.degrees(rotation) });
      }
      fs.writeFileSync(savePath(filename), await doc.save());
      return { content:[{ type:'text', text:`✅ Watermark "${text}" যোগ হয়েছে!\n🔗 ${dlUrl(filename)}` }] };
    }
  );

  server.tool('add_text_overlay',
    'Existing PDF-এর নির্দিষ্ট position-এ text যোগ করে। Page, x, y, font size, color সব customize করা যায়।',
    { pdfUrl:z.string(), filename:z.string(), overlays:z.array(z.object({ page:z.number().optional(), text:z.string(), x:z.number(), y:z.number(), size:z.number().optional(), color:z.string().optional() })) },
    async ({ pdfUrl, filename, overlays }) => {
      const { pdfLib } = await getPdfLib();
      const doc = await pdfLib.PDFDocument.load(await fetchBytes(pdfUrl));
      const font = await doc.embedFont(pdfLib.StandardFonts.Helvetica);
      for (const o of overlays) {
        const c = hexToRgb(o.color||'#000000');
        doc.getPage((o.page||1)-1).drawText(o.text, { x:o.x, y:o.y, size:o.size||12, font, color:pdfLib.rgb(c.r,c.g,c.b) });
      }
      fs.writeFileSync(savePath(filename), await doc.save());
      return { content:[{ type:'text', text:`✅ Text overlay যোগ হয়েছে!\n🔗 ${dlUrl(filename)}` }] };
    }
  );

  server.tool('fill_pdf_form',
    'Existing PDF form-এর fields fill করে। Text fields, checkboxes, radio buttons, dropdowns সব fill করা যায়।',
    { pdfUrl:z.string(), filename:z.string(), fields:z.record(z.any()), flatten:z.boolean().optional() },
    async ({ pdfUrl, filename, fields, flatten }) => {
      const { pdfLib } = await getPdfLib();
      const doc = await pdfLib.PDFDocument.load(await fetchBytes(pdfUrl));
      const form = doc.getForm();
      for (const [name, value] of Object.entries(fields)) {
        try {
          const field = form.getField(name);
          const t = field.constructor.name;
          if (t.includes('Text')) field.setText(String(value));
          else if (t.includes('CheckBox')) value ? field.check() : field.uncheck();
          else if (t.includes('Dropdown')) field.select(String(value));
          else if (t.includes('RadioGroup')) field.select(String(value));
        } catch {}
      }
      if (flatten) form.flatten();
      fs.writeFileSync(savePath(filename), await doc.save());
      return { content:[{ type:'text', text:`✅ Form fill হয়েছে! ${Object.keys(fields).length}টি field\n🔗 ${dlUrl(filename)}` }] };
    }
  );

  server.tool('encrypt_pdf',
    'PDF-এ password protection দেয়। User password ও owner password আলাদা। Print/copy/edit permission control।',
    { pdfUrl:z.string(), filename:z.string(), userPassword:z.string(), ownerPassword:z.string().optional() },
    async ({ pdfUrl, filename, userPassword, ownerPassword }) => {
      const { pdfLib } = await getPdfLib();
      const doc = await pdfLib.PDFDocument.load(await fetchBytes(pdfUrl));
      const bytes = await doc.save({ userPassword, ownerPassword:ownerPassword||userPassword+'_owner', permissions:{ printing:'none', modifying:false, copying:false, annotating:false } });
      fs.writeFileSync(savePath(filename), bytes);
      return { content:[{ type:'text', text:`✅ PDF encrypt হয়েছে! Password protected.\n🔗 ${dlUrl(filename)}` }] };
    }
  );

  server.tool('decrypt_pdf',
    'Password-protected PDF থেকে password remove করে। Owner password দিলে protection সরে যাবে।',
    { pdfUrl:z.string(), filename:z.string(), password:z.string() },
    async ({ pdfUrl, filename, password }) => {
      const { pdfLib } = await getPdfLib();
      const doc = await pdfLib.PDFDocument.load(await fetchBytes(pdfUrl), { password });
      fs.writeFileSync(savePath(filename), await doc.save());
      return { content:[{ type:'text', text:`✅ PDF decrypt হয়েছে!\n🔗 ${dlUrl(filename)}` }] };
    }
  );

