use crate::{actor, camera, starchart, nature};
use bevy::prelude::*;
//use bevy::core_pipeline::Skybox;
//use bevy::asset::LoadState;
//use bevy::render::render_resource::{TextureViewDescriptor, TextureViewDimension};
use bevy::pbr::CascadeShadowConfigBuilder;
use bevy::core_pipeline::bloom::{BloomCompositeMode, BloomSettings};
use std::f32::consts::PI;

const ASTEROID_SIZE: f32 = 100.0;
const MOON_SIZE: f32 = 50.0;
const MARS_SIZE: f32 = 10.0;
const ASTRONAUT_SIZE: f32 = 5.0;

//const SKYBOX_BRIGHTNESS: f32 = 300.0;
//const SKYBOX_BRIGHTNESS_AR: f32 = 100.0;

//const ASSET_CUBEMAP: &str = "textures/cubemap-fs8.png";
//const ASSET_CUBEMAP_AR: &str = "textures/out.png";
const ASSET_ASTRONAUT: &str = "tmp/alien.glb#Scene0";

pub struct WorldPlugin;
impl Plugin for WorldPlugin {
    fn build(&self, app: &mut App) {
        app.add_systems(Startup, setup);
        //app.add_systems(Update, asset_loaded.after(load_cubemap_asset));
        //app.add_systems(Update, swap_world_on_ar_toggle);
        app.insert_resource(ClearColor(Color::rgb(0.0, 0.0, 0.0)));
    }
}

#[derive(Component)]
pub struct Star;

//#[derive(Resource)]
//pub struct WorldState {
//    is_loaded: bool,
//    entities_viewn_through_ar: bool,
//    cubemap_handle: Handle<Image>,
//    cubemap_ar_handle: Handle<Image>,
//}
//impl WorldState {
//    pub fn get_cubemap_handle(&self) -> Handle<Image> {
//        if self.entities_viewn_through_ar {
//            self.cubemap_ar_handle.clone()
//        } else {
//            self.cubemap_handle.clone()
//        }
//    }
//}

pub fn setup(
    mut commands: Commands,
    mut meshes: ResMut<Assets<Mesh>>,
    mut materials: ResMut<Assets<StandardMaterial>>,
    mut ambient_light: ResMut<AmbientLight>,
//    settings: Res<settings::Settings>,
    asset_server: Res<AssetServer>,
) {
//    let cubemap_handle = asset_server.load(ASSET_CUBEMAP);
//    commands.insert_resource(WorldState {
//        is_loaded: false,
//        entities_viewn_through_ar: settings.hud_active,
//        cubemap_handle: asset_server.load(ASSET_CUBEMAP),
//        cubemap_ar_handle: asset_server.load(ASSET_CUBEMAP_AR),
//    });

    // Add player
    commands.spawn((
        actor::Player,
        actor::Actor::default(),
        actor::LifeForm::default(),
        actor::Suit {
            oxygen: actor::OXY_M,
            ..default()
        }
    ));

    commands.spawn((
        Camera3dBundle {
            camera: Camera {
                hdr: true, // HDR is required for bloom
                ..default()
            },
            transform: Transform::from_xyz(0.0, 0.0, 8.0).looking_at(Vec3::ZERO, Vec3::Y),
            ..default()
        },
        camera::CameraController::default(),
//        Skybox {
//            image: cubemap_handle,
//            brightness: SKYBOX_BRIGHTNESS,
//        },
        BloomSettings {
            composite_mode: BloomCompositeMode::EnergyConserving,
            ..default()
        },
    ));

    // Add some hand-placed asteroids
    let sphere_handle = meshes.add(Sphere::new(1.0));
    let gray_handle = materials.add(StandardMaterial {
        base_color: Color::GRAY,
        perceptual_roughness: 1.0,
        ..default()
    });
    let brown_handle = materials.add(StandardMaterial {
        base_color: Color::Rgba { alpha: 1.0, red: 0.8, green: 0.5, blue: 0.1 },
        perceptual_roughness: 1.0,
        ..default()
    });
    commands.spawn((
        actor::Actor::default(),
        PbrBundle {
            mesh: sphere_handle.clone(),
            material: gray_handle.clone(),
            transform: Transform::from_xyz(
                0.0,
                0.0,
                -500.0,
            ).with_scale(Vec3::splat(MOON_SIZE)),
            ..default()
        },
    ));
    commands.spawn((
        actor::Actor::default(),
        PbrBundle {
            mesh: sphere_handle.clone(),
            material: brown_handle.clone(),
            transform: Transform::from_xyz(
                300.0,
                40.0,
                250.0,
            ).with_scale(Vec3::splat(MARS_SIZE)),
            ..default()
        },
    ));

