feat(msteams): make ref pruning configurable and atomic

docs/chat-apps.md

@@ -642,7 +642,10 @@ Create or reuse a Microsoft Teams / Azure bot app registration. Set the bot mess
       "allowFrom": ["*"],
       "replyInThread": true,
       "mentionOnlyResponse": "Hi — what can I help with?",
-      "validateInboundAuth": true
+      "validateInboundAuth": true,
+      "refTtlDays": 30,
+      "pruneWebChatRefs": true,
+      "pruneNonPersonalRefs": true
     }
   }
 }
@@ -651,7 +654,9 @@ Create or reuse a Microsoft Teams / Azure bot app registration. Set the bot mess
 > - `replyInThread: true` replies to the triggering Teams activity when a stored `activity_id` is available.
 > - `mentionOnlyResponse` controls what Nanobot receives when a user sends only a bot mention (`<at>Nanobot</at>`). Set to `""` to ignore mention-only messages.
 > - `validateInboundAuth: true` enables inbound Bot Framework bearer-token validation (signature, issuer, audience, lifetime, `serviceUrl`). This is the safe default for public deployments. Only set it to `false` for local development or tightly controlled testing.
-> - Conversation refs are auto-pruned to avoid bad outbound routing: Web Chat refs, non-`personal` refs, and refs older than 30 days are removed.
+> - `refTtlDays` (default `30`) controls how old stored conversation refs can be before they are pruned.
+> - `pruneWebChatRefs` (default `true`) drops refs with `webchat.botframework.com` service URLs.
+> - `pruneNonPersonalRefs` (default `true`) drops refs whose `conversation_type` is not `personal`.
 
 **4. Run**
 

nanobot/channels/msteams.py

@@ -15,7 +15,9 @@ import asyncio
 import html
 import importlib.util
 import json
+import os
 import re
+import tempfile
 import threading
 import time
 from dataclasses import dataclass
@@ -63,6 +65,9 @@ class MSTeamsConfig(Base):
     reply_in_thread: bool = True
     mention_only_response: str = "Hi — what can I help with?"
     validate_inbound_auth: bool = True
+    ref_ttl_days: int = Field(default=MSTEAMS_REF_TTL_DAYS, ge=1)
+    prune_web_chat_refs: bool = True
+    prune_non_personal_refs: bool = True
 
 
 @dataclass
@@ -516,16 +521,17 @@ class MSTeamsChannel(BaseChannel):
             return False
 
         now_ts = time.time() if now is None else now
-        stale_before = now_ts - MSTEAMS_REF_TTL_S
+        ttl_days = int(self.config.ref_ttl_days)
+        stale_before = now_ts - (ttl_days * 24 * 60 * 60)
         keys_to_drop: list[str] = []
 
         for key, ref in self._conversation_refs.items():
-            if self._is_webchat_service_url(ref.service_url):
+            if self.config.prune_web_chat_refs and self._is_webchat_service_url(ref.service_url):
                 keys_to_drop.append(key)
                 continue
 
             conv_type = str(ref.conversation_type or "").strip().lower()
-            if conv_type and conv_type != "personal":
+            if self.config.prune_non_personal_refs and conv_type and conv_type != "personal":
                 keys_to_drop.append(key)
                 continue
 
@@ -544,10 +550,32 @@ class MSTeamsChannel(BaseChannel):
         logger.info(
             "MSTeams pruned {} stale/unsupported conversation refs (ttl={} days)",
             len(keys_to_drop),
-            MSTEAMS_REF_TTL_DAYS,
+            ttl_days,
         )
         return True
 
+    def _write_refs_atomically(self, data: dict[str, Any]) -> None:
+        """Write refs JSON atomically to reduce corruption risk during crashes."""
+        payload = json.dumps(data, indent=2)
+        tmp_path: str | None = None
+        try:
+            fd, tmp_path = tempfile.mkstemp(
+                dir=str(self._refs_path.parent),
+                prefix=f"{self._refs_path.name}.",
+                suffix=".tmp",
+            )
+            with os.fdopen(fd, "w", encoding="utf-8") as f:
+                f.write(payload)
+                f.flush()
+                os.fsync(f.fileno())
+            os.replace(tmp_path, self._refs_path)
+        finally:
+            if tmp_path and os.path.exists(tmp_path):
+                try:
+                    os.unlink(tmp_path)
+                except OSError:
+                    pass
+
     def _save_refs(self, *, prune: bool = True) -> None:
         """Persist conversation references."""
         try:
@@ -565,7 +593,7 @@ class MSTeamsChannel(BaseChannel):
                 }
                 for key, ref in self._conversation_refs.items()
             }
-            self._refs_path.write_text(json.dumps(data, indent=2), encoding="utf-8")
+            self._write_refs_atomically(data)
         except Exception as e:
             logger.warning("Failed to save MSTeams conversation refs: {}", e)
 

tests/test_msteams.py

@@ -206,6 +206,115 @@ def test_save_prunes_unsupported_conversation_refs(make_channel, tmp_path, monke
     assert set(saved.keys()) == {"conv-valid"}
 
