mod support;

use glam::f32::*;
use support::deg;

const IDENTITY: [[f32; 2]; 2] = [[1.0, 0.0], [0.0, 1.0]];

const MATRIX: [[f32; 2]; 2] = [[1.0, 2.0], [3.0, 4.0]];

const ZERO: [[f32; 2]; 2] = [[0.0; 2]; 2];

#[test]
fn test_mat2_align() {
    use std::mem;
    assert_eq!(16, mem::size_of::<Mat2>());
    if cfg!(feature = "scalar-math") {
        assert_eq!(4, mem::align_of::<Mat2>());
    } else {
        assert_eq!(16, mem::align_of::<Mat2>());
    }
}

#[test]
fn test_mat2_identity() {
    let identity = Mat2::identity();
    assert_eq!(IDENTITY, identity.to_cols_array_2d());
    assert_eq!(Mat2::from_cols_array_2d(&IDENTITY), identity);
    assert_eq!(identity, identity * identity);
    assert_eq!(identity, Mat2::default());
}

#[test]
fn test_mat2_zero() {
    assert_eq!(Mat2::from_cols_array_2d(&ZERO), Mat2::zero());
}

#[test]
fn test_mat2_accessors() {
    let mut m = Mat2::zero();
    m.set_x_axis(Vec2::new(1.0, 2.0));
    m.set_y_axis(Vec2::new(3.0, 4.0));
    assert_eq!(Mat2::from_cols_array_2d(&MATRIX), m);
    assert_eq!(Vec2::new(1.0, 2.0), m.x_axis());
    assert_eq!(Vec2::new(3.0, 4.0), m.y_axis());
}

#[test]
fn test_mat2_from_axes() {
    let a = Mat2::from_cols_array_2d(&[[1.0, 2.0], [3.0, 4.0]]);
    assert_eq!(MATRIX, a.to_cols_array_2d());
    let b = Mat2::from_cols(vec2(1.0, 2.0), vec2(3.0, 4.0));
    assert_eq!(a, b);
    let c = mat2(vec2(1.0, 2.0), vec2(3.0, 4.0));
    assert_eq!(a, c);
    let d = b.to_cols_array();
    let f = Mat2::from_cols_array(&d);
    assert_eq!(b, f);
}

#[test]
fn test_mat2_mul() {
    let mat_a = Mat2::from_angle(deg(90.0));
    let res_a = mat_a * Vec2::unit_y();
    assert_approx_eq!(vec2(-1.0, 0.0), res_a);
    let res_b = mat_a * Vec2::unit_x();
    assert_approx_eq!(vec2(0.0, 1.0), res_b);
}

#[test]
fn test_from_scale() {
    let m = Mat2::from_scale(Vec2::new(2.0, 4.0));
    assert_approx_eq!(m * Vec2::new(1.0, 1.0), Vec2::new(2.0, 4.0));
    assert_approx_eq!(Vec2::unit_x() * 2.0, m.x_axis());
    assert_approx_eq!(Vec2::unit_y() * 4.0, m.y_axis());

    let rot = Mat2::from_scale_angle(Vec2::new(4.0, 2.0), deg(180.0));
    assert_approx_eq!(Vec2::unit_x() * -4.0, rot * Vec2::unit_x(), 1.0e-6);
    assert_approx_eq!(Vec2::unit_y() * -2.0, rot * Vec2::unit_y(), 1.0e-6);
}

#[test]
fn test_mat2_transpose() {
    let m = mat2(vec2(1.0, 2.0), vec2(3.0, 4.0));
    let mt = m.transpose();
    assert_eq!(mt.x_axis(), vec2(1.0, 3.0));
    assert_eq!(mt.y_axis(), vec2(2.0, 4.0));
}

#[test]
fn test_mat2_det() {
    assert_eq!(0.0, Mat2::zero().determinant());
    assert_eq!(1.0, Mat2::identity().determinant());
    assert_eq!(1.0, Mat2::from_angle(deg(90.0)).determinant());
    assert_eq!(1.0, Mat2::from_angle(deg(180.0)).determinant());
    assert_eq!(1.0, Mat2::from_angle(deg(270.0)).determinant());
    assert_eq!(2.0 * 2.0, Mat2::from_scale(vec2(2.0, 2.0)).determinant());
    assert_eq!(
        1.0 * 4.0 - 2.0 * 3.0,
        Mat2::from_cols_array(&[1.0, 2.0, 3.0, 4.0]).determinant()
    );
}

