first commit

backend/app/dependencies.py

@@ -0,0 +1,58 @@
+from datetime import datetime, timedelta, timezone
+from typing import Optional
+from fastapi import Depends, HTTPException, status
+from fastapi.security import HTTPBearer, HTTPAuthorizationCredentials
+from jose import JWTError, jwt
+from app.config import get_settings
+from app.database import get_db
+
+settings = get_settings()
+bearer_scheme = HTTPBearer(auto_error=False)
+
+
+def create_access_token(data: dict) -> str:
+    payload = data.copy()
+    expire = datetime.now(timezone.utc) + timedelta(hours=settings.jwt_expire_hours)
+    payload.update({"exp": expire, "iat": datetime.now(timezone.utc)})
+    return jwt.encode(payload, settings.jwt_secret, algorithm=settings.jwt_algorithm)
+
+
+def decode_token(token: str) -> Optional[dict]:
+    try:
+        return jwt.decode(
+            token,
+            settings.jwt_secret,
+            algorithms=[settings.jwt_algorithm],
+        )
+    except JWTError:
+        return None
+
+
+async def get_current_user(
+    credentials: Optional[HTTPAuthorizationCredentials] = Depends(bearer_scheme),
+    db=Depends(get_db),
+):
+    """FastAPI dependency: validates JWT and returns the current user doc."""
+    if not credentials:
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="Not authenticated",
+            headers={"WWW-Authenticate": "Bearer"},
+        )
+
+    payload = decode_token(credentials.credentials)
+    if not payload:
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="Invalid or expired token",
+            headers={"WWW-Authenticate": "Bearer"},
+        )
+
+    user = await db["users"].find_one({"google_id": payload.get("sub")})
+    if not user:
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="User not found",
+        )
+
+    return user