feat(chatd): use last assistant message as push notification summary (#22671)

Instead of the static 'Agent has finished running.' text, extract a
summary from the last assistant message to give users meaningful context
about what the agent accomplished. Falls back to the static text if no
suitable message is found.

Co-authored-by: Kyle Carberry <kyle@carberry.com>

coderd/database/dbauthz/dbauthz.go

@@ -2831,6 +2831,15 @@ func (q *querier) GetInboxNotificationsByUserID(ctx context.Context, userID data
 	return fetchWithPostFilter(q.auth, policy.ActionRead, q.db.GetInboxNotificationsByUserID)(ctx, userID)
 }
 
+func (q *querier) GetLastChatMessageByRole(ctx context.Context, arg database.GetLastChatMessageByRoleParams) (database.ChatMessage, error) {
+	// Authorize read on the parent chat.
+	_, err := q.GetChatByID(ctx, arg.ChatID)
+	if err != nil {
+		return database.ChatMessage{}, err
+	}
+	return q.db.GetLastChatMessageByRole(ctx, arg)
+}
+
 func (q *querier) GetLastUpdateCheck(ctx context.Context) (string, error) {
 	if err := q.authorizeContext(ctx, policy.ActionRead, rbac.ResourceSystem); err != nil {
 		return "", err

coderd/database/dbauthz/dbauthz_test.go

@@ -488,6 +488,14 @@ func (s *MethodTestSuite) TestChats() {
 		dbm.EXPECT().GetChatMessagesByChatID(gomock.Any(), arg).Return(msgs, nil).AnyTimes()
 		check.Args(arg).Asserts(chat, policy.ActionRead).Returns(msgs)
 	}))
+	s.Run("GetLastChatMessageByRole", s.Mocked(func(dbm *dbmock.MockStore, faker *gofakeit.Faker, check *expects) {
+		chat := testutil.Fake(s.T(), faker, database.Chat{})
+		msg := testutil.Fake(s.T(), faker, database.ChatMessage{ChatID: chat.ID})
+		arg := database.GetLastChatMessageByRoleParams{ChatID: chat.ID, Role: "assistant"}
+		dbm.EXPECT().GetChatByID(gomock.Any(), chat.ID).Return(chat, nil).AnyTimes()
+		dbm.EXPECT().GetLastChatMessageByRole(gomock.Any(), arg).Return(msg, nil).AnyTimes()
+		check.Args(arg).Asserts(chat, policy.ActionRead).Returns(msg)
+	}))
 	s.Run("GetChatMessagesForPromptByChatID", s.Mocked(func(dbm *dbmock.MockStore, faker *gofakeit.Faker, check *expects) {
 		chat := testutil.Fake(s.T(), faker, database.Chat{})
 		msgs := []database.ChatMessage{testutil.Fake(s.T(), faker, database.ChatMessage{ChatID: chat.ID})}

coderd/database/dbmetrics/querymetrics.go

@@ -1407,6 +1407,14 @@ func (m queryMetricsStore) GetInboxNotificationsByUserID(ctx context.Context, ar
 	return r0, r1
 }
 
+func (m queryMetricsStore) GetLastChatMessageByRole(ctx context.Context, arg database.GetLastChatMessageByRoleParams) (database.ChatMessage, error) {
+	start := time.Now()
+	r0, r1 := m.s.GetLastChatMessageByRole(ctx, arg)
+	m.queryLatencies.WithLabelValues("GetLastChatMessageByRole").Observe(time.Since(start).Seconds())
+	m.queryCounts.WithLabelValues(httpmw.ExtractHTTPRoute(ctx), httpmw.ExtractHTTPMethod(ctx), "GetLastChatMessageByRole").Inc()
+	return r0, r1
+}
+
 func (m queryMetricsStore) GetLastUpdateCheck(ctx context.Context) (string, error) {
 	start := time.Now()
 	r0, r1 := m.s.GetLastUpdateCheck(ctx)

coderd/database/dbmock/dbmock.go

@@ -2587,6 +2587,21 @@ func (mr *MockStoreMockRecorder) GetInboxNotificationsByUserID(ctx, arg any) *go
 	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "GetInboxNotificationsByUserID", reflect.TypeOf((*MockStore)(nil).GetInboxNotificationsByUserID), ctx, arg)
 }
 
