use std::rc::Rc;
use tracker::track;

use super::transforms::trackball::TrackballModel;
use super::{AttaWithProgram, AttachWithIO};
use crate::camera::{self, Camera};
use crate::errors::*;
use crate::pg::layout_type::ViewPort;
use crate::ui::operation::Projection;
use glow::HasContext;
use nalgebra_glm::{Mat4, Vec3};

#[derive(Clone)]
pub struct Trackball {
    trackball: TrackballModel,
}

impl Trackball {
    pub fn new(aspect: f32, z_near: f32, z_far: f32, fov: f32) -> Result<Self> {
        let trackball = TrackballModel::new(0.0, 90.0, 20.0);

        Ok(Self { trackball })
    }
}

impl Default for Trackball {
    fn default() -> Self {
        Self::new(16.0 / 9.0, 0.1, 1000.0, 45.0).unwrap()
    }
}

impl AttaWithProgram for Trackball {
    fn attach_with_program(
        &self,
        gl: &glow::Context,
        program: &crate::components::Program,
    ) -> Result<()> {
        self.trackball.attach_with_program(gl, program);
        Ok(())
    }
}

impl AttachWithIO for Trackball {
    type State = super::MouseState;
    fn attach_with_mouse(
        &mut self,
        state: &Self::State,
        camera: &mut Camera,
        projection: &mut Projection,
        viewport: &ViewPort,
    ) -> bool {
        match state {
            &super::MouseState::Wheel(delta) => {
                projection.set_fov((projection.fov() - delta).clamp(15.0, 120.0));
                true
            }
            super::MouseState::Drag { from, delta } => {
                self.trackball.drag_to(from[0], from[1], delta[0], delta[1]);
                true
            }
            _ => false,
        }
    }

    fn reset(&mut self) {
        self.trackball.set_phi(90.0);
        self.trackball.set_theta(0.0);
    }

    fn init_camera(&self) -> Camera {
        Camera::new(
            Vec3::new(0.0, 30.0, 10.0),
            Vec3::new(0.0, 1.0, 0.0),
            Vec3::new(0.0, 0.0, 0.0),
        )
    }
}