import streamlit as st
from datetime import datetime

# App title
st.title("Chat and Call Application")

# Sidebar for navigation
menu = ["Home", "Add Contact", "Chat", "Call"]
choice = st.sidebar.selectbox("Menu", menu)

# Global variables (for simulation)
if 'contacts' not in st.session_state:
    st.session_state['contacts'] = {}
if 'chat_history' not in st.session_state:
    st.session_state['chat_history'] = {}

# Home page
if choice == "Home":
    st.header("Welcome to the Chat and Call App")
    st.write("Use the sidebar to navigate between features.")

# Add Contact page
elif choice == "Add Contact":
    st.header("Add a New Contact")
    with st.form("add_contact_form"):
        name = st.text_input("Contact Name")
        phone = st.text_input("Phone Number")
        submit = st.form_submit_button("Add Contact")

        if submit:
            if name and phone:
                st.session_state['contacts'][name] = phone
                st.success(f"Contact {name} added successfully!")
            else:
                st.error("Please provide both name and phone number.")

# Chat page
elif choice == "Chat":
    st.header("Chat with Your Contacts")

    if not st.session_state['contacts']:
        st.warning("No contacts available. Please add contacts first.")
    else:
        contact = st.selectbox("Select a Contact", list(st.session_state['contacts'].keys()))

        if contact:
            st.write(f"Chatting with: {contact}")
            chat_key = contact

            # Display chat history
            if chat_key not in st.session_state['chat_history']:
                st.session_state['chat_history'][chat_key] = []

            chat_history = st.session_state['chat_history'][chat_key]
            for message in chat_history:
                st.write(message)

            # Input for sending a message
            with st.form("send_message_form"):
                message = st.text_input("Enter your message")
                send = st.form_submit_button("Send")

                if send:
                    if message:
                        timestamp = datetime.now().strftime("%Y-%m-%d %H:%M:%S")
                        chat_history.append(f"You ({timestamp}): {message}")
                        st.session_state['chat_history'][chat_key] = chat_history
                        st.experimental_rerun()
                    else:
                        st.error("Message cannot be empty.")

# Call page
elif choice == "Call":
    st.header("Make a Call")

    if not st.session_state['contacts']:
        st.warning("No contacts available. Please add contacts first.")
    else:
        contact = st.selectbox("Select a Contact to Call", list(st.session_state['contacts'].keys()))

        if contact:
            st.write(f"Calling {contact}...")
            st.button("End Call", on_click=lambda: st.success(f"Call with {contact} ended."))