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

class app:
    def __init__(self):
        self.app_cfg = yaml.safe_load(open('./cfg.yaml')) or {}
        self.OPCon = opcua_connector(self.app_cfg)

    def initialize_connection(self):
        """Initialize OPC UA connection"""
        try:
            self.OPCon.connect()
            if self.OPCon.check_connection() == 1:
                st.session_state.connection_status = "Connected"
                print("🎉 Connection initialized successfully")
                return True
            st.session_state.connection_status = "Disconnected"
            return False
        except Exception as e:
            print(f"❌ Failed to initialize connection: {e}")
            st.session_state.connection_status = "Disconnected"
            return False

    def execute_button_action(self, button_name):
        """Execute button action with proper error handling"""
        if button_name == 'INIT':
            self.OPCon.adapt_access_rights()
            print(f"🔧 INIT button pressed - Access rights adapted")
        else:
            self.OPCon.press_btn(button_name)
            print(f"🔘 {button_name} button pressed")
        return True

# Load config early for password if present
app = app()

# 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)

# Initialize session state
if 'connection_status' not in st.session_state:
    st.session_state.connection_status = "Disconnected"
if 'authenticated' not in st.session_state:
    st.session_state.authenticated = False

# 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

st.session_state.connection_status = (
    "Connected" if is_opcua_connected(app.OPCon) else "Disconnected"
)



# 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..."):
            app.initialize_connection()
            st.rerun()
    
    # Disconnect button
    if st.button("🔌 Disconnect", use_container_width=True):
        try:
            app.OPCon.disconnect()
            print("🔌 Disconnected from OPC UA server")
        except Exception as e:
            print(f"⚠️ Warning during disconnect: {e}")
        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.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):
            app.execute_button_action('INIT')

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

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

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

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

# Footer removed for minimal UI