🛡️ fix(concurrency): serializar chats e blindar conflitos de locacao

Serializa o processamento do Telegram por chat com workers dedicados e semaforo global, evitando que uma mensagem lenta bloqueie os demais atendimentos enquanto preserva a ordem dentro de cada conversa.

Protege a abertura de locacao com row lock no veiculo e adiciona lock de slot para agendamento e remarcacao de revisao, reduzindo o risco de corrida em reservas simultaneas.

Amplia a cobertura com testes para paralelismo no satellite do Telegram, lock da locacao e lock dos horarios de revisao.

app/integrations/telegram_satellite_service.py

@@ -21,6 +21,7 @@ from app.services.user.user_service import UserService
 logger = logging.getLogger(__name__)
 
 TELEGRAM_MESSAGE_SAFE_LIMIT = 3800
+TELEGRAM_MAX_CONCURRENT_CHATS = 8
 
 
 def _split_telegram_text(text: str, limit: int = TELEGRAM_MESSAGE_SAFE_LIMIT) -> List[str]:
@@ -130,6 +131,10 @@ class TelegramSatelliteService:
         self.polling_timeout = settings.telegram_polling_timeout
         self.request_timeout = settings.telegram_request_timeout
         self._last_update_id = -1
+        self._chat_queues: dict[int, asyncio.Queue[Dict[str, Any]]] = {}
+        self._chat_workers: dict[int, asyncio.Task[None]] = {}
+        self._chat_workers_lock = asyncio.Lock()
+        self._chat_processing_semaphore = asyncio.Semaphore(TELEGRAM_MAX_CONCURRENT_CHATS)
 
     async def run(self) -> None:
         """Inicia loop de long polling para consumir atualizacoes do bot."""
@@ -139,6 +144,7 @@ class TelegramSatelliteService:
         timeout = aiohttp.ClientTimeout(total=self.request_timeout)
 
         async with aiohttp.ClientSession(timeout=timeout) as session:
+            try:
                 offset = await self._initialize_offset(session=session)
                 while True:
                     updates = await self._get_updates(session=session, offset=offset)
@@ -150,7 +156,89 @@ class TelegramSatelliteService:
                             continue
                         self._last_update_id = update_id
                         offset = update_id + 1
+                        await self._schedule_update_processing(session=session, update=update)
+            finally:
+                await self._shutdown_chat_workers()
+
+    def _extract_chat_id(self, update: Dict[str, Any]) -> int | None:
+        message = update.get("message", {})
+        chat = message.get("chat", {})
+        chat_id = chat.get("id")
+        return chat_id if isinstance(chat_id, int) else None
+
+    async def _schedule_update_processing(
+        self,
+        session: aiohttp.ClientSession,
+        update: Dict[str, Any],
+    ) -> None:
+        chat_id = self._extract_chat_id(update)
+        if chat_id is None:
+            async with self._chat_processing_semaphore:
                 await self._handle_update(session=session, update=update)
+            return
+
+        async with self._chat_workers_lock:
+            queue = self._chat_queues.get(chat_id)
+            if queue is None:
+                queue = asyncio.Queue()
+                self._chat_queues[chat_id] = queue
+            queue.put_nowait(update)
+
+            worker = self._chat_workers.get(chat_id)
+            if worker is None or worker.done():
+                self._chat_workers[chat_id] = asyncio.create_task(
+                    self._run_chat_worker(
+                        chat_id=chat_id,
+                        session=session,
+                        queue=queue,
+                    )
+                )
+
+    async def _run_chat_worker(
+        self,
+        *,
+        chat_id: int,
+        session: aiohttp.ClientSession,
+        queue: asyncio.Queue[Dict[str, Any]],
+    ) -> None:
+        current_task = asyncio.current_task()
+        try:
+            while True:
+                update = await queue.get()
+                try:
+                    async with self._chat_processing_semaphore:
+                        await self._handle_update(session=session, update=update)
+                finally:
+                    queue.task_done()
+
+                async with self._chat_workers_lock:
+                    if queue.empty():
+                        if self._chat_workers.get(chat_id) is current_task:
+                            self._chat_workers.pop(chat_id, None)
+                        if self._chat_queues.get(chat_id) is queue:
+                            self._chat_queues.pop(chat_id, None)
+                        return
+        except asyncio.CancelledError:
+            raise
+        except Exception:
+            logger.exception("Falha inesperada no worker do chat %s.", chat_id)
+        finally:
+            async with self._chat_workers_lock:
+                if self._chat_workers.get(chat_id) is current_task:
+                    self._chat_workers.pop(chat_id, None)
+                if self._chat_queues.get(chat_id) is queue and queue.empty():
+                    self._chat_queues.pop(chat_id, None)
+
+    async def _shutdown_chat_workers(self) -> None:
+        async with self._chat_workers_lock:
+            workers = list(self._chat_workers.values())
+            self._chat_workers = {}
+            self._chat_queues = {}
+
+        for worker in workers:
+            worker.cancel()
+        if workers:
+            await asyncio.gather(*workers, return_exceptions=True)
 
