# Data Conversion Summary

## Overview

This document summarizes the data conversion implementation from the old tldraw sync format to the new automerge sync format.

## Conversion Paths

The system handles three data formats automatically:

### 1. Automerge Array Format
- **Format**: `[{ state: { id: "...", ... } }, ...]`
- **Conversion**: `convertAutomergeToStore()`
- **Handles**: Raw Automerge document format

### 2. Store Format (Already Converted)
- **Format**: `{ store: { "recordId": {...}, ... }, schema: {...} }`
- **Conversion**: None needed - already in correct format
- **Handles**: Previously converted documents

### 3. Old Documents Format (Legacy)
- **Format**: `{ documents: [{ state: {...} }, ...] }`
- **Conversion**: `migrateDocumentsToStore()`
- **Handles**: Old tldraw sync format

## Validation & Error Handling

### Record Validation
- ✅ Validates `state` property exists
- ✅ Validates `state.id` exists and is a string
- ✅ Validates `state.typeName` exists (for documents format)
- ✅ Skips invalid records with detailed logging
- ✅ Preserves valid records

### Shape Migration
- ✅ Ensures required properties (x, y, rotation, opacity, isLocked, meta, index)
- ✅ Moves `w`/`h` from top-level to `props` for geo shapes
- ✅ Fixes richText structure
- ✅ Preserves custom shape properties (ObsNote, Holon, etc.)
- ✅ Tracks and verifies custom shapes

### Custom Records
- ✅ Preserves `obsidian_vault:` records
- ✅ Tracks custom record count
- ✅ Logs custom record IDs for verification

## Logging & Statistics

All conversion functions now provide comprehensive statistics:

### Conversion Statistics Include:
- Total records processed
- Successfully converted count
- Skipped records (with reasons)
- Errors encountered
- Custom records preserved
- Shape types distribution
- Custom shapes preserved

### Log Levels:
- **Info**: Conversion statistics, successful conversions
- **Warn**: Skipped records, warnings (first 10 shown)
- **Error**: Conversion errors with details

## Data Preservation Guarantees

### What is Preserved:
- ✅ All valid shape data
- ✅ All custom shape properties (ObsNote, Holon, etc.)
- ✅ All custom records (obsidian_vault)
- ✅ All metadata
- ✅ All text content
- ✅ All richText content (structure fixed, content preserved)

### What is Fixed:
- 🔧 Missing required properties (defaults added)
- 🔧 Invalid property locations (w/h moved to props)
- 🔧 Malformed richText structure
- 🔧 Missing typeName (inferred where possible)

### What is Skipped:
- ⚠️ Records with missing `state` property
- ⚠️ Records with missing `state.id`
- ⚠️ Records with invalid `state.id` type
- ⚠️ Records with missing `state.typeName` (for documents format)

## Testing

### Unit Tests
- `test-data-conversion.ts`: Tests edge cases with malformed data
- Covers: missing fields, null records, invalid types, custom records

### Integration Testing
- Test with real R2 data (see `test-r2-conversion.md`)
- Verify data integrity after conversion
- Check logs for warnings/errors

## Migration Safety

### Safety Features:
1. **Non-destructive**: Original R2 data is not modified until first save
2. **Error handling**: Invalid records are skipped, not lost
3. **Comprehensive logging**: All actions are logged for debugging
4. **Fallback**: Creates empty document if conversion fails completely

### Rollback:
- Original data remains in R2 until overwritten
- Can restore from backup if needed
- Conversion errors don't corrupt existing data

## Performance

- Conversion happens once per room (cached)
- Statistics logging is efficient (limited to first 10 errors)
- Shape migration only processes shapes (not all records)
- Custom record tracking is lightweight

## Next Steps

1. ✅ Conversion logic implemented and validated
2. ✅ Comprehensive logging added
3. ✅ Custom records/shapes preservation verified
4. ✅ Edge case handling implemented
5. ⏳ Test with real R2 data (manual process)
6. ⏳ Monitor production conversions

## Files Modified

- `worker/AutomergeDurableObject.ts`: Main conversion logic
  - `getDocument()`: Format detection and routing
  - `convertAutomergeToStore()`: Automerge array conversion
  - `migrateDocumentsToStore()`: Old documents format conversion
  - `migrateShapeProperties()`: Shape property migration

## Key Improvements

1. **Validation**: All records are validated before conversion
2. **Logging**: Comprehensive statistics for debugging
3. **Error Handling**: Graceful handling of malformed data
4. **Preservation**: Custom records and shapes are tracked and verified
5. **Safety**: Non-destructive conversion with fallbacks
