import re from difflib import SequenceMatcher def normalize(text): """Lowercase, strip, collapse whitespace.""" return re.sub(r'\s+', ' ', text.lower().strip()) def word_overlap_score(query_words, text): """Score how many query words appear in text.""" text_lower = text.lower() return sum(1 for w in query_words if w in text_lower) def similarity(a, b): """Simple string similarity ratio.""" return SequenceMatcher(None, a.lower(), b.lower()).ratio() def generate_response(chat, user_message): """ Match user message against vendor data (FAQs, products, policies, description). Returns (response_text, suggests_handoff) tuple. """ try: vendor_config = chat.vendor.ai_config except Exception: return ("This shop's assistant isn't set up yet. Please contact the vendor directly.", True) vendor = vendor_config.vendor message = normalize(user_message) words = [w for w in message.split() if len(w) > 2] # --- 1. Try FAQ matching --- best_faq = None best_faq_score = 0 for faq in vendor_config.faqs.filter(is_active=True): sim = similarity(message, normalize(faq.question)) overlap = word_overlap_score(words, faq.question) / max(len(words), 1) score = max(sim, overlap) if score > best_faq_score: best_faq_score = score best_faq = faq if best_faq and best_faq_score >= 0.45: return (best_faq.answer, False) # --- 2. Try product matching --- from products.models import Product products = Product.objects.filter(vendor=vendor, status='active') price_keywords = ['price', 'cost', 'how much', 'bei', 'shilingi', 'ksh', 'kes'] asking_price = any(kw in message for kw in price_keywords) avail_keywords = ['available', 'in stock', 'do you have', 'stock', 'iko'] asking_availability = any(kw in message for kw in avail_keywords) matched_products = [] for product in products: name_score = word_overlap_score(words, product.name) desc_score = word_overlap_score(words, product.description or '') * 0.5 cat_score = word_overlap_score(words, product.category or '') * 0.3 score = name_score + desc_score + cat_score if score >= 1.5: matched_products.append((product, score)) matched_products.sort(key=lambda x: x[1], reverse=True) if matched_products: if asking_price and len(matched_products) == 1: p = matched_products[0][0] response = f"{p.name} is KES {p.price}" if p.old_price and float(p.old_price) > float(p.price): response += f" (was KES {p.old_price})" if p.is_negotiable: response += ". The price is negotiable." return (response, False) if asking_availability and len(matched_products) == 1: p = matched_products[0][0] if p.is_available: return (f"Yes, {p.name} is available! It's KES {p.price}.", False) else: return (f"Sorry, {p.name} is currently out of stock.", False) top = matched_products[:5] lines = [] for p, _ in top: line = f"- {p.name}: KES {p.price}" if not p.is_available: line += " (Out of stock)" if p.is_negotiable: line += " (Negotiable)" lines.append(line) intro = "Here's what I found:" if len(top) > 1 else "I found this:" return (f"{intro}\n" + "\n".join(lines), False) # --- 3. Check for general info keywords --- greeting_keywords = ['hi', 'hello', 'hey', 'habari', 'sasa', 'niaje', 'mambo'] if any(message.strip() == kw or message.startswith(kw + ' ') for kw in greeting_keywords): return (f"Hi! Welcome to {vendor.shop_name}. How can I help you today? You can ask about our products, prices, or policies.", False) policy_keywords = ['return', 'refund', 'warranty', 'delivery', 'shipping', 'payment', 'policy', 'policies', 'mpesa', 'pay'] if any(kw in message for kw in policy_keywords): if vendor_config.policies: return (vendor_config.policies, False) return (f"For details about our policies, please contact {vendor.shop_name} directly.", True) about_keywords = ['about', 'who are you', 'tell me about', 'what do you sell', 'what does', 'describe'] if any(kw in message for kw in about_keywords): if vendor_config.business_description: return (vendor_config.business_description, False) return (f"{vendor.shop_name} is a {vendor.shop_category} shop located in {vendor.town_area}.", False) location_keywords = ['where', 'location', 'located', 'address', 'find you', 'directions', 'wapi', 'mahali'] if any(kw in message for kw in location_keywords): county = vendor.user.county or '' return (f"{vendor.shop_name} is located in {vendor.town_area}{', ' + county if county else ''}.", False) product_list_keywords = ['products', 'what do you sell', 'catalog', 'catalogue', 'items', 'bidhaa', 'all products'] if any(kw in message for kw in product_list_keywords): top_products = products[:8] if top_products: lines = [f"- {p.name}: KES {p.price}" for p in top_products] more = products.count() - len(top_products) result = f"Here are some of our products:\n" + "\n".join(lines) if more > 0: result += f"\n\n...and {more} more. Browse the shop to see everything!" return (result, False) return ("We don't have any products listed at the moment. Check back soon!", False) hours_keywords = ['hours', 'open', 'close', 'time', 'working hours', 'saa'] if any(kw in message for kw in hours_keywords): if vendor_config.custom_instructions and any(kw in vendor_config.custom_instructions.lower() for kw in ['hour', 'open', 'time']): return (vendor_config.custom_instructions, False) return (f"For our working hours, please contact {vendor.shop_name} directly.", True) # --- 4. Partial FAQ match (lower threshold) --- if best_faq and best_faq_score >= 0.3: return (best_faq.answer, False) # --- 5. Fallback: don't have enough knowledge --- return ( f"I don't have enough information to answer that question accurately. " f"I can only help with questions about our products, prices, policies, and location. " f"For anything else, please reach out to {vendor.shop_name} directly — they'll be happy to assist you!", True )