  server.tool('add_page_numbers',
    'PDF-এর প্রতিটি page-এ page number যোগ করে। Position, format, font size, color customize করা যায়।',
    { pdfUrl:z.string(), filename:z.string(), position:z.string().optional(), format:z.string().optional(), startNumber:z.number().optional(), fontSize:z.number().optional(), skipFirstPage:z.boolean().optional() },
    async ({ pdfUrl, filename, position='bottom-center', format='simple', startNumber=1, fontSize=10, skipFirstPage }) => {
      const { pdfLib } = await getPdfLib();
      const doc = await pdfLib.PDFDocument.load(await fetchBytes(pdfUrl));
      const font = await doc.embedFont(pdfLib.StandardFonts.Helvetica);
      const total = doc.getPageCount();
      doc.getPages().forEach((page,i) => {
        if (skipFirstPage && i===0) return;
        const { width, height } = page.getSize();
        const num = i+startNumber;
        const text = format==='full' ? `Page ${num} of ${total}` : String(num);
        let x=width/2-10, y=20;
        if (position.includes('top')) y=height-20;
        if (position.includes('left')) x=30;
        if (position.includes('right')) x=width-40;
        page.drawText(text, { x, y, size:fontSize, font, color:pdfLib.rgb(0,0,0) });
      });
      fs.writeFileSync(savePath(filename), await doc.save());
      return { content:[{ type:'text', text:`✅ Page numbers যোগ হয়েছে!\n🔗 ${dlUrl(filename)}` }] };
    }
  );

  server.tool('add_header_footer',
    'PDF-এর প্রতিটি page-এ header ও footer যোগ করে। Left, center, right তিনটি column support।',
    { pdfUrl:z.string(), filename:z.string(), header:z.object({ left:z.string().optional(), center:z.string().optional(), right:z.string().optional() }).optional(), footer:z.object({ left:z.string().optional(), center:z.string().optional(), right:z.string().optional() }).optional() },
    async ({ pdfUrl, filename, header, footer }) => {
      const { pdfLib } = await getPdfLib();
      const doc = await pdfLib.PDFDocument.load(await fetchBytes(pdfUrl));
      const font = await doc.embedFont(pdfLib.StandardFonts.Helvetica);
      const gray = pdfLib.rgb(0.4,0.4,0.4);
      for (const page of doc.getPages()) {
        const { width, height } = page.getSize();
        const draw = (section, y) => {
          if (!section) return;
          if (section.left) page.drawText(section.left, { x:30, y, size:9, font, color:gray });
          if (section.center) page.drawText(section.center, { x:width/2-50, y, size:9, font, color:gray });
          if (section.right) page.drawText(section.right, { x:width-100, y, size:9, font, color:gray });
        };
        draw(header, height-20);
        draw(footer, 10);
      }
      fs.writeFileSync(savePath(filename), await doc.save());
      return { content:[{ type:'text', text:`✅ Header/Footer যোগ হয়েছে!\n🔗 ${dlUrl(filename)}` }] };
    }
  );

  server.tool('compress_pdf',
    'PDF file size কমায়। Object streams optimize করে file ছোট করে। Email বা upload-এর জন্য।',
    { pdfUrl:z.string(), filename:z.string() },
    async ({ pdfUrl, filename }) => {
      const { pdfLib } = await getPdfLib();
      const bytes = await fetchBytes(pdfUrl);
      const doc = await pdfLib.PDFDocument.load(bytes);
      const newBytes = await doc.save({ useObjectStreams:true });
      fs.writeFileSync(savePath(filename), newBytes);
      const reduction = (((bytes.length-newBytes.length)/bytes.length)*100).toFixed(1);
      return { content:[{ type:'text', text:`✅ Compressed!\n📦 ${(bytes.length/1024).toFixed(1)}KB → ${(newBytes.length/1024).toFixed(1)}KB (${reduction}% reduction)\n🔗 ${dlUrl(filename)}` }] };
    }
  );

