use std::cell::RefCell;
use std::rc::Rc;
use raidillon_platform::{Platform, PlatformContext};
use glium::backend::glutin::Display;
use glium::backend::glutin::SimpleWindowBuilder;
use glium::glutin::surface::WindowSurface;
use glium::winit::event_loop::EventLoop;
use glium::winit::window::Window;
use glium::Surface;
use crate::system::{RenderingContext, RenderingSystemManager};
use winit::event::{Event, WindowEvent};
use raidillon_assets::ModelManagerRef;
use raidillon_core::engine::EngineTrait;
use crate::render::debug_ui::ImguiBridge;
use crate::render::BasicMeshRenderingSystem;
use crate::GliumAssetManager;

pub struct GliumPlatform<E: EngineTrait> {
    event_loop: EventLoop<()>,
    window: Window,
    display: Display<WindowSurface>,
    rendering_system_manager: RenderingSystemManager,
    asset_manager: ModelManagerRef,
    engine: E,
}

impl<E: EngineTrait> Platform<E> for GliumPlatform<E> {
    fn initialize(mut engine: E, title: String, width: u32, height: u32) -> Self {
        let event_loop = glium::winit::event_loop::EventLoop::builder()
            .build()
            .expect("create event-loop");

        let (window, display) = SimpleWindowBuilder::new()
            .with_title(title.as_str())
            .with_inner_size(width, height)
            .build(&event_loop);

        let asset_manager: ModelManagerRef = Rc::new(RefCell::new(Box::new(GliumAssetManager::new(Box::new(display.clone())))));
        let mut rendering_system_manager = RenderingSystemManager::new();

        // Install rendering systems
        rendering_system_manager.add::<BasicMeshRenderingSystem>(&display, &window);
        rendering_system_manager.add::<ImguiBridge>(&display, &window);

        Self {
            event_loop,
            window,
            display,
            rendering_system_manager,
            asset_manager,
            engine,
        }
    }

    fn run(mut self) {
        let (w, h): (u32, u32) = self.window.inner_size().into();
        let ctx = PlatformContext {
            current_event: Event::AboutToWait,
            asset_manager: self.asset_manager.clone(),
            frame_width: w as f32,
            frame_height: h as f32,
        };
        self.engine.initialize(ctx.clone());
        let _ = &self.event_loop.run(move |event, el| {
            self.rendering_system_manager
                .systems
                .values_mut()
                .for_each(|system| system.handle_event(&mut self.window, event.clone()));

            match event {
                Event::WindowEvent { event, .. } => match event {
                    WindowEvent::CloseRequested => {
                        // TODO: Run uninitialize on renderer and engine
                        el.exit();
                    },
                    WindowEvent::RedrawRequested => {
                        let mut target = self.display.draw();
                        target.clear_color_and_depth((0.1, 0.1, 0.15, 1.0), 1.0);
                        let (scene_mut, debug_ui_buffer) = self.engine.scene_and_debug_ui_buffer_mut();
                        let mut context = RenderingContext {
                            scene: scene_mut,
                            target: &mut target,
                            asset_manager: self.asset_manager.clone(),
                            window: &mut self.window,
                            debug_ui_buffer,
                        };

                        self.rendering_system_manager
                            .systems
                            .values_mut()
                            .for_each(|system| system.render(&mut context));
                        target.finish().unwrap();
                    }
                    _ => {},
                },
                Event::AboutToWait => {
                    let mut ctx2 = ctx.clone();
                    ctx2.current_event = event.clone();
                    self.engine.update(ctx2);
                    self.rendering_system_manager
                        .systems
                        .values_mut()
                        .for_each(|system| system.prepare_frame(&mut self.window));
                    self.window.request_redraw();
                }
                _ => {},
            }
        });
    }
}