extern crate chipmunk;

use chipmunk::space::Space;
use chipmunk::body::Body;
use chipmunk::shape::Shape;
use chipmunk::util::*;

fn main() {
    let gravity = (0.0, -100.0);
    let floor_friction = 1.0;
    let ball_friction = 0.7;
    let ball_radius = 5.0;
    let ball_mass = 1.0;
    let ball_pos = (0.0, 15.0);
    let ball_moment = moment_of_circle(ball_mass, ball_radius, 0.0);
    let floor_start = (-20.0, 0.0);
    let floor_end = (20.0, 0.0);
    let floor_radius = 0.0;
    let zero = (0.0, 0.0);
    let time_step = 1.0 / 60.0;

    // The space contains everything in the simulation.
    let mut space = Space::new();
    space.set_gravity(gravity.0, gravity.1);

    // Set up a floor for our ball to bounce off of.
    let mut floor_body = Body::new_static();
    let mut floor_shape = Shape::new_segment(
        &mut floor_body, floor_start, floor_end, floor_radius);

    floor_shape.set_friction(floor_friction);
    space.add_body(&mut floor_body);
    space.add_shape(&mut floor_shape);


    // Add a bouncing ball to the scene.
    let mut ball_body = Body::new(ball_mass, ball_moment);
    let mut ball_shape = Shape::new_circle(&mut ball_body, ball_radius, zero);

    ball_body.set_position(ball_pos.0, ball_pos.1);
    ball_shape.set_friction(ball_friction);

    space.add_body(&mut ball_body);
    space.add_shape(&mut ball_shape);

    let mut y_coords = vec![];

    // Run the simulation!
    for i in 0 .. 60 {
        let time = time_step * (i as f64);
        let pos = ball_body.position();
        let vel = ball_body.velocity();
        space.step(time_step);
        y_coords.push(pos.1);

        println!("t: {:?}, p: {:?}, v: {:?}", time, pos, vel);
    }

    let min = y_coords.iter()
                      .cloned()
                      .map(|a| a as i32)
                      .min().unwrap();
    for coord in y_coords {
        let coord = ((coord - min as f64) * 10.0) as usize;
        let s: String = ::std::iter::repeat(' ').take(coord).collect();
        println!("{}#", s);
    }
}