  server.tool('set_pdf_metadata',
    'PDF-এর metadata update করে। Title, author, subject, keywords, creator সব modify করা যায়।',
    { pdfUrl:z.string(), filename:z.string(), title:z.string().optional(), author:z.string().optional(), subject:z.string().optional(), keywords:z.string().optional(), creator:z.string().optional() },
    async ({ pdfUrl, filename, title, author, subject, keywords, creator }) => {
      const { pdfLib } = await getPdfLib();
      const doc = await pdfLib.PDFDocument.load(await fetchBytes(pdfUrl));
      if (title) doc.setTitle(title);
      if (author) doc.setAuthor(author);
      if (subject) doc.setSubject(subject);
      if (keywords) doc.setKeywords(keywords.split(',').map(k=>k.trim()));
      if (creator) doc.setCreator(creator);
      fs.writeFileSync(savePath(filename), await doc.save());
      return { content:[{ type:'text', text:`✅ Metadata update হয়েছে!\n🔗 ${dlUrl(filename)}` }] };
    }
  );

  server.tool('add_digital_signature',
    'PDF-এ visible digital signature box যোগ করে। Signer name, designation, organization, date সহ।',
    { pdfUrl:z.string(), filename:z.string(), signerName:z.string(), designation:z.string().optional(), organization:z.string().optional(), date:z.string().optional(), page:z.number().optional() },
    async ({ pdfUrl, filename, signerName, designation, organization, date, page=1 }) => {
      const { pdfLib } = await getPdfLib();
      const doc = await pdfLib.PDFDocument.load(await fetchBytes(pdfUrl));
      const font = await doc.embedFont(pdfLib.StandardFonts.HelveticaBold);
      const pg = doc.getPage(page-1);
      const { height } = pg.getSize();
      pg.drawRectangle({ x:50, y:50, width:200, height:70, borderColor:pdfLib.rgb(0,0,0), borderWidth:1 });
      pg.drawText(signerName, { x:55, y:95, size:12, font, color:pdfLib.rgb(0,0,0) });
      if (designation) pg.drawText(designation, { x:55, y:80, size:9, font });
      if (organization) pg.drawText(organization, { x:55, y:67, size:9, font });
      pg.drawText(date||new Date().toLocaleDateString(), { x:55, y:55, size:8, font });
      fs.writeFileSync(savePath(filename), await doc.save());
      return { content:[{ type:'text', text:`✅ Signature যোগ হয়েছে! Signed by: ${signerName}\n🔗 ${dlUrl(filename)}` }] };
    }
  );

  // ════════════════════════════════════════════
  // GROUP 3: puppeteer (3 more tools)
  // ════════════════════════════════════════════

  server.tool('url_to_pdf',
    'যেকোনো website URL থেকে PDF তৈরি করে। Live webpage ভিজিট করে PDF বানায়।',
    { filename:z.string(), url:z.string(), pageSize:z.string().optional(), orientation:z.string().optional(), waitFor:z.number().optional() },
    async ({ filename, url, pageSize, orientation, waitFor }) => {
      const puppeteer = await getPuppeteer();
      const browser = await puppeteer.launch({ args:['--no-sandbox','--disable-setuid-sandbox'] });
      const page = await browser.newPage();
      await page.goto(url, { waitUntil:'networkidle2', timeout:30000 });
      await new Promise(r=>setTimeout(r, waitFor||2000));
      const out = savePath(filename);
      await page.pdf({ path:out, format:pageSize||'A4', landscape:orientation==='landscape', printBackground:true });
      await browser.close();
      return { content:[{ type:'text', text:`✅ "${url}" → PDF!\n🔗 ${dlUrl(filename)}` }] };
    }
  );

