fix(dingtalk): isolate shared group sessions

Author: hongxicheng

src/qwenpaw/app/channels/dingtalk/channel.py

@@ -77,6 +77,7 @@
 from .content_utils import (
     parse_data_url,
     session_param_from_webhook_url,
+    shared_group_session_id_from_conversation_id,
     short_session_id_from_conversation_id,
 )
 from .handler import DingTalkChannelHandler
@@ -368,10 +369,13 @@ def resolve_session_id(
         sender_id: str,
         channel_meta: Optional[Dict[str, Any]] = None,
     ) -> str:
-        """Session_id = short suffix of conversation_id for cron lookup."""
+        """Resolve session_id from conversation metadata."""
         meta = channel_meta or {}
         cid = meta.get("conversation_id")
         if cid:
+            # Shared groups need full-ID entropy because user_id is "group".
+            if meta.get("is_group") and self.share_session_in_group:
+                return shared_group_session_id_from_conversation_id(cid)
             return short_session_id_from_conversation_id(cid)
         return f"{self.channel}:{sender_id}"
 
@@ -2503,12 +2507,12 @@ def _merge_native(self, items: list) -> dict:
             payload = it if isinstance(it, dict) else {}
             merged_parts.extend(payload.get("content_parts") or [])
             m = payload.get("meta") or {}
+            # Keep first sender identity; refresh only delivery metadata.
             for k in (
                 "conversation_id",
                 "session_webhook",
                 "session_webhook_expired_time",
                 "conversation_type",
-                "sender_staff_id",
             ):
                 if k in m:
                     merged_meta[k] = m[k]

src/qwenpaw/app/channels/dingtalk/constants.py

@@ -7,6 +7,9 @@
 # Short suffix length for session_id from conversation_id
 DINGTALK_SESSION_ID_SUFFIX_LEN = 8
 
+# Shared-group session IDs use 64 bits from SHA-256.
+DINGTALK_SHARED_SESSION_HASH_LEN = 16
+
 # DingTalk message type to runtime content type
 DINGTALK_TYPE_MAPPING = {
     "picture": "image",

src/qwenpaw/app/channels/dingtalk/content_utils.py

@@ -5,6 +5,7 @@
 
 import base64
 import binascii
+import hashlib
 import re
 from typing import Any, Optional
 from urllib.parse import parse_qs, urlparse
@@ -20,6 +21,7 @@
 
 from .constants import (
     DINGTALK_SESSION_ID_SUFFIX_LEN,
+    DINGTALK_SHARED_SESSION_HASH_LEN,
     DINGTALK_TYPE_MAPPING,
 )
 
@@ -126,6 +128,14 @@ def short_session_id_from_conversation_id(conversation_id: str) -> str:
     )
 
 
+def shared_group_session_id_from_conversation_id(
+    conversation_id: str,
+) -> str:
+    """Hash a group conversation ID into a short stable session ID."""
+    digest = hashlib.sha256(conversation_id.encode("utf-8")).hexdigest()
+    return digest[:DINGTALK_SHARED_SESSION_HASH_LEN]
+
+
 def session_param_from_webhook_url(url: str) -> Optional[str]:
     """Extract session= param from sendBySession URL for debug logging."""
     if not url or "?" not in url:

tests/unit/channels/test_dingtalk.py

@@ -985,6 +985,15 @@ def test_route_from_handle_empty(self, dingtalk_channel):
 # =============================================================================
 
 
+def _shared_sid(conversation_id: str) -> str:
+    """Expected shared-group session_id for a conversation_id."""
+    from qwenpaw.app.channels.dingtalk.content_utils import (
+        shared_group_session_id_from_conversation_id,
+    )
+
+    return shared_group_session_id_from_conversation_id(conversation_id)
+
+
 class TestDingTalkShareSessionInGroup:
     """Tests for per-user vs shared context in group chats."""
 
