update auth.py

backend/auth.py

@@ -2,6 +2,7 @@ from database import execute, fetch_one
 import bcrypt
 from jose import jwt, JWTError
 from datetime import datetime, timedelta
+from fastapi import Header, HTTPException   
 
 SECRET_KEY = ""
 ALGORITHM = "HS256"
@@ -56,4 +57,35 @@ def verify_user(username, password):
     ):
         return user["id"]
 
-    return None
+    return None
+
+
+def get_current_user(authorization: str = Header(None)):
+
+    if authorization is None:
+        raise HTTPException(
+            status_code=401,
+            detail="Missing token"
+        )
+
+    try:
+        scheme, token = authorization.split(" ")
+
+        if scheme.lower() != "bearer":
+            raise Exception()
+
+        payload = jwt.decode(
+            token,
+            SECRET_KEY,
+            algorithms=[ALGORITHM]
+        )
+
+        user_id = payload["user_id"]
+
+        return user_id
+
+    except JWTError:
+        raise HTTPException(
+            status_code=401,
+            detail="Invalid token"
+        )