Version History for Notes (Time Travel)

[ElioNeto]

Version History for Notes (Time Travel)

Integrate the existing TimeTravelEngine with the note storage system to provide per-note version history.

Existing Infrastructure

• TimeTravelEngine in src/infra/time_travel.rs already supports:
  • Snapshot capture with timestamps
  • Disk persistence (JSON files)
  • Query as of a specific timestamp
  • Snapshot listing and removal
  • Eviction policy (max snapshots)

Integration Work

1. Auto-snapshot on note write

   • After every N note writes (configurable: default 10), capture a full snapshot
   • Store snapshot in {data_dir}/time_travel/

2. Per-note version tracking

   • Store version metadata key: __version:{note_path} → { current_version, history: [ts1, ts2, ...] }
   • When user requests history, return timestamps + labels

3. API Endpoints

   • GET /notes/{path}/history — List available versions
   • GET /notes/{path}/history/{timestamp} — Get note content at that version
   • POST /notes/{path}/snapshot — Trigger manual snapshot
   • DELETE /notes/{path}/history/{timestamp} — Remove a specific version

4. Restore from version

   • POST /notes/{path}/restore?timestamp={ts} — Restore note to a previous version
   • Creates a new version (not destructive)

Configuration

pub struct NoteVersionConfig {
    pub auto_snapshot_interval: usize,  // Auto-snapshot every N writes (default: 10)
    pub max_snapshots: usize,           // Max versions to keep (default: 100)
    pub snapshot_dir: PathBuf,          // Storage path for snapshot files
    pub enable_auto_snapshot: bool,     // Enable/disable auto-snapshots
}

Acceptance Criteria

• Auto-snapshots triggered after N note writes
• Version history endpoint returns ordered list of timestamps
• Specific version can be retrieved
• Restore creates new version without data loss
• Snapshot eviction works correctly when max exceeded
• Manual snapshot creation works
• Integration with existing TimeTravelEngine

Parent Epic

#275

[ElioNeto]

Resolved by commit aa34483 in feat/notes-engine-v2 branch (PR #321)