  server.tool('generate_chart_pdf',
    'Data থেকে chart সহ PDF তৈরি করে। Bar, line, pie, doughnut chart support। Multiple charts একই PDF-এ।',
    { filename:z.string(), title:z.string().optional(), charts:z.array(z.object({ type:z.string(), title:z.string().optional(), labels:z.array(z.string()), datasets:z.array(z.object({ label:z.string().optional(), data:z.array(z.number()), backgroundColor:z.any().optional() })) })), pageOrientation:z.string().optional() },
    async ({ filename, title, charts, pageOrientation }) => {
      const { ChartJSNodeCanvas } = await import('chartjs-node-canvas');
      const puppeteer = await getPuppeteer();
      const canvas = new ChartJSNodeCanvas({ width:700, height:350 });
      let html = `<html><head><style>body{font-family:Arial;padding:20px;}h1{color:#2C3E50;}.chart{margin:20px 0;}</style></head><body>`;
      if (title) html += `<h1>${title}</h1>`;
      for (const chart of charts) {
        const buf = await canvas.renderToBuffer({ type:chart.type||'bar', data:{ labels:chart.labels, datasets:chart.datasets }, options:{ responsive:false, plugins:{ title:{ display:!!chart.title, text:chart.title } } } });
        html += `<div class="chart"><img src="data:image/png;base64,${buf.toString('base64')}" style="max-width:100%;"/></div>`;
      }
      html += '</body></html>';
      const browser = await puppeteer.launch({ args:['--no-sandbox'] });
      const page = await browser.newPage();
      await page.setContent(html);
      const out = savePath(filename);
      await page.pdf({ path:out, format:'A4', landscape:pageOrientation==='landscape', printBackground:true });
      await browser.close();
      return { content:[{ type:'text', text:`✅ ${charts.length}টি chart সহ PDF!\n🔗 ${dlUrl(filename)}` }] };
    }
  );

  server.tool('html_template_to_pdf',
    'Handlebars template ও data দিয়ে PDF তৈরি করে। {{variable}} syntax দিয়ে dynamic data inject করা যায়।',
    { filename:z.string(), template:z.string(), data:z.record(z.any()), pageSize:z.string().optional() },
    async ({ filename, template, data, pageSize }) => {
      const Handlebars = (await import('handlebars')).default;
      const puppeteer = await getPuppeteer();
      const compiled = Handlebars.compile(template);
      const html = compiled(data);
      const browser = await puppeteer.launch({ args:['--no-sandbox'] });
      const page = await browser.newPage();
      await page.setContent(html, { waitUntil:'networkidle0' });
      const out = savePath(filename);
      await page.pdf({ path:out, format:pageSize||'A4', printBackground:true });
      await browser.close();
      return { content:[{ type:'text', text:`✅ Template → PDF!\n🔗 ${dlUrl(filename)}` }] };
    }
  );

  // ════════════════════════════════════════════
  // GROUP 4: pdf-parse — Read + Extract (12)
  // ════════════════════════════════════════════

  server.tool('extract_text',
    'PDF থেকে সম্পূর্ণ text content বের করে। AI analysis, search indexing, translation-এর জন্য PDF content readable করে।',
    { pdfUrl:z.string(), includePageMarkers:z.boolean().optional() },
    async ({ pdfUrl, includePageMarkers=true }) => {
      const pdfParse = await getPdfParse();
      const bytes = await fetchBytes(pdfUrl);
      const data = await pdfParse(bytes);
      const text = includePageMarkers ? `[Pages: ${data.numpages}]\n\n${data.text}` : data.text;
      return { content:[{ type:'text', text:`✅ Text extracted!\n📄 Pages: ${data.numpages} | Chars: ${data.text.length}\n\n${text.substring(0,8000)}${text.length>8000?'\n[truncated...]':''}` }] };
    }
  );

  server.tool('extract_metadata',
    'PDF-এর সম্পূর্ণ metadata বের করে। Title, author, subject, keywords, creation date, page count সব।',
    { pdfUrl:z.string() },
    async ({ pdfUrl }) => {
      const pdfParse = await getPdfParse();
      const data = await pdfParse(await fetchBytes(pdfUrl));
      const m = data.info||{};
      return { content:[{ type:'text', text:`✅ Metadata:\n📌 Title: ${m.Title||'N/A'}\n👤 Author: ${m.Author||'N/A'}\n📋 Subject: ${m.Subject||'N/A'}\n🏷️ Keywords: ${m.Keywords||'N/A'}\n📅 Created: ${m.CreationDate||'N/A'}\n📄 Pages: ${data.numpages}\n📊 PDF Version: ${m.PDFFormatVersion||'N/A'}` }] };
    }
  );