     async def _warmup_llm(self) -> None:
         """Preaquece o LLM no startup do satelite para reduzir latencia do primeiro usuario."""

app/services/domain/rental_service.py

@@ -132,18 +132,18 @@ def _calculate_rental_days(start: datetime, end: datetime) -> int:
 
 
 # Busca o veiculo da locacao por id ou placa normalizada.
-def _lookup_rental_vehicle(
+def _build_rental_vehicle_query(
     db,
     *,
     rental_vehicle_id: int | None = None,
     placa: str | None = None,
-) -> RentalVehicle | None:
+) -> Any:
     if rental_vehicle_id is not None:
-        return db.query(RentalVehicle).filter(RentalVehicle.id == rental_vehicle_id).first()
+        return db.query(RentalVehicle).filter(RentalVehicle.id == rental_vehicle_id)
 
     normalized_plate = technical_normalizer.normalize_plate(placa)
     if normalized_plate:
-        return db.query(RentalVehicle).filter(RentalVehicle.placa == normalized_plate).first()
+        return db.query(RentalVehicle).filter(RentalVehicle.placa == normalized_plate)
 
     raise_tool_http_error(
         status_code=400,
@@ -152,8 +152,34 @@ def _lookup_rental_vehicle(
         retryable=True,
         field="placa",
     )
-    return None
+    return db.query(RentalVehicle).filter(RentalVehicle.id.is_(None))
+
+
+def _lookup_rental_vehicle(
+    db,
+    *,
+    rental_vehicle_id: int | None = None,
+    placa: str | None = None,
+) -> RentalVehicle | None:
+    return _build_rental_vehicle_query(
+        db,
+        rental_vehicle_id=rental_vehicle_id,
+        placa=placa,
+    ).first()
+
 
+# Recupera e trava o veiculo no mesmo turno transacional para evitar dupla locacao.
+def _get_rental_vehicle_for_update(
+    db,
+    *,
+    rental_vehicle_id: int | None = None,
+    placa: str | None = None,
+) -> RentalVehicle | None:
+    return _build_rental_vehicle_query(
+        db,
+        rental_vehicle_id=rental_vehicle_id,
+        placa=placa,
+    ).with_for_update().first()
 
 # Prioriza contratos do proprio usuario antes de cair para contratos sem dono.
 def _lookup_contract_by_user_preference(query, user_id: int | None):
@@ -307,7 +333,11 @@ async def abrir_locacao_aluguel(
 
     db = SessionMockLocal()
     try:
-        vehicle = _lookup_rental_vehicle(db, rental_vehicle_id=vehicle_id, placa=placa)
+        vehicle = _get_rental_vehicle_for_update(
+            db,
+            rental_vehicle_id=vehicle_id,
+            placa=placa,
+        )
         if vehicle is None:
             raise_tool_http_error(
                 status_code=404,

app/services/domain/review_service.py

@@ -4,7 +4,9 @@ from datetime import datetime, timedelta, timezone
 from typing import Any
 
 from fastapi import HTTPException
-from sqlalchemy import func
+from sqlalchemy import func, text
+
+from sqlalchemy.exc import OperationalError, SQLAlchemyError
 
 from app.db.mock_database import SessionMockLocal
 from app.db.mock_models import ReviewSchedule
@@ -132,6 +134,49 @@ def _find_next_available_review_slot(
     return None
 
