use cgmath::{Point3, Vector3, Matrix4, Deg, InnerSpace, Zero};


pub struct Camera {
    position: Point3<f32>,
    proj_matrix: Matrix4<f32>,
    view_matrix: Matrix4<f32>
}

impl Camera {

    pub fn new(aspect: f32) -> Self {
        let mut instance = Self { 
            position: (2.0,1.0,2.0).into(),
            view_matrix: Matrix4::look_to_rh(
                (0.0,0.0,0.0).into(), 
                Vector3{ x:0.66, y:0.0, z:0.66}.normalize(), 
                Vector3::unit_y()
            ), 
            proj_matrix: Matrix4::zero()
        };
        instance.set_aspect(aspect);
        instance
    }

    pub fn set_aspect(&mut self, aspect: f32) { self.proj_matrix = cgmath::perspective(Deg(60.0), aspect, 0.1, 100.0); }
    pub fn get_projection(&self) -> Matrix4<f32> { self.proj_matrix }
    pub fn get_view(&self) -> Matrix4<f32> { self.view_matrix }
    pub fn get_position(&self) -> Point3<f32> { self.position }
}

pub trait CameraTransform {
    fn update(&mut self, position: Point3<f32>, forward: Vector3<f32>, up: Vector3<f32>);
}

impl CameraTransform for Camera {
    fn update(&mut self, position: Point3<f32>, forward: Vector3<f32>, up: Vector3<f32>) { 
        self.position = position; 
        self.view_matrix = Matrix4::look_to_rh((0.0,0.0,0.0).into(), forward, up); 
    }
}