Primera versión del backend

backend/app/core/errors.py

@@ -0,0 +1,56 @@
+from fastapi import FastAPI, Request
+from fastapi.exceptions import RequestValidationError
+from fastapi.responses import ORJSONResponse
+from starlette.exceptions import HTTPException as StarletteHTTPException
+
+
+class AppError(Exception):
+    def __init__(self, message: str, status_code: int = 400, code: str = "app_error") -> None:
+        self.message = message
+        self.status_code = status_code
+        self.code = code
+
+
+class NotFoundError(AppError):
+    def __init__(self, message: str = "Resource not found") -> None:
+        super().__init__(message=message, status_code=404, code="not_found")
+
+
+class LLMUnavailableError(AppError):
+    def __init__(self, message: str = "LLM service is unavailable") -> None:
+        super().__init__(message=message, status_code=503, code="llm_unavailable")
+
+
+class ParseError(AppError):
+    def __init__(self, message: str = "Unable to parse AI output") -> None:
+        super().__init__(message=message, status_code=422, code="parse_error")
+
+
+def error_payload(code: str, message: str, details: object | None = None) -> dict[str, object]:
+    payload: dict[str, object] = {"error": {"code": code, "message": message}}
+    if details is not None:
+        payload["error"]["details"] = details
+    return payload
+
+
+def register_exception_handlers(app: FastAPI) -> None:
+    @app.exception_handler(AppError)
+    async def app_error_handler(_: Request, exc: AppError) -> ORJSONResponse:
+        return ORJSONResponse(
+            status_code=exc.status_code,
+            content=error_payload(exc.code, exc.message),
+        )
+
+    @app.exception_handler(StarletteHTTPException)
+    async def http_error_handler(_: Request, exc: StarletteHTTPException) -> ORJSONResponse:
+        return ORJSONResponse(
+            status_code=exc.status_code,
+            content=error_payload("http_error", str(exc.detail)),
+        )
+
+    @app.exception_handler(RequestValidationError)
+    async def validation_error_handler(_: Request, exc: RequestValidationError) -> ORJSONResponse:
+        return ORJSONResponse(
+            status_code=422,
+            content=error_payload("validation_error", "Invalid request payload", exc.errors()),
+        )