use crate::model::Model;
use crate::camera::Camera;
use crate::shader::shader;
use std::sync::Arc;
use std::rc::Rc;
use glow::*;

use imgui_glow_renderer::AutoRenderer;
use imgui_sdl2_support::SdlPlatform;

use cgmath::{Matrix4, vec3, Point3, Deg, perspective};
use cgmath::prelude::*;

use sdl2::keyboard::Keycode;
use sdl2::event::Event;

const SCR_WIDTH: u32 = 1600;
const SCR_HEIGHT: u32 = 900;

const MODELS: [&str; 3]= ["resources/models/TestCarModel/CarW4.obj", "resources/models/TestCarModel/CarW1.obj",
"resources/models/TestCarModel/CarW0.obj"];


/// XXX this is temporary, thus the name
pub struct tempData {
    pub projection: Matrix4<f32>,
    pub spinSpeed: f32,
    pub current_rad: f32,
    pub currentFrame: f32,
    pub deltaTime: f32,
    pub lastFrame: f32,
    DebugMode: bool,
}
use crate::debug::Debug;

pub enum SceneEnum {
    Exit,
    Pause,
    Resume,
}


pub struct Scene {
    gl: Arc<glow::Context>,
    pub Car: Model,
    camera: Camera,
    debug: Debug,
    shaders: Vec<Rc<shader>>,
    time: std::time::Instant,
    tempData: tempData,
}

impl Scene{
    pub fn new(gl: Arc<glow::Context>) -> Scene
        {
            let Car = Model::new(MODELS[0], Arc::clone(&gl));

            let shader = Rc::new(shader::new("model", Arc::clone(&gl)));

            let time = std::time::Instant::now();

            let camera = Camera {
                Position: Point3::new(0.0, 0.40, 1.0),
                Pitch: -20.0,
                ..Camera::default()
            };

            let tempData = tempData {
                projection: perspective(Deg(45.0), 1600.0/ 900.0, 0.1, 100.0),
                spinSpeed: 1.0,
                current_rad: 1.0,
                currentFrame: 0.0,
                deltaTime: 0.0,
                lastFrame: 0.0,
                DebugMode: false,

            };

            let debug = Debug::new(gl.clone());
            Scene{
                gl,
                Car,
                camera,
                debug,
                shaders: vec![shader],
                time,
                tempData,
            }
        }

    pub fn update(&mut self ,events_loop: &mut sdl2::EventPump, window: &sdl2::video::Window) -> SceneEnum
        {
            self.tempData.currentFrame = self.time.elapsed().as_secs_f32();
            self.tempData.deltaTime = self.tempData.currentFrame - self.tempData.lastFrame;
            self.tempData.lastFrame = self.tempData.currentFrame;
            self.tempData.current_rad += self.tempData.spinSpeed/15.0;
            let mut ret = SceneEnum::Resume;

            unsafe {
                self.gl.enable(glow::DEPTH_TEST);
                self.gl.clear(glow::COLOR_BUFFER_BIT | glow::DEPTH_BUFFER_BIT);

                self.shaders[0].Use();
                self.tempData.projection = perspective(Deg(self.camera.Zoom), SCR_WIDTH as f32 /SCR_HEIGHT as f32, 0.1, 100.0);
                let view = self.camera.GetViewMatrix();
                self.shaders[0].setMat4("projection", &self.tempData.projection);
                self.shaders[0].setMat4("view", &view);

                let mut model: Matrix4<f32> = Matrix4::from_axis_angle(vec3(0.0, -1.0, 0.0).normalize(),
                cgmath::Rad(self.tempData.current_rad));

                model = model * Matrix4::from_scale(0.2);
                self.shaders[0].setMat4("model", &model);
            }
            self.Car.Draw(&self.shaders[0]);

            if self.tempData.DebugMode{
                for command in self.debug.drawImgui(&events_loop, &window, &mut self.tempData, &self.Car)
                    {
                        use crate::debug::dEvent;
                        match command
                            {
                                dEvent::exit => ret = SceneEnum::Exit,
                                dEvent::loadModel(i) => {
                                    self.Car = Model::new(MODELS[i as usize], Arc::clone(&self.gl));
                                }
                                _ => (),
                            }
                    }
            }

            for event in events_loop.poll_iter() {
                if self.tempData.DebugMode {
                self.debug.handle(&event);
                }
                match event {
                    Event::Quit {..} |
                    Event::KeyDown { keycode: Some(Keycode::Escape), .. } => {
                        ret = SceneEnum::Exit;
                    },
                    Event::KeyDown {keycode: Some(Keycode::P), ..} => {
                    },
                    Event::KeyDown {keycode: Some(Keycode::D), ..} => {
                        self.tempData.DebugMode = !self.tempData.DebugMode
                    }
                        _ => {}
                    }

            }

                ret
        }


}