import os
import re
import gradio as gr
from gtts import gTTS
from datetime import datetime
from openpyxl import Workbook, load_workbook
from langchain.memory import ConversationBufferMemory

# --- Gemini setup ---
import google.generativeai as genai
genai.configure(api_key="AIzaSyBJFmohAmhmqXQlM3fVxj8MLegVb26kyJk")  

model = genai.GenerativeModel("models/gemini-1.5-flash-latest")

# --- Restaurant menu ---
MENU = {
    "Cheeseburger": 5.99,
    "Fries": 2.99,
    "Coke": 1.99,
    "Pizza": 12.99,
    "Chicken Wings": 7.99,
    "Salad": 6.99
}

# --- Memory with LangChain ---
memory = ConversationBufferMemory(return_messages=True)
chat_history = []
order = []
customer_name = ""

# --- Excel Setup ---
EXCEL_FILE = "orders.xlsx"
def setup_excel():
    if not os.path.exists(EXCEL_FILE):
        wb = Workbook()
        ws = wb.active
        ws.title = "Orders"
        ws.append(["Order ID", "Date", "Customer", "Items", "Total", "Time"])
        wb.save(EXCEL_FILE)
setup_excel()

def save_to_excel(name, items):
    wb = load_workbook(EXCEL_FILE)
    ws = wb.active
    order_id = f"ORD{ws.max_row:04d}"
    now = datetime.now()
    total = sum(qty * MENU[item] for item, qty in items)
    items_str = ", ".join(f"{qty} x {item}" for item, qty in items)
    ws.append([order_id, now.strftime("%Y-%m-%d"), name, items_str, f"${total:.2f}", now.strftime("%H:%M:%S")])
    wb.save(EXCEL_FILE)
    return order_id

# --- TTS ---
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:"
    return text.strip()

def speak(text, filename="response.mp3"):
    tts = gTTS(text=clean_text(text))
    tts.save(filename)
    return filename

# --- Generate Gemini response ---
def generate_response(user_input):
    global order, customer_name

    menu_str = "\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"

    prompt = f"""
You are a friendly, intelligent restaurant assistant at 'Systaurant'.

Menu:
{menu_str}

Customer Name: {customer_name}
Current Order: {order_summary}

Instructions:
- Ask for name if not known
- Show menu if asked
- Extract food items and quantity
- Say "Order summary" and ask "Confirm?" when user is done
- Respond naturally, no "Bot:" prefix

Conversation so far:
"""

    for m in memory.chat_memory.messages:
        role = "Customer" if m.type == "human" else "Bot"
        prompt += f"{role}: {m.content}\n"

    prompt += f"Customer: {user_input}\nBot:"

    try:
        response = model.generate_content(prompt)
        return response.text
    except Exception as e:
        return f"❌ Gemini Error: {e}"

# --- Chat handler ---
def handle_chat(user_input):
    global customer_name, order

    memory.chat_memory.add_user_message(user_input)
    bot_reply = generate_response(user_input)
    memory.chat_memory.add_ai_message(bot_reply)

    if "my name is" in user_input.lower():
        customer_name = user_input.split("my name is")[-1].strip().split()[0].title()

    for item in MENU:
        if item.lower() in user_input.lower():
            qty = 1
            for word in user_input.lower().split():
                if word.isdigit():
                    qty = int(word)
                    break
            order.append((item, qty))

    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 Systaurant!"

    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 here..."),
    outputs=[
        gr.Textbox(label="🤖 Bot Response"),
        gr.Audio(label="🔊 Speaking", autoplay=True)
    ],
    title="🍔 Systaurant Voice Bot",
    description="A smart voice-enabled assistant to take food orders.",
    theme="soft"
).launch(share=True)