riversong-code-showcase/Source/Riversong/Game/GameSpeed/GameSpeedSystem.cs

using System;
using Cysharp.Threading.Tasks;
using UnityEngine;
using UnityEngine.InputSystem;

namespace DanieleMarotta.RiversongCodeShowcase
{
    [Service(typeof(IGameSpeed))]
    [GameSystemGroup(typeof(EarlyGameSystemGroup))]
    [RequiresWorldReadyForUpdate]
    [UpdateBefore(typeof(WorldTimeSystem))]
    public class GameSpeedSystem : GameSystem, IGameSpeed, IInitializable, IUpdatable, IDisposable
    {
        private const float NormalSpeed = 1;

        private const float FastSpeed = 2;

        private const float VeryFastSpeed = 4;

        public GameSpeedSystem(IServiceLocator serviceLocator) : base(serviceLocator)
        {
        }

        public int SpeedLevel { get; private set; }

        public UniTask InitializeAsync()
        {
            SetSpeedLevel(0);

            return UniTask.CompletedTask;
        }

        public void Dispose()
        {
            SetSpeedLevel(0);
        }

        public void Update()
        {
            if (Keyboard.current.digit1Key.wasPressedThisFrame)
                SetSpeedLevel(0);
            else if (Keyboard.current.digit2Key.wasPressedThisFrame)
                SetSpeedLevel(1);
            else if (Keyboard.current.digit3Key.wasPressedThisFrame) SetSpeedLevel(2);

            Time.timeScale = GetTimeScale();
        }

        public void SetSpeedLevel(int speedLevel)
        {
            SpeedLevel = speedLevel;
        }

        private float GetTimeScale()
        {
            return SpeedLevel switch
            {
                1 => FastSpeed,
                2 => VeryFastSpeed,
                _ => NormalSpeed
            };
        }
    }
}