Ahmed-Raza/phase-3-backend

1from fastapi import HTTPException, status, Depends2from fastapi.security import HTTPBearer, HTTPAuthorizationCredentials3import jwt4import os5from datetime import datetime, timedelta6 7# Get secret from environment8SECRET_KEY = os.getenv("JWT_SECRET", "fallback-secret-key-for-development")9ALGORITHM = "HS256"10 11security = HTTPBearer()12 13def verify_token(token: str) -> dict:14    """Verify JWT token and return payload"""15    try:16        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])17        return payload18    except jwt.ExpiredSignatureError:19        raise HTTPException(20            status_code=status.HTTP_401_UNAUTHORIZED,21            detail="Token has expired",22            headers={"WWW-Authenticate": "Bearer"},23        )24    except jwt.JWTError:25        raise HTTPException(26            status_code=status.HTTP_401_UNAUTHORIZED,27            detail="Could not validate credentials",28            headers={"WWW-Authenticate": "Bearer"},29        )30 31async def get_current_user(credentials: HTTPAuthorizationCredentials = Depends(security)) -> str:32    """Get current user ID from JWT token"""33    token = credentials.credentials34    payload = verify_token(token)35    user_id: str = payload.get("sub")36 37    if user_id is None:38        raise HTTPException(39            status_code=status.HTTP_401_UNAUTHORIZED,40            detail="Could not validate credentials",41            headers={"WWW-Authenticate": "Bearer"},42        )43 44    return user_id45 46def create_access_token(data: dict, expires_delta=None):47    """Create JWT access token"""48    to_encode = data.copy()49    if expires_delta:50        expire = datetime.utcnow() + expires_delta51    else:52        # Default to 7 days expiration53        expire = datetime.utcnow() + timedelta(days=7)54 55    to_encode.update({"exp": expire})56    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)57    return encoded_jwt