using UnityEngine;
using UnityEngine.UI;
using System.Collections.Generic;
using Cysharp.Threading.Tasks;

/// <summary>
/// 妞渾褰㈤伄缃╃粍浠?
/// 鍩轰簬妯℃澘娴嬭瘯瀹炵幇妞渾褰㈤伄缃╂晥鏋?
/// </summary>
[RequireComponent(typeof(RectTransform))]
[AddComponentMenu("UI/Effects/Ellipse Mask")]
[ExecuteInEditMode]
public class EllipseMask : MonoBehaviour
{


    [Header("妞渾鍙傛暟")]
    [SerializeField] private Vector2 m_EllipseCenter = new Vector2(0.5f, 0.5f);
    [SerializeField] private Vector2 m_EllipseRadius = new Vector2(0.5f, 0.5f);
    [SerializeField] [Range(0, 0.5f)] private float m_Softness = 0f;    //鏆傛棤鏁堟灉
    [SerializeField] private int m_StencilID = 1;   //澶氫釜閬僵鏃?
    [SerializeField] private bool m_ShowMaskGraphic = false;

    private Material m_MaskMaterial;
    private Image m_MaskImage;
    private RectTransform m_RectTransform;
    private List<Graphic> m_MaskedChildren = new List<Graphic>();
    // 缂撳瓨GetComponentsInChildren缁撴灉锛岄伩鍏嶆瘡娆nEnable鍒嗛厤鏁扮粍
    private static List<Graphic> _graphicCacheList = new List<Graphic>();
    private bool m_MaskShaderLoading = false;

    public Vector2 EllipseCenter
    {
        get => m_EllipseCenter;
        set
        {
            if (m_EllipseCenter != value)
            {
                m_EllipseCenter = value;
                UpdateMask();
            }
        }
    }

    public Vector2 EllipseRadius
    {
        get => m_EllipseRadius;
        set
        {
            if (m_EllipseRadius != value)
            {
                m_EllipseRadius = value;
                UpdateMask();
            }
        }
    }

    public float Softness
    {
        get => m_Softness;
        set
        {
            if (m_Softness != value)
            {
                m_Softness = Mathf.Clamp(value, 0, 0.5f);
                UpdateMask();
            }
        }
    }

    public int StencilID
    {
        get => m_StencilID;
        set
        {
            if (m_StencilID != value)
            {
                m_StencilID = value;
                UpdateMask();
                UpdateChildrenStencil();
            }
        }
    }

    public bool ShowMaskGraphic
    {
        get => m_ShowMaskGraphic;
        set
        {
            if (m_ShowMaskGraphic != value)
            {
                m_ShowMaskGraphic = value;
                UpdateMaskVisibility();
            }
        }
    }
    static int order=1;
    protected virtual void Awake()
    {
        order++;
        StencilID = order;
        m_RectTransform = GetComponent<RectTransform>();
        
        // 鍒涘缓閬僵鍥惧儚
        CreateMaskImage();
        
        // 鍒涘缓閬僵鏉愯川
        CreateMaskMaterial();
        
        UpdateMask();
    }

    protected virtual void OnEnable()
    {
        CreateMaskMaterial();
        UpdateMask();
        
        // 涓烘墍鏈夊瓙瀵硅薄娣诲姞妯℃澘娴嬭瘯
        UpdateChildrenStencil();
    }

    protected virtual void OnDisable()
    {
        if (m_MaskMaterial != null)
        {
            DestroyImmediate(m_MaskMaterial);
            m_MaskMaterial = null;
        }
        m_MaskShaderLoading = false;
        
        // 绉婚櫎瀛愬璞＄殑妯℃澘娴嬭瘯
        RemoveChildrenStencil();
    }

    protected virtual void OnDestroy()
    {
        if (m_MaskMaterial != null)
        {
            DestroyImmediate(m_MaskMaterial);
        }
    }

