feat: add snapshot CLI commands (#1268)

mnemosyne snapshot create|list|restore|diff

nexus/mnemosyne/cli.py

@@ -6,7 +6,8 @@ Provides: mnemosyne ingest, mnemosyne search, mnemosyne link, mnemosyne stats,
           mnemosyne tag, mnemosyne untag, mnemosyne retag,
           mnemosyne timeline, mnemosyne neighbors, mnemosyne path,
           mnemosyne touch, mnemosyne decay, mnemosyne vitality,
-          mnemosyne fading, mnemosyne vibrant
+          mnemosyne fading, mnemosyne vibrant,
+          mnemosyne snapshot create|list|restore|diff
 """
 
 from __future__ import annotations
@@ -18,6 +19,7 @@ import sys
 from nexus.mnemosyne.archive import MnemosyneArchive
 from nexus.mnemosyne.entry import ArchiveEntry
 from nexus.mnemosyne.ingest import ingest_event
+from nexus.mnemosyne.snapshot import snapshot_create, snapshot_list, snapshot_restore, snapshot_diff
 
 
 def cmd_stats(args):
@@ -315,6 +317,58 @@ def cmd_vibrant(args):
         print()
 
 
+
+def cmd_snapshot_create(args):
+    archive = MnemosyneArchive()
+    result = snapshot_create(archive, label=args.label)
+    print(f"Snapshot created: {result['snapshot_id']}")
+    print(f"  Entries: {result['entry_count']}")
+    print(f"  Label: {result['label'] or '(none)'}")
+    print(f"  Path: {result['path']}")
+
+
+def cmd_snapshot_list(args):
+    archive = MnemosyneArchive()
+    snaps = snapshot_list(archive)
+    if not snaps:
+        print("No snapshots found.")
+        return
+    for s in snaps:
+        label = f" ({s['label']})" if s['label'] else ""
+        print(f"  {s['snapshot_id']}  {s['created_at'][:19]}  {s['entry_count']} entries{label}")
+
+
+def cmd_snapshot_restore(args):
+    archive = MnemosyneArchive()
+    try:
+        result = snapshot_restore(archive, args.snapshot_id)
+    except FileNotFoundError as e:
+        print(str(e))
+        sys.exit(1)
+    print(f"Restored snapshot {result['snapshot_id']}")
+    print(f"  Entries restored: {result['restored_entries']}")
+    print(f"  Previous count: {result['previous_count']}")
+
+
+def cmd_snapshot_diff(args):
+    archive = MnemosyneArchive()
+    try:
+        result = snapshot_diff(archive, args.snapshot_id)
+    except FileNotFoundError as e:
+        print(str(e))
+        sys.exit(1)
+    print(f"Diff: snapshot {result['snapshot_id']} vs current")
+    print(f"  Snapshot: {result['snapshot_entries']} entries")
+    print(f"  Current:  {result['current_entries']} entries")
+    print(f"  Added:    {result['added']}")
+    print(f"  Removed:  {result['removed']}")
+    print(f"  Changed:  {result['changed']}")
+    if result['changed_details']:
+        print()
+        for c in result['changed_details']:
+            print(f"    [{c['id'][:8]}] {c['title']}")
+
+
 def main():
     parser = argparse.ArgumentParser(prog="mnemosyne", description="The Living Holographic Archive")
     sub = parser.add_subparsers(dest="command")
@@ -406,6 +460,21 @@ def main():
         parser.print_help()
         sys.exit(1)
 
+    # Snapshot subcommands
+    sp = sub.add_parser("snapshot", help="Archive snapshot operations")
+    sp_sub = sp.add_subparsers(dest="snapshot_command")
+
+    sp_create = sp_sub.add_parser("create", help="Create a point-in-time snapshot")
+    sp_create.add_argument("-l", "--label", default="", help="Human-readable label")
+
+    sp_sub.add_parser("list", help="List available snapshots")
+
+    sp_restore = sp_sub.add_parser("restore", help="Restore from a snapshot")
+    sp_restore.add_argument("snapshot_id", help="Snapshot ID (or prefix)")
+
+    sp_diff = sp_sub.add_parser("diff", help="Diff snapshot vs current archive")
+    sp_diff.add_argument("snapshot_id", help="Snapshot ID (or prefix)")
+
     dispatch = {
         "stats": cmd_stats,
         "search": cmd_search,
@@ -430,9 +499,26 @@ def main():
         "vitality": cmd_vitality,
         "fading": cmd_fading,
         "vibrant": cmd_vibrant,
+        "snapshot": lambda args: _dispatch_snapshot(args),
     }
     dispatch[args.command](args)
 
 
+def _dispatch_snapshot(args):
+    """Route snapshot subcommands to handlers."""
+    cmd = getattr(args, "snapshot_command", None)
+    if cmd == "create":
+        cmd_snapshot_create(args)
+    elif cmd == "list":
+        cmd_snapshot_list(args)
+    elif cmd == "restore":
+        cmd_snapshot_restore(args)
+    elif cmd == "diff":
+        cmd_snapshot_diff(args)
+    else:
+        print("Usage: mnemosyne snapshot {create|list|restore|diff}")
+        sys.exit(1)
+
+
 if __name__ == "__main__":
     main()