use rapier2d::prelude::*;
use rapier_testbed2d::Testbed;

pub fn init_world(testbed: &mut Testbed) {
    /*
     * World
     */
    let mut bodies = RigidBodySet::new();
    let mut colliders = ColliderSet::new();
    let impulse_joints = ImpulseJointSet::new();
    let multibody_joints = MultibodyJointSet::new();

    /*
     * Ground
     */
    let ground_size = 25.0;

    let rigid_body = RigidBodyBuilder::new_static().build();
    let handle = bodies.insert(rigid_body);
    let collider = ColliderBuilder::cuboid(ground_size, 1.2).build();
    colliders.insert_with_parent(collider, handle, &mut bodies);

    let rigid_body = RigidBodyBuilder::new_static()
        .rotation(std::f32::consts::FRAC_PI_2)
        .translation(vector![ground_size, ground_size * 2.0])
        .build();
    let handle = bodies.insert(rigid_body);
    let collider = ColliderBuilder::cuboid(ground_size * 2.0, 1.2).build();
    colliders.insert_with_parent(collider, handle, &mut bodies);

    let rigid_body = RigidBodyBuilder::new_static()
        .rotation(std::f32::consts::FRAC_PI_2)
        .translation(vector![-ground_size, ground_size * 2.0])
        .build();
    let handle = bodies.insert(rigid_body);
    let collider = ColliderBuilder::cuboid(ground_size * 2.0, 1.2).build();
    colliders.insert_with_parent(collider, handle, &mut bodies);

    /*
     * Create the cubes
     */
    let num = 26;
    let rad = 0.5;

    let shift = rad * 2.0;
    let centerx = shift * (num as f32) / 2.0;
    let centery = shift / 2.0;

    for i in 0..num {
        for j in 0usize..num * 5 {
            let x = i as f32 * shift - centerx;
            let y = j as f32 * shift + centery + 2.0;

            // Build the rigid body.
            let rigid_body = RigidBodyBuilder::new_dynamic()
                .translation(vector![x, y])
                .build();
            let handle = bodies.insert(rigid_body);
            let collider = ColliderBuilder::cuboid(rad, rad).build();
            colliders.insert_with_parent(collider, handle, &mut bodies);
        }
    }

    /*
     * Set up the testbed.
     */
    testbed.set_world(bodies, colliders, impulse_joints, multibody_joints);
    testbed.look_at(point![0.0, 50.0], 10.0);
}
