//-------------------------------------------------------------------------
// @file vector3.rs
//
// @date 06/02/20 18:50:41
// @author Martin Noblia
// @email mnoblia@disroot.org
//
// @brief
//
// @detail
//
// Licence MIT:
// Copyright <2020> <Martin Noblia>
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.  THE SOFTWARE IS PROVIDED
// "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
// LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
// ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//-------------------------------------------------------------------------
use std::fmt;
use num::{Float, Zero, Num};
use std::ops::{Deref, DerefMut};

use std::ops::{Add, Mul, Sub};
// use std::ops::{AddAssign, DivAssign, MulAssign, SubAssign};

use crate::errors::VectorErrors;
use crate::matrix3x3::M33;
//-------------------------------------------------------------------------
//                        code
//-------------------------------------------------------------------------
#[derive(Copy, Clone, Debug, PartialEq)]
pub struct V3<T>([T; 3]);

impl<T> V3<T> {
    pub fn new(input: [T; 3]) -> V3<T> {
        V3(input)
    }
}

impl<T: Num + Copy> V3<T> {
    pub fn zeros() -> V3<T> {
        <V3<T> as Zero>::zero()
    }

    /// calculate the cross product
    pub fn cross(&self, rhs: Self) -> Self {
        let u_x = rhs[0];
        let u_y = rhs[1];
        let u_z = rhs[2];

        Self::new([u_y * self[2] - u_z * self[1],
                 u_z * self[0] - u_x * self[2],
                 u_x * self[1] - u_y * self[0]])
    }

}

impl<T: Float> V3<T> {
    /// calculate the euclidean norm of the vector
    pub fn norm2(&self) -> T {
        let a = self[0];
        let b = self[1];
        let c = self[2];
        T::sqrt(a * a + b * b + c * c)
    }

    /// normalize the current vector
    pub fn normalize(&self) -> Result<Self, VectorErrors> {
        let n = self.norm2();
        if n != T::zero() {
            // this method return a new fresh and clean vector :)
            let mut result = Self::zeros();
            for i in 0..self.len() {
                result[i] = self[i] / n;
            }
            Ok(result)
        } else {
            Err(VectorErrors::Norm2IsZero)
        }
    }
}

//-------------------------------------------------------------------------
//                        maths basic operations
//-------------------------------------------------------------------------

// V3 * const
impl<T: Num + Copy> Mul<T> for V3<T> {
    type Output = V3<T>;

    fn mul(self, rhs: T) -> Self::Output {
        let a0 = self[0] * rhs;
        let a1 = self[1] * rhs;
        let a2 = self[2] * rhs;
        V3::new([a0, a1, a2])
    }
}

// FIXME(elsuizo:2020-06-19): this is a hack
impl Mul<V3<f32>> for f32 {
    type Output = V3<f32>;

    fn mul(self, rhs: V3<f32>) -> Self::Output {
        let a0 = rhs[0] * self;
        let a1 = rhs[1] * self;
        let a2 = rhs[2] * self;
        V3::new([a0, a1, a2])
    }
}

// V3 * V3
impl<T: Num + Copy> Mul for V3<T> {
    type Output = T;

    fn mul(self, rhs: Self) -> T {
        let a1 = self[0];
        let a2 = self[1];
        let a3 = self[2];

        let b1 = rhs[0];
        let b2 = rhs[1];
        let b3 = rhs[2];

        a1 * b1 + a2 * b2 + a3 * b3
    }
}

// V3 * M33
impl<T: Num + Copy> Mul<M33<T>> for V3<T> {
    type Output = V3<T>;

    fn mul(self, rhs: M33<T>) -> V3<T> {
        let a11 = rhs[(0, 0)];
        let a12 = rhs[(0, 1)];
        let a13 = rhs[(0, 2)];
        let a21 = rhs[(1, 0)];
        let a22 = rhs[(1, 1)];
        let a23 = rhs[(1, 2)];
        let a31 = rhs[(2, 0)];
        let a32 = rhs[(2, 1)];
        let a33 = rhs[(2, 2)];

        let v1 = self[0];
        let v2 = self[1];
        let v3 = self[2];

        V3::new([
            a11 * v1 + a12 * v2 + a13 * v3,
            a21 * v1 + a22 * v2 + a23 * v3,
            a31 * v1 + a32 * v2 + a33 * v3,
        ])
    }
}

// V3 - V3
impl<T: Num + Copy> Sub for V3<T> {
    type Output = Self;

    fn sub(self, rhs: Self) -> Self {
        let v0 = self[0];
        let v1 = self[1];
        let v2 = self[2];

        let a0 = rhs[0];
        let a1 = rhs[1];
        let a2 = rhs[2];

        V3::new([v0 - a0, v1 - a1, v2 - a2])
    }
}

// V3 + V3
impl<T: Num + Copy> Add for V3<T> {
    type Output = Self;

    fn add(self, rhs: Self) -> Self {
        let v1 = self[0];
        let v2 = self[1];
        let v3 = self[2];

        let a1 = rhs[0];
        let a2 = rhs[1];
        let a3 = rhs[2];

