using UnityEngine;
using BaseGames.Core.Events;

namespace BaseGames.Support.Accessibility
{
/// <summary>
/// 无障碍功能管理器（架构 16_SupportingModules §6.1）。
/// 响应设置变更，广播色盲模式事件；提供 CanPlayScreenShake() 供 FeedbackSystem 查询。
/// </summary>
public class AccessibilityManager : MonoBehaviour
{
    [Header("设置资产")]
    [SerializeField] private AccessibilitySettingsSO _settings;

    [Header("事件频道（输出）")]
    [SerializeField] private ColorblindModeEventChannelSO _onColorblindModeChanged;
    [SerializeField] private BoolEventChannelSO           _onScreenShakeChanged;

    private static AccessibilityManager _instance;

    // ── 静态查询接口（供 FeedbackSystem 使用） ───────────────────────────────
    public static bool CanPlayScreenShake()
        => _instance == null || (_instance._settings != null && _instance._settings.ScreenShake);

    private void Awake()
    {
        if (_instance != null && _instance != this)
        {
            Debug.LogWarning("[AccessibilityManager] 已存在实例，请确保本组件仅放置在 Persistent 场景中。", this);
            Destroy(this);
            return;
        }
        _instance = this;
        if (_settings != null)
            _settings.Load();
    }

    private void Start()
    {
        // 初始化时广播当前色盲模式
        if (_settings != null)
            _onColorblindModeChanged?.Raise(_settings.ColorblindMode);
    }

    private void OnDestroy()
    {
        if (_instance == this) _instance = null;
    }

    /// <summary>应用新的设置并持久化。</summary>
    public void Apply(AccessibilitySettingsSO newSettings)
    {
        _settings.ScreenShake    = newSettings.ScreenShake;
        _settings.ReducedFlash   = newSettings.ReducedFlash;
        _settings.LargeText      = newSettings.LargeText;
        _settings.HighContrast   = newSettings.HighContrast;
        _settings.UIScale        = newSettings.UIScale;

        bool colorblindChanged = _settings.ColorblindMode != newSettings.ColorblindMode;
        _settings.ColorblindMode = newSettings.ColorblindMode;

        _settings.Save();

        _onScreenShakeChanged?.Raise(_settings.ScreenShake);
        if (colorblindChanged)
            _onColorblindModeChanged?.Raise(_settings.ColorblindMode);
    }

    /// <summary>直接设置色盲模式。</summary>
    public void SetColorblindMode(ColorblindMode mode)
    {
        if (_settings == null) return;
        _settings.ColorblindMode = mode;
        _settings.Save();
        _onColorblindModeChanged?.Raise(mode);
    }

    /// <summary>直接设置屏幕抖动开关。</summary>
    public void SetScreenShake(bool enabled)
    {
        if (_settings == null) return;
        _settings.ScreenShake = enabled;
        _settings.Save();
        _onScreenShakeChanged?.Raise(enabled);
    }

    public AccessibilitySettingsSO Settings => _settings;
}
}