use bevy::prelude::*;
use bevy_mod_picking::{
    events::{Click, Pointer},
    prelude::On,
    DefaultPickingPlugins,
};
use woodpecker_ui::prelude::*;

#[derive(Component, PartialEq, Default, Debug, Clone)]
pub struct CounterState {
    count: u32,
}

#[derive(Widget, Component, Reflect, PartialEq, Default, Debug, Clone)]
#[auto_update(render)]
#[props(CounterWidget)]
#[state(CounterState)]
pub struct CounterWidget {
    initial_count: u32,
}

#[derive(Bundle, Default, Clone)]
pub struct CounterWidgetBundle {
    pub counter: CounterWidget,
    pub styles: WoodpeckerStyle,
    pub children: WidgetChildren,
}

fn render(
    current_widget: Res<CurrentWidget>,
    mut commands: Commands,
    mut query: Query<(&CounterWidget, &mut WidgetChildren)>,
    state_query: Query<&CounterState>,
    mut hooks: ResMut<HookHelper>,
) {
    let Ok((widget, mut children)) = query.get_mut(**current_widget) else {
        return;
    };

    let state_entity = hooks.use_state(
        &mut commands,
        *current_widget,
        CounterState {
            count: widget.initial_count,
        },
    );

    let Ok(state) = state_query.get(state_entity) else {
        return;
    };

    // Dereference so we don't move the reference into the on click closure.
    let current_widget = *current_widget;
    *children = WidgetChildren::default().with_child::<Element>(ElementBundle {
        styles: WoodpeckerStyle {
            width: Units::Percentage(100.0),
            flex_direction: WidgetFlexDirection::Column,
            justify_content: Some(WidgetAlignContent::Center),
            align_items: Some(WidgetAlignItems::Center),
            ..Default::default()
        },
        children: WidgetChildren::default()
            .with_child::<Element>((
                ElementBundle {
                    styles: WoodpeckerStyle {
                        font_size: 50.0,
                        margin: Edge::all(10.0),
                        ..Default::default()
                    },
                    ..Default::default()
                },
                WidgetRender::Text {
                    content: format!("Current Count: {}", state.count),
                    word_wrap: false,
                },
            ))
            .with_child::<WButton>((
                WButtonBundle {
                    children: WidgetChildren::default().with_child::<Element>((
                        ElementBundle {
                            styles: WoodpeckerStyle {
                                font_size: 14.0,
                                margin: Edge::all(10.0),
                                ..Default::default()
                            },
                            ..Default::default()
                        },
                        WidgetRender::Text {
                            content: "Increase Count".into(),
                            word_wrap: false,
                        },
                    )),
                    ..Default::default()
                },
                On::<Pointer<Click>>::run(move |mut query: Query<&mut CounterState>| {
                    let Ok(mut state) = query.get_mut(state_entity) else {
                        return;
                    };
                    state.count += 1;
                }),
            )),
        ..Default::default()
    });

    children.apply(current_widget.as_parent());
}

fn main() {
    App::new()
        .add_plugins(DefaultPlugins)
        .add_plugins(WoodpeckerUIPlugin::default())
        .add_plugins(DefaultPickingPlugins)
        .add_systems(Startup, startup)
        .register_widget::<CounterWidget>()
        .run();
}

fn startup(
    mut commands: Commands,
    mut ui_context: ResMut<WoodpeckerContext>,
    mut font_manager: ResMut<FontManager>,
    asset_server: Res<AssetServer>,
) {
    commands.spawn(Camera2dBundle::default());

    let font = asset_server.load("Outfit/static/Outfit-Regular.ttf");
    font_manager.add(&font);

    let root = commands
        .spawn(WoodpeckerAppBundle {
            children: WidgetChildren::default().with_child::<CounterWidget>(CounterWidgetBundle {
                styles: WoodpeckerStyle {
                    width: Units::Percentage(100.0),
                    ..Default::default()
                },
                ..Default::default()
            }),
            ..Default::default()
        })
        .id();
    ui_context.set_root_widget(root);
}