import streamlit as st
from pdf_reader import extract_text_from_pdf
from qa_utils import split_text, create_vector_store, answer_question

st.set_page_config(page_title="📄 PDF Q&A App")
st.title("📄 Ask Questions from PDF")

# Upload PDF
uploaded_file = st.file_uploader("Upload a PDF file", type="pdf")

# Load and process PDF
if uploaded_file and "vectorstore" not in st.session_state:
    with st.spinner("Reading and processing the PDF..."):
        text = extract_text_from_pdf(uploaded_file)
        chunks = split_text(text)
        vectorstore = create_vector_store(chunks)
        st.session_state.vectorstore = vectorstore
    st.success("✅ PDF loaded and ready for questions!")

# Ask questions
if "vectorstore" in st.session_state:
    query = st.text_input("Ask a question about the PDF:")
    if query:
        with st.spinner("Generating answer..."):
            answer = answer_question(st.session_state.vectorstore, query)
            st.write("**Answer:**", answer)