import streamlit as st
from PyPDF2 import PdfReader
from concurrent.futures import ThreadPoolExecutor
from base64 import b64encode
from fpdf import FPDF
import io, string, re, math
from io import StringIO
from streamlit_pdf_viewer import pdf_viewer

# Importing the Fastify Class
from fast_reader import Fastify_Reader

def pdf_extract_text(pdf_docs):
    '''
    Basic function for extracting text from the PDFs
    '''
    text = ""
    for pdf in pdf_docs:
        pdf_reader = PdfReader(pdf)
        for page in pdf_reader.pages:
            text += page.extract_text()
    return text

def text_to_pdf_fastify(text):    
    '''
    Basic function to apply fastification on the input text and convert it to bytes for PDF rendering
    '''
    # Applying the Fastify Logic
    bold_text = Fastify_Reader(text).fastify()
    bold_text = bold_text.encode('latin-1', 'ignore').decode('latin-1') #since fpdf works with latin-1 encoding
    
    # Creating the PDF
    pdf = FPDF()
    pdf.add_page()
    pdf.set_font("Arial", size = 12)
    pdf.multi_cell(0, 10, txt = bold_text, markdown=True)
    return bytes(pdf.output())

def text_to_pdf(text):
    '''
    Basic function on the input text and convert it to bytes for PDF rendering
    '''
    text = text.encode('latin-1', 'ignore').decode('latin-1') #since fpdf works with latin-1 encoding
    # Creating the PDF
    pdf = FPDF()
    pdf.add_page()
    pdf.set_font("Arial", size = 12)
    pdf.multi_cell(0, 10, txt = text, markdown=True)
    return bytes(pdf.output())

#Setting the page config
st.set_page_config(page_title="Fastify Reader",
                   page_icon=":books:",
                   layout="wide")

# Due to browser cache and streamlit issue, sometimes the PDFs are not rendered properly.
note_text = """
                    If the PDF is not being rendered by your browser, <br>
                    &emsp;1. Try this link - (https://akarshrajsingh7-fastify-reader.hf.space/) <br>
                    &emsp;2. Download the PDF and open it in a PDF viewer.
                    """
# Sidebar
with st.sidebar:
    st.image("Logo.jpg")
    st.markdown("<div style='text-align: center;'>How fast can you read?</div>", unsafe_allow_html=True)

# Main Page
tab1, tab2= st.tabs(["Input Text", "PDF file"])

# First tab where Text is input
with tab1:
    user_input = st.text_input("Enter some text")

    # Compare Check Box
    compare = st.checkbox('Compare with Fastified Text', value=False, key='compare')
    
    # Submit Button
    if st.button("Submit", key="input-text"):
        #Progess Bar for the processing
        with st.spinner("Processing"):
            text = user_input

            # Generating base64 encoded text bytes for PDF rendering
            original_pdf = b64encode(text_to_pdf(text)).decode("utf-8")
            base64_pdf = b64encode(text_to_pdf_fastify(text)).decode("utf-8")

            # Embedding the PDFs in the HTML
            original_display = f'<embed src="data:application/pdf;base64,{original_pdf}" width = "100%" height = 600 type="application/pdf" download="original.pdf">'
            pdf_display = f'<embed src="data:application/pdf;base64,{base64_pdf}" width = "100%" height = 600 type="application/pdf" download="Modified.pdf">'

            # original_display = f"""<embed class="pdfobject" type="application/pdf" title="Original PDF" src="data:application/pdf;base64,{original_pdf}" style=" width: 100%; height: 150%;">"""
            # pdf_display = f"""<embed class="pdfobject" type="application/pdf" title="Modified PDF" src="data:application/pdf;base64,{base64_pdf}" style=" width: 100%; height: 150%;">"""
            
            # original_display = f'<iframe src="data:application/pdf;base64,{original_pdf}" width = "100%" height = 600 type="application/pdf" download="original.pdf"></iframe>'
            # pdf_display = f'<iframe src="data:application/pdf;base64,{base64_pdf}" width = "100%" height = 600 type="application/pdf" download="Modified.pdf"></iframe>'
            
            # original_display = f"""
            #     <div class="pdf-container" style="height: 500px;">
            #         <embed class="pdfobject" type="application/pdf" title="Modified PDF" src="data:application/pdf;base64,{original_pdf}" style="width: 100%; height: 100%;">
            #     </div>
            #     """
            # pdf_display = f"""
            #     <div class="pdf-container" style="height: 500px;">
            #         <embed class="pdfobject" type="application/pdf" title="Modified PDF" src="data:application/pdf;base64,{base64_pdf}" style="width: 100%; height: 100%;">
            #     </div>
            #     """

            # Compare Logic implementation
            if compare:
                col1, col2, col3 = st.columns(3)
                with col3:
                    st.download_button(label="Download Fastified PDF", data=text_to_pdf_fastify(text), file_name='output.pdf', mime='application/pdf')
                
                # Side by Side comparison
                col1, col2 = st.columns([1, 1], gap="small")
                with col1:
                    with st.container(border = True):
                        st.markdown("<div style='text-align: center;'><strong>Original PDF viewer</strong></div>", unsafe_allow_html=True)
                        st.markdown(original_display, unsafe_allow_html=True)
                with col2:
                    with st.container(border = True):
                        st.markdown("<div style='text-align: center;'><strong>Fastified PDF viewer</strong></div>", unsafe_allow_html=True)
                        st.markdown(pdf_display, unsafe_allow_html=True)
                
