I hope the boss doesn't mind me sharing this file... wait, I am the boss!

InputLayer.cs

using System;
using UnityEngine;

//DOCS: INPUT_KEYBOARD falls back to the legacy unity input system
//TODO: nintendo switch controls

public static class InputLayer {
	//virtual inputs for Candy Raid
	public enum Button {
		ATTACK, SWITCH, PAUSE
	}

	public enum Axis {
		HORIZONTAL, VERTICAL
	}

	public static bool GetButton(Button button) {
#if INPUT_KEYBOARD
		switch(button) {
			case Button.ATTACK:
				return Input.GetButton("Attack");
			case Button.SWITCH:
				return Input.GetButton("Switch");
			case Button.PAUSE:
				return Input.GetButton("Pause");
			default:
				throw new ArgumentException("unknown button");
		}
#else
		throw new InvalidOperationException("method not implemented");
#endif
	}

	public static bool GetButtonDown(Button button) {
#if INPUT_KEYBOARD
		switch(button) {
			case Button.ATTACK:
				return Input.GetButtonDown("Attack");
			case Button.SWITCH:
				return Input.GetButtonDown("Switch");
			case Button.PAUSE:
				return Input.GetButtonDown("Pause");
			default:
				throw new ArgumentException("unknown button");
		}
#else
		throw new InvalidOperationException("method not implemented");
#endif
	}

	public static bool GetButtonUp(Button button) {
#if INPUT_KEYBOARD
		switch(button) {
			case Button.ATTACK:
				return Input.GetButtonUp("Attack");
			case Button.SWITCH:
				return Input.GetButtonUp("Switch");
			case Button.PAUSE:
				return Input.GetButtonUp("Pause");
			default:
				throw new ArgumentException("unknown button");
		}
#else
		throw new InvalidOperationException("method not implemented");
#endif
	}

	public static float GetAxis(Axis axis) {
#if INPUT_KEYBOARD
		switch(axis) {
			case Axis.VERTICAL:
				return Input.GetAxis("Vertical");
			case Axis.HORIZONTAL:
				return Input.GetAxis("Horizontal");
			default:
				throw new ArgumentException("unknown axis");
		}
#else
		throw new InvalidOperationException("method not implemented");
#endif
	}
}