use std::sync::{
    atomic::{AtomicBool, Ordering},
    Arc,
};

use bevy::prelude::*;
use bevy_terminal_display::{
    crossterm::event::{Event, KeyCode, KeyEventKind},
    input::events::TerminalInputEvent,
    ratatui::{
        layout::Rect, style::{Color, Modifier, Style}, widgets::{Block, Borders, Clear, HighlightSpacing, List, ListItem, ListState}
    },
    widgets::TerminalWidget,
};

pub struct MenuWidget<E: bevy::prelude::Event> {
    pub items: Vec<MenuOption<E>>,
    pub state: ListState,
    pub enabled_color: Color,
    pub disabled_color: Color,
    pub selected_style: Style,
    pub area_function: Option<Box<dyn Fn(Rect) -> Rect + Send + Sync>>,
}

impl<E: bevy::prelude::Event> Default for MenuWidget<E> {
    fn default() -> Self {
        Self {
            items: vec![],
            state: ListState::default().with_selected(Some(0)),
            enabled_color: Color::White,
            disabled_color: Color::Gray,
            selected_style: Style::new()
                .add_modifier(Modifier::UNDERLINED)
                .add_modifier(Modifier::BOLD),
            area_function: None,
        }
    }
}

pub struct MenuOption<E: bevy::prelude::Event> {
    pub enabled: Arc<AtomicBool>,
    pub label: String,
    pub event: E,
}

impl<E: bevy::prelude::Event + Clone> TerminalWidget for MenuWidget<E> {
    fn render(
        &mut self,
        frame: &mut bevy_terminal_display::ratatui::Frame,
        rect: bevy_terminal_display::ratatui::prelude::Rect,
    ) {
        let block = Block::new().borders(Borders::all());
        let items: Vec<ListItem> = self
            .items
            .iter()
            .map(|item| {
                ListItem::from(item).style(Style::new().fg(
                    if item.enabled.load(Ordering::Relaxed) {
                        self.enabled_color
                    } else {
                        self.disabled_color
                    },
                ))
            })
            .collect();

        let list = List::new(items)
            .block(block)
            .highlight_style(self.selected_style)
            .highlight_symbol(">")
            .highlight_spacing(HighlightSpacing::Always);

        let area = if let Some(area) = &self.area_function {
            area(rect)
        } else {
            rect
        };
        frame.render_widget(Clear, area);
        frame.render_stateful_widget(list, area, &mut self.state);
    }

    fn handle_events(
        &mut self,
        event: &bevy_terminal_display::input::events::TerminalInputEvent,
        commands: &mut Commands,
    ) {
        if let TerminalInputEvent(Event::Key(key_event)) = event {
            if key_event.kind == KeyEventKind::Press {
                match key_event.code {
                    KeyCode::Enter => {
                        if let Some(selected) = self.state.selected() {
                            if let Some(item) = self.items.get(selected) {
                                if item.enabled.load(Ordering::Relaxed) {
                                    commands.send_event(item.event.clone());
                                }
                            }
                        }
                    },
                    KeyCode::Up => self.state.select_previous(),
                    KeyCode::Down => self.state.select_next(),
                    _ => (),
                }
            }
        }
    }
}

impl<E: bevy::prelude::Event> FromIterator<(&'static str, E)> for MenuWidget<E> {
    fn from_iter<I: IntoIterator<Item = (&'static str, E)>>(iter: I) -> Self {
        let items = iter
            .into_iter()
            .map(|(label, event)| MenuOption {
                enabled: Arc::new(true.into()),
                label: label.into(),
                event,
            })
            .collect();
        Self {
            items,
            ..Default::default()
        }
    }
}

impl<E: bevy::prelude::Event> From<&MenuOption<E>> for ListItem<'_> {
    fn from(value: &MenuOption<E>) -> Self {
        ListItem::new(value.label.clone())
    }
}