feat(backend): expose GET /api/v1/alerts

Consultation des alertes de consommation, filtrable par site_id et
severity a l'identique du contrat GET /alerts de l'API Mock. Reprend
le gabarit endpoints -> services -> repositories -> models pose par
sites, sur la table alert deja creee par la revision Alembic
e6d2026091501.

Generalise aussi le garde-fou OpenAPI du 403 (ROUTES_A_ROLE) au-dela
du seul tag users, pour que l'ajout d'alerts a la liste des routes
protegees par role soit reellement verifie.

Closes #59

apps/backend/app/api/deps.py

@@ -21,11 +21,13 @@ from app.core.roles import AccountKind, Role, has_at_least
 from app.core.security import TokenExpiredError, TokenInvalidError, TokenPolicy
 from app.core.security import decode_access_token as decode_token
 from app.db.session import get_session
+from app.repositories.alert import AlertRepository
 from app.repositories.audit_log import AuditLogRepository
 from app.repositories.login_attempt import LoginAttemptRepository
 from app.repositories.refresh_token import RefreshTokenRepository
 from app.repositories.site import SiteRepository
 from app.repositories.user import UserRepository
+from app.services.alert import AlertService
 from app.services.auth import AuthService, LoginPolicy
 from app.services.site import SiteService
 from app.services.user import UserService
@@ -140,6 +142,13 @@ def get_site_service(session: SessionDep) -> SiteService:
 SiteServiceDep = Annotated[SiteService, Depends(get_site_service)]
 
 
+def get_alert_service(session: SessionDep) -> AlertService:
+    return AlertService(alerts=AlertRepository(session))
+
+
+AlertServiceDep = Annotated[AlertService, Depends(get_alert_service)]
+
+
 async def get_current_principal(
     credentials: CredentialsDep,
     session: SessionDep,

apps/backend/app/api/openapi.py

@@ -54,6 +54,11 @@ TAGS: Final[list[dict[str, Any]]] = [
         "name": "sites",
         "description": "Consultation du parc de sites. Accessible à partir du rôle `lecteur`.",
     },
+    {
+        "name": "alerts",
+        "description": "Consultation des alertes de consommation. Accessible à partir du rôle "
+        "`lecteur`.",
+    },
 ]
 
 cookie_de_rafraichissement = APIKeyCookie(

apps/backend/app/api/v1/endpoints/alerts.py

@@ -0,0 +1,23 @@
+from fastapi import APIRouter
+
+from app.api.deps import AlertServiceDep, LecteurDep
+from app.api.openapi import REPONSE_VALIDATION
+from app.schemas.alert import AlertResponse, AlertSeverity
+
+router = APIRouter()
+
+
+@router.get(
+    "",
+    response_model=list[AlertResponse],
+    summary="Liste les alertes",
+    responses=REPONSE_VALIDATION,
+)
+async def list_alerts(
+    _: LecteurDep,
+    service: AlertServiceDep,
+    site_id: str | None = None,
+    severity: AlertSeverity | None = None,
+) -> list[AlertResponse]:
+    alertes = await service.list_all(site_id=site_id, severity=severity)
+    return [AlertResponse.model_validate(alerte) for alerte in alertes]

apps/backend/app/api/v1/router.py

@@ -1,10 +1,13 @@
 from fastapi import APIRouter
 
 from app.api.openapi import REPONSE_SERVEUR, REPONSES_ADMIN, REPONSES_LECTEUR
-from app.api.v1.endpoints import auth, health, sites, users
+from app.api.v1.endpoints import alerts, auth, health, sites, users
 
 api_router = APIRouter(responses=REPONSE_SERVEUR)
 api_router.include_router(health.router, prefix="/health", tags=["health"])
 api_router.include_router(auth.router, prefix="/auth", tags=["auth"])
 api_router.include_router(users.router, prefix="/users", tags=["users"], responses=REPONSES_ADMIN)
 api_router.include_router(sites.router, prefix="/sites", tags=["sites"], responses=REPONSES_LECTEUR)
+api_router.include_router(
+    alerts.router, prefix="/alerts", tags=["alerts"], responses=REPONSES_LECTEUR
+)

apps/backend/app/repositories/alert.py

@@ -0,0 +1,21 @@
+from collections.abc import Sequence
+
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.models.energy import Alert
+
+
+class AlertRepository:
+    def __init__(self, session: AsyncSession) -> None:
+        self._session = session
+
+    async def list_all(
+        self, *, site_id: str | None = None, severity: str | None = None
+    ) -> Sequence[Alert]:
+        requete = select(Alert).order_by(Alert.timestamp.desc(), Alert.alert_id.desc())
+        if site_id is not None:
+            requete = requete.where(Alert.site_id == site_id)
+        if severity is not None:
+            requete = requete.where(Alert.severity == severity)
+        return (await self._session.scalars(requete)).all()

apps/backend/app/schemas/alert.py

@@ -0,0 +1,34 @@
+from datetime import datetime
+from enum import StrEnum
+
+from pydantic import BaseModel, ConfigDict
+
+
+class AlertType(StrEnum):
+    SPIKE = "spike"
+    THRESHOLD = "threshold"
+    ANOMALY = "anomaly"
+    OUTAGE = "outage"
+    SENSOR = "sensor"
+
+
+class AlertSeverity(StrEnum):
+    LOW = "low"
+    MEDIUM = "medium"
+    HIGH = "high"
+    CRITICAL = "critical"
+
+
+class AlertResponse(BaseModel):
+    model_config = ConfigDict(from_attributes=True)
+
+    alert_id: int
+    site_id: str
+    timestamp: datetime
+    type: AlertType
+    severity: AlertSeverity
+    message: str
+    value: float | None
+    threshold: float | None
+    metric: str | None
+    prediction_id: int | None

apps/backend/app/services/alert.py

@@ -0,0 +1,14 @@
+from collections.abc import Sequence
+
+from app.models.energy import Alert
+from app.repositories.alert import AlertRepository
+
+
+class AlertService:
+    def __init__(self, *, alerts: AlertRepository) -> None:
+        self._alerts = alerts
+
+    async def list_all(
+        self, *, site_id: str | None = None, severity: str | None = None
+    ) -> Sequence[Alert]:
+        return await self._alerts.list_all(site_id=site_id, severity=severity)