 
+def _review_slot_lock_name(requested_dt: datetime) -> str:
+    return f"orquestrador:review_slot:{_normalize_review_slot(requested_dt).isoformat()}"
+
+
+def _acquire_review_slot_lock(
+    db,
+    *,
+    requested_dt: datetime,
+    timeout_seconds: int = 5,
+    field_name: str = "data_hora",
+) -> str | None:
+    lock_name = _review_slot_lock_name(requested_dt)
+    try:
+        acquired = db.execute(
+            text("SELECT GET_LOCK(:lock_name, :timeout_seconds)"),
+            {"lock_name": lock_name, "timeout_seconds": timeout_seconds},
+        ).scalar()
+    except (OperationalError, SQLAlchemyError):
+        return None
+
+    if int(acquired or 0) != 1:
+        raise_tool_http_error(
+            status_code=409,
+            code="review_slot_busy",
+            message="Outro atendimento esta finalizando este horario de revisao. Tente novamente.",
+            retryable=True,
+            field=field_name,
+        )
+    return lock_name
+
+
+def _release_review_slot_lock(db, lock_name: str | None) -> None:
+    if not lock_name:
+        return
+    try:
+        db.execute(
+            text("SELECT RELEASE_LOCK(:lock_name)"),
+            {"lock_name": lock_name},
+        )
+    except (OperationalError, SQLAlchemyError):
+        pass
+
+
 def build_review_conflict_detail(
     requested_dt: datetime,
     suggested_dt: datetime | None = None,
@@ -223,7 +268,9 @@ async def agendar_revisao(
     protocolo = f"REV-{dt.strftime('%Y%m%d')}-{entropy}"
 
     db = SessionMockLocal()
+    review_slot_lock_name: str | None = None
     try:
+        review_slot_lock_name = _acquire_review_slot_lock(db, requested_dt=dt)
         conflito_horario = (
             db.query(ReviewSchedule)
             .filter(ReviewSchedule.data_hora == dt)
@@ -279,6 +326,7 @@ async def agendar_revisao(
             "valor_revisao": valor_revisao,
         }
     finally:
+        _release_review_slot_lock(db, review_slot_lock_name)
         db.close()
 
 
@@ -413,6 +461,7 @@ async def editar_data_revisao(
         )
 
     db = SessionMockLocal()
+    review_slot_lock_name: str | None = None
     try:
         agendamento = (
             db.query(ReviewSchedule)
@@ -437,6 +486,13 @@ async def editar_data_revisao(
                 retryable=False,
             )
 
+        if agendamento.data_hora != nova_data:
+            review_slot_lock_name = _acquire_review_slot_lock(
+                db,
+                requested_dt=nova_data,
+                field_name="nova_data_hora",
+            )
+
         conflito = (
             db.query(ReviewSchedule)
             .filter(ReviewSchedule.id != agendamento.id)
@@ -465,4 +521,5 @@ async def editar_data_revisao(
             "status": agendamento.status,
         }
     finally:
+        _release_review_slot_lock(db, review_slot_lock_name)
         db.close()

tests/test_rental_service.py

@@ -1,7 +1,9 @@
 import unittest
 from datetime import datetime
+from types import SimpleNamespace
 from unittest.mock import patch
 
+from fastapi import HTTPException
 from sqlalchemy import create_engine
 from sqlalchemy.orm import sessionmaker
 
@@ -10,6 +12,48 @@ from app.db.mock_models import RentalContract, RentalFine, RentalPayment, Rental
 from app.services.domain import rental_service
 
 
+class RentalLockingQuery:
+    def __init__(self, result):
+        self.result = result
+        self.with_for_update_called = False
+
+    def filter(self, *args, **kwargs):
+        return self
+
+    def with_for_update(self):
+        self.with_for_update_called = True
+        return self
+
+    def first(self):
+        return self.result
+
+
+class RentalLockingSession:
+    def __init__(self, vehicle=None):
+        self.vehicle = vehicle
+        self.query_instance = RentalLockingQuery(vehicle)
+        self.added = []
+        self.committed = False
+        self.closed = False
+        self.refreshed = []
+
+    def query(self, model):
+        if model is rental_service.RentalVehicle:
+            return self.query_instance
+        raise AssertionError(f"unexpected model query: {model}")
+
+    def add(self, item):
+        self.added.append(item)
+
+    def commit(self):
+        self.committed = True
+
+    def refresh(self, item):
+        self.refreshed.append(item)
+
+    def close(self):
+        self.closed = True
+
 class RentalServiceTests(unittest.IsolatedAsyncioTestCase):
     def _build_session_local(self):
         engine = create_engine("sqlite:///:memory:")
@@ -151,6 +195,67 @@ class RentalServiceTests(unittest.IsolatedAsyncioTestCase):
         finally:
             db.close()
 
