Stirling-PDF/CLAUDE.md

CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

Common Development Commands

Build and Test

• Build project: ./gradlew clean build
• Run locally: ./gradlew bootRun
• Full test suite: ./test.sh (builds all Docker variants and runs comprehensive tests)
• Code formatting: ./gradlew spotlessApply (runs automatically before compilation)

Docker Development

• Build ultra-lite: docker build -t stirlingtools/stirling-pdf:latest-ultra-lite -f ./Dockerfile.ultra-lite .
• Build standard: docker build -t stirlingtools/stirling-pdf:latest -f ./Dockerfile .
• Build fat version: docker build -t stirlingtools/stirling-pdf:latest-fat -f ./Dockerfile.fat .
• Example compose files: Located in exampleYmlFiles/ directory

Security Mode Development

Set DOCKER_ENABLE_SECURITY=true environment variable to enable security features during development. This is required for testing the full version locally.

Frontend Development

• Frontend dev server: cd frontend && npm run dev (requires backend on localhost:8080)
• Tech Stack: Vite + React + TypeScript + Mantine UI + TailwindCSS
• Proxy Configuration: Vite proxies /api/* calls to backend (localhost:8080)
• Build Process: DO NOT run build scripts manually - builds are handled by CI/CD pipelines
• Package Installation: DO NOT run npm install commands - package management handled separately
• Deployment Options:
  • Desktop App: npm run tauri-build (native desktop application)
  • Web Server: npm run build then serve dist/ folder
  • Development: npm run tauri-dev for desktop dev mode

Multi-Tool Workflow Architecture

Frontend designed for stateful document processing:

• Users upload PDFs once, then chain tools (split → merge → compress → view)
• File state and processing results persist across tool switches
• No file reloading between tools - performance critical for large PDFs (up to 100GB+)

FileContext - Central State Management

Location: src/contexts/FileContext.tsx

• Active files: Currently loaded PDFs and their variants
• Tool navigation: Current mode (viewer/pageEditor/fileEditor/toolName)
• Memory management: PDF document cleanup, blob URL lifecycle, Web Worker management
• IndexedDB persistence: File storage with thumbnail caching
• Preview system: Tools can preview results (e.g., Split → Viewer → back to Split) without context pollution

Critical: All file operations go through FileContext. Don't bypass with direct file handling.

Processing Services

• enhancedPDFProcessingService: Background PDF parsing and manipulation
• thumbnailGenerationService: Web Worker-based with main-thread fallback
• fileStorage: IndexedDB with LRU cache management

Memory Management Strategy

Why manual cleanup exists: Large PDFs (up to 100GB+) through multiple tools accumulate:

• PDF.js documents that need explicit .destroy() calls
• Blob URLs from tool outputs that need revocation
• Web Workers that need termination Without cleanup: browser crashes with memory leaks.

Tool Development

Architecture: Modular hook-based system with clear separation of concerns:

• useToolOperation (frontend/src/hooks/tools/shared/useToolOperation.ts): Main orchestrator hook

  • Coordinates all tool operations with consistent interface
  • Integrates with FileContext for operation tracking
  • Handles validation, error handling, and UI state management

• Supporting Hooks:

  • useToolState: UI state management (loading, progress, error, files)
  • useToolApiCalls: HTTP requests and file processing
  • useToolResources: Blob URLs, thumbnails, ZIP downloads

• Utilities:

  • toolErrorHandler: Standardized error extraction and i18n support
  • toolResponseProcessor: API response handling (single/zip/custom)
  • toolOperationTracker: FileContext integration utilities

Three Tool Patterns:

Pattern 1: Single-File Tools (Individual processing)

• Backend processes one file per API call
• Set multiFileEndpoint: false
• Examples: Compress, Rotate

return useToolOperation({
  operationType: 'compress',
  endpoint: '/api/v1/misc/compress-pdf',
  buildFormData: (params, file: File) => { /* single file */ },
  multiFileEndpoint: false,
});

Pattern 2: Multi-File Tools (Batch processing)

• Backend accepts MultipartFile[] arrays in single API call
• Set multiFileEndpoint: true
• Examples: Split, Merge, Overlay

return useToolOperation({
  operationType: 'split',
  endpoint: '/api/v1/general/split-pages',
  buildFormData: (params, files: File[]) => { /* all files */ },
  multiFileEndpoint: true,
  filePrefix: 'split_',
});

Pattern 3: Complex Tools (Custom processing)

• Tools with complex routing logic or non-standard processing
• Provide customProcessor for full control
• Examples: Convert, OCR

return useToolOperation({
  operationType: 'convert',
  customProcessor: async (params, files) => { /* custom logic */ },
});

Benefits:

• No Timeouts: Operations run until completion (supports 100GB+ files)
• Consistent: All tools follow same pattern and interface
• Maintainable: Single responsibility hooks, easy to test and modify
• i18n Ready: Built-in internationalization support
• Type Safe: Full TypeScript support with generic interfaces
• Memory Safe: Automatic resource cleanup and blob URL management

