rabidus-test/Assets/Scripts/GameManager.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Events;
using UnityEngine.SceneManagement;
using UnityEngine.UI;


public enum GameState
{
    None,
    Started,
    Ended,
}

public class GameManager : MonoBehaviour
{
    public static GameManager Instance { get; private set; }

    public UnityEvent OnGameInit;
    public UnityEvent OnGameStarted;
    public UnityEvent OnGameEnded;

    public GameState CurrentGameState = GameState.None;


    private void Awake()
    {
        if (Instance == null)
        {
            Instance = this;
        }
        else if (Instance != this)
        {
            Destroy(gameObject);
            return;
        }

        InitReferences();
    }

    private void Start()
    {
        LeaderboardController.Instance.RefreshEntries();
    }

    private void InitReferences()
    {
        OnGameInit?.Invoke();
    }

    public void ChangeState(GameState newState)
    {
        if (CurrentGameState == newState)
            return;

        Debug.Log($"Change GameState [{CurrentGameState}]=>[{newState}]", this);
        CurrentGameState = newState;


        switch (CurrentGameState)
        {
            case GameState.Started:
                {
                    OnGameStarted?.Invoke();
                }
                break;
            case GameState.Ended:
                {
                    OnGameEnded?.Invoke();
                }
                break;
        }
    }

    private bool _startedOnce = false;

    public UITextShow TextShow;

    [ContextMenu("Debug Start")]
    public void OnStartGame()
    {
        Debug.Log($"Try start. Flag: {_startedOnce}", this);
        if (_startedOnce)
            return;

        _startedOnce = true;
        Debug.Log($"Try run timer", this);
        TextShow.ShowTimer(3, "СТАРТ!", 1, null, () =>
        {
            Debug.Log($"End timer. Change game to start", this);
            ChangeState(GameState.Started);
        });
    }
}