use std::time::{Duration, Instant};

use win64::prelude::*;
use windows::core::HSTRING;

use self::win32::SetWindowTextW;

fn main() {
  let window = Window::new(
    &WindowClass::new(&WindowClassDescriptor::default()),
    &WindowDescriptor::default()
      .with_title("Test")
      .with_size(Some((800, 500))),
    UserData::new(),
  )
  .unwrap();

  let mut then = Instant::now();
  let mut delta = Duration::ZERO;
  let mut timer = Duration::ZERO;
  let period = Duration::from_secs_f64(0.2);

  MessagePump::poll().for_each(|_| {
    let now = Instant::now();
    delta = now - then;
    then = now;
    timer += delta;
    if timer > period {
      let _ = unsafe {
        SetWindowTextW(
          window.as_handle(),
          &HSTRING::from(format!("{:?} fps", 1. / (delta.as_secs_f64() * 1000.))),
        )
      };
      timer = Duration::ZERO;
    }
  });
}

struct UserData {}

impl UserData {
  fn new() -> Self {
    Self {}
  }
}

impl WindowProcedure for UserData {
  fn on_message(&mut self, window: Window, message: Message) -> ProcedureResult {
    if let win32::WM_DESTROY = message.id() {
      window.quit()
    }

    self.default_window_procedure(window, message)
  }
}