  server.tool('get_pdf_info',
    'PDF সম্পর্কে বিস্তারিত technical information। Page count, size, encryption status, fonts, file size সব।',
    { pdfUrl:z.string() },
    async ({ pdfUrl }) => {
      const pdfParse = await getPdfParse();
      const bytes = await fetchBytes(pdfUrl);
      const data = await pdfParse(bytes);
      const { pdfLib } = await getPdfLib();
      const doc = await pdfLib.PDFDocument.load(bytes, { ignoreEncryption:true });
      const pages = doc.getPages();
      const sizes = pages.slice(0,3).map((p,i)=>{ const s=p.getSize(); return `  Page ${i+1}: ${s.width.toFixed(0)}×${s.height.toFixed(0)} pts`; });
      return { content:[{ type:'text', text:`✅ PDF Info:\n📄 Pages: ${doc.getPageCount()}\n📦 Size: ${(bytes.length/1024).toFixed(1)} KB\n📊 Version: ${data.info?.PDFFormatVersion||'N/A'}\n📐 Page sizes:\n${sizes.join('\n')}` }] };
    }
  );

  server.tool('search_in_pdf',
    'PDF-এর ভেতরে text search করে। Keyword কোন page-এ কতবার আছে, context সহ দেখায়।',
    { pdfUrl:z.string(), query:z.string(), caseSensitive:z.boolean().optional(), contextChars:z.number().optional() },
    async ({ pdfUrl, query, caseSensitive, contextChars=100 }) => {
      const pdfParse = await getPdfParse();
      const data = await pdfParse(await fetchBytes(pdfUrl));
      const text = data.text;
      const flags = caseSensitive?'g':'gi';
      const pattern = new RegExp(query.replace(/[.*+?^${}()|[\]\\]/g,'\\$&'), flags);
      const matches = [];
      let m;
      while ((m=pattern.exec(text))!==null && matches.length<15) {
        const start = Math.max(0,m.index-contextChars);
        const end = Math.min(text.length,m.index+query.length+contextChars);
        matches.push(`...${text.substring(start,end)}...`);
      }
      return { content:[{ type:'text', text: matches.length>0 ? `✅ "${query}" — ${matches.length}টি match:\n\n${matches.join('\n---\n')}` : `❌ "${query}" পাওয়া যায়নি।` }] };
    }
  );

  server.tool('extract_form_data',
    'Filled PDF form-এর সব field value বের করে JSON format-এ। Government forms, applications সব থেকে data extract।',
    { pdfUrl:z.string() },
    async ({ pdfUrl }) => {
      const { pdfLib } = await getPdfLib();
      const doc = await pdfLib.PDFDocument.load(await fetchBytes(pdfUrl), { ignoreEncryption:true });
      let form;
      try { form = doc.getForm(); } catch { return { content:[{ type:'text', text:'❌ এই PDF-এ কোনো form নেই।' }] }; }
      const fields = {};
      for (const field of form.getFields()) {
        const name = field.getName();
        const type = field.constructor.name;
        let value = null;
        try {
          if (type.includes('Text')) value = field.getText();
          else if (type.includes('CheckBox')) value = field.isChecked();
          else if (type.includes('Dropdown')) value = field.getSelected();
          else if (type.includes('RadioGroup')) value = field.getSelected();
        } catch {}
        if (value!==null) fields[name] = { type, value };
      }
      return { content:[{ type:'text', text:`✅ Form data:\n\n${JSON.stringify(fields,null,2)}` }] };
    }
  );

  server.tool('count_words',
    'PDF-এর word count, character count, sentence count, estimated reading time বের করে।',
    { pdfUrl:z.string() },
    async ({ pdfUrl }) => {
      const pdfParse = await getPdfParse();
      const data = await pdfParse(await fetchBytes(pdfUrl));
      const text = data.text;
      const words = text.split(/\s+/).filter(Boolean).length;
      const chars = text.replace(/\s/g,'').length;
      const sentences = text.split(/[.!?]+/).filter(Boolean).length;
      const readTime = Math.ceil(words/200);
      return { content:[{ type:'text', text:`✅ Word Count:\n📝 Words: ${words.toLocaleString()}\n🔡 Characters: ${chars.toLocaleString()}\n📖 Sentences: ${sentences.toLocaleString()}\n📄 Pages: ${data.numpages}\n⏱️ Reading time: ~${readTime} min` }] };
    }
  );

