//! Demonstrates how you can animate the movement of the camera

use bevy::prelude::*;
use bevy_panorbit_camera::{PanOrbitCamera, PanOrbitCameraPlugin};
use std::f32::consts::TAU;

fn main() {
    App::new()
        .add_plugins(DefaultPlugins)
        .add_plugins(PanOrbitCameraPlugin)
        .add_systems(Startup, setup)
        .add_systems(Update, animate)
        .run();
}

fn setup(
    mut commands: Commands,
    mut meshes: ResMut<Assets<Mesh>>,
    mut materials: ResMut<Assets<StandardMaterial>>,
) {
    // Ground
    commands.spawn((
        Mesh3d(meshes.add(Plane3d::default().mesh().size(5.0, 5.0))),
        MeshMaterial3d(materials.add(Color::srgb(0.3, 0.5, 0.3))),
    ));
    // Cube
    commands.spawn((
        Mesh3d(meshes.add(Cuboid::new(1.0, 1.0, 1.0))),
        MeshMaterial3d(materials.add(Color::srgb(0.8, 0.7, 0.6))),
        Transform::from_xyz(0.0, 0.5, 0.0),
    ));
    // Light
    commands.spawn((
        PointLight {
            shadows_enabled: true,
            ..default()
        },
        Transform::from_xyz(4.0, 8.0, 4.0),
    ));
    // Camera
    commands.spawn((
        Transform::from_translation(Vec3::new(0.0, 1.5, 5.0)),
        PanOrbitCamera {
            // Disable smoothing, since the animation takes care of that
            orbit_smoothness: 0.0,
            // Probably want to disable the controls
            enabled: false,
            ..default()
        },
    ));
}

// Animate the camera's position
fn animate(time: Res<Time>, mut pan_orbit_query: Query<&mut PanOrbitCamera>) {
    for mut pan_orbit in pan_orbit_query.iter_mut() {
        // Must set target values, not yaw/pitch directly
        pan_orbit.target_yaw += 15f32.to_radians() * time.delta_secs();
        pan_orbit.target_pitch = time.elapsed_secs_wrapped().sin() * TAU * 0.1;
        pan_orbit.radius =
            Some((((time.elapsed_secs_wrapped() * 2.0).cos() + 1.0) * 0.5) * 2.0 + 4.0);

        // Force camera to update its transform
        pan_orbit.force_update = true;
    }
}