Update app.py

app.py

@@ -1,23 +1,39 @@
 import os
+import re
 import gradio as gr
 from gtts import gTTS
 from datetime import datetime
 from openpyxl import Workbook, load_workbook
-import re
 
-# Ensure the required library is installed
+# --- Install required packages on first run (optional) ---
 try:
     import google.generativeai as genai
-except ModuleNotFoundError:
+except ImportError:
     import subprocess
     subprocess.check_call(["pip", "install", "google-generativeai"])
     import google.generativeai as genai
 
-# ========== SETUP ==========
-genai.configure(api_key="AIzaSyBJFmohAmhmqXQlM3fVxj8MLegVb26kyJk") 
+try:
+    from langchain.chat_models import ChatGoogleGenerativeAI
+    from langchain.chains import ConversationChain
+    from langchain.memory import ConversationBufferMemory
+except ImportError:
+    import subprocess
+    subprocess.check_call(["pip", "install", "langchain"])
+    from langchain.chat_models import ChatGoogleGenerativeAI
+    from langchain.chains import ConversationChain
+    from langchain.memory import ConversationBufferMemory
+
+# ========== API Setup ==========
+genai.configure(api_key="AIzaSyBJFmohAmhmqXQlM3fVxj8MLegVb26kyJk")  # Replace with your key
 model_name = "models/gemini-1.5-flash-latest"
-model = genai.GenerativeModel(model_name)
 
+# LangChain LLM + Memory
+llm = ChatGoogleGenerativeAI(model=model_name, google_api_key=os.getenv("GOOGLE_API_KEY", "AIzaSyBJFmohAmhmqXQlM3fVxj8MLegVb26kyJk"))
+memory = ConversationBufferMemory(return_messages=True)
+conversation = ConversationChain(llm=llm, memory=memory)
+
+# ========== Menu ==========
 MENU = {
     "Cheeseburger": 5.99,
     "Fries": 2.99,
@@ -27,7 +43,6 @@ MENU = {
     "Salad": 6.99
 }
 
-chat_history = []
 order = []
 customer_name = ""
 
@@ -53,10 +68,10 @@ def save_to_excel(name, items):
     wb.save(EXCEL_FILE)
     return order_id
 
-# ========== Text-to-Speech ==========
+# ========== Voice ==========
 def clean_text(text):
-    text = re.sub(r"\*\*(.*?)\*\*", r"\1", text)  # remove **bold**
-    text = re.sub(r"Bot\s*:\s*", "", text, flags=re.IGNORECASE)  # remove "Bot:" label
+    text = re.sub(r"\*\*(.*?)\*\*", r"\1", text)  # Remove bold symbols
+    text = re.sub(r"Bot\s*:\s*", "", text, flags=re.IGNORECASE)  # Remove "Bot:" label
     return text.strip()
 
 def speak(text, filename="response.mp3"):
@@ -65,44 +80,15 @@ def speak(text, filename="response.mp3"):
     tts.save(filename)
     return filename
 
-# ========== Gemini Prompt ==========
+# ========== Gemini + LangChain Response ==========
 def generate_response(user_input):
-    global customer_name, order
-
-    menu_description = "\n".join([f"{item}: ${price}" for item, price in MENU.items()])
-    order_summary = ", ".join([f"{qty} x {item}" for item, qty in order]) if order else "No items yet"
-
-    context = f"""
-You are a friendly, helpful restaurant assistant at 'Systaurant'.
-
-MENU:
-{menu_description}
-
-Customer name: {customer_name}
-Current order: {order_summary}
-
-Instructions:
-- Ask for name if not known.
-- Show menu if requested.
-- Extract item names and quantities from messages.
-- Say 'Order summary' and ask 'Confirm?' when user is done.
-- Respond only as the bot, no need to prefix with "Bot:".
-- Keep tone human, natural, and friendly.
-
-Conversation:
-"""
-    for u, b in chat_history:
-        context += f"\nCustomer: {u}\n{b}"
-
-    context += f"\nCustomer: {user_input}\n"
-
     try:
-        response = model.generate_content(context)
-        return response.text
+        response = conversation.predict(input=user_input)
+        return response
     except Exception as e:
         return f"❌ Error from Gemini: {str(e)}"
 
-
+# ========== Handle Chat ==========
 def handle_chat(user_input):
     global customer_name, order
 
@@ -112,7 +98,7 @@ def handle_chat(user_input):
     if "my name is" in user_input.lower():
         customer_name = user_input.split("my name is")[-1].strip().split()[0].title()
 
-    # Extract items
+    # Detect order items
     for item in MENU:
         if item.lower() in user_input.lower():
             qty = 1
@@ -122,17 +108,16 @@ def handle_chat(user_input):
                     break
             order.append((item, qty))
 
-    # Confirm order
+    # Confirm and save
     if "confirm" in user_input.lower() or "yes" in user_input.lower():
         if customer_name and order:
             order_id = save_to_excel(customer_name, order)
             bot_reply += f"\n✅ Your order ID is {order_id}. Thank you for ordering from Saad's Restaurant!"
 
-    chat_history.append((user_input, bot_reply))
     audio_file = speak(bot_reply)
     return bot_reply, audio_file
 
-
+# ========== Gradio UI ==========
 gr.Interface(
     fn=handle_chat,
     inputs=gr.Textbox(label="👤 You", placeholder="Type your order..."),
@@ -140,9 +125,7 @@ gr.Interface(
         gr.Textbox(label="🤖 Bot Response"),
         gr.Audio(label="🔊 Speaking", autoplay=True)
     ],
-    title="🍔 SysTaurant Voice Bot",
-    description="Talk to the bot and it will handle your order.",
+    title="🍔 SysTaurant Voice Bot (LangChain + Gemini)",
+    description="Talk to the bot and it will handle your order with memory.",
     theme="soft"
 ).launch(share=True)
-
-#hello# ###