"""
Python Backend API to chat with private data  

08/17/2023
D.M. Theekshana Samaradiwakara
"""

import os
import streamlit as st
from streamlit.logger import get_logger
from io import StringIO

logger = get_logger(__name__)

from dataPipeline import DataPipeline

def initialize_session_state():
    # Initialise all session state variables with defaults
    SESSION_DEFAULTS = {
        "data_index": None,
        "published_year": 2023,
        "is_parameters_changed":False,
        "is_input_validated":False,
    }

    for k, v in SESSION_DEFAULTS.items():
        if k not in st.session_state:
            st.session_state[k] = v

def update_parameters_change():
    st.session_state.is_parameters_changed = True

def validate_index():
    index = st.session_state.data_index
    if (not index) or  (not index.strip()):
        st.error("Empty index directory name!")
        st.stop()

    st.info(f"file persist directory name: {index}")

def validate_files(uploaded_file):
    if not uploaded_file:
        st.error("No uploaded files to process!")
        st.stop()

    st.info(f"No of files uploaded       : {len(uploaded_file)}")

def validate_published_year():
    if not st.session_state.published_year:
        st.error("Invalid year!")
        st.stop()

    st.info(f"file published year        : {st.session_state.published_year}")

def validate_inputs(uploaded_file):
    validate_index()
    validate_published_year()
    validate_files(uploaded_file)

    return True


def process_files(uploaded_files, data_index):

    try:
        
        st.info(uploaded_files)
        dataPipe = DataPipeline()

        documents = dataPipe.load_streamlit_documents(uploaded_files, st.session_state.published_year)
 
        # documents = dataPipe.add_metadata(documents, "year", st.session_state.published_year)
        # process_docs = dataPipe.process_documents(documents)
        # st.success("files successfully processed!")

        # dataPipe.persist_documents(data_index, process_docs)
        # st.success("files successfully stored!")
        
    except Exception as e:
        st.error(str(e))
                    

#sidebar function
def sidebar():
    with st.sidebar:
        st.subheader("Data indexing parameters")

        persist_index_name = st.text_input(
            label="file persist directory name",
            placeholder="enter index name",
            key="persist_index_name",
            help="name of the directory which processed files need to persisted.",
            on_change=update_parameters_change,
        )

        publish_year = st.number_input(
            label="published year",
            min_value=1950, 
            value=2023,
            max_value=2025,
            key="publish_year",
            help="year of the files are published.",
            on_change=update_parameters_change,
        )

        if st.session_state.is_parameters_changed:
            st.session_state.data_index = persist_index_name
            st.session_state.published_year = publish_year
            st.session_state.is_parameters_changed = False
            st.info(f"file persist directory name: {st.session_state.data_index}")
            st.info(f"file published year        : {st.session_state.published_year}")


#main function
def main():
    st.set_page_config(page_title="upload files to databse", page_icon="📖")#, layout="wide")
    st.header("📖Boardpac chat App")

    initialize_session_state()

    sidebar()
   
    uploaded_file = st.file_uploader(
        "Upload your filess here and click on 'Process'",
        key = "uploaded_file",
        accept_multiple_files=True,
        help="Upload files here!",
    )

    col1, col2 = st.columns(2)
    
    with col1:
        if st.button("validate"):
            if validate_inputs(uploaded_file):
                st.session_state.is_input_validated=True

                       
    with col2:
        if st.session_state.is_input_validated:
            if st.button("process"):
                with st.spinner("Indexing document... This may take a while⏳"):
                    process_files(uploaded_file,st.session_state.data_index)
                    uploaded_file = None
                    st.session_state.is_input_validated = False


if __name__ == "__main__":
    main()