Document Generation PDF

Need to fill existing form? → pdf-lib
Need complex layouts? → Puppeteer (HTML/CSS)
Need academic formatting? → LaTeX
Need to merge PDFs? → pdf-lib
Need digital signatures? → pdf-lib + DocuSign API

// ❌ Puppeteer for simple form filling (SLOW!)
import puppeteer from 'puppeteer';

async function fillForm(data: FormData): Promise<Buffer> {
  const browser = await puppeteer.launch();
  const page = await browser.newPage();

  // Load PDF in browser
  await page.goto(`file://${pdfPath}`);

  // Somehow fill form fields? (hacky)
  await page.evaluate((data) => {
    // Can't easily access PDF form fields from DOM
    // Would need to convert PDF → HTML first
  }, data);

  const pdf = await page.pdf();
  await browser.close();

  return pdf;
}

// ✅ pdf-lib for form filling (FAST!)
import { PDFDocument } from 'pdf-lib';

async function fillForm(templatePath: string, data: FormData): Promise<Uint8Array> {
  // Load existing PDF form
  const existingPdfBytes = await fs.readFile(templatePath);
  const pdfDoc = await PDFDocument.load(existingPdfBytes);

  // Get form
  const form = pdfDoc.getForm();

  // Fill text fields
  form.getTextField('applicant_name').setText(data.name);
  form.getTextField('case_number').setText(data.caseNumber);
  form.getTextField('date_of_birth').setText(data.dob);

  // Fill checkboxes
  if (data.hasPriorConvictions) {
    form.getCheckBox('prior_convictions').check();
  }

  // Fill dropdowns
  form.getDropdown('state').select(data.state);

  // Flatten form (make non-editable)
  form.flatten();

  // Save
  return await pdfDoc.save();
}

// ❌ Don't flatten - form stays editable
const pdfDoc = await PDFDocument.load(existingPdfBytes);
const form = pdfDoc.getForm();

form.getTextField('name').setText('John Doe');

const pdfBytes = await pdfDoc.save();
// User can open PDF and change "John Doe" to anything!

// ✅ Flatten form after filling
const pdfDoc = await PDFDocument.load(existingPdfBytes);
const form = pdfDoc.getForm();

form.getTextField('name').setText('John Doe');

// Flatten (convert fields to static text)
form.flatten();

const pdfBytes = await pdfDoc.save();
// User can't edit filled values ✅

// ❌ No page break control
const html = `
  <div class="contract">
    <h1>Mutual Agreement</h1>
    <p>Long paragraph that might split across pages...</p>
    <section>
      <h2>Terms and Conditions</h2>
      <ol>
        <li>Term 1 that could get cut off...</li>
        <li>Term 2...</li>
      </ol>
    </section>
  </div>
`;

const pdf = await page.pdf({ format: 'A4' });
// Result: Ugly page breaks in middle of sections

// ✅ Explicit page break control with CSS
const html = `
  <style>
    @media print {
      .page-break { page-break-after: always; }
      .avoid-break { page-break-inside: avoid; }

      h1, h2, h3 {
        page-break-after: avoid;
        page-break-inside: avoid;
      }

      section {
        page-break-inside: avoid;
      }
    }
  </style>

  <div class="contract">
    <section class="avoid-break">
      <h1>Mutual Agreement</h1>
      <p>This entire section stays together...</p>
    </section>

    <div class="page-break"></div>

    <section class="avoid-break">
      <h2>Terms and Conditions</h2>
      <ol>
        <li>Term 1</li>
        <li>Term 2</li>
      </ol>
    </section>
  </div>
`;

const pdf = await page.pdf({
  format: 'A4',
  printBackground: true,
  margin: {
    top: '1in',
    right: '1in',
    bottom: '1in',
    left: '1in'
  }
});

