// Take a look at the license at the top of the repository in the LICENSE file.

use crate::Matrix;
use crate::Point3D;
use crate::Vec3;
use crate::Vec4;
use glib::translate::*;
use std::fmt;

impl Matrix {
    /// Initializes a [`Matrix`][crate::Matrix] from the values of an affine
    /// transformation matrix.
    ///
    /// The arguments map to the following matrix layout:
    ///
    ///
    ///
    /// **⚠️ The following code is in plain ⚠️**
    ///
    /// ```plain
    ///   ⎛ xx  yx ⎞   ⎛  a   b  0 ⎞
    ///   ⎜ xy  yy ⎟ = ⎜  c   d  0 ⎟
    ///   ⎝ x0  y0 ⎠   ⎝ tx  ty  1 ⎠
    /// ```
    ///
    /// This function can be used to convert between an affine matrix type
    /// from other libraries and a [`Matrix`][crate::Matrix].
    /// ## `xx`
    /// the xx member
    /// ## `yx`
    /// the yx member
    /// ## `xy`
    /// the xy member
    /// ## `yy`
    /// the yy member
    /// ## `x_0`
    /// the x0 member
    /// ## `y_0`
    /// the y0 member
    ///
    /// # Returns
    ///
    /// the initialized matrix
    #[doc(alias = "graphene_matrix_init_from_2d")]
    #[doc(alias = "init_from_2d")]
    pub fn from_2d(xx: f64, yx: f64, xy: f64, yy: f64, x_0: f64, y_0: f64) -> Self {
        assert_initialized_main_thread!();
        unsafe {
            let mut mat = Self::uninitialized();
            ffi::graphene_matrix_init_from_2d(mat.to_glib_none_mut().0, xx, yx, xy, yy, x_0, y_0);
            mat
        }
    }

    /// Initializes a [`Matrix`][crate::Matrix] with the given array of floating
    /// point values.
    /// ## `v`
    /// an array of at least 16 floating
    ///  point values
    ///
    /// # Returns
    ///
    /// the initialized matrix
    #[doc(alias = "graphene_matrix_init_from_float")]
    #[doc(alias = "init_from_float")]
    pub fn from_float(v: [f32; 16]) -> Self {
        assert_initialized_main_thread!();
        unsafe {
            let mut mat = Self::uninitialized();
            ffi::graphene_matrix_init_from_float(mat.to_glib_none_mut().0, v.as_ptr() as *const _);
            mat
        }
    }

    /// Initializes a [`Matrix`][crate::Matrix] with the given four row
    /// vectors.
    /// ## `v0`
    /// the first row vector
    /// ## `v1`
    /// the second row vector
    /// ## `v2`
    /// the third row vector
    /// ## `v3`
    /// the fourth row vector
    ///
    /// # Returns
    ///
    /// the initialized matrix
    #[doc(alias = "graphene_matrix_init_from_vec4")]
    #[doc(alias = "init_from_vec4")]
    pub fn from_vec4(v0: &Vec4, v1: &Vec4, v2: &Vec4, v3: &Vec4) -> Self {
        assert_initialized_main_thread!();
        unsafe {
            let mut mat = Self::uninitialized();
            ffi::graphene_matrix_init_from_vec4(
                mat.to_glib_none_mut().0,
                v0.to_glib_none().0,
                v1.to_glib_none().0,
                v2.to_glib_none().0,
                v3.to_glib_none().0,
            );
            mat
        }
    }

    /// Initializes a [`Matrix`][crate::Matrix] compatible with [`Frustum`][crate::Frustum].
    ///
    /// See also: [`Frustum::from_matrix()`][crate::Frustum::from_matrix()]
    /// ## `left`
    /// distance of the left clipping plane
    /// ## `right`
    /// distance of the right clipping plane
    /// ## `bottom`
    /// distance of the bottom clipping plane
    /// ## `top`
    /// distance of the top clipping plane
    /// ## `z_near`
    /// distance of the near clipping plane
    /// ## `z_far`
    /// distance of the far clipping plane
    ///
    /// # Returns
    ///
    /// the initialized matrix
    #[doc(alias = "graphene_matrix_init_frustum")]
    #[doc(alias = "init_frustum")]
    pub fn new_frustum(
        left: f32,
        right: f32,
        bottom: f32,
        top: f32,
        z_near: f32,
        z_far: f32,
    ) -> Self {
        assert_initialized_main_thread!();
        unsafe {
            let mut mat = Self::uninitialized();
            ffi::graphene_matrix_init_frustum(
                mat.to_glib_none_mut().0,
                left,
                right,
                bottom,
                top,
                z_near,
                z_far,
            );
            mat
        }
    }