 
+def test_init_respects_prune_toggle_flags(make_channel, tmp_path, monkeypatch):
+    now = 1_800_000_000.0
+    monkeypatch.setattr(msteams_module.time, "time", lambda: now)
+
+    state_dir = tmp_path / "state"
+    state_dir.mkdir(parents=True, exist_ok=True)
+    refs_path = state_dir / "msteams_conversations.json"
+    refs_path.write_text(
+        json.dumps(
+            {
+                "conv-webchat": {
+                    "service_url": "https://webchat.botframework.com/",
+                    "conversation_id": "conv-webchat",
+                    "conversation_type": "personal",
+                    "updated_at": now - 60,
+                },
+                "conv-group": {
+                    "service_url": "https://smba.trafficmanager.net/amer/",
+                    "conversation_id": "conv-group",
+                    "conversation_type": "channel",
+                    "updated_at": now - 60,
+                },
+            },
+            indent=2,
+        ),
+        encoding="utf-8",
+    )
+
+    ch = make_channel(pruneWebChatRefs=False, pruneNonPersonalRefs=False)
+
+    assert set(ch._conversation_refs.keys()) == {"conv-webchat", "conv-group"}
+    persisted = json.loads(refs_path.read_text(encoding="utf-8"))
+    assert set(persisted.keys()) == {"conv-webchat", "conv-group"}
+
+
+def test_init_respects_custom_ref_ttl_days(make_channel, tmp_path, monkeypatch):
+    now = 1_800_000_000.0
+    monkeypatch.setattr(msteams_module.time, "time", lambda: now)
+
+    state_dir = tmp_path / "state"
+    state_dir.mkdir(parents=True, exist_ok=True)
+    refs_path = state_dir / "msteams_conversations.json"
+    refs_path.write_text(
+        json.dumps(
+            {
+                "conv-fresh": {
+                    "service_url": "https://smba.trafficmanager.net/amer/",
+                    "conversation_id": "conv-fresh",
+                    "conversation_type": "personal",
+                    "updated_at": now - 12 * 60 * 60,
+                },
+                "conv-old": {
+                    "service_url": "https://smba.trafficmanager.net/amer/",
+                    "conversation_id": "conv-old",
+                    "conversation_type": "personal",
+                    "updated_at": now - 10 * 24 * 60 * 60,
+                },
+            },
+            indent=2,
+        ),
+        encoding="utf-8",
+    )
+
+    ch = make_channel(refTtlDays=1)
+
+    assert set(ch._conversation_refs.keys()) == {"conv-fresh"}
+    persisted = json.loads(refs_path.read_text(encoding="utf-8"))
+    assert set(persisted.keys()) == {"conv-fresh"}
+
+
+def test_save_uses_atomic_replace_and_keeps_existing_file_on_replace_error(make_channel, tmp_path, monkeypatch):
+    ch = make_channel()
+    refs_path = tmp_path / "state" / "msteams_conversations.json"
+    refs_path.write_text(
+        json.dumps(
+            {
+                "conv-old": {
+                    "service_url": "https://smba.trafficmanager.net/amer/",
+                    "conversation_id": "conv-old",
+                    "conversation_type": "personal",
+                    "updated_at": 1_700_000_000.0,
+                }
+            },
+            indent=2,
+        ),
+        encoding="utf-8",
+    )
+
+    ch._conversation_refs = {
+        "conv-new": ConversationRef(
+            service_url="https://smba.trafficmanager.net/amer/",
+            conversation_id="conv-new",
+            conversation_type="personal",
+            updated_at=1_800_000_000.0,
+        )
+    }
+
+    def _raise_replace(_src, _dst):
+        raise OSError("replace failed")
+
+    monkeypatch.setattr(msteams_module.os, "replace", _raise_replace)
+    ch._save_refs()
+
+    persisted = json.loads(refs_path.read_text(encoding="utf-8"))
+    assert set(persisted.keys()) == {"conv-old"}
+    tmp_files = list((tmp_path / "state").glob("msteams_conversations.json.*.tmp"))
+    assert tmp_files == []
+
+
 @pytest.mark.asyncio
 async def test_handle_activity_ignores_group_messages(make_channel):
     ch = make_channel()
@@ -644,6 +753,9 @@ def test_msteams_default_config_includes_restart_notify_fields():
     cfg = MSTeamsChannel.default_config()
 
     assert cfg["validateInboundAuth"] is True
+    assert cfg["refTtlDays"] == msteams_module.MSTEAMS_REF_TTL_DAYS
+    assert cfg["pruneWebChatRefs"] is True
+    assert cfg["pruneNonPersonalRefs"] is True
     assert "restartNotifyEnabled" not in cfg
     assert "restartNotifyPreMessage" not in cfg
     assert "restartNotifyPostMessage" not in cfg