Update app.py

app.py

@@ -4,55 +4,23 @@ import gradio as gr
 from gtts import gTTS
 from datetime import datetime
 from openpyxl import Workbook, load_workbook
+import google.generativeai as genai
 
-from langchain_community.chat_models import ChatGoogleGenerativeAI
+# LangChain memory
+from langchain_core.prompts import ChatPromptTemplate
+from langchain_core.messages import HumanMessage, AIMessage
+from langchain_google_genai import ChatGoogleGenerativeAI
 from langchain.memory import ConversationBufferMemory
 from langchain.chains import ConversationChain
-from langchain.prompts import PromptTemplate
-
-import google.generativeai as genai
-
-# ========== API Setup ==========
-genai.configure(api_key="AIzaSyBJFmohAmhmqXQlM3fVxj8MLegVb26kyJk") 
 
-llm = ChatGoogleGenerativeAI(model="gemini-1.5-flash-latest", convert_system_message_to_human=True)
-memory = ConversationBufferMemory()
+# ========== SETUP ==========
+genai.configure(api_key="AIzaSyBJFmohAmhmqXQlM3fVxj8MLegVb26kyJk")
 
-template = """
-You are a friendly, helpful restaurant assistant at 'Systaurant'.
+llm = ChatGoogleGenerativeAI(model="gemini-1.5-flash", convert_system_message_to_human=True)
+memory = ConversationBufferMemory(return_messages=True)
+chain = ConversationChain(llm=llm, memory=memory, verbose=False)
 
-MENU:
-{menu}
-
-Customer name: {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:
-{history}
-Customer: {input}
-Bot:"""
-
-prompt = PromptTemplate(
-    input_variables=["history", "input", "menu", "name", "order_summary"],
-    template=template
-)
-
-chain = ConversationChain(
-    llm=llm,
-    memory=memory,
-    prompt=prompt,
-    verbose=False
-)
-
-# ========== Menu & Order State ==========
+# Menu & State
 MENU = {
     "Cheeseburger": 5.99,
     "Fries": 2.99,
@@ -61,12 +29,10 @@ MENU = {
     "Chicken Wings": 7.99,
     "Salad": 6.99
 }
-
-chat_history = []
 order = []
 customer_name = ""
 
-# ========== Excel Setup ==========
+# Excel Setup
 EXCEL_FILE = "orders.xlsx"
 def setup_excel():
     if not os.path.exists(EXCEL_FILE):
@@ -75,7 +41,6 @@ def setup_excel():
         ws.title = "Orders"
         ws.append(["Order ID", "Date", "Customer", "Items", "Total", "Time"])
         wb.save(EXCEL_FILE)
-
 setup_excel()
 
 def save_to_excel(name, items):
@@ -89,7 +54,8 @@ def save_to_excel(name, items):
     wb.save(EXCEL_FILE)
     return order_id
 
-# ========== Voice Output ==========
+# Voice
+
 def clean_text(text):
     text = re.sub(r"\*\*(.*?)\*\*", r"\1", text)
     text = re.sub(r"Bot\s*:\s*", "", text, flags=re.IGNORECASE)
@@ -101,15 +67,37 @@ def speak(text, filename="response.mp3"):
     tts.save(filename)
     return filename
 
-# ========== Bot Logic ==========
-def handle_chat(user_input):
+# Prompt Template
+system_prompt = """
+You are a helpful restaurant assistant at 'Systaurant'.
+
+Your job is to:
+- Greet the user and ask their name if not known.
+- Show the menu if requested.
+- Extract food items and quantities from the customer's message.
+- If the user says 'done', summarize the order and ask for confirmation.
+- If confirmed, respond with a thank you and order ID.
+- Keep the tone friendly and human. Do not prefix with "Bot:".
+
+Menu:
+{menu}
+Customer name: {name}
+Order so far: {summary}
+"""
+
+prompt = ChatPromptTemplate.from_messages([
+    ("system", system_prompt),
+    ("human", "{input}")
+])
+
+def generate_response(user_input):
     global customer_name, order
 
-    # Name detection
+    # Track name
     if "my name is" in user_input.lower():
         customer_name = user_input.split("my name is")[-1].strip().split()[0].title()
 
-    # Menu parsing
+    # Track items
     for item in MENU:
         if item.lower() in user_input.lower():
             qty = 1
@@ -119,26 +107,32 @@ def handle_chat(user_input):
                     break
             order.append((item, qty))
 
-    order_summary = ", ".join([f"{qty} x {item}" for item, qty in order]) if order else "No items yet"
-    menu_description = "\n".join([f"{item}: ${price}" for item, price in MENU.items()])
-    
-    bot_reply = chain.run({
+    # Confirmation
+    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)
+            memory.chat_memory.add_user_message(user_input)
+            memory.chat_memory.add_ai_message(f"✅ Your order ID is {order_id}. Thank you for ordering from Saad's Restaurant!")
+            return f"✅ Your order ID is {order_id}. Thank you for ordering from Saad's Restaurant!"
+
+    menu_text = "\n".join([f"{item}: ${price}" for item, price in MENU.items()])
+    summary = ", ".join([f"{qty} x {item}" for item, qty in order]) if order else "No items yet"
+
+    filled_prompt = prompt.invoke({
         "input": user_input,
-        "menu": menu_description,
+        "menu": menu_text,
         "name": customer_name or "Not provided",
-        "order_summary": order_summary
+        "summary": summary
     })
 
-    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!"
+    return chain.invoke(filled_prompt.to_string())
 
-    chat_history.append((user_input, bot_reply))
+def handle_chat(user_input):
+    bot_reply = generate_response(user_input)
     audio_file = speak(bot_reply)
     return bot_reply, audio_file
 
-# ========== Gradio UI ==========
+# Gradio Interface
 gr.Interface(
     fn=handle_chat,
     inputs=gr.Textbox(label="👤 You", placeholder="Type your order..."),
@@ -146,7 +140,7 @@ 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 with Memory",
+    description="Place your restaurant order through chat with memory.",
     theme="soft"
 ).launch(share=True)