feat: add FastAPI manager API compatibility baseline

main/manager-api-fastapi/app/core/responses.py

@@ -0,0 +1,66 @@
+from __future__ import annotations
+
+import json
+from typing import Any
+
+from fastapi import Request
+from starlette.responses import JSONResponse, Response
+
+from app.core.i18n import message_for
+from app.core.serialization import java_compatible
+
+
+class JavaJSONResponse(JSONResponse):
+    def render(self, content: Any) -> bytes:
+        return json.dumps(
+            java_compatible(content),
+            ensure_ascii=False,
+            allow_nan=False,
+            separators=(",", ":"),
+        ).encode("utf-8")
+
+
+def envelope(data: Any = None, *, code: int = 0, msg: str = "success") -> dict[str, Any]:
+    return {"code": code, "msg": msg, "data": data}
+
+
+def ok(data: Any = None) -> JavaJSONResponse:
+    return JavaJSONResponse(envelope(data))
+
+
+def error_response(
+    request: Request,
+    code: int,
+    message: str | None = None,
+    *,
+    status_code: int = 200,
+    params: tuple[object, ...] = (),
+    media_type: str = "application/json",
+) -> JavaJSONResponse:
+    translated = message or message_for(code, request.headers.get("Accept-Language"), *params)
+    return JavaJSONResponse(
+        envelope(None, code=code, msg=translated),
+        status_code=status_code,
+        media_type=media_type,
+    )
+
+
+def raw_json(content: Any, *, exclude_none: bool = False, status_code: int = 200) -> Response:
+    normalized = java_compatible(content)
+    if exclude_none:
+        normalized = _drop_none(normalized)
+    body = json.dumps(normalized, ensure_ascii=False, allow_nan=False, separators=(",", ":")).encode("utf-8")
+    return Response(
+        body,
+        status_code=status_code,
+        media_type="application/json",
+        headers={"Content-Length": str(len(body))},
+    )
+
+
+def _drop_none(value: Any) -> Any:
+    if isinstance(value, dict):
+        return {key: _drop_none(item) for key, item in value.items() if item is not None}
+    if isinstance(value, list):
+        return [_drop_none(item) for item in value]
+    return value