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

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

    [Header("Панель смерти")]
    public GameObject deathPanel;
    public CanvasGroup canvasGroup;

    [Header("Кнопки")]
    public Button restartButton;
    public Button mainMenuButton;

    [Header("Настройки")]
    public float fadeDuration = 0.8f;
    public string mainMenuSceneName = "MainMenu";

    private bool isShown = false;
    public bool IsShown => isShown;

    private void Awake()
    {
        if (Instance == null) Instance = this;

        if (deathPanel != null)
        {
            deathPanel.SetActive(false);
        }

        if (restartButton != null)
        {
            restartButton.onClick.AddListener(RestartGame);
        }

        if (mainMenuButton != null)
        {
            mainMenuButton.onClick.AddListener(ReturnToMainMenu);
        }
    }

    /// <summary>
    /// Показывает экран смерти с плавным затемнением и открывает курсор
    /// </summary>
    public void ShowDeathScreen()
    {
        if (isShown) return;
        isShown = true;

        if (deathPanel != null)
        {
            deathPanel.SetActive(true);
            StartCoroutine(FadeInRoutine());
        }

        // Разблокируем курсор для кликов по кнопкам
        Cursor.lockState = CursorLockMode.None;
        Cursor.visible = true;
    }

    private IEnumerator FadeInRoutine()
    {
        if (canvasGroup != null)
        {
            canvasGroup.alpha = 0f;
            float elapsed = 0f;
            while (elapsed < fadeDuration)
            {
                elapsed += Time.unscaledDeltaTime;
                canvasGroup.alpha = Mathf.Clamp01(elapsed / fadeDuration);
                yield return null;
            }
            canvasGroup.alpha = 1f;
        }
    }

    /// <summary>
    /// Перезапускает текущую игровую сцену
    /// </summary>
    public void RestartGame()
    {
        Time.timeScale = 1f;
        Cursor.lockState = CursorLockMode.Locked;
        Cursor.visible = false;
        Scene currentScene = SceneManager.GetActiveScene();
        SceneManager.LoadScene(currentScene.name);
    }

    /// <summary>
    /// Возвращает игрока в главное меню
    /// </summary>
    public void ReturnToMainMenu()
    {
        Time.timeScale = 1f;
        Cursor.lockState = CursorLockMode.None;
        Cursor.visible = true;
        SceneManager.LoadScene(mainMenuSceneName);
    }
}