import streamlit as st
from landing_page import display_landing_page
from about_page import display_about_page
from css_styles import load_css
from hydrogen_analyzer import run_analyzer

# Main application function
def main():
    # Set page config
    st.set_page_config(
        page_title="EcoLytics: Intelligent Hydrogen Economics Platform",
        page_icon="⚡",
        layout="wide",
        initial_sidebar_state="expanded"
    )
    
    # Load custom CSS
    load_css()
    
    # Initialize session state for navigation
    if "page" not in st.session_state:
        st.session_state.page = "Home"
    
    # Sidebar navigation
    with st.sidebar:
        st.markdown("# EcoLytics")
        st.markdown("## Hydrogen Economics Platform")
        st.markdown("---")
        
        if st.button("Home", use_container_width=True):
            st.session_state.page = "Home"
            st.experimental_rerun()
            
        if st.button("Hydrogen Analyzer", use_container_width=True):
            st.session_state.page = "Hydrogen Analyzer"
            st.experimental_rerun()
            
        if st.button("About", use_container_width=True):
            st.session_state.page = "About"
            st.experimental_rerun()
            
        st.markdown("---")
        st.markdown("### EcoLytics")
        st.markdown("Version 1.0")
    
    # Display current page
    if st.session_state.page == "Home":
        display_landing_page()
    elif st.session_state.page == "Hydrogen Analyzer":
        run_analyzer()
    else:
        display_about_page()

if __name__ == "__main__":
    main()