import time
import streamlit as st


def clear_uploader():
    st.rerun()

def undo():
    if len(st.session_state.messages) > 0:
        st.query_params.clear()
        msg = st.session_state.messages.pop()
        time.sleep(0.1)
        st.rerun()

def restart():
    st.query_params.clear()
    st.session_state.messages = []
    st.session_state.cost = []
    time.sleep(0.2)
    clear_uploader()