// ❌ Add signature as image (not a real signature field)
const pdfDoc = await PDFDocument.load(existingPdfBytes);

const signatureImage = await pdfDoc.embedPng(signaturePngBytes);
const page = pdfDoc.getPage(0);

page.drawImage(signatureImage, {
  x: 100,
  y: 100,
  width: 200,
  height: 50
});

await pdfDoc.save();
// Not a real signature field - can't be signed digitally

// ✅ Create signature field for electronic signing
const pdfDoc = await PDFDocument.load(existingPdfBytes);
const form = pdfDoc.getForm();

// Create signature field
const signatureField = form.createTextField('applicant_signature');
signatureField.addToPage(pdfDoc.getPage(0), {
  x: 100,
  y: 100,
  width: 200,
  height: 50
});

// Mark as signature field (metadata)
signatureField.updateWidgets({
  borderWidth: 1,
  borderColor: { type: 'RGB', red: 0, green: 0, blue: 0 }
});

await pdfDoc.save();
// DocuSign can now detect and fill this field ✅

// ✅ Send to DocuSign for e-signature
import { ApiClient, EnvelopesApi } from 'docusign-esign';

async function sendForSignature(pdfBytes: Uint8Array, signerEmail: string) {
  const apiClient = new ApiClient();
  apiClient.setBasePath('https://demo.docusign.net/restapi');

  const envelopesApi = new EnvelopesApi(apiClient);

  const envelope = {
    emailSubject: 'Please sign: Expungement Petition',
    documents: [{
      documentBase64: Buffer.from(pdfBytes).toString('base64'),
      name: 'Petition.pdf',
      fileExtension: 'pdf',
      documentId: '1'
    }],
    recipients: {
      signers: [{
        email: signerEmail,
        name: 'John Doe',
        recipientId: '1',
        tabs: {
          signHereTabs: [{
            documentId: '1',
            pageNumber: '1',
            xPosition: '100',
            yPosition: '100'
          }]
        }
      }]
    },
    status: 'sent'
  };

  return await envelopesApi.createEnvelope(accountId, { envelopeDefinition: envelope });
}

// ❌ Save PDF to disk unencrypted
const pdfBytes = await pdfDoc.save();
await fs.writeFile(`./documents/${caseId}.pdf`, pdfBytes);
// Sensitive data accessible to anyone with file system access

// ✅ Encrypt PDF with user password
const pdfBytes = await pdfDoc.save({
  userPassword: generateSecurePassword(),
  ownerPassword: process.env.PDF_OWNER_PASSWORD,
  permissions: {
    printing: 'highResolution',
    modifying: false,
    copying: false,
    annotating: false,
    fillingForms: false,
    contentAccessibility: true,
    documentAssembly: false
  }
});

await fs.writeFile(`./documents/${caseId}.pdf`, pdfBytes);

// ✅ Upload to S3 with server-side encryption
import { S3Client, PutObjectCommand } from '@aws-sdk/client-s3';

const s3Client = new S3Client({ region: 'us-east-1' });

await s3Client.send(new PutObjectCommand({
  Bucket: 'expungement-documents',
  Key: `cases/${caseId}/petition.pdf`,
  Body: pdfBytes,
  ServerSideEncryption: 'AES256',
  Metadata: {
    caseId: caseId,
    documentType: 'petition',
    generatedAt: new Date().toISOString()
  },
  ACL: 'private'  // Not publicly accessible
}));

// Store S3 URL in database (encrypted)
await db.documents.insert({
  case_id: caseId,
  s3_url: encrypt(`s3://expungement-documents/cases/${caseId}/petition.pdf`),
  created_at: new Date()
});

□ Form fields filled correctly (test with validation)
□ Forms flattened after filling (non-editable)
□ Page breaks controlled (no mid-sentence splits)
□ Signature fields created (for DocuSign/Adobe Sign)
□ PDFs encrypted at rest (S3 SSE or user password)
□ Access logged (who viewed/downloaded)
□ Auto-deletion scheduled (retention policy)
□ Fonts embedded (cross-platform compatibility)
□ File size optimized (<5MB per document)
□ Batch generation tested (1000+ PDFs)