+    async def test_abrir_locacao_aluguel_uses_row_lock_before_reserving_vehicle(self):
+        vehicle = RentalVehicle(
+            id=8,
+            placa="ABC1D23",
+            modelo="Chevrolet Tracker",
+            categoria="suv",
+            ano=2024,
+            valor_diaria=219.9,
+            status="disponivel",
+        )
+        session = RentalLockingSession(vehicle=vehicle)
+        fake_uuid = SimpleNamespace(hex="abc123def456")
+        fixed_now = datetime(2026, 3, 20, 9, 0)
+
+        with patch.object(rental_service, "SessionMockLocal", return_value=session), patch.object(
+            rental_service,
+            "uuid4",
+            return_value=fake_uuid,
+        ), patch.object(rental_service, "utc_now", return_value=fixed_now):
+            result = await rental_service.abrir_locacao_aluguel(
+                rental_vehicle_id=8,
+                data_inicio="17/03/2026 10:00",
+                data_fim_prevista="20/03/2026 10:00",
+            )
+
+        self.assertTrue(session.query_instance.with_for_update_called)
+        self.assertTrue(session.committed)
+        self.assertEqual(len(session.added), 1)
+        self.assertEqual(session.added[0].rental_vehicle_id, 8)
+        self.assertEqual(vehicle.status, "alugado")
+        self.assertEqual(result["contrato_numero"], "LOC-20260320-ABC123DE")
+        self.assertEqual(result["status_veiculo"], "alugado")
+        self.assertTrue(session.closed)
+
+    async def test_abrir_locacao_aluguel_returns_conflict_when_vehicle_status_is_already_rented_after_lock(self):
+        vehicle = RentalVehicle(
+            id=8,
+            placa="ABC1D23",
+            modelo="Chevrolet Tracker",
+            categoria="suv",
+            ano=2024,
+            valor_diaria=219.9,
+            status="alugado",
+        )
+        session = RentalLockingSession(vehicle=vehicle)
+
+        with patch.object(rental_service, "SessionMockLocal", return_value=session):
+            with self.assertRaises(HTTPException) as ctx:
+                await rental_service.abrir_locacao_aluguel(
+                    rental_vehicle_id=8,
+                    data_inicio="17/03/2026 10:00",
+                    data_fim_prevista="20/03/2026 10:00",
+                )
+
+        self.assertTrue(session.query_instance.with_for_update_called)
+        self.assertEqual(ctx.exception.status_code, 409)
+        self.assertEqual(ctx.exception.detail["code"], "rental_vehicle_unavailable")
+        self.assertFalse(session.committed)
+        self.assertEqual(session.added, [])
+        self.assertTrue(session.closed)
+
     async def test_registrar_devolucao_aluguel_fecha_contrato_e_libera_veiculo(self):
         SessionLocal = self._build_session_local()
         db = SessionLocal()

