using UnityEngine;

/// <summary>
/// 安全区域适配组件 - 自动适配刘海屏和异形屏
/// </summary>
[RequireComponent(typeof(RectTransform))]
[ExecuteInEditMode]
public class SafeAreaAdapter : MonoBehaviour
{
    [Header("适配设置")]
    [Tooltip("是否在编辑器模式下模拟安全区域")]
    public bool simulateInEditor = false;
    
    [Tooltip("适配边缘（Top, Bottom, Left, Right）")]
    public bool adaptTop = true;
    public bool adaptBottom = true;
    public bool adaptLeft = true;
    public bool adaptRight = true;
    
    [Header("调试信息")]
    [SerializeField] private Rect currentSafeArea;
    [SerializeField] private Vector2Int screenSize;
    
    private RectTransform _rectTransform;
    private Rect _lastSafeArea = Rect.zero;
    private Vector2Int _lastScreenSize = Vector2Int.zero;
    
    private void Awake()
    {
        _rectTransform = GetComponent<RectTransform>();
        ApplySafeArea();
    }
    
    private void Update()
    {
        // 检测屏幕变化或安全区域变化
        if (HasScreenChanged())
        {
            ApplySafeArea();
        }
    }
    
    /// <summary>
    /// 检测屏幕是否发生变化
    /// </summary>
    private bool HasScreenChanged()
    {
        Rect safeArea = GetSafeArea();
        Vector2Int screenSize = new Vector2Int(Screen.width, Screen.height);
        
        bool changed = safeArea != _lastSafeArea || screenSize != _lastScreenSize;
        
        _lastSafeArea = safeArea;
        _lastScreenSize = screenSize;
        
        return changed;
    }
    
    /// <summary>
    /// 获取安全区域
    /// </summary>
    private Rect GetSafeArea()
    {
        #if UNITY_EDITOR
        if (simulateInEditor)
        {
            // 编辑器模式下模拟 iPhone X 的安全区域
            float screenWidth = Screen.width;
            float screenHeight = Screen.height;
            
            // 模拟刘海（顶部 44px）和底部手势条（底部 34px）
            float topInset = 44f;
            float bottomInset = 34f;
            float leftInset = 0f;
            float rightInset = 0f;
            
            return new Rect(
                leftInset,
                bottomInset,
                screenWidth - leftInset - rightInset,
                screenHeight - topInset - bottomInset
            );
        }
        #endif
        
        return Screen.safeArea;
    }
    
    /// <summary>
    /// 应用安全区域适配
    /// </summary>
    private void ApplySafeArea()
    {
        if (_rectTransform == null)
            return;
        
        Rect safeArea = GetSafeArea();
        currentSafeArea = safeArea;
        screenSize = new Vector2Int(Screen.width, Screen.height);
        
        // 计算锚点位置
        Vector2 anchorMin = safeArea.position;
        Vector2 anchorMax = safeArea.position + safeArea.size;
        
        // 转换为标准化坐标 (0-1)
        anchorMin.x /= Screen.width;
        anchorMin.y /= Screen.height;
        anchorMax.x /= Screen.width;
        anchorMax.y /= Screen.height;
        
        // 根据设置决定是否适配各个边缘
        Vector2 finalAnchorMin = _rectTransform.anchorMin;
        Vector2 finalAnchorMax = _rectTransform.anchorMax;
        
        if (adaptLeft)
            finalAnchorMin.x = anchorMin.x;
        
        if (adaptBottom)
            finalAnchorMin.y = anchorMin.y;
        
        if (adaptRight)
            finalAnchorMax.x = anchorMax.x;
        
        if (adaptTop)
            finalAnchorMax.y = anchorMax.y;
        
        _rectTransform.anchorMin = finalAnchorMin;
        _rectTransform.anchorMax = finalAnchorMax;
        
        // 重置偏移
        _rectTransform.offsetMin = Vector2.zero;
        _rectTransform.offsetMax = Vector2.zero;
        
        Debug.Log($"[SafeAreaAdapter] 安全区域已应用: {safeArea}, 屏幕: {screenSize}");
    }
    
    /// <summary>
    /// 强制重新应用安全区域
    /// </summary>
    public void ForceApply()
    {
        ApplySafeArea();
    }
    
    #if UNITY_EDITOR
    private void OnValidate()
    {
        if (_rectTransform == null)
            _rectTransform = GetComponent<RectTransform>();
        
        ApplySafeArea();
    }
    #endif
}