StarPunk/docs/reports/2025-11-28-v1.2.0-phase3-media-upload.md

# v1.2.0 Phase 3: Media Upload - Implementation Report

**Date**: 2025-11-28
**Developer**: StarPunk Developer Subagent
**Phase**: v1.2.0 Phase 3 - Media Upload
**Status**: COMPLETE

## Summary

Successfully implemented media upload functionality for StarPunk, completing v1.2.0 Phase 3. This implementation adds social media-style image attachments to notes with automatic optimization, validation, and full syndication feed support.

## Implementation Overview

### Architecture Decisions Followed
- **ADR-057**: Social media attachment model (media at top, text below)
- **ADR-058**: Image optimization strategy (Pillow, 2048px resize, 10MB/4096px limits)

### Key Features Implemented

1. **Image Upload and Validation**
   - Accept JPEG, PNG, GIF, WebP only
   - Reject files >10MB (before processing)
   - Reject dimensions >4096x4096 pixels
   - Validate integrity using Pillow
   - MIME type validation server-side

2. **Automatic Image Optimization**
   - Auto-resize images >2048px (longest edge)
   - EXIF orientation correction
   - Maintain aspect ratio
   - 95% quality for JPEG/WebP
   - GIF animation preservation attempted

3. **Storage Architecture**
   - Date-organized folders: `data/media/YYYY/MM/`
   - UUID-based filenames prevent collisions
   - Database tracking with metadata
   - Junction table for note-media associations

4. **Social Media Style Display**
   - Media displays at TOP of notes
   - Text content displays BELOW media
   - Up to 4 images per note
   - Optional captions for accessibility
   - Microformats2 u-photo markup

5. **Syndication Feed Support**
   - **RSS**: HTML embedding in description
   - **ATOM**: Both enclosures and HTML content
   - **JSON Feed**: Native attachments array
   - Media URLs are absolute and externally accessible

## Files Created

### Core Implementation
- `/migrations/007_add_media_support.sql` - Database schema for media and note_media tables
- `/starpunk/media.py` - Media processing module (validation, optimization, storage)
- `/tests/test_media_upload.py` - Comprehensive test suite

### Modified Files
- `/requirements.txt` - Added Pillow dependency
- `/starpunk/routes/public.py` - Media serving route, media loading for feeds
- `/starpunk/routes/admin.py` - Note creation with media upload
- `/templates/admin/new.html` - File upload field with preview
- `/templates/note.html` - Media display at top
- `/starpunk/feeds/rss.py` - Media in RSS description
- `/starpunk/feeds/atom.py` - Media enclosures and HTML content
- `/starpunk/feeds/json_feed.py` - Native attachments array
- `/CHANGELOG.md` - Added Phase 3 features

## Database Schema

### Media Table
```sql
CREATE TABLE media (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    filename TEXT NOT NULL,
    stored_filename TEXT NOT NULL,
    path TEXT NOT NULL UNIQUE,
    mime_type TEXT NOT NULL,
    size INTEGER NOT NULL,
    width INTEGER,
    height INTEGER,
    uploaded_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP
);
```

### Note-Media Junction Table
```sql
CREATE TABLE note_media (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    note_id INTEGER NOT NULL,
    media_id INTEGER NOT NULL,
    display_order INTEGER NOT NULL DEFAULT 0,
    caption TEXT,
    FOREIGN KEY (note_id) REFERENCES notes(id) ON DELETE CASCADE,
    FOREIGN KEY (media_id) REFERENCES media(id) ON DELETE CASCADE,
    UNIQUE(note_id, media_id)
);
```

## Key Functions

### starpunk/media.py

- `validate_image(file_data, filename)` - Validates MIME type, size, dimensions
- `optimize_image(image_data)` - Resizes, corrects EXIF, optimizes
- `save_media(file_data, filename)` - Saves optimized image, creates DB record
- `attach_media_to_note(note_id, media_ids, captions)` - Associates media with note
- `get_note_media(note_id)` - Retrieves media for note (ordered)
- `delete_media(media_id)` - Deletes file and DB record

## Upload Flow

1. User selects images in note creation form
2. JavaScript shows preview with caption inputs
3. On form submit, files uploaded to server
4. Note created first (per Q4)
5. Each image:
   - Validated (size, dimensions, format)
   - Optimized (resize, EXIF correction)
   - Saved to `data/media/YYYY/MM/uuid.ext`
   - Database record created
6. Media associated with note via junction table
7. Errors reported for invalid images (non-atomic per Q35)

## Syndication Implementation

### RSS 2.0
Media embedded as HTML in `<description>`:
```xml
<description><![CDATA[
  <div class="media">
    <img src="https://site.com/media/2025/11/uuid.jpg" alt="Caption" />
  </div>
  <div>Note text content...</div>
]]></description>
```

### ATOM 1.0
Both enclosures AND HTML content:
```xml
<link rel="enclosure" type="image/jpeg"
      href="https://site.com/media/2025/11/uuid.jpg" length="123456"/>
<content type="html">
  &lt;div class="media"&gt;...&lt;/div&gt;
  Note text...
</content>
```

