app.py

import os
import streamlit as st
import tempfile
from pymongo import MongoClient
from datetime import datetime
from pathlib import Path
from document_chunker import DocumentChunker
from urllib.parse import quote_plus

# === MongoDB connection via Hugging Face secrets ===
user = quote_plus(os.getenv("MONGO_USER"))
password = quote_plus(os.getenv("MONGO_PASS"))
cluster = os.getenv("MONGO_CLUSTER")
db_name = os.environ.get("MONGO_DB", "grant_docs")
mongo_uri = f"mongodb+srv://{user}:{password}@{cluster}/{db_name}?retryWrites=true&w=majority&tls=true&tlsAllowInvalidCertificates=true"
client = MongoClient(mongo_uri, tls=True, tlsAllowInvalidCertificates=True, serverSelectionTimeoutMS=20000)
db = client[db_name]

# === Streamlit UI ===
st.set_page_config(page_title="Doc Chunker", layout="wide")
st.title("📄 Document Chunker & Uploader")

with st.sidebar:
    st.header("Settings")

    # Fetch collection names for dropdown
    try:
        existing_categories = db["final_chunks"].distinct("collection_category") or []
    except Exception:
        existing_categories = []
    existing_categories=sorted([c for c in existing_categories if c])+["Create New Category"]
    selected_category = st.selectbox(
        "Choose Category (collection_category)",
        existing_categories,
        index=existing_categories.index("Create New Category") if "Create New Category" in existing_categories else 0
    )
    if selected_category == "Create New Category":
        selected_category = st.sidebar.text_input("Enter Category Name:")
        if not selected_category:
            st.warning("⚠️ Enter a category name to proceed.")
            st.stop()

    is_grant_app = st.toggle("Is this a Grant Application?", value=False)

uploaded_file = st.file_uploader("Upload a DOCX, TXT, or PDF file", type=["docx", "txt", "pdf"])

if uploaded_file:
    temp_path = Path(tempfile.gettempdir()) / uploaded_file.name
    with open(temp_path, "wb") as f:
        f.write(uploaded_file.getbuffer())

    st.success(f"Uploaded `{uploaded_file.name}`")

    modified_time = datetime.now().isoformat()
    collection = db['final_chunks']
    already = collection.find_one({
        "metadata.title": uploaded_file.name,
        "collection_category": selected_category
    })

    if already:
        st.warning(f"⚠️ `{uploaded_file.name}` already exists in category `{selected_category}`. Skipping…")
    else:
        st.write("⏳ Processing with DocumentChunker...")
        chunker = DocumentChunker()
        chunks = chunker.process_document(str(temp_path))

        if chunks:
            for chunk in chunks:
                chunk['collection_category']=selected_category
                chunk['metadata'].update({
                    "title": uploaded_file.name,
                    "uploaded_at": modified_time,
                    "is_grant_app": is_grant_app,
                })
                collection.insert_one(chunk)

            st.success(f"✅ {len(chunks)} chunks inserted into `final_chunks` (category: `{selected_category}`)")

            # Show a few previews
            for i, c in enumerate(chunks[:3]):
                st.subheader(f"Chunk {i+1}: {c['metadata'].get('header') or 'No Header'}")
                st.markdown(c['text'][:400] + "...")
                st.caption(f"Topics: {', '.join(c['metadata']['topics'])} | Category: {c['metadata']['category']}")
                st.progress(c['metadata']['confidence_score'])

            if len(chunks) > 3:
                st.info(f"... and {len(chunks)-3} more chunks processed.")

        else:
            st.warning("⚠️ No chunks were generated.")

    # try:
    #     os.remove(temp_path)
    # except Exception as e:
    #     st.warning(f"⚠️ Could not delete temp file: {e}")