import streamlit as st
from fpdf import FPDF
import base64

def calculate_bmi(height_ft, height_in, weight_kg):
    total_height_m = (height_ft * 0.3048) + (height_in * 0.0254)
    if total_height_m > 0:
        bmi = weight_kg / (total_height_m ** 2)
        return round(bmi, 2)
    else:
        return None

def create_pdf(user_name, bmi):
    pdf = FPDF()
    pdf.add_page()
    pdf.set_font("Arial", 'B', 16)
    pdf.cell(0, 10, "App by Amna Shoukat", ln=True, align="C")
    pdf.ln(10)
    pdf.set_font("Arial", '', 14)
    pdf.cell(0, 10, f"User Name: {user_name}", ln=True)
    pdf.cell(0, 10, f"Your BMI is: {bmi}", ln=True)
    return pdf

def download_pdf(pdf):
    pdf_output = pdf.output(dest='S').encode('latin1')
    b64 = base64.b64encode(pdf_output).decode()
    href = f'<a href="data:application/octet-stream;base64,{b64}" download="bmi_report.pdf">Download BMI Report</a>'
    st.markdown(href, unsafe_allow_html=True)

def main():
    st.title("BMI Converter")

    user_name = st.text_input("Enter your name")
    height_ft = st.number_input("Enter height (feet)", min_value=0, format="%d")
    height_in = st.number_input("Enter height (inches)", min_value=0, format="%d")
    weight_kg = st.number_input("Enter weight (kg)", min_value=0.0, format="%f")

    if st.button("Calculate BMI"):
        bmi = calculate_bmi(height_ft, height_in, weight_kg)
        if bmi:
            st.success(f"Hello {user_name}, your BMI is: {bmi}")
            pdf = create_pdf(user_name, bmi)
            download_pdf(pdf)
        else:
            st.error("Please enter valid height.")

if __name__ == "__main__":
    main()