mod audio;
mod credits;
mod debug;
mod display2d;
mod display3d;
mod game;
mod loading;
mod menu;
mod prelude;

use std::time::Duration;

use bevy::{
    asset::{ChangeWatcher, HandleId},
    input::{keyboard::KeyboardInput, ButtonState},
};

use crate::prelude::*;

fn main() {
    if std::env::var_os("CARGO_MANIFEST_DIR").is_none() {
        std::env::set_var("CARGO_MANIFEST_DIR", ".");
    }

    App::new()
        .add_state::<GameState>()
        .add_systems(Update, state.run_if(resource_changed::<State<GameState>>()))
        .add_systems(Update, loading.run_if(in_state(GameState::Loading)))
        .add_systems(
            Update,
            toggle_display_mode.run_if(on_event::<KeyboardInput>()),
        )
        .add_plugins((
            DefaultPlugins
                .set(ImagePlugin::default_nearest())
                .set(WindowPlugin {
                    primary_window: Some(Window {
                        title: "Martian Chess".into(),
                        resolution: (640., 480.).into(),
                        ..default()
                    }),
                    ..default()
                })
                .set(AssetPlugin {
                    watch_for_changes: ChangeWatcher::with_delay(Duration::from_millis(200)),
                    ..default()
                }),
            audio::AudioPlugin,
            credits::CreditsPlugin,
            debug::DebugPlugin,
            display2d::Display2dPlugin,
            display3d::Display3dPlugin,
            game::GamePlugin,
            loading::LoadingPlugin,
            menu::MenuPlugin,
        ))
        .run();
}

#[derive(Clone, Copy, PartialEq, Eq, Hash, Debug, Default, States, Component)]
pub enum GameState {
    #[default]
    Loading,
    Menu,
    Credits,
    Display2d,
    Display3d,
}

fn loading(
    server: Res<AssetServer>,
    sprites: Res<Assets<Image>>,
    gltfs: Res<Assets<Gltf>>,
    mut next_state: ResMut<NextState<GameState>>,
) {
    let s_ids = sprites
        .ids()
        .filter(|&id| matches!(id, HandleId::AssetPathId(_)))
        .collect::<Vec<HandleId>>();

    let g_ids = gltfs
        .ids()
        .filter(|&id| matches!(id, HandleId::AssetPathId(_)))
        .collect::<Vec<HandleId>>();

    debug!(
        "Sprite len: {:?} | GLTF len: {:?}",
        s_ids.len(),
        g_ids.len()
    );

    if s_ids.len() > 0 && g_ids.len() > 0 {
        let s_ready = s_ids
            .iter()
            .all(|&id| server.get_load_state(id) == LoadState::Loaded);
        let g_ready = g_ids
            .iter()
            .all(|&id| server.get_load_state(id) == LoadState::Loaded);
        if s_ready && g_ready {
            next_state.set(GameState::Menu)
        }
    }
}

/// System for printing the current state
///
/// Only runs when state is modified.
fn state(state: Res<State<GameState>>) {
    info!("State is {:?}", *state);
}

fn toggle_display_mode(
    mut events: EventReader<KeyboardInput>,
    state: Res<State<GameState>>,
    mut next_state: ResMut<NextState<GameState>>,
) {
    events
        .iter()
        .filter(
            |KeyboardInput {
                 key_code, state, ..
             }| (*key_code, *state) == (Some(KeyCode::Space), ButtonState::Pressed),
        )
        .for_each(|_| match state.get() {
            GameState::Display2d => next_state.set(GameState::Display3d),
            GameState::Display3d => next_state.set(GameState::Display2d),
            _ => (),
        })
}

fn activate<Marker: Component>(
    mut cameras: Query<&mut Camera, With<Marker>>,
    mut entities: Query<&mut Visibility, With<Marker>>,
) {
    cameras.iter_mut().for_each(|mut camera| {
        camera.is_active = true;
    });
    entities.iter_mut().for_each(|mut visibility| {
        *visibility = Visibility::Visible;
    });
}

fn deactivate<Marker: Component>(
    mut cameras: Query<&mut Camera, With<Marker>>,
    mut entities: Query<&mut Visibility, With<Marker>>,
) {
    cameras.iter_mut().for_each(|mut camera| {
        camera.is_active = false;
    });
    entities.iter_mut().for_each(|mut visibility| {
        *visibility = Visibility::Hidden;
    });
}

pub(crate) fn any_component_changed<C: Component>(q: Query<Entity, Changed<C>>) -> bool {
    !q.is_empty()
}

pub(crate) fn any_component_added<C: Component>(q: Query<Entity, Added<C>>) -> bool {
    !q.is_empty()
}