@@ -1040,7 +1049,8 @@ def test_group_shared_collapses_user_id(
         )
 
         assert request.user_id == "group"
-        assert request.session_id == "Y7890XYZ"
+        assert request.session_id == _shared_sid("cidQWERTY7890XYZ")
+        assert request.session_id != "Y7890XYZ"
 
     def test_shared_user_id_has_no_underscore(
         self,
@@ -1056,9 +1066,10 @@ def test_shared_user_id_has_no_underscore(
             session_id=request.session_id,
         )
 
-        assert to_handle == "dingtalk:sw:group_Y7890XYZ"
+        sid = _shared_sid("cidQWERTY7890XYZ")
+        assert to_handle == f"dingtalk:sw:group_{sid}"
         fallback = channel._suffix_only_webhook_key(to_handle)
-        assert fallback == "dingtalk:sw:Y7890XYZ"
+        assert fallback == f"dingtalk:sw:{sid}"
 
     def test_dm_unaffected_by_sharing(self, dingtalk_channel_shared_group):
         """Direct messages keep their own user_id when sharing is on."""
@@ -1082,7 +1093,7 @@ def test_debounce_key_shared_drops_sender(
             self._group_payload(),
         )
 
-        assert key == "Y7890XYZ"
+        assert key == _shared_sid("cidQWERTY7890XYZ")
 
     def test_debounce_key_shared_dm_keeps_sender(
         self,
@@ -1113,6 +1124,87 @@ def test_from_config_passes_flag(self, mock_process_handler):
 
         assert channel.share_session_in_group is True
 
+    def test_merge_two_members_keeps_first_sender_identity(
+        self,
+        dingtalk_channel_shared_group,
+    ):
+        """Merging members must not mix sender identity fields."""
+        channel = dingtalk_channel_shared_group
+        alice = self._group_payload()
+        alice["meta"]["sender_staff_id"] = "staff_alice"
+        alice["meta"]["user_name"] = "Alice"
+        bob = self._group_payload()
+        bob["sender_id"] = "Bob#5678"
+        bob["acl_sender_id"] = "staff_bob"
+        bob["meta"]["sender_staff_id"] = "staff_bob"
+        bob["meta"]["user_name"] = "Bob"
+
+        merged = channel.merge_native_items([alice, bob])
+
+        assert merged["sender_id"] == "Alice#1234"
+        assert merged["acl_sender_id"] == "staff_alice"
+        assert merged["meta"]["user_name"] == "Alice"
+        assert merged["meta"]["sender_staff_id"] == "staff_alice"
+
+    def test_merge_two_members_tracks_newest_session(
+        self,
+        dingtalk_channel_shared_group,
+    ):
+        """Conversation/webhook state still follows the newest item."""
+        channel = dingtalk_channel_shared_group
+        alice = self._group_payload()
+        alice["meta"]["session_webhook"] = "https://old.example"
+        bob = self._group_payload()
+        bob["sender_id"] = "Bob#5678"
+        bob["meta"]["session_webhook"] = "https://new.example"
+
+        merged = channel.merge_native_items([alice, bob])
+
+        assert merged["meta"]["session_webhook"] == "https://new.example"
+        assert merged["meta"]["batched_count"] == 2
+
+    def test_shared_groups_with_same_suffix_stay_separate(
+        self,
+        dingtalk_channel_shared_group,
+    ):
+        """Groups sharing an 8-char suffix stay isolated."""
+        channel = dingtalk_channel_shared_group
+        first = self._group_payload()
+        first["meta"]["conversation_id"] = "cidAAAASAME8888"
+        second = self._group_payload()
+        second["meta"]["conversation_id"] = "cidBBBBSAME8888"
+
+        req_a = channel.build_agent_request_from_native(first)
+        req_b = channel.build_agent_request_from_native(second)
+
+        assert first["meta"]["conversation_id"][-8:] == (
+            second["meta"]["conversation_id"][-8:]
+        )
+        assert req_a.session_id != req_b.session_id
+        assert channel.get_debounce_key(first) != channel.get_debounce_key(
+            second,
+        )
+
+    def test_shared_session_id_is_underscore_free(
+        self,
+        dingtalk_channel_shared_group,
+    ):
+        """Hash must stay "_"-free for the webhook fallback key split."""
+        channel = dingtalk_channel_shared_group
+        request = channel.build_agent_request_from_native(
+            self._group_payload(),
+        )
+
+        assert "_" not in request.session_id
+
+    def test_isolated_mode_keeps_short_suffix(self, dingtalk_channel):
+        """Isolated mode keeps the legacy suffix (no state migration)."""
+        request = dingtalk_channel.build_agent_request_from_native(
+            self._group_payload(),
+        )
+
+        assert request.session_id == "Y7890XYZ"
+
 
 # =============================================================================
 # P2: Open API Fallback (Critical for CHAN-D02)