// Copyright 2018-2020 argmin developers
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://apache.org/licenses/LICENSE-2.0> or the MIT license <LICENSE-MIT or
// http://opensource.org/licenses/MIT>, at your option. This file may not be
// copied, modified, or distributed except according to those terms.

use crate::core::math::ArgminEye;

macro_rules! make_eye {
    ($t:ty) => {
        impl ArgminEye for Vec<Vec<$t>> {
            #[allow(clippy::cast_lossless)]
            #[inline]
            fn eye_like(&self) -> Vec<Vec<$t>> {
                let n = self.len();
                let mut out = vec![vec![0 as $t; n]; n];
                for i in 0..n {
                    out[i][i] = 1 as $t;
                }
                out
            }

            #[allow(clippy::cast_lossless)]
            #[inline]
            fn eye(n: usize) -> Vec<Vec<$t>> {
                let mut out = vec![vec![0 as $t; n]; n];
                for i in 0..n {
                    out[i][i] = 1 as $t;
                }
                out
            }
        }
    };
}

make_eye!(f32);
make_eye!(f64);
make_eye!(i8);
make_eye!(i16);
make_eye!(i32);
make_eye!(i64);
make_eye!(u8);
make_eye!(u16);
make_eye!(u32);
make_eye!(u64);
make_eye!(isize);
make_eye!(usize);

#[cfg(test)]
mod tests {
    use super::*;
    use paste::item;

    macro_rules! make_test {
        ($t:ty) => {
            item! {
                #[test]
                fn [<test_eye_ $t>]() {
                    let e: Vec<Vec<$t>> = <Vec<Vec<$t>> as ArgminEye>::eye(3);
                    let res = vec![
                        vec![1 as $t, 0 as $t, 0 as $t],
                        vec![0 as $t, 1 as $t, 0 as $t],
                        vec![0 as $t, 0 as $t, 1 as $t]
                    ];
                    for i in 0..3 {
                        for j in 0..3 {
                            assert!((((res[i][j] - e[i][j]) as f64).abs()) < std::f64::EPSILON);
                        }
                    }
                }
            }

            item! {
                #[test]
                fn [<test_eye_like_ $t>]() {
                    let a = vec![
                        vec![0 as $t, 2 as $t, 6 as $t],
                        vec![3 as $t, 2 as $t, 7 as $t],
                        vec![9 as $t, 8 as $t, 1 as $t]
                    ];
                    let e: Vec<Vec<$t>> = a.eye_like();
                    let res = vec![
                        vec![1 as $t, 0 as $t, 0 as $t],
                        vec![0 as $t, 1 as $t, 0 as $t],
                        vec![0 as $t, 0 as $t, 1 as $t]
                    ];
                    for i in 0..3 {
                        for j in 0..3 {
                            assert!((((res[i][j] - e[i][j]) as f64).abs()) < std::f64::EPSILON);
                        }
                    }
                }
            }
        };
    }

    make_test!(isize);
    make_test!(usize);
    make_test!(i8);
    make_test!(u8);
    make_test!(i16);
    make_test!(u16);
    make_test!(i32);
    make_test!(u32);
    make_test!(i64);
    make_test!(u64);
    make_test!(f32);
    make_test!(f64);
}
