Danro/Assets/Scripts/UI/PauseMenu.cs

using System;
using System.Collections;
using UnityEngine;
using UnityEngine.UI;
using UnityEngine.InputSystem;
using UnityEngine.EventSystems;

using RR.Game2D.Core.Managers;

namespace RR.Common.UI
{
    public class PauseMenu : MonoBehaviour
    {
        [Header("Управление")]
        [SerializeField] private InputActionReference close;

        [Header("UI")]
        [SerializeField] private CanvasGroup panel;
        [SerializeField] private Button resumeButton;
        [SerializeField] private Button quitButton;
        
        [Header("Связь с другими элементами")]
        [SerializeField] private GameEndUIController bannerController;
        //[SerializeField] private Button restartButton;
        //[SerializeField] private KeyCode toggleKey = KeyCode.Escape; // Esc

        private bool isActive = true;

        private void OnEnable()
        {
            if (GameManager.Instance != null)
                GameManager.Instance.PauseStateChanged += HandlePauseChanged;

            bannerController.WinBannerShown += (f) => { isActive = false; };
            bannerController.LoseBannerShown += (f) => { isActive = false; };
            bannerController.BannerDismissed += () => { isActive = true; };
        }

        private void OnDisable()
        {
            if (GameManager.Instance != null)
                GameManager.Instance.PauseStateChanged -= HandlePauseChanged;
        }

        private void OnDestroy()
        {
            // ReSharper disable once EventUnsubscriptionViaAnonymousDelegate
            if (close) close.action.performed -= _ => GameManager.Instance.TogglePause();
        }

        private void Awake()
        {
            if (resumeButton) resumeButton.onClick.AddListener(OnResumeClicked);
            if (quitButton) quitButton.onClick.AddListener(OnQuitClicked);
            //if (restartButton) restartButton.onClick.AddListener(OnRestartClicked);

            // Изначально скрыто
            SetVisible(false, true);
            
            if (close) close.action.performed += _ => GameManager.Instance.TogglePause();
        }

        // private void Update()
        // {
        //     if (close.action.WasPressedThisFrame() && !GameManager.Instance.IsPaused)
        //         GameManager.Instance.TogglePause();
        // }

        /// <summary>
        /// Обработка события паузы
        /// </summary>
        /// <param name="paused">Ставить ли на паузу</param>
        private void HandlePauseChanged(bool paused)
        {
            if (!isActive) return;
            
            if (paused)
            {
                EventSystem.current.firstSelectedGameObject = resumeButton.gameObject;
                EventSystem.current.SetSelectedGameObject(resumeButton.gameObject);
            }
            
            SetVisible(paused);
        }

        /// <summary>
        /// Метод для изменения отображения
        /// </summary>
        /// <param name="visible">Отображать ли меню паузы</param>
        /// <param name="instant">Мгновенно или нет</param>
        private void SetVisible(bool visible, bool instant = false)
        {
            if (!panel) return;

            panel.interactable = visible;
            panel.blocksRaycasts = visible;

            if (instant)
            {
                panel.alpha = visible ? 1f : 0f;
            }
            else
            {
                StopAllCoroutines();
                StartCoroutine(Fade(panel, visible ? 1f : 0f, 0.15f));
            }
        }

        /// <summary>
        /// Метод для плавного изменения видимости
        /// </summary>
        /// <param name="cg">Группа холстов</param>
        /// <param name="target">Целевое значение альфа-канала</param>
        /// <param name="duration">Продолжительность перехода</param>
        private static IEnumerator Fade(CanvasGroup cg, float target, float duration)
        {
            float start = cg.alpha;
            float t = 0f;
            while (t < duration)
            {
                t += Time.unscaledDeltaTime;
                cg.alpha = Mathf.Lerp(start, target, t / duration);
                yield return null;
            }
            cg.alpha = target;
        }

        /// <summary>
        /// Метод для возобновления игры
        /// </summary>
        public static void OnResumeClicked() => GameManager.Instance.TogglePause();

        //public void OnRestartClicked()
        //{
        //    GameManager.Instance.SetPause(false);
        //    GameManager.Instance.ResetLevel();
        //}

        /// <summary>
        /// Метод для выхода в главное меню
        /// </summary>
        public void OnQuitClicked()
        {
            GameManager.Instance.SetPause(false);
            GameManager.Instance.LoadScene("MainMenu", false);
        }
    }
}