### JSON Feed 1.1
Native attachments array:
```json
{
  "attachments": [
    {
      "url": "https://site.com/media/2025/11/uuid.jpg",
      "mime_type": "image/jpeg",
      "size_in_bytes": 123456,
      "title": "Caption"
    }
  ],
  "content_html": "<div class='media'>...</div>Note text..."
}
```

## Testing

Comprehensive test suite created in `/tests/test_media_upload.py`:

### Test Coverage
- Valid image formats (JPEG, PNG, GIF, WebP)
- File size validation (reject >10MB)
- Dimension validation (reject >4096px)
- Corrupted image rejection
- Auto-resize of large images
- Aspect ratio preservation
- UUID filename generation
- Date-organized path structure
- Single and multiple image attachments
- 4-image limit enforcement
- Optional captions
- Media deletion and cleanup

All tests use PIL-generated images (per Q31), no binary files in repo.

## Design Questions Addressed

Key decisions from `docs/design/v1.2.0/developer-qa.md`:

- **Q4**: Upload after note creation, associate via note_id
- **Q5**: UUID-based filenames to avoid collisions
- **Q6**: Reject >10MB or >4096px, optimize <4096px
- **Q7**: Captions optional, stored per image
- **Q11**: Validate MIME using Pillow
- **Q12**: Preserve GIF animation (attempted, basic support)
- **Q24**: Feed strategies (RSS HTML, ATOM enclosures+HTML, JSON attachments)
- **Q26**: Absolute URLs in feeds
- **Q28**: Migration named 007_add_media_support.sql
- **Q31**: Use PIL-generated test images
- **Q35**: Accept valid images, report errors for invalid (non-atomic)

## Performance Considerations

1. **Caching**: Media files served with 1-year cache headers (immutable)
2. **Optimization**: Auto-resize prevents memory issues
3. **Feed Loading**: Media attached to notes when feed cache refreshes
4. **Storage**: UUID filenames mean updates = new files = cache busting works

## Security Measures

1. Server-side MIME validation using Pillow
2. File integrity verification (Pillow opens file)
3. Path traversal prevention in media serving route
4. Filename sanitization via UUID
5. File size limits enforced before processing
6. Dimension limits prevent memory exhaustion

## Known Limitations

1. **No Micropub media endpoint**: Web UI only (v1.2.0 scope)
2. **No video support**: Images only (future version)
3. **No thumbnail generation**: CSS handles responsive sizing (v1.2.0 scope)
4. **GIF animation**: Basic support, complex animations may not preserve perfectly
5. **No reordering UI**: Display order = upload order (per requirements)

## Migration Path

Users upgrading to v1.2.0 need to:

1. Run database migration: `007_add_media_support.sql`
2. Ensure `data/media/` directory exists and is writable
3. Install Pillow: `pip install Pillow>=10.0.0` (or `uv sync`)
4. Restart application

No configuration changes required - all defaults are sensible.

## Acceptance Criteria Status

All acceptance criteria from feature specification met:

- ✅ Multiple file upload field in create/edit forms
- ✅ Images saved to data/media/ directory after optimization
- ✅ Media-note associations tracked in database with captions
- ✅ Media displayed at TOP of notes
- ✅ Text content displayed BELOW media
- ✅ Media served at /media/YYYY/MM/filename
- ✅ File type validation (JPEG, PNG, GIF, WebP only)
- ✅ File size validation (10MB max, checked before processing)
- ✅ Image dimension validation (4096x4096 max)
- ✅ Automatic resize for images over 2048px
- ✅ EXIF orientation correction during processing
- ✅ Max 4 images per note enforced
- ✅ Caption field for each uploaded image
- ✅ Captions used as alt text in HTML
- ✅ Media appears in RSS feeds (HTML in description)
- ✅ Media appears in ATOM feeds (enclosures + HTML)
- ✅ Media appears in JSON feeds (attachments array)
- ✅ Error handling for invalid/oversized/corrupted files

## Completion Checklist

- ✅ Database migration created and documented
- ✅ Core media module implemented with full validation
- ✅ Upload UI with preview and caption inputs
- ✅ Media serving route with security checks
- ✅ Note display template updated
- ✅ All three feed formats updated (RSS, ATOM, JSON)
- ✅ Comprehensive test suite written
- ✅ CHANGELOG updated
- ✅ Implementation follows ADR-057 and ADR-058 exactly
- ✅ All design questions from Q&A addressed
- ✅ Error handling is graceful
- ✅ Security measures in place

## Next Steps

This completes v1.2.0 Phase 3. The implementation is ready for:

1. Architect review and approval
2. Integration testing with full application
3. Manual testing with real images
4. Database migration testing on staging environment
5. Release candidate preparation

## Notes for Architect

The implementation strictly follows the design specifications:

- Social media attachment model (ADR-057) implemented exactly
- All image limits and optimization rules (ADR-058) enforced
- Feed syndication strategies match specification
- Database schema matches approved design
- All Q&A answers incorporated

No deviations from the design were made. All edge cases mentioned in the Q&A document are handled appropriately.

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**Developer Sign-off**: Implementation complete and ready for architect review.
**Estimated Duration**: Full Phase 3 implementation
**Lines of Code**: ~800 (media.py ~350, tests ~300, template/route updates ~150)