using UnityEngine;

[ExecuteAlways]
[RequireComponent(typeof(RectTransform))]
public class SafeAreaUI : MonoBehaviour
{

    public const int SafeWidth = 75;

    public enum SimDevice { None, IphoneX }
    public static SimDevice Sim
    {
        set { LocalSave.SetInt("SimDevice", (int)value); }
        get { return (SimDevice)LocalSave.GetInt("SimDevice"); }
    }

    Rect[] NSA_IphoneX = new Rect[]
    {
        new Rect (0f, 102f / 2436f, 1f, 2202f / 2436f),  // Portrait
        new Rect (132f / 2436f, 63f / 1125f, 2172f / 2436f, 1062f / 1125f)  // Landscape
    };

    RectTransform _Panel;
    Rect LastSafeArea = new Rect(0, 0, 0, 0);
    Rect LastRect = new Rect(0, 0, 0, 0);

    RectTransform Panel
    {
        get
        {
            if (_Panel == null)
                _Panel = GetComponent<RectTransform>();
            return _Panel;
        }
    }

    void Awake()
    {
        Refresh();
    }

    void Update()
    {
        Refresh();
    }

    void Refresh()
    {
        // Rect safeArea = GetSafeArea();
        // if (safeArea != LastSafeArea || LastRect != Panel.rect)
        if (LastRect != Panel.rect)
            ApplySafeArea();
    }

    public void ApplySafeArea()
    {
        Panel.anchorMin = Vector2.zero;
        Panel.anchorMax = Vector2.one;
        //竖屏
        if (Screen.height > Screen.width)
        {
            if (Screen.height / Screen.width > 1.8)//宽屏需要适配
            {
                //上下各间隔SafeWidth
                Panel.offsetMin = new Vector2(0, SafeWidth);
                Panel.offsetMax = new Vector2(0, -SafeWidth);
            }
            else
            {
                Panel.offsetMin = new Vector2(0, 0);
                Panel.offsetMax = new Vector2(0, 0);
            }
        }
        else
        {//横屏
            if (Screen.width / Screen.height > 1.8)//宽屏需要适配
            {
                //两边各间隔SafeWidth
                Panel.offsetMin = new Vector2(SafeWidth, 0);
                Panel.offsetMax = new Vector2(-SafeWidth, 0);
            }
            else
            {
                Panel.offsetMin = new Vector2(0, 0);
                Panel.offsetMax = new Vector2(0, 0);
            }
        }
        LastRect = Panel.rect;
    }
    #region 系统api的安全区
    Rect GetSafeArea()
    {
        if (!Application.isEditor)
            return Screen.safeArea;

        Rect safeArea = Screen.safeArea;

        if (Sim != SimDevice.None)
        {
            Rect nsa = new Rect(0, 0, Screen.width, Screen.height);

            switch (Sim)
            {
                case SimDevice.IphoneX:
                    if (Screen.height > Screen.width)  // Portrait
                        nsa = NSA_IphoneX[0];
                    else  // Landscape
                        nsa = NSA_IphoneX[1];
                    break;
                default:
                    break;
            }

            safeArea = new Rect(Screen.width * nsa.x, Screen.height * nsa.y, Screen.width * nsa.width, Screen.height * nsa.height);
        }
        return safeArea;

    }

    void ApplySafeArea(Rect safeArea)
    {
        DebugEx.LogFormat("ApplySafeArea：{0} ; rect:{1}", safeArea, Panel.rect);

        Panel.anchorMin = Vector2.zero;
        Panel.anchorMax = Vector2.one;

        //适配四个方向
        // Panel.offsetMin = safeArea.min;
        // Panel.offsetMax = new Vector2(-(Screen.width - safeArea.max.x), -(Screen.height - safeArea.max.y));

        //只适配两边
        Panel.offsetMin = new Vector2(safeArea.min.x, 0);
        Panel.offsetMax = new Vector2(-(Screen.width - safeArea.max.x), 0);

        LastRect = Panel.rect;
        LastSafeArea = safeArea;
    }
    #endregion 
}