                # Browser Cache Note
                st.markdown(f"""
                        <div style='background-color: #FFD580; border-radius: 5px;'>
                            <p style='color: black;'><strong>Note</strong> - {note_text}</p>
                        </div>
                        """, unsafe_allow_html=True)
            else:
                # No Comparisons
                col1, col2, col3 = st.columns(3)
                with col2:
                    st.download_button(label="Download Fastified PDF", data=text_to_pdf_fastify(text), file_name='output.pdf', mime='application/pdf')
                with st.container(border = True):
                    st.markdown("<div style='text-align: center;'><strong>Fastified PDF viewer</strong></div>", unsafe_allow_html=True)
                    st.markdown(pdf_display, unsafe_allow_html=True)
                
                # Browser Cache Note
                    st.markdown(f"""
                        <div style='background-color: #FFD580; border-radius: 5px;'>
                            <p style='color: black;'><strong>Note</strong> - {note_text}</p>
                        </div>
                        """, unsafe_allow_html=True)
    
# Added support for PDFs having text
with tab2:
        uploaded_file = st.file_uploader("Upload a PDF file", type="pdf", accept_multiple_files=True)

        # Compare Check Box
        compare = st.checkbox('Compare with Fastified Text', value=False, key='compare_pdf')

        # Submit Button
        if st.button("Submit", key="pdf"):
            #Progess Bar for the processing
            with st.spinner("Processing"):
                text = pdf_extract_text(uploaded_file)

                # Generating base64 encoded text bytes for PDF rendering
                original_pdf = b64encode(text_to_pdf(text)).decode("utf-8")
                base64_pdf = b64encode(text_to_pdf_fastify(text)).decode("utf-8")

                # Embedding the PDFs in the HTML
                original_display = f'<embed src="data:application/pdf;base64,{original_pdf}" width = "100%" height = 600 type="application/pdf" download="original.pdf">'
                pdf_display = f'<embed src="data:application/pdf;base64,{base64_pdf}" width = "100%" height = 600 type="application/pdf" download="Modified.pdf">'

                
                # original_display = f"""<embed class="pdfobject" type="application/pdf" title="Original PDF" src="data:application/pdf;base64,{original_pdf}" style=" width: 100%; height: 150%;">"""
                # pdf_display = f"""<embed class="pdfobject" type="application/pdf" title="Modified PDF" src="data:application/pdf;base64,{base64_pdf}" style=" width: 100%; height: 150%;">"""
                
                # original_display = f'<iframe src="data:application/pdf;base64,{original_pdf}" width = "100%" height = 600 type="application/pdf" download="original.pdf"></iframe>'
                # pdf_display = f'<iframe src="data:application/pdf;base64,{base64_pdf}" width = "100%" height = 600 type="application/pdf" download="Modified.pdf"></iframe>'
            
                # original_display = f"""
                # <div class="pdf-container" style="height: 500px;">
                #     <embed class="pdfobject" type="application/pdf" title="Modified PDF" src="data:application/pdf;base64,{original_pdf}" style="width: 100%; height: 100%;">
                # </div>
                # """
                # pdf_display = f"""
                # <div class="pdf-container" style="height: 500px;">
                #     <embed class="pdfobject" type="application/pdf" title="Modified PDF" src="data:application/pdf;base64,{base64_pdf}" style="width: 100%; height: 100%;">
                # </div>
                # """



                # Compare Logic implementation
                if compare:
                    col1, col2, col3 = st.columns(3)
                    with col3:
                        st.download_button(label="Download Fastified PDF", data=text_to_pdf_fastify(text), file_name='output.pdf', mime='application/pdf')
                    
                    # Side by Side comparison
                    col1, col2 = st.columns([1, 1], gap="small")
                    with col1:
                        with st.container(border = True):
                            st.markdown("<div style='text-align: center;'><strong>Original PDF viewer</strong></div>", unsafe_allow_html=True)
                            st.markdown(original_display, unsafe_allow_html=True)
                    with col2:
                        with st.container(border = True):
                            st.markdown("<div style='text-align: center;'><strong>Fastified PDF viewer</strong></div>", unsafe_allow_html=True)
                            st.markdown(pdf_display, unsafe_allow_html=True)
                    # Browser Cache Note
                    st.markdown(f"""
                        <div style='background-color: #FFD580; border-radius: 5px;'>
                            <p style='color: black;'><strong>Note</strong> - {note_text}</p>
                        </div>
                        """, unsafe_allow_html=True)
                else:
                    # No Comparison
                    col1, col2, col3 = st.columns(3)
                    with col2:
                        st.download_button(label="Download Fastified PDF", data=text_to_pdf_fastify(text), file_name='output.pdf', mime='application/pdf')
                    with st.container(border = True):
                        st.markdown("<div style='text-align: center;'><strong>Fastified PDF viewer</strong></div>", unsafe_allow_html=True)
                        st.markdown(pdf_display, unsafe_allow_html=True)
                    
                    # Browser Cache Note
                    st.markdown(f"""
                        <div style='background-color: #FFD580; border-radius: 5px;'>
                            <p style='color: black;'><strong>Note</strong> - {note_text}</p>
                        </div>
                        """, unsafe_allow_html=True)