    /// Initializes a [`Matrix`][crate::Matrix] with the identity matrix.
    ///
    /// # Returns
    ///
    /// the initialized matrix
    #[doc(alias = "graphene_matrix_init_identity")]
    #[doc(alias = "init_identity")]
    pub fn new_identity() -> Self {
        assert_initialized_main_thread!();
        unsafe {
            let mut mat = Self::uninitialized();
            ffi::graphene_matrix_init_identity(mat.to_glib_none_mut().0);
            mat
        }
    }

    /// Initializes a [`Matrix`][crate::Matrix] so that it positions the "camera"
    /// at the given `eye` coordinates towards an object at the `center`
    /// coordinates. The top of the camera is aligned to the direction
    /// of the `up` vector.
    ///
    /// Before the transform, the camera is assumed to be placed at the
    /// origin, looking towards the negative Z axis, with the top side of
    /// the camera facing in the direction of the Y axis and the right
    /// side in the direction of the X axis.
    ///
    /// In theory, one could use `self` to transform a model of such a camera
    /// into world-space. However, it is more common to use the inverse of
    /// `self` to transform another object from world coordinates to the view
    /// coordinates of the camera. Typically you would then apply the
    /// camera projection transform to get from view to screen
    /// coordinates.
    /// ## `eye`
    /// the vector describing the position to look from
    /// ## `center`
    /// the vector describing the position to look at
    /// ## `up`
    /// the vector describing the world's upward direction; usually,
    ///  this is the [`Vec3::y_axis()`][crate::Vec3::y_axis()] vector
    ///
    /// # Returns
    ///
    /// the initialized matrix
    #[doc(alias = "graphene_matrix_init_look_at")]
    #[doc(alias = "init_look_at")]
    pub fn new_look_at(eye: &Vec3, center: &Vec3, up: &Vec3) -> Self {
        assert_initialized_main_thread!();
        unsafe {
            let mut mat = Self::uninitialized();
            ffi::graphene_matrix_init_look_at(
                mat.to_glib_none_mut().0,
                eye.to_glib_none().0,
                center.to_glib_none().0,
                up.to_glib_none().0,
            );
            mat
        }
    }

    /// Initializes a [`Matrix`][crate::Matrix] with an orthographic projection.
    /// ## `left`
    /// the left edge of the clipping plane
    /// ## `right`
    /// the right edge of the clipping plane
    /// ## `top`
    /// the top edge of the clipping plane
    /// ## `bottom`
    /// the bottom edge of the clipping plane
    /// ## `z_near`
    /// the distance of the near clipping plane
    /// ## `z_far`
    /// the distance of the far clipping plane
    ///
    /// # Returns
    ///
    /// the initialized matrix
    #[doc(alias = "graphene_matrix_init_ortho")]
    #[doc(alias = "init_ortho")]
    pub fn new_ortho(
        left: f32,
        right: f32,
        top: f32,
        bottom: f32,
        z_near: f32,
        z_far: f32,
    ) -> Self {
        assert_initialized_main_thread!();
        unsafe {
            let mut mat = Self::uninitialized();
            ffi::graphene_matrix_init_ortho(
                mat.to_glib_none_mut().0,
                left,
                right,
                top,
                bottom,
                z_near,
                z_far,
            );
            mat
        }
    }

    /// Initializes a [`Matrix`][crate::Matrix] with a perspective projection.
    /// ## `fovy`
    /// the field of view angle, in degrees
    /// ## `aspect`
    /// the aspect value
    /// ## `z_near`
    /// the near Z plane
    /// ## `z_far`
    /// the far Z plane
    ///
    /// # Returns
    ///
    /// the initialized matrix
    #[doc(alias = "graphene_matrix_init_perspective")]
    #[doc(alias = "init_perspective")]
    pub fn new_perspective(fovy: f32, aspect: f32, z_near: f32, z_far: f32) -> Self {
        assert_initialized_main_thread!();
        unsafe {
            let mut mat = Self::uninitialized();
            ffi::graphene_matrix_init_perspective(
                mat.to_glib_none_mut().0,
                fovy,
                aspect,
                z_near,
                z_far,
            );
            mat
        }
    }

