import jwt
import os
from datetime import datetime, timedelta, timezone
from dotenv import load_dotenv

load_dotenv()

SECRET_KEY = os.getenv("SECRET_KEY")

def generate_jwt(user_id, username, email):
    payload = {
        "user_id": str(user_id),
        "username": username,
        "email": email,
        "exp": datetime.now(timezone.utc) + timedelta(days=7),
        "iat": datetime.now(timezone.utc)
    }
    return jwt.encode(payload, SECRET_KEY, algorithm="HS256")

def decode_jwt(token):
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=["HS256"])
        return payload
    except jwt.ExpiredSignatureError:
        raise Exception("Token has expired")
    except jwt.InvalidTokenError:
        raise Exception("Invalid token")