use rand;
use rand::Rng;

use camera::Camera;
use hitable::Hit;
use hitable_list::HitableList;
use kdtree::KDTree;
use material::Dielectric;
use material::Lambertian;
use material::Metal;
use renderer::Opt;
use renderer::Scene;
use sphere::Sphere;
use vec3::Vec3;

pub fn new(opt: &Opt) -> Scene {
    let lookfrom = Vec3::new(13., 2., 3.);
    let lookat = Vec3::new(0., 0., 0.);
    let dist_to_focus = 10.;
    let aperture = 0.1;
    let time_min = 0.;
    let time_max = 1.;
    let camera = Camera::new(
        lookfrom,
        lookat,
        Vec3::new(0., 1., 0.),
        20.,
        opt.width as f32 / opt.height as f32,
        aperture,
        dist_to_focus,
        time_min,
        time_max,
    );
    let ground_color = if opt.use_accel {
        Vec3::new(1.0, 0.4, 0.4)
    } else {
        Vec3::new(0.4, 1.0, 0.4)
    };
    let world: Box<Hit> = if opt.use_accel {
        Box::new(KDTree::new(random_scene(ground_color), time_min, time_max))
    } else {
        Box::new(HitableList::new(random_scene(ground_color)))
    };
    Scene {
        camera,
        world,
        subsamples: opt.subsamples,
        width: opt.width,
        height: opt.height,
    }
}

fn random_scene(background_color: Vec3) -> Vec<Box<Hit>> {
    let mut rng = rand::thread_rng();
    let mut objects: Vec<Box<Hit>> = vec![Box::new(Sphere::new(
        Vec3::new(0., -1000., 0.),
        1000.,
        Box::new(Lambertian::new(background_color)),
    ))];
    let mut random = || rng.gen_range::<f32>(0., 1.);

    for a in -11..11 {
        for b in -11..11 {
            let choose_mat = random();
            let center = Vec3::new(a as f32 + 0.9 * random(), 0.2, b as f32 + 0.9 * random());
            if (center - Vec3::new(4., 0.2, 0.)).length() > 0.9 {
                let sphere = if choose_mat < 0.8 {
                    // diffuse
                    Box::new(Sphere::new(
                        center,
                        0.2,
                        Box::new(Lambertian::new(Vec3::new(
                            random() * random(),
                            random() * random(),
                            random() * random(),
                        ))),
                    ))
                } else if choose_mat < 0.95 {
                    // metal
                    Box::new(Sphere::new(
                        center,
                        0.2,
                        Box::new(Metal::new(
                            Vec3::new(
                                0.5 * (1. + random()),
                                0.5 * (1. + random()),
                                0.5 * (1. + random()),
                            ),
                            0.5 * random(),
                        )),
                    ))
                } else {
                    // glass
                    Box::new(Sphere::new(center, 0.2, Box::new(Dielectric::new(1.5))))
                };
                objects.push(sphere);
            };
        }
    }

    let more: Vec<Box<Hit>> = vec![
        Box::new(Sphere::new(
            Vec3::new(0., 1., 0.),
            1.0,
            Box::new(Dielectric::new(1.5)),
        )),
        Box::new(Sphere::new(
            Vec3::new(-4., 1., 0.),
            1.0,
            Box::new(Lambertian::new(Vec3::new(0.4, 0.2, 0.1))),
        )),
        Box::new(Sphere::new(
            Vec3::new(4., 1., 0.),
            1.0,
            Box::new(Metal::new(Vec3::new(0.7, 0.6, 0.5), 0.0)),
        )),
    ];
    objects.extend(more);
    objects
}