#[test]
fn test_mat2_inverse() {
    let inv = Mat2::identity().inverse();
    assert_approx_eq!(Mat2::identity(), inv);

    let rot = Mat2::from_angle(deg(90.0));
    let rot_inv = rot.inverse();
    assert_approx_eq!(Mat2::identity(), rot * rot_inv);
    assert_approx_eq!(Mat2::identity(), rot_inv * rot);

    let scale = Mat2::from_scale(vec2(4.0, 5.0));
    let scale_inv = scale.inverse();
    assert_approx_eq!(Mat2::identity(), scale * scale_inv);
    assert_approx_eq!(Mat2::identity(), scale_inv * scale);

    let m = scale * rot;
    let m_inv = m.inverse();
    assert_approx_eq!(Mat2::identity(), m * m_inv);
    assert_approx_eq!(Mat2::identity(), m_inv * m);
    assert_approx_eq!(m_inv, rot_inv * scale_inv);
}

#[test]
fn test_mat2_ops() {
    let m0 = Mat2::from_cols_array_2d(&MATRIX);
    assert_eq!(
        Mat2::from_cols_array_2d(&[[2.0, 4.0], [6.0, 8.0]]),
        m0 * 2.0
    );
    assert_eq!(
        Mat2::from_cols_array_2d(&[[2.0, 4.0], [6.0, 8.0]]),
        2.0 * m0
    );
    assert_eq!(Mat2::from_cols_array_2d(&[[2.0, 4.0], [6.0, 8.0]]), m0 + m0);
    assert_eq!(Mat2::zero(), m0 - m0);
    assert_approx_eq!(
        Mat2::from_cols_array_2d(&[[1.0, 2.0], [3.0, 4.0]]),
        m0 * Mat2::identity()
    );
    assert_approx_eq!(
        Mat2::from_cols_array_2d(&[[1.0, 2.0], [3.0, 4.0]]),
        Mat2::identity() * m0
    );
}

#[test]
fn test_mat2_fmt() {
    let a = Mat2::from_cols_array_2d(&MATRIX);
    assert_eq!(format!("{}", a), "[[1, 2], [3, 4]]");
}

#[cfg(feature = "serde")]
#[test]
fn test_mat2_serde() {
    let a = Mat2::from_cols(vec2(1.0, 2.0), vec2(3.0, 4.0));
    let serialized = serde_json::to_string(&a).unwrap();
    assert_eq!(serialized, "[1.0,2.0,3.0,4.0]");
    let deserialized = serde_json::from_str(&serialized).unwrap();
    assert_eq!(a, deserialized);
    let deserialized = serde_json::from_str::<Mat2>("[]");
    assert!(deserialized.is_err());
    let deserialized = serde_json::from_str::<Mat2>("[1.0]");
    assert!(deserialized.is_err());
    let deserialized = serde_json::from_str::<Mat2>("[1.0,2.0]");
    assert!(deserialized.is_err());
    let deserialized = serde_json::from_str::<Mat2>("[1.0,2.0,3.0]");
    assert!(deserialized.is_err());
    let deserialized = serde_json::from_str::<Mat2>("[1.0,2.0,3.0,4.0,5.0]");
    assert!(deserialized.is_err());
    let deserialized = serde_json::from_str::<Mat2>("[[1.0,2.0],[3.0,4.0]]");
    assert!(deserialized.is_err());
}

#[cfg(feature = "rand")]
#[test]
fn test_mat2_rand() {
    use rand::{Rng, SeedableRng};
    use rand_xoshiro::Xoshiro256Plus;
    let mut rng1 = Xoshiro256Plus::seed_from_u64(0);
    let a = Mat2::from_cols_array(&rng1.gen::<[f32; 4]>());
    let mut rng2 = Xoshiro256Plus::seed_from_u64(0);
    let b = rng2.gen::<Mat2>();
    assert_eq!(a, b);
}