        V3::new([v1 + a1, v2 + a2, v3 + a3])
    }
}

// impl the Zero trait
impl<T: Num + Copy> Zero for V3<T> {
    fn zero() -> V3<T> {
        V3::new([T::zero(); 3])
    }

    fn is_zero(&self) -> bool {
        *self == V3::zero()
    }
}

impl<T> Deref for V3<T> {
    type Target = [T; 3];
    #[inline]
    fn deref(&self) -> &Self::Target {
        &self.0
    }
}

impl<T> DerefMut for V3<T> {
    #[inline]
    fn deref_mut(&mut self) -> &mut Self::Target {
        &mut self.0
    }
}

impl<T> From<[T; 3]> for V3<T> {
    fn from(data: [T; 3]) -> V3<T> {
        V3(data)
    }
}

//-------------------------------------------------------------------------
//                        Display impl
//-------------------------------------------------------------------------
impl<T: Num + fmt::Display> fmt::Display for V3<T> {
    fn fmt(&self, dest: &mut fmt::Formatter) -> fmt::Result {
        println!("");
        write!(dest, "[{0:^3.2} {1:^3.2} {2:^3.2}]\n", self[0], self[1], self[2])
    }
}

//-------------------------------------------------------------------------
//                        tests
//-------------------------------------------------------------------------
#[cfg(test)]
mod vector3_test {

    use crate::vector3::V3;

    #[test]
    fn create_vector3_test() {
        let v = V3::new([1.0, 1.0, 1.0]);
        assert_eq!(v[0], 1.0);
        assert_eq!(v[1], 1.0);
        assert_eq!(v[2], 1.0);
    }

    #[test]
    fn zero_vector3_test() {
        let result: V3<f64> = V3::zeros();
        let expected = V3::new([0.0, 0.0, 0.0]);
        assert_eq!(
            &result[..],
            &expected[..],
            "\nExpected\n{:?}\nfound\n{:?}",
            &result[..],
            &expected[..]
        );
    }

    #[test]
    fn product_test() {
        let v1 = V3::new([1.0, 2.0, 3.0]);
        let v2 = V3::new([4.0, 5.0, 6.0]);
        let result = v1 * v2;
        let expected = 32.0;
        assert_eq!(result, expected);
    }

    #[test]
    fn add_test() {
        let v1 = V3::new([1.0, 2.0, 3.0]);
        let v2 = V3::new([4.0, 5.0, 6.0]);
        let result = v1 + v2;
        let expected = V3::new([5.0, 7.0, 9.0]);
        assert_eq!(
            &result[..],
            &expected[..],
            "\nExpected\n{:?}\nfound\n{:?}",
            &result[..],
            &expected[..]
        );
    }

    #[test]
    fn norm2_test() {
        let v1 = V3::new([1.0, 2.0, 3.0]);
        let expected = 3.7416573867739413;
        let result = v1.norm2();
        assert_eq!(result, expected);
    }

    #[test]
    fn mul_const_rhs() {
        let v = V3::new([1.0, 2.0, 3.0]);
        let result = 2.0 * v;
        let expected = V3::new([2.0, 4.0, 6.0]);
        assert_eq!(
            &result[..],
            &expected[..],
            "\nExpected\n{:?}\nfound\n{:?}",
            &result[..],
            &expected[..]
        );
    }

    #[test]
    fn mul_const() {
        let v = V3::new([1.0, 2.0, 3.0]);
        let result = v * 2.0;
        let expected = V3::new([2.0, 4.0, 6.0]);
        assert_eq!(
            &result[..],
            &expected[..],
            "\nExpected\n{:?}\nfound\n{:?}",
            &result[..],
            &expected[..]
        );
    }

    #[test]
    fn sub_test() {
        let v1 = V3::new([1.0, 1.0, 1.0]);
        let v2 = V3::new([2.0, 3.0, 4.0]);
        let result = v1 - v2;
        let expected = V3::new([-1.0, -2.0, -3.0]);
        assert_eq!(
            &result[..],
            &expected[..],
            "\nExpected\n{:?}\nfound\n{:?}",
            &result[..],
            &expected[..]
        );
    }

    #[test]
    fn normalize_test() {
        let result = V3::new([1.0, 1.0, 1.0]).normalize().unwrap();
        let expected = V3::new([0.5773502691896258, 0.5773502691896258, 0.5773502691896258]);
        assert_eq!(
            &result[..],
            &expected[..],
            "\nExpected\n{:?}\nfound\n{:?}",
            &result[..],
            &expected[..]
        );
    }

    #[test]
    fn cross_test() {
        let x = V3::new([1.0, 0.0, 0.0]);
        let y = V3::new([0.0, 1.0, 0.0]);

        let result = y.cross(x);
        // z
        let expected = V3::new([0.0, 0.0, 1.0]);
        assert_eq!(
            &result[..],
            &expected[..],
            "\nExpected\n{:?}\nfound\n{:?}",
            &result[..],
            &expected[..]
        );
    }
}