import streamlit as st
from fpdf import FPDF
import unicodedata

# Function to sanitize text by removing unsupported characters
def sanitize_text(text):
    return ''.join(
        c for c in unicodedata.normalize('NFKD', text)
        if ord(c) < 128  # Retain only ASCII characters
    )

# Function to identify headings, subheadings, and paragraphs
def process_text(input_text):
    lines = input_text.split('\n')
    structured_text = []
    for line in lines:
        line = line.strip()
        if not line:
            continue
        if line.isupper():
            structured_text.append({'type': 'heading', 'text': line})
        elif line[0].isupper():
            structured_text.append({'type': 'subheading', 'text': line})
        else:
            structured_text.append({'type': 'paragraph', 'text': line})
    return structured_text

# Function to generate a PDF
def generate_pdf(structured_text):
    pdf = FPDF()
    pdf.set_auto_page_break(auto=True, margin=15)
    pdf.add_page()
    pdf.set_font("Arial", size=12)

    for item in structured_text:
        sanitized_text = sanitize_text(item['text'])
        if item['type'] == 'heading':
            pdf.set_font("Arial", size=16, style='B')
            pdf.cell(0, 10, txt=sanitized_text, ln=True)
        elif item['type'] == 'subheading':
            pdf.set_font("Arial", size=14, style='B')
            pdf.cell(0, 10, txt=sanitized_text, ln=True)
        else:  # Paragraph or body text
            pdf.set_font("Arial", size=12)
            pdf.multi_cell(0, 10, txt=sanitized_text)
    
    # Save PDF in-memory
    return pdf.output(dest='S').encode('latin1')

# Streamlit app
st.title("Intelligent Text Evaluator and PDF Generator")

st.markdown("""
This app identifies headings, subheadings, and paragraphs from the input text and generates a professionally formatted PDF.
""")

# Text input
input_text = st.text_area("Enter your text below:", height=300)

if st.button("Generate PDF"):
    if input_text.strip():
        # Warn the user if unsupported characters are removed
        if any(ord(char) > 255 for char in input_text):
            st.warning("Some special characters or emojis have been removed to generate the PDF.")

        # Process the input text and generate the PDF
        structured_text = process_text(input_text)
        pdf_data = generate_pdf(structured_text)
        
        # Download the PDF
        st.download_button(
            label="Download PDF",
            data=pdf_data,
            file_name="formatted_text.pdf",
            mime="application/pdf",
        )
    else:
        st.error("Please enter some text before generating the PDF.")