import streamlit as st
import os
import PyPDF2
import nltk
nltk.download('punkt')
from nltk.tokenize import sent_tokenize
from sentence_transformers import SentenceTransformer
import numpy as np
from numpy.linalg import norm

url = "https://www.independentschoolparent.com/wp-content/uploads/2018/01/AI.jpg"

st.title("AIP-S³")
st.write("AI Powered Smart Search System")
st.image(url)

st.markdown('_Welcome to Question Answering System 🧠 🤖_')

a = st.sidebar.radio("SELECT -", ['PDF', 'Website'])

if a == 'PDF' :
    
    uploaded_files = st.file_uploader("Upload files - ", accept_multiple_files=True , 
                  type = ['pdf'] )

    if st.button("Process!"):
        for i in uploaded_files:
            if i.type == "application/pdf" :
                reader = PyPDF2.PdfReader(i)
      
        text_ext = []
        for i in range(len(reader.pages)):
            pageObj = reader.pages[i] 
        # extracting text from page 
            text_ext.append(pageObj.extract_text())

        sent_toks = []
        for i in text_ext:
            sent_toks.append(sent_tokenize(i))
            concat_list = [j for i in sent_toks for j in i]
        
            filt1_list = []
            for i in concat_list:
                a = (i.replace('\n', ' '))
                filt1_list.append(a)

      

        model = SentenceTransformer('sentence-transformers/all-MiniLM-L6-v2')
        embeddings = model.encode(filt1_list)
        
        st.write("Process Completed")


        query = st.text_input('Ask me anything!', placeholder = 'Type.....')
        if st.button("Confirm!"):
            model = SentenceTransformer('sentence-transformers/all-MiniLM-L6-v2')
            query_embedding = model.encode(query)

            cosine_lis = []
            for i in range(len(filt1_list)):
                cosine = np.dot(query_embedding , embeddings[i])/ (norm(query_embedding)*norm(embeddings[i]))
                cosine_lis.append(cosine)


            N = 3
            list1 = cosine_lis

            indexes_final= sorted(range(len(list1)), key=lambda i: list1[i], reverse=True)[:N]

            for i in indexes_final:
                st.write(filt1_list[i])
                st.write("")