    /// <summary>
    /// 鍒涘缓閬僵鍥惧儚
    /// </summary>
    private void CreateMaskImage()
    {
        if (m_MaskImage == null)
        {
            m_MaskImage = GetComponent<Image>();
            if (m_MaskImage == null)
            {
                m_MaskImage = gameObject.AddComponent<Image>();
                m_MaskImage.color = Color.white;
            }
        }
        #if !UNITY_EDITOR
        // 鍦╯hader寮傛鍔犺浇瀹屾垚鍓嶈涓哄叏閫忔槑锛岄槻姝㈤粯璁hader娓叉煋鍑虹櫧鑹茬煩褰?
        if (m_MaskMaterial == null)
        {
            m_MaskImage.color = Color.clear;
        }
        #endif
    }

    /// <summary>
    /// 鍒涘缓閬僵鏉愯川
    /// </summary>
    private void CreateMaskMaterial()
    {
        #if !UNITY_EDITOR
        if (m_MaskMaterial == null && !m_MaskShaderLoading)
        {
            m_MaskShaderLoading = true;
            ResManager.Instance.LoadAssetAsync<Shader>("Shader", "GUI_EllipseMask").ContinueWith(ellipseShader =>
            {
                m_MaskShaderLoading = false;
                if (this == null) { return; }
                if (ellipseShader != null)
                {
                    m_MaskMaterial = new Material(ellipseShader);
                    // shader使用ColorMask 0，恢复color不会显示颜色，但保证Canvas提交DrawCall写入stencil
                    if (m_MaskImage != null)
                        m_MaskImage.color = Color.white;
                    UpdateMask();
                    UpdateChildrenStencil();
                }
            }).Forget();
        }
        #else
        if (m_MaskMaterial == null)
        {
            m_MaskMaterial = new Material(Shader.Find("GUI/EllipseMask"));
        }
        #endif
    }

    /// <summary>
    /// 鏇存柊閬僵
    /// </summary>
    private void UpdateMask()
    {
        if (m_MaskMaterial != null && m_MaskImage != null)
        {
            UpdateMaterialProperties();
            
            // 璁剧疆鏉愯川鍒癐mage
            m_MaskImage.material = m_MaskMaterial;
            
            // 寮哄埗閲嶇粯
            m_MaskImage.SetMaterialDirty();
        }
    }

    /// <summary>
    /// 鏇存柊鏉愯川灞炴€?
    /// </summary>
    private void UpdateMaterialProperties()
    {
        if (m_MaskMaterial != null)
        {
            m_MaskMaterial.SetVector("_EllipseCenter", new Vector4(m_EllipseCenter.x, m_EllipseCenter.y, 0, 0));
            m_MaskMaterial.SetVector("_EllipseRadius", new Vector4(m_EllipseRadius.x, m_EllipseRadius.y, 0, 0));
            m_MaskMaterial.SetFloat("_Softness", m_Softness);
            m_MaskMaterial.SetInt("_Stencil", m_StencilID);
        }
    }

    /// <summary>
    /// 鏇存柊閬僵鍙鎬?
    /// </summary>
    private void UpdateMaskVisibility()
    {
        if (m_MaskImage != null)
        {
            m_MaskImage.enabled = m_ShowMaskGraphic;
        }
    }

    /// <summary>
    /// 涓哄瓙瀵硅薄娣诲姞妯℃澘娴嬭瘯
    /// </summary>
    public void UpdateChildrenStencil()
    {
        // 娓呴櫎涔嬪墠鐨勫垪琛?
        m_MaskedChildren.Clear();
        
        // 浣跨敤闈欐€佺紦瀛樺垪琛ㄩ伩鍏嶆瘡娆″垎閰嶆暟缁?
        _graphicCacheList.Clear();
        GetComponentsInChildren(false, _graphicCacheList);
        for (int i = 0; i < _graphicCacheList.Count; i++)
        {
            var graphic = _graphicCacheList[i];
            // 璺宠繃閬僵鏈韩
            if (graphic.gameObject == this.gameObject)
                continue;
            
