"""Entry point for the Streamlit app.

Runs with: streamlit run frontend/app.py

Responsibilities:
- Configure the page layout
- Inject global CSS tweaks
- Render the sidebar (navigation + file explorer)
- Delegate to the correct view (Chat or Code Editor) based on the radio selection
"""

import streamlit as st
import sys
from pathlib import Path

# Add the project root to sys.path so backend imports work regardless of
# where streamlit is launched from.
sys.path.insert(0, str(Path(__file__).parent.parent))

from frontend.sidebar import render_sidebar
from frontend.editor import render_editor
from frontend.chat import render_chat
from frontend.state import init_state

# Initialise all session-state keys before any widget is rendered
init_state()


def main():
    st.set_page_config(page_title="Lightweight code editor", layout="wide")

    # Small spacing corrections applied globally:
    # - Reduce the default top padding of the main content area
    # - Pull the sidebar content up so the logo sits at the very top
    st.markdown(
        """
        <style>
        .block-container { padding-top: 1rem; }
        [data-testid="stSidebarContent"] { padding-top: 0rem; margin-top: -2rem; }
        </style>
    """,
        unsafe_allow_html=True,
    )

    st.title("Lightweight code editor")

    # REVIEW: redundant — init_state() is already called at module level (line 26) before main() runs;
    # calling it again here is unnecessary since Streamlit reruns the whole module on each reload.
    # Re-run init_state to cover any keys that might have been missed on cold start
    init_state()

    render_sidebar()

    # Switch between the two main views based on the sidebar radio button
    if st.session_state.get("radio_interface_options") == "Code Editor":
        render_editor()
    elif st.session_state.get("radio_interface_options") == "Chat with AI Assistant":
        render_chat()


if __name__ == "__main__":
    main()