feat: add JWT auth module

backend/app/auth.py

@@ -0,0 +1,51 @@
+from datetime import datetime, timedelta, timezone
+from typing import Optional
+from jose import JWTError, jwt
+from passlib.context import CryptContext
+from fastapi import Cookie, HTTPException, status, Depends
+from sqlalchemy.orm import Session
+from app.database import get_db, settings
+from app import models
+
+pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")
+
+
+def hash_password(password: str) -> str:
+    return pwd_context.hash(password)
+
+
+def verify_password(plain: str, hashed: str) -> bool:
+    return pwd_context.verify(plain, hashed)
+
+
+def create_access_token(user_id: int) -> str:
+    expire = datetime.now(timezone.utc) + timedelta(minutes=settings.jwt_expire_minutes)
+    return jwt.encode(
+        {"sub": str(user_id), "exp": expire},
+        settings.jwt_secret_key,
+        algorithm=settings.jwt_algorithm,
+    )
+
+
+def get_current_user(
+    access_token: Optional[str] = Cookie(default=None),
+    db: Session = Depends(get_db),
+) -> models.User:
+    credentials_exception = HTTPException(
+        status_code=status.HTTP_401_UNAUTHORIZED,
+        detail="Not authenticated",
+    )
+    if not access_token:
+        raise credentials_exception
+    try:
+        payload = jwt.decode(access_token, settings.jwt_secret_key, algorithms=[settings.jwt_algorithm])
+        user_id: str = payload.get("sub")
+        if user_id is None:
+            raise credentials_exception
+    except JWTError:
+        raise credentials_exception
+
+    user = db.get(models.User, int(user_id))
+    if user is None or not user.is_active:
+        raise credentials_exception
+    return user