using UnityEngine;
using System.Collections;

public class StartManager : MonoBehaviour
{
    public static StartManager Instance;

    [Header("开场 UI")]
    public GameObject startCanvas;
    public GameObject backgroundCanvas;

    public bool gameStarted = false;
    public bool isOnStartScreen = true;
    public bool isTransitioning = false; // ← public

    void Awake()
    {
        Instance = this;
    }

    void Start()
    {
        gameStarted = false;
        isOnStartScreen = true;
        isTransitioning = false;

        if (startCanvas != null)
            startCanvas.SetActive(true);

        if (backgroundCanvas != null)
            backgroundCanvas.SetActive(false);

        Time.timeScale = 0f;

        Debug.Log("✅ StartManager 初始化完成");
    }

    public void PressStart()
    {
        if (gameStarted) return;
        if (isTransitioning) return;

        Debug.Log("✅ PressStart 被调用");
        StartCoroutine(StartSequence());
    }

    IEnumerator StartSequence()
    {
        isTransitioning = true;
        isOnStartScreen = false;

        if (startCanvas != null)
            startCanvas.SetActive(false);

        Debug.Log("✅ StartCanvas 已隐藏");

        if (backgroundCanvas != null)
            backgroundCanvas.SetActive(true);

        Debug.Log("✅ BackgroundCanvas 已显示");

        // 用 unscaledDeltaTime 计时
        // 不受 timeScale 影响
        float elapsed = 0f;
        while (elapsed < 5f)
        {
            elapsed += Time.unscaledDeltaTime;
            yield return null;
        }

        if (backgroundCanvas != null)
            backgroundCanvas.SetActive(false);

        gameStarted = true;
        isTransitioning = false;
        Time.timeScale = 1f;

        Debug.Log("✅ 游戏正式开始！");
    }
}