initial commit

backend/app/auth.py

@@ -0,0 +1,61 @@
+"""FluentGerman.ai — Authentication & authorization utilities."""
+
+from datetime import datetime, timedelta, timezone
+
+import bcrypt
+from fastapi import Depends, HTTPException, status
+from fastapi.security import OAuth2PasswordBearer
+from jose import JWTError, jwt
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.config import get_settings
+from app.database import get_db
+from app.models import User
+
+oauth2_scheme = OAuth2PasswordBearer(tokenUrl="/api/auth/login")
+
+
+def hash_password(password: str) -> str:
+    return bcrypt.hashpw(password.encode(), bcrypt.gensalt()).decode()
+
+
+def verify_password(plain: str, hashed: str) -> bool:
+    return bcrypt.checkpw(plain.encode(), hashed.encode())
+
+
+def create_access_token(data: dict) -> str:
+    settings = get_settings()
+    expire = datetime.now(timezone.utc) + timedelta(minutes=settings.access_token_expire_minutes)
+    to_encode = {**data, "exp": expire}
+    return jwt.encode(to_encode, settings.secret_key, algorithm=settings.algorithm)
+
+
+async def get_current_user(
+    token: str = Depends(oauth2_scheme),
+    db: AsyncSession = Depends(get_db),
+) -> User:
+    credentials_exc = HTTPException(
+        status_code=status.HTTP_401_UNAUTHORIZED,
+        detail="Invalid credentials",
+        headers={"WWW-Authenticate": "Bearer"},
+    )
+    try:
+        payload = jwt.decode(token, get_settings().secret_key, algorithms=[get_settings().algorithm])
+        user_id: int | None = payload.get("sub")
+        if user_id is None:
+            raise credentials_exc
+    except JWTError:
+        raise credentials_exc
+
+    result = await db.execute(select(User).where(User.id == int(user_id)))
+    user = result.scalar_one_or_none()
+    if user is None or not user.is_active:
+        raise credentials_exc
+    return user
+
+
+async def require_admin(user: User = Depends(get_current_user)) -> User:
+    if not user.is_admin:
+        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Admin access required")
+    return user