Python-code moved to backend/ directory.

backend/app/auth.py

@@ -0,0 +1,66 @@
+from datetime import datetime, timedelta
+from typing import Optional
+
+from fastapi import Depends, HTTPException, status
+from fastapi.security import OAuth2PasswordBearer, OAuth2PasswordRequestForm
+from jose import jwt, JWTError
+from passlib.context import CryptContext
+from sqlalchemy.orm import Session
+
+from .db import SessionLocal
+from . import models
+from .config import settings
+
+SECRET_KEY = settings.secret_key
+ALGORITHM = "HS256"
+ACCESS_TOKEN_EXPIRE_MINUTES = 60
+
+pwd_context = CryptContext(schemes=["bcrypt_sha256"], deprecated="auto")
+oauth2_scheme = OAuth2PasswordBearer(tokenUrl="/auth/token")
+
+def get_db():
+    db = SessionLocal()
+    try:
+        yield db
+    finally:
+        db.close()
+
+def verify_password(plain_password, hashed_password):
+    return pwd_context.verify(plain_password, hashed_password)
+
+def get_password_hash(password):
+    return pwd_context.hash(password)
+
+def authenticate_user(db: Session, username: str, password: str) -> Optional[models.User]:
+    user = db.query(models.User).filter(models.User.username == username).first()
+    if not user or not verify_password(password, user.password_hash):
+        return None
+    return user
+
+def create_access_token(data: dict, expires_delta: Optional[timedelta] = None):
+    to_encode = data.copy()
+    expire = datetime.utcnow() + (expires_delta or timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES))
+    to_encode.update({"exp": expire})
+    return jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
+
+async def get_current_user(
+    token: str = Depends(oauth2_scheme),
+    db: Session = Depends(get_db),
+) -> models.User:
+    credentials_exception = HTTPException(
+        status_code=status.HTTP_401_UNAUTHORIZED,
+        detail="Could not validate credentials",
+        headers={"WWW-Authenticate": "Bearer"},
+    )
+    try:
+        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
+        username: str | None = payload.get("preferred_username") or payload.get("sub")
+        if username is None:
+            raise credentials_exception
+    except JWTError:
+        raise credentials_exception
+    user = db.query(models.User).filter(models.User.username == username).first()
+    if user is None:
+        raise credentials_exception
+    return user
+