            // 涓哄瓙瀵硅薄鍒涘缓閬僵鏉愯川
            CreateChildMaskMaterial(graphic);
            m_MaskedChildren.Add(graphic);
        }
        _graphicCacheList.Clear();
    }

    /// <summary>
    /// 涓哄瓙瀵硅薄鍒涘缓閬僵鏉愯川
    /// </summary>
    private void CreateChildMaskMaterial(Graphic graphic)
    {
        if (graphic.material == null || !graphic.material.shader.name.Contains("EllipseMaskedContent"))
        {

#if !UNITY_EDITOR            
            ResManager.Instance.LoadAssetAsync<Shader>("Shader", "GUI_EllipseMaskedContent").ContinueWith(maskedShader =>
            {
                if (this == null || graphic == null) { return; }
                if (maskedShader != null)
                {
                    Material maskedMaterial = new Material(maskedShader);
                    maskedMaterial.SetInt("_Stencil", m_StencilID);
                    maskedMaterial.SetInt("_StencilComp", 3); // Equal
                    graphic.material = maskedMaterial;
                    graphic.SetMaterialDirty();
                }
            }).Forget();
#else
            Shader maskedShader = Shader.Find("GUI/EllipseMaskedContent");
            if (maskedShader != null)
            {
                Material maskedMaterial = new Material(maskedShader);
                maskedMaterial.SetInt("_Stencil", m_StencilID);
                maskedMaterial.SetInt("_StencilComp", 3); // Equal
                graphic.material = maskedMaterial;
            }
#endif
        }
        else
        {
            // 鏇存柊鐜版湁鏉愯川鐨勬ā鏉縄D
            graphic.material.SetInt("_Stencil", m_StencilID);
        }
    }

    /// <summary>
    /// 绉婚櫎瀛愬璞＄殑妯℃澘娴嬭瘯
    /// </summary>
    private void RemoveChildrenStencil()
    {
        foreach (var graphic in m_MaskedChildren)
        {
            if (graphic != null && graphic.material != null)
            {
                // 閲嶇疆鏉愯川
                graphic.material = null;
            }
        }
        m_MaskedChildren.Clear();
    }

    /// <summary>
    /// 璁剧疆妞渾鍙傛暟
    /// </summary>
    /// <param name="center">妞渾涓績锛堝綊涓€鍖栧潗鏍囷級</param>
    /// <param name="radius">妞渾鍗婂緞锛堝綊涓€鍖栧潗鏍囷級</param>
    /// <param name="softness">杈圭紭鏌斿寲绋嬪害</param>
    public void SetEllipseParameters(Vector2 center, Vector2 radius, float softness = 0.1f)
    {
        m_EllipseCenter = center;
        m_EllipseRadius = radius;
        m_Softness = Mathf.Clamp(softness, 0, 0.5f);
        UpdateMask();
    }

    /// <summary>
    /// 璁剧疆鍦嗗舰鍙傛暟锛堢壒娈婃儏鍐电殑妞渾锛?
    /// </summary>
    /// <param name="center">鍦嗗績锛堝綊涓€鍖栧潗鏍囷級</param>
    /// <param name="radius">鍗婂緞锛堝綊涓€鍖栧潗鏍囷級</param>
    /// <param name="softness">杈圭紭鏌斿寲绋嬪害</param>
    public void SetCircleParameters(Vector2 center, float radius, float softness = 0.1f)
    {
        SetEllipseParameters(center, new Vector2(radius, radius), softness);
    }

#if UNITY_EDITOR
    protected virtual void OnValidate()
    {
        if (m_MaskMaterial != null)
        {
            UpdateMaterialProperties();
            UpdateChildrenStencil();
        }
    }
#endif
}