+// GetLastChatMessageByRole mocks base method.
+func (m *MockStore) GetLastChatMessageByRole(ctx context.Context, arg database.GetLastChatMessageByRoleParams) (database.ChatMessage, error) {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "GetLastChatMessageByRole", ctx, arg)
+	ret0, _ := ret[0].(database.ChatMessage)
+	ret1, _ := ret[1].(error)
+	return ret0, ret1
+}
+
+// GetLastChatMessageByRole indicates an expected call of GetLastChatMessageByRole.
+func (mr *MockStoreMockRecorder) GetLastChatMessageByRole(ctx, arg any) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "GetLastChatMessageByRole", reflect.TypeOf((*MockStore)(nil).GetLastChatMessageByRole), ctx, arg)
+}
+
 // GetLastUpdateCheck mocks base method.
 func (m *MockStore) GetLastUpdateCheck(ctx context.Context) (string, error) {
 	m.ctrl.T.Helper()

coderd/database/querier.go

@@ -284,6 +284,7 @@ type sqlcQuerier interface {
 	// param created_at_opt: The created_at timestamp to filter by. This parameter is usd for pagination - it fetches notifications created before the specified timestamp if it is not the zero value
 	// param limit_opt: The limit of notifications to fetch. If the limit is not specified, it defaults to 25
 	GetInboxNotificationsByUserID(ctx context.Context, arg GetInboxNotificationsByUserIDParams) ([]InboxNotification, error)
+	GetLastChatMessageByRole(ctx context.Context, arg GetLastChatMessageByRoleParams) (ChatMessage, error)
 	GetLastUpdateCheck(ctx context.Context) (string, error)
 	GetLatestCryptoKeyByFeature(ctx context.Context, feature CryptoKeyFeature) (CryptoKey, error)
 	GetLatestWorkspaceAppStatusByAppID(ctx context.Context, appID uuid.UUID) (WorkspaceAppStatus, error)

coderd/database/queries.sql.go

@@ -3536,6 +3536,48 @@ func (q *sqlQuerier) GetChatsByOwnerID(ctx context.Context, arg GetChatsByOwnerI
 	return items, nil
 }
 
+const getLastChatMessageByRole = `-- name: GetLastChatMessageByRole :one
+SELECT
+    id, chat_id, model_config_id, created_at, role, content, visibility, input_tokens, output_tokens, total_tokens, reasoning_tokens, cache_creation_tokens, cache_read_tokens, context_limit, compressed
+FROM
+    chat_messages
+WHERE
+    chat_id = $1::uuid
+    AND role = $2::text
+ORDER BY
+    created_at DESC, id DESC
+LIMIT
+    1
+`
+
+type GetLastChatMessageByRoleParams struct {
+	ChatID uuid.UUID `db:"chat_id" json:"chat_id"`
+	Role   string    `db:"role" json:"role"`
+}
+
+func (q *sqlQuerier) GetLastChatMessageByRole(ctx context.Context, arg GetLastChatMessageByRoleParams) (ChatMessage, error) {
+	row := q.db.QueryRowContext(ctx, getLastChatMessageByRole, arg.ChatID, arg.Role)
+	var i ChatMessage
+	err := row.Scan(
+		&i.ID,
+		&i.ChatID,
+		&i.ModelConfigID,
+		&i.CreatedAt,
+		&i.Role,
+		&i.Content,
+		&i.Visibility,
+		&i.InputTokens,
+		&i.OutputTokens,
+		&i.TotalTokens,
+		&i.ReasoningTokens,
+		&i.CacheCreationTokens,
+		&i.CacheReadTokens,
+		&i.ContextLimit,
+		&i.Compressed,
+	)
+	return i, err
+}
+
 const getStaleChats = `-- name: GetStaleChats :many
 SELECT
     id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error

coderd/database/queries/chats.sql

@@ -433,5 +433,18 @@ WHERE id = (
 )
 RETURNING *;
 
+-- name: GetLastChatMessageByRole :one
+SELECT
+    *
+FROM
+    chat_messages
+WHERE
+    chat_id = @chat_id::uuid
+    AND role = @role::text
+ORDER BY
+    created_at DESC, id DESC
+LIMIT
+    1;
+
 -- name: GetChatByIDForUpdate :one
 SELECT * FROM chats WHERE id = @id::uuid FOR UPDATE;