feat: implement local authentication mode and update related components

backend/app/core/auth.py

@@ -1,8 +1,9 @@
-"""User authentication helpers backed by Clerk JWT verification."""
+"""User authentication helpers for Clerk and local-token auth modes."""
 
 from __future__ import annotations
 
 from dataclasses import dataclass
+from hmac import compare_digest
 from typing import TYPE_CHECKING, Literal
 
 import httpx
@@ -29,6 +30,9 @@ logger = get_logger(__name__)
 security = HTTPBearer(auto_error=False)
 SECURITY_DEP = Depends(security)
 SESSION_DEP = Depends(get_session)
+LOCAL_AUTH_USER_ID = "local-auth-user"
+LOCAL_AUTH_EMAIL = "admin@home.local"
+LOCAL_AUTH_NAME = "Local User"
 
 
 class ClerkTokenPayload(BaseModel):
@@ -45,6 +49,18 @@ class AuthContext:
     user: User | None = None
 
 
+def _extract_bearer_token(authorization: str | None) -> str | None:
+    if not authorization:
+        return None
+    value = authorization.strip()
+    if not value:
+        return None
+    if not value.lower().startswith("bearer "):
+        return None
+    token = value.split(" ", maxsplit=1)[1].strip()
+    return token or None
+
+
 def _non_empty_str(value: object) -> str | None:
     if not isinstance(value, str):
         return None
@@ -228,6 +244,9 @@ async def _fetch_clerk_profile(clerk_user_id: str) -> tuple[str | None, str | No
 
 async def delete_clerk_user(clerk_user_id: str) -> None:
     """Delete a Clerk user via the official Clerk SDK."""
+    if settings.auth_mode != "clerk":
+        return
+
     secret = settings.clerk_secret_key.strip()
     secret_kind = secret.split("_", maxsplit=1)[0] if "_" in secret else "unknown"
     server_url = _normalize_clerk_server_url(settings.clerk_api_url or "")
@@ -343,6 +362,55 @@ async def _get_or_sync_user(
     return user
 
 
+async def _get_or_create_local_user(session: AsyncSession) -> User:
+    defaults: dict[str, object] = {
+        "email": LOCAL_AUTH_EMAIL,
+        "name": LOCAL_AUTH_NAME,
+    }
+    user, _created = await crud.get_or_create(
+        session,
+        User,
+        clerk_user_id=LOCAL_AUTH_USER_ID,
+        defaults=defaults,
+    )
+    changed = False
+    if not user.email:
+        user.email = LOCAL_AUTH_EMAIL
+        changed = True
+    if not user.name:
+        user.name = LOCAL_AUTH_NAME
+        changed = True
+    if changed:
+        session.add(user)
+        await session.commit()
+        await session.refresh(user)
+
+    from app.services.organizations import ensure_member_for_user
+
+    await ensure_member_for_user(session, user)
+    return user
+
+
+async def _resolve_local_auth_context(
+    *,
+    request: Request,
+    session: AsyncSession,
+    required: bool,
+) -> AuthContext | None:
+    token = _extract_bearer_token(request.headers.get("Authorization"))
+    if token is None:
+        if required:
+            raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED)
+        return None
+    expected = settings.local_auth_token.strip()
+    if not expected or not compare_digest(token, expected):
+        if required:
+            raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED)
+        return None
+    user = await _get_or_create_local_user(session)
+    return AuthContext(actor_type="user", user=user)
+
+
 def _parse_subject(claims: dict[str, object]) -> str | None:
     payload = ClerkTokenPayload.model_validate(claims)
     return payload.sub
@@ -353,7 +421,17 @@ async def get_auth_context(
     credentials: HTTPAuthorizationCredentials | None = SECURITY_DEP,
     session: AsyncSession = SESSION_DEP,
 ) -> AuthContext:
-    """Resolve required authenticated user context from Clerk JWT headers."""
+    """Resolve required authenticated user context for the configured auth mode."""
+    if settings.auth_mode == "local":
+        local_auth = await _resolve_local_auth_context(
+            request=request,
+            session=session,
+            required=True,
+        )
+        if local_auth is None:  # pragma: no cover
+            raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED)
+        return local_auth
+
     request_state = await _authenticate_clerk_request(request)
     if request_state.status != AuthStatus.SIGNED_IN or not isinstance(request_state.payload, dict):
         raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED)
@@ -388,6 +466,13 @@ async def get_auth_context_optional(
     """Resolve user context if available, otherwise return `None`."""
     if request.headers.get("X-Agent-Token"):
         return None
+    if settings.auth_mode == "local":
+        return await _resolve_local_auth_context(
+            request=request,
+            session=session,
+            required=False,
+        )
+
     request_state = await _authenticate_clerk_request(request)
     if request_state.status != AuthStatus.SIGNED_IN or not isinstance(request_state.payload, dict):
         return None