use crate::display::window::Window;
use crate::renderer::{vulkan::VkRenderContext, Renderable};
use winit::application::ApplicationHandler;
use winit::event::WindowEvent;
use winit::event_loop::ActiveEventLoop;
use winit::window::WindowId;
use crate::scene::TriangleScene;

pub struct App {
    window: Window,
    render_context: Option<VkRenderContext>,
    scene: Option<Box<dyn Renderable>>,
}

impl App {
    pub fn new(window: Window) -> Self {
        Self {
            window,
            render_context: None,
            scene: None,
        }
    }

    pub fn set_scene(&mut self, mut scene: Box<dyn Renderable>) {
        let result = self.render_context.as_mut()
            .ok_or_else(|| anyhow::anyhow!("No render context"))
            .and_then(|render_context| render_context.init_scene(&mut scene));

        match result {
            Ok(_) => self.scene = Some(scene),
            Err(err) => log::warn!("{err}"),
        }
    }
}

impl ApplicationHandler for App {
    fn resumed(&mut self, event_loop: &ActiveEventLoop) {
        self.window
            .create_window(event_loop)
            .map_err(|err| format!("Failed to create window: {}", err))
            .unwrap();

        self.render_context = VkRenderContext::init(&self.window).ok();

        let scene = TriangleScene::new();
        self.set_scene(Box::new(scene));
    }

    fn window_event(&mut self, event_loop: &ActiveEventLoop, _id: WindowId, event: WindowEvent) {
        match event {
            WindowEvent::CloseRequested => {
                match self.render_context.as_ref() {
                    Some(render_context) => render_context.exit(),
                    None => log::warn!("Window closed but no render context found"),
                };

                log::debug!("The close button was pressed; stopping");
                event_loop.exit();
            }
            WindowEvent::Resized(size) => {
                match self.render_context.as_mut() {
                    Some(render_context) => {
                        if let Err(error) =
                            render_context.update_resolution(size.width, size.height)
                        {
                            log::error!(
                                "Failed to update resolution of render context : {}",
                                error
                            );
                        }
                    }
                    None => log::warn!("Window resized but no render context found"),
                };
            }
            WindowEvent::RedrawRequested => {
                if !event_loop.exiting() {
                    match self.render_context.as_mut() {
                        Some(render_context) => {
                            if let Err(error) = render_context.render(self.scene.as_ref()) {
                                log::error!("Failed to render with render context : {}", error);
                                event_loop.exit();
                            }
                        }
                        None => log::warn!("Window resized but no render context found"),
                    };
                }

                self.window.request_redraw();
            }
            _ => {}
        }
    }
}