tests/test_review_service.py

@@ -0,0 +1,133 @@
+import unittest
+from datetime import datetime
+from types import SimpleNamespace
+from unittest.mock import patch
+
+from fastapi import HTTPException
+
+from app.db.mock_models import ReviewSchedule
+from app.services.domain import review_service
+
+
+class ReviewLockingQuery:
+    def __init__(self, results=None):
+        self.results = list(results or [])
+
+    def filter(self, *args, **kwargs):
+        return self
+
+    def first(self):
+        if self.results:
+            return self.results.pop(0)
+        return None
+
+
+class ReviewLockingSession:
+    def __init__(self, *, query_results=None, lock_acquired=1):
+        self.query_instance = ReviewLockingQuery(query_results)
+        self.lock_acquired = lock_acquired
+        self.execute_calls = []
+        self.added = []
+        self.committed = False
+        self.closed = False
+        self.refreshed = []
+
+    def query(self, model):
+        if model is review_service.ReviewSchedule:
+            return self.query_instance
+        raise AssertionError(f"unexpected model query: {model}")
+
+    def execute(self, statement, params=None):
+        sql_text = str(statement)
+        self.execute_calls.append((sql_text, params))
+        if "GET_LOCK" in sql_text:
+            return SimpleNamespace(scalar=lambda: self.lock_acquired)
+        if "RELEASE_LOCK" in sql_text:
+            return SimpleNamespace(scalar=lambda: 1)
+        raise AssertionError(f"unexpected execute call: {sql_text}")
+
+    def add(self, item):
+        self.added.append(item)
+
+    def commit(self):
+        self.committed = True
+
+    def refresh(self, item):
+        self.refreshed.append(item)
+
+    def close(self):
+        self.closed = True
+
+
+class ReviewServiceLockingTests(unittest.IsolatedAsyncioTestCase):
+    def test_acquire_review_slot_lock_returns_conflict_when_slot_is_busy(self):
+        session = ReviewLockingSession(lock_acquired=0)
+
+        with self.assertRaises(HTTPException) as ctx:
+            review_service._acquire_review_slot_lock(
+                session,
+                requested_dt=datetime(2026, 3, 18, 9, 0),
+            )
+
+        self.assertEqual(ctx.exception.status_code, 409)
+        self.assertEqual(ctx.exception.detail["code"], "review_slot_busy")
+        self.assertTrue(any("GET_LOCK" in sql for sql, _ in session.execute_calls))
+
+    async def test_agendar_revisao_uses_slot_lock_and_releases_after_success(self):
+        session = ReviewLockingSession(query_results=[None, None])
+
+        with patch.object(review_service, "SessionMockLocal", return_value=session):
+            result = await review_service.agendar_revisao(
+                placa="ABC1234",
+                data_hora="18/03/2026 09:00",
+                modelo="Onix",
+                ano=2022,
+                km=15000,
+                revisao_previa_concessionaria=False,
+                user_id=7,
+            )
+
+        self.assertTrue(any("GET_LOCK" in sql for sql, _ in session.execute_calls))
+        self.assertTrue(any("RELEASE_LOCK" in sql for sql, _ in session.execute_calls))
+        self.assertTrue(session.committed)
+        self.assertEqual(len(session.added), 1)
+        self.assertEqual(result["status"], "agendado")
+        self.assertTrue(session.closed)
+
+    async def test_editar_data_revisao_releases_slot_lock_when_conflict_is_detected(self):
+        current_schedule = ReviewSchedule(
+            id=1,
+            protocolo="REV-20260318-AAAA1111",
+            user_id=7,
+            placa="ABC1234",
+            data_hora=datetime(2026, 3, 18, 9, 0),
+            status="agendado",
+        )
+        conflicting_schedule = ReviewSchedule(
+            id=2,
+            protocolo="REV-20260319-BBBB2222",
+            user_id=8,
+            placa="XYZ9876",
+            data_hora=datetime(2026, 3, 19, 10, 0),
+            status="agendado",
+        )
+        session = ReviewLockingSession(query_results=[current_schedule, conflicting_schedule])
+
+        with patch.object(review_service, "SessionMockLocal", return_value=session):
+            with self.assertRaises(HTTPException) as ctx:
+                await review_service.editar_data_revisao(
+                    protocolo=current_schedule.protocolo,
+                    nova_data_hora="19/03/2026 10:00",
+                    user_id=7,
+                )
+
+        self.assertTrue(any("GET_LOCK" in sql for sql, _ in session.execute_calls))
+        self.assertTrue(any("RELEASE_LOCK" in sql for sql, _ in session.execute_calls))
+        self.assertEqual(ctx.exception.status_code, 409)
+        self.assertEqual(ctx.exception.detail["code"], "review_schedule_conflict")
+        self.assertFalse(session.committed)
+        self.assertTrue(session.closed)
+
+
+if __name__ == "__main__":
+    unittest.main()

tests/test_telegram_multimodal.py

@@ -1,4 +1,5 @@
 import unittest
+import asyncio
 from types import SimpleNamespace
 from unittest.mock import AsyncMock, patch
 
