use bevy::prelude::*;
use cyber_rider::flycam::{MovementSettings, PlayerPlugin, PLANET_RADIUS};

/*
stolen with neither shame nor pity from
git@github.com:sburris0/bevy_flycam.git, b90f6fc, which is copyright 2020
Spencer Burris
*/

const LIGHT_RANGE: f32 = PLANET_RADIUS * 2.2;
const LIGHT_DIST: f32 = PLANET_RADIUS * 1.2;

fn main() {
    App::new()
        .insert_resource(Msaa { samples: 4 })
        .add_plugins(DefaultPlugins)
        .add_plugin(PlayerPlugin)
        .insert_resource(MovementSettings {
            sensitivity: 0.3, // default: 1.0
            accel: 20.0,      // default: 40.0
            drag: 0.1,        // default: 0.05
            gravity: 10.0,    // default: 10.0
        })
        .add_startup_system(setup.label("world"))
        .add_startup_system(disable_cursor.after("world"))
        .add_system(animate_lights)
        .add_system(bevy::input::system::exit_on_esc_system)
        .run();
}

fn disable_cursor(mut windows: ResMut<Windows>) {
    let window = windows.get_primary_mut().unwrap();
    window.set_cursor_lock_mode(false);
    window.set_cursor_visibility(true);
}

#[derive(Component)]
struct Animate;

fn setup(
    mut commands: Commands,
    mut meshes: ResMut<Assets<Mesh>>,
    mut materials: ResMut<Assets<StandardMaterial>>,
) {
    let red_light = PointLight {
        intensity: 5_000.0,
        range: LIGHT_RANGE,
        color: Color::RED,
        ..Default::default()
    };

    let blue_light = PointLight {
        intensity: 5_000.0,
        range: LIGHT_RANGE,
        color: Color::BLUE,
        ..Default::default()
    };

    let purple_light = PointLight {
        intensity: 5_000.0,
        range: LIGHT_RANGE,
        color: Color::PURPLE,
        ..Default::default()
    };

    commands.insert_resource(AmbientLight {
        color: Color::WHITE,
        brightness: 0.12,
    });

    // world
    commands.spawn_bundle(PbrBundle {
        mesh: meshes.add(Mesh::from(shape::Icosphere {
            radius: PLANET_RADIUS,
            subdivisions: 6,
        })),
        material: materials.add(StandardMaterial {
            base_color: Color::GRAY,
            metallic: 0.7,
            perceptual_roughness: 0.5,
            ..Default::default()
        }),

        ..Default::default()
    });

    // east light
    commands
        .spawn_bundle(PointLightBundle {
            transform: Transform::from_xyz(LIGHT_DIST, 0.0, 0.0),
            point_light: purple_light,
            ..Default::default()
        })
        .with_children(|builder| {
            builder.spawn_bundle(PbrBundle {
                mesh: meshes.add(Mesh::from(shape::UVSphere {
                    radius: 10.0,
                    ..Default::default()
                })),
                material: materials.add(StandardMaterial {
                    base_color: Color::PURPLE,
                    emissive: Color::rgba_linear(50.0, 0.0, 50.0, 0.0),
                    ..Default::default()
                }),
                ..Default::default()
            });
        })
        .insert(Animate);

    // west light
    commands
        .spawn_bundle(PointLightBundle {
            transform: Transform::from_xyz(-LIGHT_DIST, 0.0, 0.0),
            point_light: purple_light,
            ..Default::default()
        })
        .with_children(|builder| {
            builder.spawn_bundle(PbrBundle {
                mesh: meshes.add(Mesh::from(shape::UVSphere {
                    radius: 10.0,
                    ..Default::default()
                })),
                material: materials.add(StandardMaterial {
                    base_color: Color::PURPLE,
                    emissive: Color::rgba_linear(50.0, 0.0, 50.0, 0.0),
                    ..Default::default()
                }),
                ..Default::default()
            });
        })
        .insert(Animate);
    // north light
    commands
        .spawn_bundle(PointLightBundle {
            transform: Transform::from_xyz(0.0, 0.0, LIGHT_DIST),
            point_light: purple_light,
            ..Default::default()
        })
        .with_children(|builder| {
            builder.spawn_bundle(PbrBundle {
                mesh: meshes.add(Mesh::from(shape::UVSphere {
                    radius: 10.0,
                    ..Default::default()
                })),
                material: materials.add(StandardMaterial {
                    base_color: Color::PURPLE,
                    emissive: Color::rgba_linear(50.0, 0.0, 50.0, 0.0),
                    ..Default::default()
                }),
                ..Default::default()
            });
        })
        .insert(Animate);
    // south light
    commands
        .spawn_bundle(PointLightBundle {
            transform: Transform::from_xyz(0.0, 0.0, -LIGHT_DIST),
            point_light: purple_light,
            ..Default::default()
        })
        .with_children(|builder| {
            builder.spawn_bundle(PbrBundle {
                mesh: meshes.add(Mesh::from(shape::UVSphere {
                    radius: 10.0,
                    ..Default::default()
                })),
                material: materials.add(StandardMaterial {
                    base_color: Color::PURPLE,
                    emissive: Color::rgba_linear(50.0, 0.0, 50.0, 0.0),
                    ..Default::default()
                }),
                ..Default::default()
            });
        })
        .insert(Animate);
    // up light
    commands
        .spawn_bundle(PointLightBundle {
            transform: Transform::from_xyz(0.0, LIGHT_DIST, 0.0),
            point_light: red_light,
            ..Default::default()
        })
        .with_children(|builder| {
            builder.spawn_bundle(PbrBundle {
                mesh: meshes.add(Mesh::from(shape::Icosphere {
                    radius: 10.0,
                    subdivisions: 2,
                })),
                material: materials.add(StandardMaterial {
                    base_color: Color::RED,
                    emissive: Color::rgba_linear(100.0, 0.0, 0.0, 0.0),
                    ..Default::default()
                }),
                ..Default::default()
            });
        });
    // down light
    commands
        .spawn_bundle(PointLightBundle {
            transform: Transform::from_xyz(0.0, -LIGHT_DIST, 0.0),
            point_light: blue_light,
            ..Default::default()
        })
        .with_children(|builder| {
            builder.spawn_bundle(PbrBundle {
                mesh: meshes.add(Mesh::from(shape::Icosphere {
                    radius: 10.0,
                    subdivisions: 2,
                })),
                material: materials.add(StandardMaterial {
                    base_color: Color::BLUE,
                    emissive: Color::rgba_linear(0.0, 0.0, 100.0, 0.0),
                    ..Default::default()
                }),
                ..Default::default()
            });
        });
}

fn animate_lights(mut query: Query<&mut Transform, (With<PointLight>, With<Animate>)>) {
    for mut transform in query.iter_mut() {
        let translation = &transform.translation;
        let x = translation.x;
        let y = translation.y;
        let z = if translation.z.abs() < 0.1 {
            translation.z + 0.15
        } else {
            translation.z
        };

        // 10 degrees == 0.174533 radians
        let anim_rate = 0.174533 / 5.0;
        let theta = z.atan2(x) + anim_rate;
        let x_new = LIGHT_DIST * theta.cos();
        let z_new = LIGHT_DIST * theta.sin();

        *transform = Transform::from_xyz(x_new, y, z_new);
    }
}