rebuild(stage-3): establish accounts permissions and secure settings

next/backend/http/errors.py

@@ -9,10 +9,12 @@ from fastapi.exceptions import RequestValidationError
 from fastapi.responses import JSONResponse
 from starlette.exceptions import HTTPException
 
+from backend.errors import BusinessError
+
 logger = logging.getLogger(__name__)
 
 
-@dataclass(frozen=True, slots=True)
+@dataclass(slots=True)
 class AppError(Exception):
     code: str
     message: str
@@ -39,6 +41,23 @@ def _response(request: Request, status_code: int, code: str, message: str) -> JS
 
 
 def install_error_handlers(application: FastAPI) -> None:
+    @application.exception_handler(BusinessError)
+    async def business_error(request: Request, error: BusinessError) -> JSONResponse:
+        status_code = {
+            "invalid_credentials": HTTPStatus.UNAUTHORIZED,
+            "account_unavailable": HTTPStatus.FORBIDDEN,
+            "username_taken": HTTPStatus.CONFLICT,
+            "account_not_found": HTTPStatus.NOT_FOUND,
+            "model_not_found": HTTPStatus.NOT_FOUND,
+            "permanent_membership": HTTPStatus.CONFLICT,
+            "model_in_use": HTTPStatus.CONFLICT,
+            "model_name_taken": HTTPStatus.CONFLICT,
+            "model_pool_full": HTTPStatus.CONFLICT,
+            "model_not_configured": HTTPStatus.SERVICE_UNAVAILABLE,
+            "profile_unavailable": HTTPStatus.SERVICE_UNAVAILABLE,
+        }.get(error.code, HTTPStatus.BAD_REQUEST)
+        return _response(request, status_code, error.code, error.message)
+
     @application.exception_handler(AppError)
     async def application_error(request: Request, error: AppError) -> JSONResponse:
         return _response(request, error.status_code, error.code, error.message)