use bevy::{app::AppExit, pbr::Lightmap, prelude::*};
use bevy_asset_loader::asset_collection::AssetCollection;

use crate::AppState;

pub struct MenuPlugin;

#[derive(Resource, AssetCollection)]
pub struct MenuAssets {
    #[asset(path = "logo_bw.ktx2")]
    pub logo: Handle<Image>,
    #[asset(path = "plane_map.ktx2")]
    pub plane_lightmap: Handle<Image>,
    #[asset(path = "scene.glb#Scene0")]
    pub scene: Handle<Scene>,
}

const NORMAL_BUTTON: Color = Color::BLACK;

impl Plugin for MenuPlugin {
    fn build(&self, app: &mut App) {
        app.add_systems(OnEnter(AppState::Menu), setup_menu)
            .add_systems(Update, menu.run_if(in_state(AppState::Menu)))
            .add_systems(OnExit(AppState::Menu), cleanup_menu);
    }
}

#[derive(Component)]
enum MenuButton {
    Play,
    Quit,
}

#[derive(Resource, Clone, Copy)]
pub struct MenuData {
    pub button_entity: Entity,
    pub logo_bw_entity: Entity,
}

fn cleanup_menu(mut commands: Commands, menu_data: Res<MenuData>) {
    commands.entity(menu_data.button_entity).despawn_recursive();
}

fn menu(
    mut next_state: ResMut<NextState<AppState>>,
    mut interaction_query: Query<(&Interaction, &MenuButton), Changed<Interaction>>,
    mut app_exit_events: EventWriter<AppExit>,
) {
    for (interaction, button_type) in &mut interaction_query {
        match *interaction {
            Interaction::Pressed => match *button_type {
                MenuButton::Play => next_state.set(AppState::Rooms),
                MenuButton::Quit => {
                    app_exit_events.send(AppExit);
                }
            },
            _ => {}
        }
    }
}

fn setup_menu(
    mut commands: Commands,
    assets: Res<MenuAssets>,
    mut clear_color: ResMut<ClearColor>,
    mut materials: ResMut<Assets<StandardMaterial>>,
    meshes: Query<
        (Entity, &Name, &Handle<StandardMaterial>),
        (With<Handle<Mesh>>, Without<Lightmap>),
    >,
) {
    let exposure = 250.0;
    clear_color.0 = Color::BLACK;
    for (entity, name, material) in meshes.iter() {
        if &**name == "Light" {
            materials.get_mut(material).unwrap().emissive = Color::WHITE * exposure;
            continue;
        }

        if &**name == "Plane" {
            materials.get_mut(material).unwrap().lightmap_exposure = exposure;
            commands.entity(entity).insert(Lightmap {
                image: assets.plane_lightmap.clone(),
                ..default()
            });
            continue;
        }
    }
    let logo_bw_entity = commands
        .spawn(NodeBundle {
            style: Style {
                // center button
                width: Val::Percent(100.),
                height: Val::Percent(100.),
                justify_content: JustifyContent::FlexStart,
                align_items: AlignItems::End,
                ..default()
            },
            ..Default::default()
        })
        .with_children(|parent| {
            parent.spawn(ImageBundle {
                style: Style {
                    width: Val::Auto,
                    height: Val::Auto,
                    justify_content: JustifyContent::FlexStart,
                    align_items: AlignItems::Start,
                    ..Default::default()
                },
                image: UiImage {
                    texture: assets.logo.clone(),
                    ..Default::default()
                },
                ..Default::default()
            });
        })
        .id();
    let button_entity = commands
        .spawn(NodeBundle {
            style: Style {
                // center button
                width: Val::Percent(100.),
                height: Val::Percent(100.),
                justify_content: JustifyContent::Center,
                align_items: AlignItems::Center,
                flex_direction: FlexDirection::Column,
                ..default()
            },
            ..default()
        })
        .with_children(|parent| {
            parent
                .spawn((
                    ButtonBundle {
                        style: Style {
                            width: Val::Px(150.),
                            height: Val::Px(65.),
                            // horizontally center child text
                            justify_content: JustifyContent::Center,
                            // vertically center child text
                            align_items: AlignItems::Center,
                            margin: UiRect {
                                bottom: Val::Px(16.0),
                                ..Default::default()
                            },
                            ..default()
                        },
                        background_color: NORMAL_BUTTON.into(),
                        ..default()
                    },
                    MenuButton::Play,
                ))
                .with_children(|parent| {
                    parent.spawn(TextBundle::from_section(
                        "Play",
                        TextStyle {
                            font_size: 40.0,
                            color: Color::rgb(0.9, 0.9, 0.9),
                            ..default()
                        },
                    ));
                });
            parent
                .spawn((
                    ButtonBundle {
                        style: Style {
                            width: Val::Px(150.),
                            height: Val::Px(65.),
                            // horizontally center child text
                            justify_content: JustifyContent::Center,
                            // vertically center child text
                            align_items: AlignItems::Center,
                            margin: UiRect {
                                bottom: Val::Px(16.0),
                                ..Default::default()
                            },
                            ..default()
                        },
                        background_color: NORMAL_BUTTON.into(),
                        ..default()
                    },
                    MenuButton::Quit,
                ))
                .with_children(|parent| {
                    parent.spawn(TextBundle::from_section(
                        "Quit",
                        TextStyle {
                            font_size: 40.0,
                            color: Color::rgb(0.9, 0.9, 0.9),
                            ..default()
                        },
                    ));
                });
        })
        .id();
    commands.spawn(Camera3dBundle {
        transform: Transform::from_xyz(0.0, -585.9, 193.0),
        // .with_rotation(Quat::from_rotation_x(71.0)),
        ..Default::default()
    });
    commands.insert_resource(AmbientLight::NONE);
    commands.insert_resource(MenuData {
        button_entity,
        logo_bw_entity,
    });
}