use std::any::TypeId;
use std::cell::RefCell;
use std::rc::Rc;
use std::sync::{Arc, Mutex};
use indexmap::IndexMap;
use glium::{Display, Frame};
use glium::glutin::surface::WindowSurface;
use raidillon_assets::ModelManagerRef;
use raidillon_core::{define_typemap, EguiQueue};
use raidillon_core::scene::Scene;
use glam::Vec3;
use winit::event_loop::EventLoop;
use std::cell::Cell;

pub struct RenderingContext<'a> {
    pub scene: &'a Scene,
    pub target: &'a mut Frame,
    pub window: Arc<Mutex<glium::winit::window::Window>>,
    pub display: &'a Display<WindowSurface>,
    pub asset_manager: ModelManagerRef,
    pub egui_queue: Rc<RefCell<EguiQueue>>,
    pub env_light_dir: Vec3,
    pub should_egui_receive_input_events: Rc<Cell<bool>>
}

/// The internal "rendering system" trait of glium_platform.
/// This is unrelated to the main System trait in core.
pub trait RenderingSystem {
    fn handle_event(
        &mut self,
        _window: Arc<Mutex<glium::winit::window::Window>>,
        _event: winit::event::Event<()>,
    ) {
    }
    fn prepare_frame(&mut self, _window: Arc<Mutex<glium::winit::window::Window>>) {}
    fn render(&mut self, ctx: &mut RenderingContext);
    fn initialize(display: &Display<WindowSurface>, window: Arc<Mutex<glium::winit::window::Window>>, event_loop: &EventLoop<()>) -> Self
    where
        Self: Sized;
}

// define_typemap!(RenderingSystemManager, RenderingSystem);

pub struct RenderingSystemManager {
    pub systems: IndexMap<TypeId, Box<dyn RenderingSystem>>,
}

impl RenderingSystemManager {
    pub fn new() -> Self {
        Self {
            systems: IndexMap::default(),
        }
    }

    pub fn add<R>(&mut self, display: &Display<WindowSurface>, window: Arc<Mutex<glium::winit::window::Window>>, event_loop: &EventLoop<()>)
    where
        R: RenderingSystem + 'static,
    {
        let system = R::initialize(display, window, event_loop);
        self.systems.insert(TypeId::of::<R>(), Box::new(system));
    }

    pub fn remove<R: 'static>(&mut self) {
        self.systems.shift_remove(&TypeId::of::<R>());
    }
}