use bevy::prelude::*;

use crate::geometry::PLANET_RADIUS;

pub const LIGHT_RANGE: f32 = PLANET_RADIUS * 0.6;
pub const LIGHT_DIST: f32 = PLANET_RADIUS * 1.2;

pub struct CyberSpaceLightsPlugin;

impl Plugin for CyberSpaceLightsPlugin {
    fn build(&self, app: &mut App) {
        app.add_startup_system(setup).add_system(animate_lights);
    }
}

#[derive(Component)]
struct Animate;

fn setup(
    mut commands: Commands,
    mut meshes: ResMut<Assets<Mesh>>,
    mut materials: ResMut<Assets<StandardMaterial>>,
) {
    let red_light = PointLight {
        intensity: 1_000.0,
        range: LIGHT_RANGE,
        color: Color::RED,
        radius: 1.0,
        ..Default::default()
    };

    let blue_light = PointLight {
        intensity: 1_000.0,
        range: LIGHT_RANGE,
        color: Color::BLUE,
        radius: 1.0,
        ..Default::default()
    };

    let purple_light = PointLight {
        intensity: 1_000.0,
        range: LIGHT_RANGE,
        color: Color::PURPLE,
        radius: 1.0,
        ..Default::default()
    };

    commands.insert_resource(AmbientLight {
        color: Color::WHITE,
        brightness: 0.32,
    });

    // 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(
    time: Res<Time>,
    mut query: Query<&mut Transform, (With<PointLight>, With<Animate>)>,
) {
    let dt = time.delta_seconds();
    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
        };

        let rads = 10.0f32.to_radians();
        let anim_rate = rads * dt;
        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);
    }
}