    // Generate a bunch of asteriods
    let asteroid_color_handle = materials.add(StandardMaterial {
        base_color: Color::rgb(0.25, 0.2, 0.2),
        perceptual_roughness: 1.0,
        ..default()
    });
    let maxdist = 10;
    for i in -maxdist..maxdist {
        for j in -maxdist..maxdist {
            for k in -maxdist..maxdist {
                let offset = 500.0;
                let dist = 3e4;
                let wobble = dist/2.0;
                let (i, j, k) = (i as f32, j as f32, k as f32);
                commands.spawn((
                    actor::Actor::default(),
                    PbrBundle {
                        mesh: sphere_handle.clone(),
                        material: asteroid_color_handle.clone(),
                        transform: Transform::from_xyz(
                            offset + dist * i + wobble * (j+k/PI).sin() * (k+j/PI).cos(),
                            offset + dist * j + wobble * (k+i/PI).sin() * (i+k/PI).cos(),
                            offset + dist * k + wobble * (i+j/PI).sin() * (j+i/PI).cos(),
                        ).with_scale(Vec3::splat(ASTEROID_SIZE)),
                        ..default()
                    }
                ));
            }
        }
    }

    // Generate starmap
    for star in starchart::STARS {
        let brightness = star[3] * 2000.0;
        let (r, g, b) = nature::star_color_index_to_rgb(star[4]);
        let star_color_handle = materials.add(StandardMaterial {
            base_color: Color::rgb(r, g, b),
            emissive: Color::rgb_linear(r*brightness, g*brightness, b*brightness),
            ..default()
        });
        let dist = 1e6;
        commands.spawn((
            Star,
            PbrBundle {
                mesh: sphere_handle.clone(),
                material: star_color_handle.clone(),
                transform: Transform::from_xyz(
                        dist * star[0],
                        dist * star[1],
                        dist * star[2],
                    )
                    .with_scale(Vec3::splat((1000.0*star[3]).clamp(500.0, 2000.0))),
                ..default()
            }
        ));
    }

    // Add alien
    commands.spawn(SceneBundle {
            transform: Transform {
                translation: Vec3::new(
                    0.0,
                    0.0,
                    100.0,
                ),
                rotation: Quat::from_rotation_y(-PI / 3.),
                scale: Vec3::splat(ASTRONAUT_SIZE),
            },
            scene: asset_server.load(ASSET_ASTRONAUT),
            ..default()
        });

    // Space is DARK
    ambient_light.brightness = 0.0;

    // Add Light
    commands.spawn(DirectionalLightBundle {
        directional_light: DirectionalLight {
            illuminance: 1000.0,
            shadows_enabled: false,
            ..default()
        },
        transform: Transform::from_rotation(Quat::from_euler(
            EulerRot::ZYX,
            0.0,
            PI / 1.0,
            -PI / 7.0,
        )),
        cascade_shadow_config: CascadeShadowConfigBuilder {
            first_cascade_far_bound: 7.0,
            maximum_distance: 25.0,
            ..default()
        }
        .into(),
        ..default()
    });
}

//pub fn swap_world_on_ar_toggle(
//    asset_server: Res<AssetServer>,
//    mut images: ResMut<Assets<Image>>,
//    mut worldstate: ResMut<WorldState>,
//    mut skyboxes: Query<&mut Skybox>,
//    settings: Res<settings::Settings>,
//) {
//    if settings.hud_active != worldstate.entities_viewn_through_ar {
//        worldstate.is_loaded = false;
//        worldstate.entities_viewn_through_ar = settings.hud_active;
//    }
//    if !worldstate.is_loaded && asset_server.load_state(&worldstate.get_cubemap_handle()) == LoadState::Loaded {
//        let cubemap_handle = &worldstate.get_cubemap_handle();
//        let image = images.get_mut(cubemap_handle).unwrap();
//        if image.texture_descriptor.array_layer_count() == 1 {
//            image.reinterpret_stacked_2d_as_array(image.height() / image.width());
//            image.texture_view_descriptor = Some(TextureViewDescriptor {
//                dimension: Some(TextureViewDimension::Cube),
//                ..default()
//            });
//        }
//
//        for mut skybox in &mut skyboxes {
//            skybox.image = cubemap_handle.clone();
//            skybox.brightness = if settings.hud_active {
//                SKYBOX_BRIGHTNESS_AR
//            } else {
//                SKYBOX_BRIGHTNESS
//            }
//        }
//
//        worldstate.is_loaded = true;
//    }
//}