import streamlit as st
import random
from datetime import datetime

# Mock ChatAgent class to replace the backend dependency
class MockChatAgent:
    def __init__(self):
        # Sample order data
        self.orders = {
            "ORD123": {"status": "Shipped", "date": "2023-11-15", "items": ["Laptop", "Mouse"], "total": "$1200"},
            "ORD456": {"status": "Processing", "date": "2023-11-20", "items": ["Keyboard", "Headphones"], "total": "$150"},
            "ORD789": {"status": "Delivered", "date": "2023-11-10", "items": ["Monitor", "USB Cable"], "total": "$350"},
        }
        
        # Predefined responses for common queries
        self.responses = [
            "I'm checking your order information now...",
            "Let me look that up for you...",
            "Based on our records...",
            "According to the system...",
            "I can help you with that...",
        ]
    
    def query(self, prompt):
        # Simple keyword-based response system
        prompt_lower = prompt.lower()
        
        # Check for order number pattern
        for order_id, order_info in self.orders.items():
            if order_id.lower() in prompt_lower:
                response = f"Order {order_id}: Status is {order_info['status']}. "
                response += f"Ordered on {order_info['date']}. Items: {', '.join(order_info['items'])}. "
                response += f"Total: {order_info['total']}."
                return response
        
        # Check for status queries
        if "status" in prompt_lower or "track" in prompt_lower:
            return "To check your order status, please provide your order number (e.g., ORD123)."
        
        # Check for delivery queries
        if "delivery" in prompt_lower or "deliver" in prompt_lower:
            return "Delivery times vary based on your location. Most orders arrive within 3-5 business days after shipping."
        
        # Check for return queries
        if "return" in prompt_lower:
            return "You can return items within 30 days of delivery. Please visit our returns page to initiate a return."
        
        # Default response
        return f"{random.choice(self.responses)} I'm a mock agent, so I can only provide limited information about orders. Try asking about order status, delivery, or returns, or provide an order number like ORD123."

# Initialize session state
if 'messages' not in st.session_state:
    st.session_state.messages = []
if 'agent' not in st.session_state:
    st.session_state.agent = MockChatAgent()

# Page config
st.set_page_config(page_title="AI Agent Chatbot", page_icon="🤖")

# Title
st.title("🤖 AI Agent Chatbot")
st.markdown("Ask me about your orders! (This is a demo with mock data)")

# Display chat messages
for message in st.session_state.messages:
    with st.chat_message(message["role"]):
        st.markdown(message["content"])

# Chat input
if prompt := st.chat_input("Ask about your orders..."):
    # Add user message
    st.session_state.messages.append({"role": "user", "content": prompt})
    with st.chat_message("user"):
        st.markdown(prompt)
    
    # Show loading state
    with st.chat_message("assistant"):
        thinking_placeholder = st.empty()
        thinking_placeholder.markdown("Thinking...")
        
        try:
            # Get response from agent
            response = st.session_state.agent.query(prompt)
            
            # Replace loading with response
            thinking_placeholder.markdown(response)
            
            # Update session state
            st.session_state.messages.append({"role": "assistant", "content": response})
            
        except Exception as e:
            # Show error
            thinking_placeholder.markdown(f"❌ Sorry, I encountered an error: {str(e)}")
            st.session_state.messages.append({"role": "assistant", "content": f"❌ Error: {str(e)}"})

# Sidebar for clearing chat
with st.sidebar:
    st.title("Settings")
    if st.button("Clear Chat"):
        st.session_state.messages = []
        st.session_state.agent = MockChatAgent()  # Reinitialize agent with clean memory
        st.rerun()
    
    st.markdown("---")
    st.markdown(f"**Messages:** {len(st.session_state.messages)}")
    st.markdown(f"**Agent Status:** Ready")
    st.markdown("---")
    st.markdown("**Sample Order Numbers:**")
    st.markdown("- ORD123")
    st.markdown("- ORD456")
    st.markdown("- ORD789")