import streamlit as st
import tempfile
import json

def add_upload(choice):
    """
    Provdies the user with choice to either 'Upload Document' or 'Try Example'.
    Based on user choice runs streamlit processes and save the path and name of
    the 'file' to streamlit session_state which then can be fetched later.

    """
    
    if choice == 'Upload Document':
        
       # if 'filename' in st.session_state:
          # Delete all the items in Session state
        #    for key in st.session_state.keys():
         #       del st.session_state[key]

        uploaded_file = st.sidebar.file_uploader('Upload the File',
                            type=['pdf', 'docx', 'txt'])
        if uploaded_file is not None:
            with tempfile.NamedTemporaryFile(mode="wb", delete = False) as temp:
                bytes_data = uploaded_file.getvalue()
                temp.write(bytes_data)
                st.session_state['filename'] = uploaded_file.name
                st.session_state['filepath'] = temp.name

                
    else:
        # listing the options
        with open('docStore/sample/files.json','r') as json_file:
            files = json.load(json_file)

        option = st.sidebar.selectbox('Select the example document',
                              list(files.keys()))
        file_name = file_path  = files[option]
        st.session_state['filename'] = file_name
        st.session_state['filepath'] = file_path