fix: support removing group members

docs/IM-前后端对接文档.md

@@ -2185,6 +2185,7 @@ GET /v1/im/topics/{topic}/message-mutations?since_version={localMutationVersion}
 | `POST /v1/im/groups/{topic}/leave` | `{}` | `{"topic":"grp...","status":"left"}` |
 | `GET /v1/im/groups/{topic}/members?query=&cursor=&mentionable=true` | Query only | `{"topic":"grp...","items":[{"user_id":"usr...","display_name":"张三","group_nickname":"小张","avatar_file_id":"","role":"member","member_status":"active","version":1,"joined_at":"2026-08-20T09:00:00Z","updated_at":"2026-08-20T09:00:00Z","mentionable":true,"acs":{"want":"JRWP","given":"JRWP","mode":"JRWP"}}],"next_cursor":"","sync_mode":"full","permissions":{"can_mention_all":true}}` |
 | `GET /v1/im/groups/{topic}/members/{user_id}` | Path topic/user | `{"topic":"grp...","user_id":"usr...","display_name":"张三","group_nickname":"小张","role":"member","member_status":"active","version":1,"joined_at":"2026-08-20T09:00:00Z","updated_at":"2026-08-20T09:00:00Z","sync_mode":"single","acs":{"want":"JRWP","given":"JRWP","mode":"JRWP"}}` |
+| `DELETE /v1/im/groups/{topic}/members/{user_id}` | Path topic/user；管理员可移除普通成员，群主可移除管理员和普通成员；不能移除群主或自己 | `{"topic":"grp...","user_id":"usr...","status":"left"}` |
 | `GET /v1/im/groups/{topic}/members/{user_id}/profile` | Path topic/user；`topic` 必须是 `grp...`，不能传 `usr...` | `{"topic":"grp...","user_id":"usr...","display_name":"张三","group_nickname":"小张","role":"member","relationship":"friend","capabilities":{"can_send":true,"can_call":true}}` |
 | `POST /v1/im/groups/{topic}/qrcodes` | `{"expires_in_seconds":86400}` | `{"qr_token":"token...","qr_payload":"im://qr?token=...&purpose=join_group","expires_at":"2026-08-21T09:00:00Z","group":{"topic":"grp...","name":"项目群","member_count":2},"group_snapshot":{"topic":"grp...","name":"项目群","member_count":2}}` |
 | `POST /v1/im/groups/{topic}/invitations` | `{"user_ids":["usr..."],"message":"进群一起讨论"}` | `{"topic":"grp...","items":[{"user_id":"usr...","status":"joined","invitation_id":"ginv_1"}]}` |

server/im_http.go

@@ -4138,7 +4138,7 @@ func serveIMGroupMembers(wrt http.ResponseWriter, req *http.Request, topic strin
 }
 
 func serveIMGroupMember(wrt http.ResponseWriter, req *http.Request, topic string, memberID types.Uid) {
-	if req.Method != http.MethodGet {
+	if req.Method != http.MethodGet && req.Method != http.MethodDelete {
 		writeIMError(wrt, req, http.StatusMethodNotAllowed, 30002, imReasonMethodNotAllowed, "method not allowed", nil)
 		return
 	}
@@ -4163,6 +4163,20 @@ func serveIMGroupMember(wrt http.ResponseWriter, req *http.Request, topic string
 		writeIMError(wrt, req, http.StatusNotFound, 30004, imReasonMalformedRequest, "member not found", nil)
 		return
 	}
+	if req.Method == http.MethodDelete {
+		if ok, reason := canRemoveIMGroupMember(selfSub, principal.Uid, *member); !ok {
+			writeIMError(wrt, req, http.StatusForbidden, 30005, imReasonPermissionDenied, "permission denied", map[string]any{"user_id": memberID.UserId(), "reason": reason})
+			return
+		}
+		if err := store.GroupBusiness.Leave(principal.TenantID, topic, memberID, time.Now().UTC().Round(time.Millisecond)); err != nil {
+			writeIMRelationError(wrt, req, err)
+			return
+		}
+		publishIMGroupRealtimeEvent(principal.TenantID, topic, principal.Uid, "group.member.left",
+			map[string]any{"user_id": memberID.UserId(), "removed_by": principal.Uid.UserId(), "member_sync": "single"})
+		writeIMSuccess(wrt, req, map[string]any{"topic": topic, "user_id": memberID.UserId(), "status": "left"})
+		return
+	}
 	memberSub, err := store.Subs.Get(principal.TenantID, topic, memberID, false)
 	if err != nil {
 		writeIMRelationError(wrt, req, err)
@@ -7111,6 +7125,31 @@ func canMuteIMGroupMember(tenantID types.TenantID, topic string, selfSub *types.
 	return true, ""
 }
 