  server.tool('compare_pdfs',
    'দুটো PDF ফাইলের text পার্থক্য বের করে। কোন অংশ যোগ বা বাদ হয়েছে দেখায়। Document version comparison।',
    { pdfUrl1:z.string(), pdfUrl2:z.string() },
    async ({ pdfUrl1, pdfUrl2 }) => {
      const pdfParse = await getPdfParse();
      const [d1,d2] = await Promise.all([pdfParse(await fetchBytes(pdfUrl1)), pdfParse(await fetchBytes(pdfUrl2))]);
      const l1 = new Set(d1.text.split('\n').filter(l=>l.trim()));
      const l2 = new Set(d2.text.split('\n').filter(l=>l.trim()));
      const added = [...l2].filter(l=>!l1.has(l)).slice(0,10);
      const removed = [...l1].filter(l=>!l2.has(l)).slice(0,10);
      return { content:[{ type:'text', text:`✅ Comparison:\n📄 PDF1: ${d1.numpages} pages\n📄 PDF2: ${d2.numpages} pages\n\n➕ Added:\n${added.map(l=>`+ ${l}`).join('\n')||'None'}\n\n➖ Removed:\n${removed.map(l=>`- ${l}`).join('\n')||'None'}` }] };
    }
  );

  server.tool('validate_pdf',
    'PDF ফাইলটি valid কিনা check করে। Corrupted, encrypted, missing structure সব detect করে।',
    { pdfUrl:z.string() },
    async ({ pdfUrl }) => {
      const bytes = await fetchBytes(pdfUrl);
      const results = [];
      results.push(`📦 Size: ${(bytes.length/1024).toFixed(1)} KB`);
      results.push(`🔍 Header: ${bytes.toString('ascii',0,8)}`);
      results.push(bytes.toString('ascii',0,5)==='%PDF-' ? '✅ Valid PDF header' : '❌ Invalid PDF header');
      try {
        const pdfParse = await getPdfParse();
        const data = await pdfParse(bytes);
        results.push(`✅ Parseable: ${data.numpages} pages`);
      } catch(e) { results.push(`❌ Parse error: ${e.message}`); }
      try {
        const { pdfLib } = await getPdfLib();
        await pdfLib.PDFDocument.load(bytes, { ignoreEncryption:true });
        results.push('✅ pdf-lib: Loadable');
        if (bytes.toString('utf8',0,1024).includes('/Encrypt')) results.push('🔒 Encrypted: Yes');
        else results.push('🔓 Encrypted: No');
      } catch(e) { results.push(`⚠️ pdf-lib: ${e.message}`); }
      return { content:[{ type:'text', text:`✅ Validation:\n\n${results.join('\n')}` }] };
    }
  );

  server.tool('pdf_summary',
    'PDF-এর content পড়ে structured summary তৈরি করে। Title, author, page count, key sections, reading time সহ।',
    { pdfUrl:z.string(), maxWords:z.number().optional() },
    async ({ pdfUrl, maxWords=300 }) => {
      const pdfParse = await getPdfParse();
      const bytes = await fetchBytes(pdfUrl);
      const data = await pdfParse(bytes);
      const text = data.text;
      const words = text.split(/\s+/).filter(Boolean);
      const headings = text.match(/^[A-Z][^.!?\n]{5,50}$/gm)?.slice(0,5)||[];
      return { content:[{ type:'text', text:`✅ Summary:\n📌 Title: ${data.info?.Title||'Unknown'}\n👤 Author: ${data.info?.Author||'Unknown'}\n📄 Pages: ${data.numpages}\n📝 Words: ${words.length.toLocaleString()}\n⏱️ Reading: ~${Math.ceil(words.length/200)} min\n\n📋 Key Sections:\n${headings.map(h=>`• ${h.trim()}`).join('\n')||'• (Not detected)'}\n\n📖 Preview:\n${words.slice(0,maxWords).join(' ')}${words.length>maxWords?'...':''}` }] };
    }
  );

