V2: Convert Tool (#3828)

🔄 Dynamic Processing Strategies

- Adaptive routing: Same tool uses different backend endpoints based on
file analysis
- Combined vs separate processing: Intelligently chooses between merge
operations and individual file processing
- Cross-format workflows: Enable complex conversions like "mixed files →
PDF" that other tools can't handle

  ⚙️ Format-Specific Intelligence

  Each conversion type gets tailored options:
  - HTML/ZIP → PDF: Zoom controls (0.1-3.0 increments) with live preview
  - Email → PDF: Attachment handling, size limits, recipient control
  - PDF → PDF/A: Digital signature detection with warnings
  - Images → PDF: Smart combining vs individual file options

 File Architecture

  Core Implementation:
  ├── Convert.tsx                     # Main stepped workflow UI
├── ConvertSettings.tsx # Centralized settings with smart detection
├── GroupedFormatDropdown.tsx # Enhanced format selector with grouping
├── useConvertParameters.ts # Smart detection & parameter management
  ├── useConvertOperation.ts         # Multi-strategy processing logic
  └── Settings Components:
      ├── ConvertFromWebSettings.tsx      # HTML zoom controls
      ├── ConvertFromEmailSettings.tsx    # Email attachment options
├── ConvertToPdfaSettings.tsx # PDF/A with signature detection
      ├── ConvertFromImageSettings.tsx    # Image PDF options
      └── ConvertToImageSettings.tsx      # PDF to image options

 Utility Layer

  Utils & Services:
├── convertUtils.ts # Format detection & endpoint routing
  ├── fileResponseUtils.ts          # Generic API response handling
└── setupTests.ts # Enhanced test environment with crypto mocks

  Testing & Quality

  Comprehensive Test Coverage

  Test Suite:
├── useConvertParameters.test.ts # Parameter logic & smart detection
  ├── useConvertParametersAutoDetection.test.ts  # File type analysis
├── ConvertIntegration.test.tsx # End-to-end conversion workflows
  ├── ConvertSmartDetectionIntegration.test.tsx  # Mixed file scenarios
  ├── ConvertE2E.spec.ts                     # Playwright browser tests
├── convertUtils.test.ts # Utility function validation
  └── fileResponseUtils.test.ts              # API response handling

  Advanced Test Features

  - Crypto API mocking: Proper test environment for file hashing
  - File.arrayBuffer() polyfills: Complete browser API simulation
  - Multi-file scenario testing: Complex batch processing validation
- CI/CD integration: Vitest runs in GitHub Actions with proper artifacts

---------

Co-authored-by: Connor Yoh <[email protected]>
Co-authored-by: Anthony Stirling <[email protected]>

frontend/src/hooks/usePdfSignatureDetection.ts

@@ -0,0 +1,66 @@
+import { useState, useEffect } from 'react';
+import * as pdfjsLib from 'pdfjs-dist';
+
+export interface PdfSignatureDetectionResult {
+  hasDigitalSignatures: boolean;
+  isChecking: boolean;
+}
+
+export const usePdfSignatureDetection = (files: File[]): PdfSignatureDetectionResult => {
+  const [hasDigitalSignatures, setHasDigitalSignatures] = useState(false);
+  const [isChecking, setIsChecking] = useState(false);
+
+  useEffect(() => {
+    const checkForDigitalSignatures = async () => {
+      if (files.length === 0) {
+        setHasDigitalSignatures(false);
+        return;
+      }
+
+      setIsChecking(true);
+      let foundSignature = false;
+
+      try {
+        // Set up PDF.js worker
+        pdfjsLib.GlobalWorkerOptions.workerSrc = '/pdfjs-legacy/pdf.worker.mjs';
+
+        for (const file of files) {
+          const arrayBuffer = await file.arrayBuffer();
+          
+          try {
+            const pdf = await pdfjsLib.getDocument({ data: arrayBuffer }).promise;
+
+            for (let i = 1; i <= pdf.numPages; i++) {
+              const page = await pdf.getPage(i);
+              const annotations = await page.getAnnotations({ intent: 'display' });
+
+              annotations.forEach(annotation => {
+                if (annotation.subtype === 'Widget' && annotation.fieldType === 'Sig') {
+                  foundSignature = true;
+                }
+              });
+
+              if (foundSignature) break;
+            }
+          } catch (error) {
+            console.warn('Error analyzing PDF for signatures:', error);
+          }
+
+          if (foundSignature) break;
+        }
+      } catch (error) {
+        console.warn('Error checking for digital signatures:', error);
+      }
+
+      setHasDigitalSignatures(foundSignature);
+      setIsChecking(false);
+    };
+
+    checkForDigitalSignatures();
+  }, [files]);
+
+  return {
+    hasDigitalSignatures,
+    isChecking
+  };
+};