use na::{Isometry3, Point3, Vector3};
use rapier3d::dynamics::{JointSet, RevoluteJoint, RigidBodyBuilder, RigidBodySet};
use rapier3d::geometry::{ColliderBuilder, ColliderSet};
use rapier_testbed3d::Testbed;

pub fn init_world(testbed: &mut Testbed) {
    /*
     * World
     */
    let mut bodies = RigidBodySet::new();
    let mut colliders = ColliderSet::new();
    let mut joints = JointSet::new();

    let rad = 0.4;
    let num = 10;
    let shift = 2.0;

    for l in 0..4 {
        let y = l as f32 * shift * (num as f32) * 3.0;

        for j in 0..50 {
            let x = j as f32 * shift * 4.0;

            let ground = RigidBodyBuilder::new_static()
                .translation(x, y, 0.0)
                .build();
            let mut curr_parent = bodies.insert(ground);
            let collider = ColliderBuilder::cuboid(rad, rad, rad).build();
            colliders.insert(collider, curr_parent, &mut bodies);

            for i in 0..num {
                // Create four bodies.
                let z = i as f32 * shift * 2.0 + shift;
                let positions = [
                    Isometry3::translation(x, y, z),
                    Isometry3::translation(x + shift, y, z),
                    Isometry3::translation(x + shift, y, z + shift),
                    Isometry3::translation(x, y, z + shift),
                ];

                let mut handles = [curr_parent; 4];
                for k in 0..4 {
                    let density = 1.0;
                    let rigid_body = RigidBodyBuilder::new_dynamic()
                        .position(positions[k])
                        .build();
                    handles[k] = bodies.insert(rigid_body);
                    let collider = ColliderBuilder::cuboid(rad, rad, rad)
                        .density(density)
                        .build();
                    colliders.insert(collider, handles[k], &mut bodies);
                }

                // Setup four joints.
                let o = Point3::origin();
                let x = Vector3::x_axis();
                let z = Vector3::z_axis();

                let revs = [
                    RevoluteJoint::new(o, z, Point3::new(0.0, 0.0, -shift), z),
                    RevoluteJoint::new(o, x, Point3::new(-shift, 0.0, 0.0), x),
                    RevoluteJoint::new(o, z, Point3::new(0.0, 0.0, -shift), z),
                    RevoluteJoint::new(o, x, Point3::new(shift, 0.0, 0.0), x),
                ];

                joints.insert(&mut bodies, curr_parent, handles[0], revs[0]);
                joints.insert(&mut bodies, handles[0], handles[1], revs[1]);
                joints.insert(&mut bodies, handles[1], handles[2], revs[2]);
                joints.insert(&mut bodies, handles[2], handles[3], revs[3]);

                curr_parent = handles[3];
            }
        }
    }

    /*
     * Set up the testbed.
     */
    testbed.set_world(bodies, colliders, joints);
    testbed.look_at(
        Point3::new(478.0, 83.0, 228.0),
        Point3::new(134.0, 83.0, -116.0),
    );
}

fn main() {
    let testbed = Testbed::from_builders(0, vec![("Joints", init_world)]);
    testbed.run()
}