  server.tool('extract_tables',
    'PDF-এ থাকা table গুলো detect করে structured data হিসেবে বের করে। Financial reports, data tables থেকে extract করে।',
    { pdfUrl:z.string() },
    async ({ pdfUrl }) => {
      const pdfParse = await getPdfParse();
      const data = await pdfParse(await fetchBytes(pdfUrl));
      const lines = data.text.split('\n').filter(l=>l.trim());
      const tables = [];
      let current = [];
      for (const line of lines) {
        const cols = line.split(/\s{2,}|\t/).filter(Boolean);
        if (cols.length>=2) current.push(cols.join(' | '));
        else if (current.length>1) { tables.push([...current]); current=[]; }
      }
      if (current.length>1) tables.push(current);
      return { content:[{ type:'text', text: tables.length>0 ? `✅ ${tables.length}টি table found:\n\n${tables.map((t,i)=>`Table ${i+1}:\n${t.join('\n')}`).join('\n\n')}` : '❌ No tables detected.' }] };
    }
  );

  server.tool('pdf_to_images',
    'PDF-এর প্রতিটি page কে image-এ convert করে। PNG format, custom DPI। Puppeteer দিয়ে render করে।',
    { pdfUrl:z.string(), outputPrefix:z.string(), pages:z.array(z.number()).optional() },
    async ({ pdfUrl, outputPrefix, pages }) => {
      const pdfParse = await getPdfParse();
      const puppeteer = await getPuppeteer();
      const bytes = await fetchBytes(pdfUrl);
      const data = await pdfParse(bytes);
      const totalPages = data.numpages;
      const pageList = pages?.length>0 ? pages : Array.from({length:totalPages},(_,i)=>i+1);
      const results = [];
      const b64 = bytes.toString('base64');
      const browser = await puppeteer.launch({ args:['--no-sandbox'] });
      for (const pageNum of pageList.slice(0,5)) {
        const page = await browser.newPage();
        await page.goto(`data:application/pdf;base64,${b64}`,{waitUntil:'networkidle0'});
        const imgPath = path.join(DOWNLOADS_DIR,`${outputPrefix}_page${pageNum}.png`);
        await page.screenshot({ path:imgPath, fullPage:true });
        results.push(`${BASE_URL}/download/${outputPrefix}_page${pageNum}.png`);
        await page.close();
      }
      await browser.close();
      return { content:[{ type:'text', text:`✅ ${results.length}টি page image হয়েছে:\n${results.join('\n')}` }] };
    }
  );

  server.tool('list_downloads',
    'Server-এ থাকা সব generated PDF ফাইলের list দেখায়। File name, size, creation time এবং download URL সহ।',
    { filter:z.string().optional() },
    async ({ filter }) => {
      const files = fs.readdirSync(DOWNLOADS_DIR)
        .filter(f=>filter?f.includes(filter):true)
        .map(f=>{ const s=fs.statSync(path.join(DOWNLOADS_DIR,f)); return `📄 ${f}\n   💾 ${(s.size/1024).toFixed(1)}KB | 🔗 ${BASE_URL}/download/${f}`; });
      return { content:[{ type:'text', text: files.length>0 ? `📁 ${files.length}টি ফাইল:\n\n${files.join('\n\n')}` : '📂 কোনো ফাইল নেই।' }] };
    }
  );

  // ── Connect ────────────────────────────────────────────────
  const transport = new StreamableHTTPServerTransport({ sessionIdGenerator:undefined });
  await server.connect(transport);
  await transport.handleRequest(req, res, req.body);
});

app.listen(PORT, () => {
  console.log(`\n✅ PDF MCP Server started!`);
  console.log(`📌 MCP URL  : ${BASE_URL}/mcp`);
  console.log(`📁 Files    : ${BASE_URL}/files`);
  console.log(`⬇️  Download : ${BASE_URL}/download/<filename>`);
  console.log(`🛠️  Tools    : 40\n`);
});