use std::collections::HashMap;
// Credit of most code to https://sotrh.github.io/learn-wgpu/ since I'm not familiar with wgpu
use std::sync::Arc;
use glam::{Vec2, Affine3A, Vec3, Vec4, Mat4, EulerRot, Quat};
#[cfg(target_arch = "wasm32")]
use wasm_bindgen::prelude::*;
use winit::dpi::PhysicalPosition;
#[cfg(target_arch = "wasm32")]
use winit::platform::web::EventLoopExtWebSys;
use winit::{
  application::ApplicationHandler,
  event::*,
  event_loop::{ActiveEventLoop, EventLoop},
  keyboard::{KeyCode, PhysicalKey},
  window::Window,
};
use crate::render;
use crate::render::{Renderer, SimpleTexture};
use crate::world::{SimpleObject, World};

struct Controller {
  buttons: HashMap<MouseButton,bool>,
  keys: HashMap<KeyCode,bool>,
  mouse: Vec2,
}

impl Controller {
  fn new() -> Controller {
    Controller {
      buttons: Default::default(),
      keys: HashMap::new(),
      mouse: Vec2::new(0.0,0.0),
    }
  }
}

pub struct AppState {
  world: World,
  controller: Controller,
  window: Arc<Window>,
  clients: Vec<SimpleObject>,
}

const BLOCKS: i32 = 50;

impl AppState {
  // We don't need this to be async right now,
  // but we will in the next tutorial
  pub async fn new(window: Arc<Window>) -> Result<AppState,Box<dyn std::error::Error>> {
    let size = window.inner_size();
    let mut world = World::new();
    world.add_renderer(Renderer::new(&window).await?);
    let mut clients = Vec::new();
    {
      let file = world.renderer.as_mut().unwrap().load_from_gltf( include_bytes!("assets/cube.glb"));
      let block = file.first_object().unwrap();
      //let color = &renderer.load_texture_from_bytes(include_bytes!("assets/plank/color.png"));
      //let normal = &renderer.load_texture_from_bytes(include_bytes!("assets/plank/normal.png"));
      //let roughness = &renderer.load_texture_from_bytes(include_bytes!("assets/plank/roughness.png"));
      //let mat = renderer.new_material(color,normal,roughness);
      for x in -BLOCKS..BLOCKS {
        for y in -BLOCKS..BLOCKS {
          let block = block.hard_clone();
          world.add_object(block.clone());
          {
            let mut model = block.0.borrow_mut();
            model.model.as_mut().unwrap().instance.transform = Mat4::from_translation(Vec3::new(-x as f32 * 3.0,0.0,-y as f32 * 3.0))
              * Mat4::from_rotation_z((x * y) as f32 / 1.23);
            model.model.as_mut().unwrap().instance.color = Vec4::new(0.3,(x + BLOCKS) as f32 / BLOCKS as f32,(y + BLOCKS) as f32 / BLOCKS as f32,1.0);
          }
          clients.push(block)
        }
      }
    }
    Ok(Self {
      world,
      clients,
      controller: Controller::new(),
      window,
    })
  }

  pub fn bounds(&self) -> (u32,u32) {
    let size = self.window.inner_size();
    (size.width,size.height)
  }

  pub fn resize(&mut self, width: u32, height: u32) {
    if width > 0 && height > 0 {
      let max = 2048;
      self.world.renderer.as_mut().unwrap().resize(width,height);
    }
  }

  fn update(&mut self) {
    // ...
  }

  fn handle_key(&mut self, event_loop: &ActiveEventLoop, code: KeyCode, is_pressed: bool) {
    match (code, is_pressed) {
      (KeyCode::Escape, true) => event_loop.exit(),
      (KeyCode::Space, true) => {},
      (KeyCode::KeyR, true) => {
        self.world.renderer.as_mut().unwrap().eye.frame = Affine3A::IDENTITY
      }
      _ => {}
    }
    self.controller.keys.insert(code, is_pressed);
  }

  fn handle_mouse_moved(&mut self, position: PhysicalPosition<f64>) {
    if let Some(true) = self.controller.buttons.get(&MouseButton::Right) {
      self.world.renderer.as_mut().unwrap().eye.rotate(position.x as f32 - self.controller.mouse.x, position.y as f32 - self.controller.mouse.y);
    }
    self.controller.mouse = Vec2::new(position.x as f32, position.y as f32);
  }

  fn handle_mouse_button(&mut self, button: MouseButton, state: ElementState ) {
    self.controller.buttons.insert(button,state.is_pressed());
  }
}

pub struct App {
  #[cfg(target_arch = "wasm32")]
  proxy: Option<winit::event_loop::EventLoopProxy<AppState>>,
  state: Option<AppState>,
}

impl App {
  pub fn new(#[cfg(target_arch = "wasm32")] event_loop: &EventLoop<AppState>) -> Self {
    #[cfg(target_arch = "wasm32")]
    let proxy = Some(event_loop.create_proxy());
    Self {
      state: None,
      #[cfg(target_arch = "wasm32")]
      proxy,
    }
  }
}

impl ApplicationHandler<AppState> for App {
  fn resumed(&mut self, event_loop: &ActiveEventLoop) {
    #[allow(unused_mut)]
    let mut window_attributes = Window::default_attributes();

