PERSISTENCE_IMPLEMENTATION.md

# Persistence Implementation Summary

## Overview
Successfully implemented **dual persistence** for the ReliefWeb Annotation Gradio Space:
1. **Manual Download Button** - Always available, no configuration needed
2. **Auto-Backup to HF Datasets** - Optional cloud sync with automatic persistence

## Changes Made

### 1. Dependencies (`requirements.txt`)
Added:
- `huggingface_hub>=0.20.0` - For HF authentication and API
- `datasets>=2.16.0` - For HF Datasets integration

### 2. Core Application (`app.py`)

#### New Imports
```python
import os
from huggingface_hub import HfApi, login
from datasets import Dataset, load_dataset
```

#### ValidationAnnotator Class Updates

**Constructor (`__init__`)**
- Added `hf_dataset_repo` and `hf_token` parameters
- Auto-detects HF credentials from environment variables
- Attempts to login and enable HF Datasets if credentials available
- Loads annotations from both HF Datasets (cloud) and local file

**New Method: `_push_to_hf_datasets()`**
- Converts annotations dict to Dataset format
- Pushes to HF Hub with private visibility
- Called automatically after each annotation

**Updated Method: `_load_annotations()`**
- First tries to load from HF Datasets (cloud backup)
- Then loads from local file (may have newer annotations)
- Merges both sources, with local taking precedence

**Updated Method: `_save_annotation()`**
- Saves to local file (as before)
- Automatically pushes to HF Datasets if enabled
- Gracefully handles HF push failures

#### UI Updates

**New Download Button**
```python
download_btn = gr.DownloadButton(
    "💾 Download Annotations",
    value=str(annotator.output_file) if annotator.output_file.exists() else None,
    size="sm",
    variant="secondary"
)
```
- Updates automatically after each annotation
- Always available, no configuration needed

**Status Indicator**
- Shows "☁️ Auto-backup enabled" with link to dataset if HF enabled
- Shows "⚠️ Auto-backup disabled" with setup hint if not enabled

**Button Click Handlers**
- Accept and Reject buttons now chain to update download button
- Download button gets fresh file path after each annotation

#### Main Entry Point
```python
# Get HF credentials from environment
hf_dataset_repo = os.getenv("HF_DATASET_REPO")
hf_token = os.getenv("HF_TOKEN")

# Pass to create_app
app = create_app(input_file, hf_dataset_repo, hf_token)
```

### 3. Documentation Updates

#### README.md
- Added persistence features to feature list
- New section: "Persistence Options"
- Instructions for both manual download and auto-backup
- Step-by-step HF Datasets setup guide

#### DEPLOYMENT.md
- New section: "Setting Up Persistence"
- Detailed 4-step guide for HF Datasets configuration
- Benefits of auto-backup listed
- Updated "Important Notes" section

## How It Works

### Manual Download (Always Available)
1. User clicks "💾 Download Annotations" button
2. Browser downloads the JSONL file immediately
3. File contains all annotations made so far
4. Works offline, no configuration needed

### Auto-Backup (Optional)
1. **On Startup**: 
   - Checks for `HF_TOKEN` and `HF_DATASET_REPO` env vars
   - If found, logs into HF and enables auto-backup
   - Loads existing annotations from HF Dataset

2. **On Each Annotation**:
   - Saves to local file (ephemeral)
   - Converts all annotations to Dataset format
   - Pushes to HF Hub (replaces entire dataset)
   - Shows success/failure in console logs

3. **On Space Restart**:
   - Loads annotations from HF Dataset
   - Continues from where user left off
   - No data loss!

## Configuration for Users

### For Manual Download Only
**No configuration needed!** Just use the app and click download when desired.

### For Auto-Backup
1. Create HF Dataset: https://huggingface.co/new-dataset
2. Get write token: https://huggingface.co/settings/tokens
3. Add Space secrets:
   - `HF_TOKEN`: Your write token
   - `HF_DATASET_REPO`: `username/dataset-name`
4. Restart Space

## Benefits

### Manual Download
✅ No setup required  
✅ Works offline  
✅ User controls when to backup  
✅ Simple and reliable  

### Auto-Backup
✅ Survives Space restarts  
✅ Automatic version control  
✅ Resume from any device  
✅ Collaborative annotation  
✅ Easy dataset management  
✅ No manual intervention needed  

## Testing

### Local Testing
```bash
cd /Users/rafaelmacalaba/WBG/monitoring_of_datause/revalidation/analysis/unhcr_reliefweb/reliefweb_annotation

# Without HF Datasets (download only)
uv run app.py

# With HF Datasets
export HF_TOKEN="your_token"
export HF_DATASET_REPO="username/dataset-name"
uv run app.py
```

### On HF Spaces
1. Upload files to Space
2. Optionally configure secrets
3. Space auto-deploys
4. Check console logs for HF Datasets status

## Files Modified

1. ✅ `requirements.txt` - Added HF dependencies
2. ✅ `app.py` - Implemented dual persistence
3. ✅ `README.md` - Documented features and setup
4. ✅ `DEPLOYMENT.md` - Added configuration guide

## Deployment Checklist

- [x] Dependencies updated
- [x] Download button implemented
- [x] HF Datasets integration implemented
- [x] UI indicators added
- [x] Documentation updated
- [x] Local testing completed
- [ ] Deploy to HF Spaces
- [ ] Configure HF secrets (optional)
- [ ] Test in production

## Next Steps

1. **Deploy to HF Spaces** (see DEPLOYMENT.md)
2. **Configure secrets** for auto-backup (optional)
3. **Start annotating!**
4. **Download periodically** as backup
5. **Monitor HF Dataset** for automatic backups

---

**Status**: ✅ Implementation Complete  
**Ready for Deployment**: Yes  
**Breaking Changes**: None (backward compatible)