app.py

import os
import time
import streamlit as st
from twilio.rest import Client
from twilio.base.exceptions import TwilioRestException
from pdfminer.high_level import extract_text
from sentence_transformers import SentenceTransformer
from transformers import AutoTokenizer
import faiss
import numpy as np
import docx
from groq import Groq
import PyPDF2
import requests

# --- Document Loaders ---
def extract_text_from_pdf(pdf_path):
    try:
        text = ""
        with open(pdf_path, 'rb') as file:
            pdf_reader = PyPDF2.PdfReader(file)
            for page_num in range(len(pdf_reader.pages)):
                page = pdf_reader.pages[page_num]
                page_text = page.extract_text()
                if page_text:
                    text += page_text
        return text
    except:
        return extract_text(pdf_path)

def extract_text_from_docx(docx_path):
    try:
        doc = docx.Document(docx_path)
        return '\n'.join(para.text for para in doc.paragraphs)
    except:
        return ""

def chunk_text(text, tokenizer, chunk_size=150, chunk_overlap=30):
    tokens = tokenizer.tokenize(text)
    chunks, start = [], 0
    while start < len(tokens):
        end = min(start + chunk_size, len(tokens))
        chunk_tokens = tokens[start:end]
        chunks.append(tokenizer.convert_tokens_to_string(chunk_tokens))
        start += chunk_size - chunk_overlap
    return chunks

def retrieve_chunks(question, index, embed_model, text_chunks, k=3):
    question_embedding = embed_model.encode([question])[0]
    D, I = index.search(np.array([question_embedding]), k)
    return [text_chunks[i] for i in I[0]]

# --- GROQ Answer Generation ---
def generate_answer_with_groq(question, context, retries=3, delay=2):
    url = "https://api.groq.com/openai/v1/chat/completions"
    api_key = os.environ["GROQ_API_KEY"]
    headers = {
        "Authorization": f"Bearer {api_key}",
        "Content-Type": "application/json",
    }
    prompt = f"Based on the following context, answer the question: '{question}'\n\nContext:\n{context}"
    payload = {
        "model": "llama3-8b-8192",
        "messages": [
            {"role": "system", "content": "Hey there! I'm designed to respond just like a real person would. Ask me anything, and I'll do my best to give you a thoughtful and courteous answer."},
            {"role": "user", "content": prompt},
        ],
        "temperature": 0.5,
        "max_tokens": 300,
    }

    for attempt in range(retries):
        try:
            response = requests.post(url, headers=headers, json=payload)
            result = response.json()
            return result['choices'][0]['message']['content'].strip()
        except Exception as e:
            if "503" in str(e) and attempt < retries - 1:
                time.sleep(delay)
                continue
            else:
                return f"⚠️ Groq API Error: {str(e)}"

# --- Twilio Chat Handlers ---
def fetch_latest_incoming_message(account_sid, auth_token, conversation_sid):
    client = Client(account_sid, auth_token)
    messages = client.conversations.v1.conversations(conversation_sid).messages.list(limit=10)
    for msg in reversed(messages):
        if msg.author.startswith("whatsapp:"):
            return msg.body, msg.author, msg.index
    return None, None, None

def send_twilio_message(account_sid, auth_token, conversation_sid, body):
    try:
        client = Client(account_sid, auth_token)
        message = client.conversations.v1.conversations(conversation_sid).messages.create(author="system", body=body)
        return message.sid
    except Exception as e:
        return str(e)

# --- Streamlit UI ---
st.set_page_config(page_title="Quasa – A Smart WhatsApp Chatbot", layout="wide")
st.title("📱 Quasa – A Smart WhatsApp Chatbot")

# Load from Hugging Face secrets
account_sid = st.secrets.get("TWILIO_SID")
auth_token = st.secrets.get("TWILIO_TOKEN")
GROQ_API_KEY = st.secrets.get("GROQ_API_KEY")

# Fallback for testing
if not all([account_sid, auth_token, GROQ_API_KEY]):
    st.warning("⚠️ Some secrets not found. Please enter missing credentials below:")
    account_sid = st.text_input("Twilio SID", value=account_sid or "")
    auth_token = st.text_input("Twilio Auth Token", type="password", value=auth_token or "")
    GROQ_API_KEY = st.text_input("GROQ API Key", type="password", value=GROQ_API_KEY or "")

# Always show conversation SID input
conversation_sid = st.text_input("Enter Conversation SID", value="")

# Initialize session state to track last message
if "last_index" not in st.session_state:
    st.session_state.last_index = -1

if all([account_sid, auth_token, GROQ_API_KEY, conversation_sid]):
    os.environ["GROQ_API_KEY"] = GROQ_API_KEY

    @st.cache_resource
    def setup_knowledge_base():
        folder_path = "docs"
        all_text = ""
        for file in os.listdir(folder_path):
            if file.endswith(".pdf"):
                all_text += extract_text_from_pdf(os.path.join(folder_path, file)) + "\n"
            elif file.endswith((".docx", ".doc")):
                all_text += extract_text_from_docx(os.path.join(folder_path, file)) + "\n"
        tokenizer = AutoTokenizer.from_pretrained('bert-base-uncased')
        chunks = chunk_text(all_text, tokenizer)
        model = SentenceTransformer('all-mpnet-base-v2')
        embeddings = model.encode(chunks)
        dim = embeddings[0].shape[0]
        index = faiss.IndexFlatL2(dim)
        index.add(np.array(embeddings))
        return index, model, chunks

    index, embedding_model, text_chunks = setup_knowledge_base()

    st.success("✅ Knowledge base ready. Monitoring WhatsApp...")

    if st.button("🔁 Check for New WhatsApp Query"):
        with st.spinner("Checking messages..."):
            question, sender, msg_index = fetch_latest_incoming_message(account_sid, auth_token, conversation_sid)
            if question and msg_index > st.session_state.last_index:
                st.session_state.last_index = msg_index
                st.info(f"📥 New Question from {sender}:\n\n> {question}")
                relevant_chunks = retrieve_chunks(question, index, embedding_model, text_chunks)
                context = "\n\n".join(relevant_chunks)
                answer = generate_answer_with_groq(question, context)
                send_twilio_message(account_sid, auth_token, conversation_sid, answer)
                st.success("📤 Answer sent via WhatsApp!")
                st.markdown(f"### ✨ Answer:\n\n{answer}")
            else:
                st.warning("No new messages from users found.")
else:
    st.warning("❗ Please provide all required credentials and conversation SID.")