add api/v1/text_labels/valid_labels backend endpoint (#498)

Provides the set of valid text_lables with descriptions via a REST endpoint.

backend/oasst_backend/api/v1/text_labels.py

@@ -3,6 +3,7 @@ from fastapi.security.api_key import APIKey
 from loguru import logger
 from oasst_backend.api import deps
 from oasst_backend.prompt_repository import PromptRepository
+from oasst_backend.schemas.text_labels import LabelOption, ValidLabelsResponse
 from oasst_shared.schemas import protocol as protocol_schema
 from sqlmodel import Session
 from starlette.status import HTTP_204_NO_CONTENT, HTTP_400_BAD_REQUEST
@@ -32,3 +33,10 @@ def label_text(
         raise HTTPException(
             status_code=HTTP_400_BAD_REQUEST,
         )
+
+
+@router.get("/valid_labels")
+def get_valid_lables() -> ValidLabelsResponse:
+    return ValidLabelsResponse(
+        valid_labels=[LabelOption(name=l.value, description=l.description) for l in protocol_schema.TextLabel]
+    )

backend/oasst_backend/schemas/text_labels.py

@@ -0,0 +1,10 @@
+from pydantic import BaseModel
+
+
+class LabelOption(BaseModel):
+    name: str
+    description: str
+
+
+class ValidLabelsResponse(BaseModel):
+    valid_labels: list[LabelOption]