use winit::event::{ElementState, WindowEvent, KeyEvent, Event};
use std::collections::HashSet;
use winit::event::WindowEvent::KeyboardInput;
use winit::keyboard::PhysicalKey;
use crate::keyboard::Key;

#[derive(Debug)]
pub struct InputHandler {
	keys_pressed: Vec<PhysicalKey>,
	keys_held: Vec<PhysicalKey>,
	keys_released: Vec<PhysicalKey>
}

impl InputHandler {
	pub fn new() -> Self {
		Self {
			keys_pressed: Vec::new(),
			keys_held: Vec::new(),
			keys_released: Vec::new()
		}
	}

	pub fn update<T>(&mut self, event: &Event<T>) {
		match event {
			Event::WindowEvent {
				event: WindowEvent::KeyboardInput {
					event: KeyEvent {
						state,
						physical_key: PhysicalKey::Code(keycode),
						..
					},
					..
				},
				..
			} =>
				{
					match state {
						ElementState::Pressed => {
							if self.keys_pressed.contains(&PhysicalKey::Code(keycode.clone())) {
								self.keys_held.push(PhysicalKey::Code(keycode.clone()));
							} else {
								self.keys_pressed.push(PhysicalKey::Code(keycode.clone()));
							}
							self.keys_pressed.push(PhysicalKey::Code(keycode.clone()));
						}
						ElementState::Released => {
							self.keys_released = vec![];
							if let Some(index) = self.keys_pressed.iter().position(|&x| x == PhysicalKey::Code(keycode.clone())) {
								self.keys_pressed.remove(index);
							}
							if let Some(index) = self.keys_held.iter().position(|&x| x == PhysicalKey::Code(keycode.clone())) {
								self.keys_held.remove(index);
							}
							self.keys_released.push(PhysicalKey::Code(keycode.clone()));
						}
					}
				}
			_ => {}
		}
	}

	pub fn key_pressed(&self, key: Key) -> bool {
		self.keys_pressed.contains(&PhysicalKey::Code(key))
	}

	pub fn key_held(&self, key: Key) -> bool {
		self.keys_held.contains(&PhysicalKey::Code(key))
	}

	pub fn key_released(&self, key: Key) -> bool {
		self.keys_released.contains(&PhysicalKey::Code(key))
	}
}