import streamlit as st
import yaml
import time
import os
from opcua_connector import opcua_connector

# Load config early for password if present
app_cfg = yaml.safe_load(open('./cfg.yaml')) or {}


# Page configuration
st.set_page_config(
    page_title="OPC UA Robot Control Dashboard",
    page_icon="🤖",
    layout="wide",
    initial_sidebar_state="expanded"
)

# Custom CSS for better styling (external stylesheet)
with open('styles.css') as f:
    st.markdown(f"<style>{f.read()}</style>", unsafe_allow_html=True)


def execute_button_action(button_name):
    """Execute button action with proper error handling"""
    if st.session_state.opcon is None:
        return False
        
    if button_name == 'INIT':
        st.session_state.opcon.adapt_access_rights()
        print(f"🔧 INIT button pressed - Access rights adapted")
    else:
        st.session_state.opcon.press_btn(button_name)
        print(f"🔘 {button_name} button pressed")
    return True

# Re-validate connection status each render (do this before rendering UI)
def is_opcua_connected(conn) -> bool:
    try:
        return bool(conn and conn.check_connection() == 1)
    except Exception:
        return False
    

# Initialize session state
if 'opcon' not in st.session_state:
    st.session_state.opcon = None
if 'connection_status' not in st.session_state:
    st.session_state.connection_status = "Disconnected"

# Update connection status on each render
st.session_state.connection_status = (
    "Connected" if is_opcua_connected(st.session_state.opcon) else "Disconnected"
)
if 'authenticated' not in st.session_state:
    st.session_state.authenticated = False




# Sidebar
with st.sidebar:
    st.write(f"Status: {st.session_state.connection_status}")
    
    # Initialize button
    if st.button("🔌 Initialize Connection", use_container_width=True):
        with st.spinner("Initializing connection..."):
            try:
                if st.session_state.opcon is None:
                    st.session_state.opcon = opcua_connector(app_cfg)
                
                st.session_state.opcon.connect()
                if st.session_state.opcon.check_connection() == 1:
                    st.session_state.connection_status = "Connected"
                    print("🎉 Connection initialized successfully")
                else:
                    st.session_state.connection_status = "Disconnected"
                    print("❌ Connection failed")
            except Exception as e:
                print(f"❌ Failed to initialize connection: {e}")
                st.session_state.connection_status = "Disconnected"
            st.rerun()
    
    # Disconnect button
    if st.button("🔌 Disconnect", use_container_width=True):
        try:
            if st.session_state.opcon:
                st.session_state.opcon.disconnect()
                print("🔌 Disconnected from OPC UA server")
        except Exception as e:
            print(f"⚠️ Warning during disconnect: {e}")
        st.session_state.opcon = None
        st.session_state.connection_status = "Disconnected"
        print("🔌 Connection reset")
        st.rerun()
    
    st.divider()


    
# Password gate
# Prefer cfg.yaml cred.dashboard.password, else env DASHBOARD_PASSWORD, else 'admin'
expected_password = (
    (app_cfg.get('cred', {}).get('dashboard', {}) or {}).get('password')
    or 'admin'
)
ui_locked = not st.session_state.authenticated
if ui_locked:
    pwd = st.text_input("Enter Dashboard Password", type="password")
    if st.button("Login", use_container_width=True):
        if pwd == expected_password:
            st.session_state.authenticated = True
            st.rerun()
        else:
            st.error("Wrong password")

if not ui_locked:
    # Button container
    st.markdown('<div class="button-container">', unsafe_allow_html=True)

    # Create columns for buttons
    btn_col1, btn_col2, btn_col3, btn_col4 = st.columns(4)

    buttons_disabled = st.session_state.connection_status != "Connected"

    with btn_col1:
        if st.button("🔧\n\nINIT", key="init_btn", use_container_width=True, disabled=buttons_disabled):
            execute_button_action('INIT')

    with btn_col2:
        if st.button("▶️\n\nSTART", key="start_btn", use_container_width=True, disabled=buttons_disabled):
            execute_button_action('BTN_START')

    with btn_col3:
        if st.button("⏹️\n\nSTOP", key="stop_btn", use_container_width=True, disabled=buttons_disabled):
            execute_button_action('BTN_STOP')

    with btn_col4:
        if st.button("🔄\n\nRESET", key="reset_btn", use_container_width=True, disabled=buttons_disabled):
            execute_button_action('BTN_RESET')

    st.markdown('</div>', unsafe_allow_html=True)

# Footer removed for minimal UI