# Tasks: add-watermark-feature

## Phase 1: Backend - Dependencies & Service

- [x] 1.1 Add Pillow and PyMuPDF (fitz) to requirements.txt
- [x] 1.2 Create WatermarkService class (`backend/app/services/watermark_service.py`)
- [x] 1.3 Implement `add_image_watermark(image_path, user, output_path)` method
- [x] 1.4 Implement `add_pdf_watermark(pdf_path, user, output_path)` method

## Phase 2: Backend - Integration

- [x] 2.1 Modify download endpoint to apply watermark
- [x] 2.2 Add watermark configuration (enable/disable per project)
- [x] 2.3 Handle unsupported file types gracefully (skip watermark)

## Phase 3: Backend - Testing

- [x] 3.1 Unit tests for image watermarking
- [x] 3.2 Unit tests for PDF watermarking
- [x] 3.3 Integration tests for download with watermark

## Validation Criteria

- Downloaded images contain visible watermark with user info
- Downloaded PDFs have watermark on each page
- Watermark includes: user name, employee ID, download timestamp
- Non-image/PDF files download without modification