    #[cfg(target_arch = "wasm32")]
    {
      use wasm_bindgen::JsCast;
      use winit::platform::web::WindowAttributesExtWebSys;

      const CANVAS_ID: &str = "canvas";

      let window = wgpu::web_sys::window().unwrap_throw();
      let document = window.document().unwrap_throw();
      let canvas = document.get_element_by_id(CANVAS_ID).unwrap_throw();
      let html_canvas_element = canvas.unchecked_into();
      window_attributes = window_attributes.with_canvas(Some(html_canvas_element));
    }

    let window = Arc::new(event_loop.create_window(window_attributes).unwrap());

    #[cfg(not(target_arch = "wasm32"))]
    {
      // If we are not on web we can use pollster to
      // await the window creation
      self.state = Some(pollster::block_on(AppState::new(window)).unwrap());
    }

    #[cfg(target_arch = "wasm32")]
    {
      // Run the future asynchronously and use the
      // proxy to send the results to the event loop
      if let Some(proxy) = self.proxy.take() {
        wasm_bindgen_futures::spawn_local(async move {
          assert!(
            proxy
              .send_event(
                AppState::new(window)
                  .await
                  .expect("Unable to create canvas!!!")
              )
              .is_ok()
          )
        });
      }
    }
  }

  #[allow(unused_mut)]
  fn user_event(&mut self, _event_loop: &ActiveEventLoop, mut event: AppState) {
    // This is where proxy.send_event() ends up
    #[cfg(target_arch = "wasm32")]
    {
      event.window.request_redraw();
      event.resize(
        event.window.inner_size().width,
        event.window.inner_size().height,
      );
    }
    self.state = Some(event);
  }

  fn window_event(
    &mut self,
    event_loop: &ActiveEventLoop,
    _window_id: winit::window::WindowId,
    event: WindowEvent,
  ) {
    let state = match &mut self.state {
      Some(canvas) => canvas,
      None => return,
    };

    match event {
      WindowEvent::CloseRequested => event_loop.exit(),
      WindowEvent::Resized(size) => state.resize(size.width, size.height),
      WindowEvent::RedrawRequested => {
        state.update();
        let mut movement = Vec3::new(0.0,0.0,0.0);

        let pressed = |keycode: KeyCode| {
          if let Some(true) = state.controller.keys.get(&keycode) {
            true
          } else {
            false
          }
        };

        if pressed(KeyCode::KeyA) {
          movement.x -= 1.0;
        }
        if pressed(KeyCode::KeyD) {
          movement.x += 1.0;
        }
        if pressed(KeyCode::KeyW) {
          movement.z += 1.0;
        }
        if pressed(KeyCode::KeyS) {
          movement.z -= 1.0;
        }
        if pressed(KeyCode::KeyE) {
          movement.y += 1.0;
        }
        if pressed(KeyCode::KeyQ) {
          movement.y -= 1.0;
        }

        state.world.renderer.as_mut().unwrap().eye.control(movement * 0.1);
        match state.world.renderer.as_mut().unwrap().render(&state.window) {
          Ok(_) => {}
          Err(e) => {
            // Log the error and exit gracefully
            log::error!("{e}");
            event_loop.exit();
          }
        }
        for object in state.clients.iter() {
          object.0.borrow_mut().model.as_mut().unwrap().instance.transform *= Mat4::from_rotation_translation(
            Quat::from_euler(EulerRot::XYZ,0.001,-0.001,0.001),
            Vec3::new(0.0,0.0,0.0)
          );
        }
      }
      WindowEvent::MouseInput { button, state: element, .. } => state.handle_mouse_button(button,element),
      WindowEvent::CursorMoved { position: pos, .. } => state.handle_mouse_moved(pos),
      WindowEvent::KeyboardInput {
        event:
        KeyEvent {
          physical_key: PhysicalKey::Code(code),
          state: key_state,
          ..
        },
        ..
      } => state.handle_key(event_loop, code, key_state.is_pressed()),
      _ => {}
    }
  }
}

pub fn run() -> anyhow::Result<()> {
  #[cfg(not(target_arch = "wasm32"))]
  {
    env_logger::init();
  }
  #[cfg(target_arch = "wasm32")]
  {
    console_log::init_with_level(log::Level::Info).unwrap_throw();
  }

  let event_loop = EventLoop::with_user_event().build()?;
  #[cfg(not(target_arch = "wasm32"))]
  {
    let mut app = App::new();
    event_loop.run_app(&mut app)?;
  }
  #[cfg(target_arch = "wasm32")]
  {
    let app = App::new(&event_loop);
    event_loop.spawn_app(app);
  }

  Ok(())
}

#[cfg(target_arch = "wasm32")]
#[wasm_bindgen(start)]
pub fn run_web() -> Result<(), wasm_bindgen::JsValue> {
  console_error_panic_hook::set_once();
  run().unwrap_throw();

  Ok(())
}