using System.Collections.Generic;
using System.Linq;

namespace Domain.Input {
	public class GeminadaReader : InputReader {
		protected sealed override int Key { get; } = 0x33;
		private int LKey { get; } = 76;

		private bool _lPressed;
		private bool _lWasPressed;
		private bool _dotPressed;
		private bool _dotWasPressed;

		private readonly KeyHistory _history;
		private readonly List<int> _desiredSequence;

		public GeminadaReader(KeyHistory history) {
			_history = history;
			_desiredSequence = new List<int> { LKey, Key, LKey };
		}

		public override void UpdateInput() {
			if (UpdateDotInputDown()) {
				_history.KeyPressed(Key);
			}

			WasPressed = IsPressed;
			IsPressed = _history.ContainsSequence(_desiredSequence);
		}

		private bool UpdateDotInputDown() {
			_dotWasPressed = _dotPressed;
			short dotState = Win32API.GetAsyncKeyState(Key);

			if (!_dotWasPressed && dotState != 0) {
				_dotPressed = true;
				return true;
			}
			if (_dotPressed && dotState == 0) {
				_dotPressed = false;
			}
			return false;
		}

		private bool UpdateLInputDown() {
			_lWasPressed = _lPressed;
			short lState = Win32API.GetAsyncKeyState(LKey);

			if (!_lWasPressed && lState != 0) {
				_lPressed = true;
				return true;
			}
			if (_lPressed && lState == 0) {
				_lPressed = false;
			}
			return false;
		}
	}
}