@@ -11,8 +12,14 @@ class _DummySession:
 
 
 class TelegramMultimodalTests(unittest.IsolatedAsyncioTestCase):
+    async def asyncTearDown(self):
+        service = getattr(self, "_service_under_test", None)
+        if service is not None:
+            await service._shutdown_chat_workers()
+
     async def test_process_message_uses_extracted_image_message(self):
         service = TelegramSatelliteService("token-teste")
+        self._service_under_test = service
         tools_db = _DummySession()
         mock_db = _DummySession()
 
@@ -44,6 +51,7 @@ class TelegramMultimodalTests(unittest.IsolatedAsyncioTestCase):
 
     async def test_process_message_returns_direct_failure_for_unreadable_image(self):
         service = TelegramSatelliteService("token-teste")
+        self._service_under_test = service
         tools_db = _DummySession()
         mock_db = _DummySession()
 
@@ -72,6 +80,7 @@ class TelegramMultimodalTests(unittest.IsolatedAsyncioTestCase):
 
     async def test_process_message_returns_direct_failure_for_receipt_without_watermark(self):
         service = TelegramSatelliteService("token-teste")
+        self._service_under_test = service
         tools_db = _DummySession()
         mock_db = _DummySession()
 
@@ -97,3 +106,68 @@ class TelegramMultimodalTests(unittest.IsolatedAsyncioTestCase):
 
         self.assertIn("marca d'agua SysaltiIA visivel", answer)
         self.assertFalse(orchestrator_cls.return_value.handle_message.await_count)
+
+    async def test_schedule_update_processing_allows_parallel_chats(self):
+        service = TelegramSatelliteService("token-teste")
+        self._service_under_test = service
+        release_first_chat = asyncio.Event()
+        chat_one_started = asyncio.Event()
+        started_chats: list[int] = []
+
+        async def fake_handle_update(*, session, update):
+            chat_id = update["message"]["chat"]["id"]
+            started_chats.append(chat_id)
+            if chat_id == 1:
+                chat_one_started.set()
+                await release_first_chat.wait()
+
+        with patch.object(service, "_handle_update", new=fake_handle_update):
+            await service._schedule_update_processing(
+                session=SimpleNamespace(),
+                update={"update_id": 1, "message": {"chat": {"id": 1}, "text": "primeiro"}},
+            )
+            await chat_one_started.wait()
+            await service._schedule_update_processing(
+                session=SimpleNamespace(),
+                update={"update_id": 2, "message": {"chat": {"id": 2}, "text": "segundo"}},
+            )
+            await asyncio.sleep(0)
+
+        self.assertEqual(started_chats, [1, 2])
+        release_first_chat.set()
+        await asyncio.sleep(0)
+
+    async def test_schedule_update_processing_preserves_order_per_chat(self):
+        service = TelegramSatelliteService("token-teste")
+        self._service_under_test = service
+        first_started = asyncio.Event()
+        allow_first_to_finish = asyncio.Event()
+        second_started = asyncio.Event()
+        started_updates: list[int] = []
+
+        async def fake_handle_update(*, session, update):
+            update_id = update["update_id"]
+            started_updates.append(update_id)
+            if update_id == 1:
+                first_started.set()
+                await allow_first_to_finish.wait()
+                return
+            second_started.set()
+
+        with patch.object(service, "_handle_update", new=fake_handle_update):
+            await service._schedule_update_processing(
+                session=SimpleNamespace(),
+                update={"update_id": 1, "message": {"chat": {"id": 1}, "text": "primeiro"}},
+            )
+            await first_started.wait()
+            await service._schedule_update_processing(
+                session=SimpleNamespace(),
+                update={"update_id": 2, "message": {"chat": {"id": 1}, "text": "segundo"}},
+            )
+            await asyncio.sleep(0)
+            self.assertFalse(second_started.is_set())
+
+            allow_first_to_finish.set()
+            await asyncio.wait_for(second_started.wait(), timeout=1)
+
+        self.assertEqual(started_updates, [1, 2])