using UnityEngine;
using UnityEngine.UI;

namespace GameFramework
{
    /// <summary>
    /// 主菜单 UI 控制器。
    /// 支持开始游戏、设置、制作人员、退出游戏。
    /// 修复：场景重载后自动重新查找 UI 引用，避免 DontDestroyOnLoad 导致的空引用问题。
    /// </summary>
    public class MainMenuUIController : MonoBehaviour
    {
        [Header("Buttons")]
        [SerializeField] Button startButton;
        [SerializeField] Button settingsButton;
        [SerializeField] Button creditsButton;
        [SerializeField] Button quitButton;

        [Header("Settings Panel")]
        [SerializeField] GameObject settingsPanel;
        [SerializeField] Button settingsBackButton;

        [Header("Credits Panel")]
        [SerializeField] GameObject creditsPanel;
        [SerializeField] Button creditsCloseButton;

        void Start()
        {
            // 自动查找（解决场景重载后引用失效问题）
            if (startButton == null)
                startButton = FindButton("StartButton");
            if (settingsButton == null)
                settingsButton = FindButton("SettingsButton");
            if (creditsButton == null)
                creditsButton = FindButton("CreditsButton");
            if (quitButton == null)
                quitButton = FindButton("QuitButton");

            if (settingsPanel == null)
                settingsPanel = GameObject.Find("SettingsPanel");
            if (settingsBackButton == null && settingsPanel != null)
                settingsBackButton = settingsPanel.GetComponentInChildren<Button>();

            if (creditsPanel == null)
                creditsPanel = GameObject.Find("CreditsPanel");
            if (creditsCloseButton == null && creditsPanel != null)
                creditsCloseButton = creditsPanel.GetComponentInChildren<Button>();

            // 绑定按钮事件
            if (startButton != null)
                startButton.onClick.AddListener(OnStartClick);
            if (settingsButton != null)
                settingsButton.onClick.AddListener(OnSettingsClick);
            if (creditsButton != null)
                creditsButton.onClick.AddListener(OnCreditsClick);
            if (quitButton != null)
                quitButton.onClick.AddListener(OnQuitClick);

            if (settingsBackButton != null)
                settingsBackButton.onClick.AddListener(OnSettingsBackClick);
            if (creditsCloseButton != null)
                creditsCloseButton.onClick.AddListener(OnCreditsCloseClick);

            // 确保面板初始关闭
            if (settingsPanel != null)
                settingsPanel.SetActive(false);
            if (creditsPanel != null)
                creditsPanel.SetActive(false);
        }

        Button FindButton(string name)
        {
            var btn = GameObject.Find(name);
            return btn != null ? btn.GetComponent<Button>() : null;
        }

        void OnStartClick()
        {
            if (SceneLoader.Instance != null)
                SceneLoader.Instance.LoadGameplayScene();
        }

        void OnSettingsClick()
        {
            if (settingsPanel != null)
                settingsPanel.SetActive(true);
        }

        void OnSettingsBackClick()
        {
            if (settingsPanel != null)
                settingsPanel.SetActive(false);
        }

        void OnCreditsClick()
        {
            if (creditsPanel != null)
            {
                creditsPanel.SetActive(true);
                Debug.Log($"[MainMenu] Showing credits panel: {creditsPanel.name}");
            }
            else
            {
                Debug.LogWarning("[MainMenu] creditsPanel not found! Make sure a GameObject named 'CreditsPanel' exists in the scene.");
            }
        }

        void OnCreditsCloseClick()
        {
            if (creditsPanel != null)
                creditsPanel.SetActive(false);
        }

        void OnQuitClick()
        {
#if UNITY_EDITOR
            UnityEditor.EditorApplication.isPlaying = false;
#else
            Application.Quit();
#endif
        }
    }
}