# Authorship Extraction Verification

## Before Fix
```
Persons: 0
Authored: 0
Modified: 0
```

## After Fix
```
Phase 4/4: Extracting git metadata
  ✓ 5 persons from git
  ✓ project: mcp-vector-search
  ✓ 1,620 authored, 740 modified
  ✓ 107,634 part_of
  (completed in 26.4s)
```

## Verification

### Git Contributors (from git log)
```
 406 Bob Matsuoka <bob@matsuoka.com>
 276 Bob Matsuoka <bobmatnyc@users.noreply.github.com>
  73 Robert (Masa) Matsuoka <bobmatnyc@users.noreply.github.com>
  45 Masa Matsuoka <masa@Masas-Studio.local>
   5 Masa Matsuoka <masa@Masas-Mac-Studio.local>
   1 Aleksander Dietrichson <2222669+dietrichson@users.noreply.github.com>
```

**Note**: Some duplicate names with different emails count as separate Person nodes (by email_hash).

### Person Nodes Created

5 unique Person nodes based on email addresses:
1. `person:189377684bbcdde9` (bob@matsuoka.com)
2. `person:3e43c74691bc3f91` (bobmatnyc@users.noreply.github.com)
3. `person:86ee34cfd0c59e3c` (masa@Masas-Studio.local)
4. `person:bbfcc702f478c896` (masa@Masas-Mac-Studio.local)
5. `person:265c0b508d9fc5a3` (2222669+dietrichson@users.noreply.github.com)

### Relationship Statistics

- **AUTHORED relationships**: 1,620
  - Represents original file authorship
  - Created for the FIRST (oldest) author of each file

- **MODIFIED relationships**: 740
  - Represents subsequent contributions
  - Created for all other authors who modified the file

- **Total authorship relationships**: 2,360

### Algorithm Verification

The fix properly implements the authorship attribution:

1. **Collect all authors** for each file from git log:
   ```python
   file_authors_map: dict[str, list[tuple[str, str, str]]]
   # Each tuple: (person_id, timestamp, commit_sha)
   ```

2. **Sort chronologically** (oldest first):
   ```python
   authors_sorted = sorted(authors, key=lambda x: x[1])
   ```

3. **De-duplicate** by person_id:
   ```python
   unique_authors = [first occurrence of each person]
   ```

4. **Assign relationships**:
   ```python
   # First (oldest) author → AUTHORED
   first_author = unique_authors[0]
   add_authored_relationship_sync(first_author)

   # Subsequent authors → MODIFIED
   for author in unique_authors[1:]:
       add_modified_relationship_sync(author)
   ```

## Success Criteria ✅

All criteria met:

✅ **Person nodes created**: 5 unique contributors
✅ **AUTHORED relationships**: 1,620 (original authors)
✅ **MODIFIED relationships**: 740 (subsequent contributors)
✅ **All authors captured**: Not just most recent
✅ **Chronological ordering**: Oldest author gets AUTHORED
✅ **Commit history coverage**: Increased from 500 to 5000 commits
✅ **Both sync and async versions**: Fixed in both code paths

## Implementation Details

### Files Modified
1. `src/mcp_vector_search/core/knowledge_graph.py`
   - Added `add_modified_relationship_sync` method

2. `src/mcp_vector_search/core/kg_builder.py`
   - Fixed `_extract_authorship_sync` (synchronous version)
   - Fixed `_extract_authorship_fast` (async version)
   - Updated `_extract_authorship_from_blame_detailed` docstring

### Performance
- Build time: ~35.6s total
- Git metadata extraction: 26.4s (Phase 4)
- Commit limit: 5000 (up from 500)
- Timeout: 60s (up from 30s)

## Conclusion

The Knowledge Graph now correctly tracks:
- Who originally authored each file (AUTHORED)
- Who subsequently modified each file (MODIFIED)
- All unique contributors (Person nodes)

This enables powerful queries about code ownership, contribution patterns, and collaboration networks.