Architecture Overview

Project Structure

• Backend: Spring Boot application
• Frontend: React-based SPA in /frontend directory
  • File Storage: IndexedDB for client-side file persistence and thumbnails
  • Internationalization: JSON-based translations (converted from backend .properties)
• PDF Processing: PDFBox for core PDF operations, LibreOffice for conversions, PDF.js for client-side rendering
• Security: Spring Security with optional authentication (controlled by DOCKER_ENABLE_SECURITY)
• Configuration: YAML-based configuration with environment variable overrides

Controller Architecture

• API Controllers (src/main/java/.../controller/api/): REST endpoints for PDF operations
  • Organized by function: converters, security, misc, pipeline
  • Follow pattern: @RestController + @RequestMapping("/api/v1/...")

Key Components

• SPDFApplication.java: Main application class with desktop UI and browser launching logic
• ConfigInitializer: Handles runtime configuration and settings files
• Pipeline System: Automated PDF processing workflows via PipelineController
• Security Layer: Authentication, authorization, and user management (when enabled)

Component Architecture

• React Components: Located in frontend/src/components/ and frontend/src/tools/
• Static Assets: CSS, JS, and resources in src/main/resources/static/ (legacy) + frontend/public/ (modern)
• Internationalization:
  • Backend: messages_*.properties files
  • Frontend: JSON files in frontend/public/locales/ (converted from .properties)
  • Conversion Script: scripts/convert_properties_to_json.py

Configuration Modes

• Ultra-lite: Basic PDF operations only
• Standard: Full feature set
• Fat: Pre-downloaded dependencies for air-gapped environments
• Security Mode: Adds authentication, user management, and enterprise features

Testing Strategy

• Integration Tests: Cucumber tests in testing/cucumber/
• Docker Testing: test.sh validates all Docker variants
• Manual Testing: No unit tests currently - relies on UI and API testing

Development Workflow

1. Local Development:
   • Backend: ./gradlew bootRun (runs on localhost:8080)
   • Frontend: cd frontend && npm run dev (runs on localhost:5173, proxies to backend)
2. Docker Testing: Use ./test.sh before submitting PRs
3. Code Style: Spotless enforces Google Java Format automatically
4. Translations:
   • Backend: Use helper scripts in /scripts for multi-language updates
   • Frontend: Update JSON files in frontend/public/locales/ or use conversion script
5. Documentation: API docs auto-generated and available at /swagger-ui/index.html

Frontend Architecture Status

• Core Status: React SPA architecture complete with multi-tool workflow support
• State Management: FileContext handles all file operations and tool navigation
• File Processing: Production-ready with memory management for large PDF workflows (up to 100GB+)
• Tool Integration: Modular hook architecture with useToolOperation orchestrator
  • Individual hooks: useToolState, useToolApiCalls, useToolResources
  • Utilities: toolErrorHandler, toolResponseProcessor, toolOperationTracker
  • Pattern: Each tool creates focused operation hook, UI consumes state/actions
• Preview System: Tool results can be previewed without polluting file context (Split tool example)
• Performance: Web Worker thumbnails, IndexedDB persistence, background processing

Translation Rules

• CRITICAL: Always update translations in en-GB only, never en-US
• Translation files are located in frontend/public/locales/

Important Notes

• Java Version: Minimum JDK 17, supports and recommends JDK 21
• Lombok: Used extensively - ensure IDE plugin is installed
• Desktop Mode: Set STIRLING_PDF_DESKTOP_UI=true for desktop application mode
• File Persistence:
  • Backend: Designed to be stateless - files are processed in memory/temp locations only
  • Frontend: Uses IndexedDB for client-side file storage and caching (with thumbnails)
• Security: When DOCKER_ENABLE_SECURITY=false, security-related classes are excluded from compilation
• FileContext: All file operations MUST go through FileContext - never bypass with direct File handling
• Memory Management: Manual cleanup required for PDF.js documents and blob URLs - don't remove cleanup code
• Tool Development: New tools should follow useToolOperation hook pattern (see useCompressOperation.ts)
• Performance Target: Must handle PDFs up to 100GB+ without browser crashes
• Preview System: Tools can preview results without polluting main file context (see Split tool implementation)
• Adding Tools: See ADDING_TOOLS.md for complete guide to creating new PDF tools

Communication Style

• Be direct and to the point
• No apologies or conversational filler
• Answer questions directly without preamble
• Explain reasoning concisely when asked
• Avoid unnecessary elaboration

Decision Making

• Ask clarifying questions before making assumptions
• Stop and ask when uncertain about project-specific details
• Confirm approach before making structural changes
• Request guidance on preferences (cross-platform vs specific tools, etc.)
• Verify understanding of requirements before proceeding