+func canRemoveIMGroupMember(selfSub *types.Subscription, actor types.Uid, target types.GroupMember) (bool, string) {
+	if actor.IsZero() || target.UserID.IsZero() {
+		return false, "invalid_user"
+	}
+	if actor == target.UserID {
+		return false, "self"
+	}
+	actorAccess := types.ModeNone
+	if selfSub != nil {
+		actorAccess = selfSub.ModeGiven & selfSub.ModeWant
+	}
+	if !actorAccess.IsAdmin() {
+		return false, "not_admin"
+	}
+	switch groupMemberRole(groupMemberAccess(target)) {
+	case "owner":
+		return false, "owner"
+	case "admin":
+		if !actorAccess.IsOwner() {
+			return false, "admin"
+		}
+	}
+	return true, ""
+}
+
 func groupMemberProfilePayload(topic string, sub *types.Subscription, user *types.User, ctx *types.RelationshipContext) map[string]any {
 	data := groupMemberPayload(*sub, true, ctx.Remark)
 	data["topic"] = topic

server/im_http_test.go

@@ -283,6 +283,8 @@ type testGroupBusinessStore struct {
 	updatedSettings   types.GroupSettingsPatch
 	updatedMembers    []types.GroupMemberPatch
 	updatedRoleMode   types.AccessMode
+	leftTopic         string
+	leftUID           types.Uid
 	updateSettingsErr error
 	updateMemberErr   error
 }
@@ -546,7 +548,9 @@ func (s *testGroupBusinessStore) InviteMember(_ types.TenantID, topic string, in
 	return true, nil
 }
 
-func (s *testGroupBusinessStore) Leave(_ types.TenantID, _ string, _ types.Uid, _ time.Time) error {
+func (s *testGroupBusinessStore) Leave(_ types.TenantID, topic string, uid types.Uid, _ time.Time) error {
+	s.leftTopic = topic
+	s.leftUID = uid
 	return nil
 }
 
@@ -3127,6 +3131,45 @@ func TestServeIMGroupMemberReturnsSingleSnapshot(t *testing.T) {
 	}
 }
 
+func TestServeIMGroupMemberDeleteRemovesMember(t *testing.T) {
+	ctrl := gomock.NewController(t)
+	defer ctrl.Finish()
+	expectIMBearer(t, ctrl, "token-1", 7, 42)
+	oldSubs := store.Subs
+	oldGroupBusiness := store.GroupBusiness
+	subs := mock_store.NewMockSubsPersistenceInterface(ctrl)
+	store.Subs = subs
+	target := types.Uid(101)
+	groupStore := &testGroupBusinessStore{member: &types.GroupMember{
+		ID: 101, Topic: "grpMention", UserID: target, Role: types.GroupMemberRoleMember,
+		MemberStatus: types.GroupMemberStatusActive, Version: 3,
+	}}
+	store.GroupBusiness = groupStore
+	t.Cleanup(func() {
+		store.Subs = oldSubs
+		store.GroupBusiness = oldGroupBusiness
+	})
+
+	ownerSub := &types.Subscription{TenantID: 7, User: types.Uid(42).String(), Topic: "grpMention", ModeWant: types.ModeCFull, ModeGiven: types.ModeCFull}
+	subs.EXPECT().Get(types.TenantID(7), "grpMention", types.Uid(42), false).Return(ownerSub, nil)
+
+	req := httptest.NewRequest(http.MethodDelete, "/v1/im/groups/grpMention/members/"+target.UserId(), nil)
+	req.Header.Set("Authorization", "Bearer token-1")
+	rec := httptest.NewRecorder()
+	serveIMGroupResource(rec, req)
+
+	if rec.Code != http.StatusOK {
+		t.Fatalf("status: got %d, want %d; body=%s", rec.Code, http.StatusOK, rec.Body.String())
+	}
+	if groupStore.leftTopic != "grpMention" || groupStore.leftUID != target {
+		t.Fatalf("member was not removed: topic=%q uid=%s", groupStore.leftTopic, groupStore.leftUID.UserId())
+	}
+	data := decodeIMHTTPResponse(t, rec).Data.(map[string]any)
+	if data["topic"] != "grpMention" || data["user_id"] != target.UserId() || data["status"] != "left" {
+		t.Fatalf("unexpected delete response: %#v", data)
+	}
+}
+
 func TestGroupMemberPayloadUserIDFormats(t *testing.T) {
 	raw := types.Uid(101)
 	fromRaw := groupMemberPayload(types.Subscription{