    /// Initializes `self` to represent a rotation of `angle` degrees on
    /// the axis represented by the `axis` vector.
    /// ## `angle`
    /// the rotation angle, in degrees
    /// ## `axis`
    /// the axis vector as a [`Vec3`][crate::Vec3]
    ///
    /// # Returns
    ///
    /// the initialized matrix
    #[doc(alias = "graphene_matrix_init_rotate")]
    #[doc(alias = "init_rotate")]
    pub fn new_rotate(angle: f32, axis: &Vec3) -> Self {
        assert_initialized_main_thread!();
        unsafe {
            let mut mat = Self::uninitialized();
            ffi::graphene_matrix_init_rotate(
                mat.to_glib_none_mut().0,
                angle,
                axis.to_glib_none().0,
            );
            mat
        }
    }

    /// Initializes a [`Matrix`][crate::Matrix] with the given scaling factors.
    /// ## `x`
    /// the scale factor on the X axis
    /// ## `y`
    /// the scale factor on the Y axis
    /// ## `z`
    /// the scale factor on the Z axis
    ///
    /// # Returns
    ///
    /// the initialized matrix
    #[doc(alias = "graphene_matrix_init_scale")]
    #[doc(alias = "init_scale")]
    pub fn new_scale(x: f32, y: f32, z: f32) -> Self {
        assert_initialized_main_thread!();
        unsafe {
            let mut mat = Self::uninitialized();
            ffi::graphene_matrix_init_scale(mat.to_glib_none_mut().0, x, y, z);
            mat
        }
    }

    /// Initializes a [`Matrix`][crate::Matrix] with a skew transformation
    /// with the given factors.
    /// ## `x_skew`
    /// skew factor, in radians, on the X axis
    /// ## `y_skew`
    /// skew factor, in radians, on the Y axis
    ///
    /// # Returns
    ///
    /// the initialized matrix
    #[doc(alias = "graphene_matrix_init_skew")]
    #[doc(alias = "init_skew")]
    pub fn new_skew(x_skew: f32, y_skew: f32) -> Self {
        assert_initialized_main_thread!();
        unsafe {
            let mut mat = Self::uninitialized();
            ffi::graphene_matrix_init_skew(mat.to_glib_none_mut().0, x_skew, y_skew);
            mat
        }
    }

    /// Initializes a [`Matrix`][crate::Matrix] with a translation to the
    /// given coordinates.
    /// ## `p`
    /// the translation coordinates
    ///
    /// # Returns
    ///
    /// the initialized matrix
    #[doc(alias = "graphene_matrix_init_translate")]
    #[doc(alias = "init_translate")]
    pub fn new_translate(p: &Point3D) -> Self {
        assert_initialized_main_thread!();
        unsafe {
            let mut mat = Self::uninitialized();
            ffi::graphene_matrix_init_translate(mat.to_glib_none_mut().0, p.to_glib_none().0);
            mat
        }
    }

    /// Converts a [`Matrix`][crate::Matrix] to an array of floating point
    /// values.
    ///
    /// # Returns
    ///
    ///
    /// ## `v`
    /// return location
    ///  for an array of floating point values. The array must be capable
    ///  of holding at least 16 values.
    #[doc(alias = "graphene_matrix_to_float")]
    pub fn to_float(&self) -> [f32; 16] {
        unsafe {
            let mut out = std::mem::MaybeUninit::uninit();
            ffi::graphene_matrix_to_float(self.to_glib_none().0, out.as_mut_ptr());
            out.assume_init()
        }
    }

    pub fn values(&self) -> &[[f32; 4]; 4] {
        unsafe { &*(&self.inner.value as *const ffi::graphene_simd4x4f_t as *const [[f32; 4]; 4]) }
    }
}

impl fmt::Debug for Matrix {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        f.debug_struct("Matrix")
            .field("values", &self.values())
            .finish()
    }
}

#[cfg(test)]
mod tests {
    use super::Matrix;
    #[test]
    fn test_matrix_values() {
        let matrix = Matrix::new_identity();
        assert_eq!(
            matrix.values(),
            &[
                [1.0, 0.0, 0.0, 0.0],
                [0.0, 1.0, 0.0, 0.0],
                [0.0, 0.0, 1.0, 0.0],
                [0.0, 0.0, 0.0, 1.0]
            ],
        );
    }
}