using UnityEngine;
using UnityEngine.UI;
using System.Collections.Generic;


/// <summary>
/// UGUI描边
/// </summary>
public class OutlineEx : BaseMeshEffect
{
    [Header("新shader描边")]
    public Color m_OutlineColor= new Color(0, 0, 0, 0.5f);// Color.black;
    public Color OutlineColor
    {
        get { return m_OutlineColor; }
        set
        {
            m_OutlineColor = value;
            this._Refresh();
        }
    }

    QualityTextColType m_ColorType = QualityTextColType.None;
    public QualityTextColType colorType
    {
        get { return m_ColorType; }
        set
        {
            if (m_ColorType != value)
            {
                m_ColorType = value;
                OutlineColor = UIHelper.GetUIOutlineColor(value);
            }
        }
    }


    [Range(0, 30)]
    //默认10，不同的颜色（包括调整alpha）视觉上描边粗细有差异，故shader里乘以0.2适应不同情况
    public int OutlineWidth = 10;    

    private static List<UIVertex> m_VetexList = new List<UIVertex>();

    protected override void Start()
    {
        base.Start();

        if (base.graphic)
        {
            if (base.graphic.material == null || base.graphic.material.shader.name != "TSF Shaders/UI/OutlineEx")
            {
// #if UNITY_EDITOR

                var texMaterial = ResManager.Instance.LoadAsset<Material>("Materials", "OutlineMat");
                if (texMaterial != null)
                {
                    base.graphic.material = texMaterial;
                }
                else
                {
                    Debug.LogError("没有找到材质OutlineMat.mat");
                }
// #else
//                 var shader = Shader.Find("TSF Shaders/UI/OutlineEx");
//                 base.graphic.material = new Material(shader);
// #endif
            }

            if (base.graphic.canvas)
            {
                var v1 = base.graphic.canvas.additionalShaderChannels;
                var v2 = AdditionalCanvasShaderChannels.TexCoord1;
                if ((v1 & v2) != v2)
                {
                    base.graphic.canvas.additionalShaderChannels |= v2;
                }
                v2 = AdditionalCanvasShaderChannels.TexCoord2;
                if ((v1 & v2) != v2)
                {
                    base.graphic.canvas.additionalShaderChannels |= v2;
                }
                v2 = AdditionalCanvasShaderChannels.TexCoord3;
                if ((v1 & v2) != v2)
                {
                    base.graphic.canvas.additionalShaderChannels |= v2;
                }
                v2 = AdditionalCanvasShaderChannels.Tangent;
                if ((v1 & v2) != v2)
                {
                    base.graphic.canvas.additionalShaderChannels |= v2;
                }
                v2 = AdditionalCanvasShaderChannels.Normal;
                if ((v1 & v2) != v2)
                {
                    base.graphic.canvas.additionalShaderChannels |= v2;
                }
            }
            this._Refresh();
        }
    }
    
#if UNITY_EDITOR
    protected override void OnValidate()
    {
        base.OnValidate();

        if (base.graphic.material != null)
        {
            if (base.graphic.material.shader.name != "TSF Shaders/UI/OutlineEx")
            {
                var texMaterial = ResManager.Instance.LoadAsset<Material>("Materials", "OutlineMat");
                if (texMaterial != null)
                {
                    base.graphic.material = texMaterial;
                }
                else
                {
                    Debug.LogError("没有找到材质OutlineMat.mat");
                }
                //var shader = Shader.Find("TSF Shaders/UI/OutlineEx");
                //base.graphic.material = new Material(shader);
            }
            this._Refresh();
        }
    }
#endif


    private void _Refresh()
    {
        /*if (base.graphic.material.GetInt("_OutlineWidth") != this.OutlineWidth || base.graphic.material.GetColor("_OutlineColor") != this.OutlineColor)
        {
            base.graphic.material.SetColor("_OutlineColor", this.OutlineColor);
            base.graphic.material.SetInt("_OutlineWidth", this.OutlineWidth);
        }*/
        base.graphic.SetVerticesDirty();
    }


    public override void ModifyMesh(VertexHelper vh)
    {
        vh.GetUIVertexStream(m_VetexList);

        this._ProcessVertices();

        vh.Clear();
        vh.AddUIVertexTriangleStream(m_VetexList);
    }


    private void _ProcessVertices()
    {
        for (int i = 0, count = m_VetexList.Count - 3; i <= count; i += 3)
        {
            var v1 = m_VetexList[i];
            var v2 = m_VetexList[i + 1];
            var v3 = m_VetexList[i + 2];
            // 计算原顶点坐标中心点
            //
            var minX = _Min(v1.position.x, v2.position.x, v3.position.x);
            var minY = _Min(v1.position.y, v2.position.y, v3.position.y);
            var maxX = _Max(v1.position.x, v2.position.x, v3.position.x);
            var maxY = _Max(v1.position.y, v2.position.y, v3.position.y);
            var posCenter = new Vector2(minX + maxX, minY + maxY) * 0.5f;
            // 计算原始顶点坐标和UV的方向
            //
            Vector2 triX, triY, uvX, uvY;
            Vector2 pos1 = v1.position;
            Vector2 pos2 = v2.position;
            Vector2 pos3 = v3.position;
            if (Mathf.Abs(Vector2.Dot((pos2 - pos1).normalized, Vector2.right))
                > Mathf.Abs(Vector2.Dot((pos3 - pos2).normalized, Vector2.right)))
            {
                triX = pos2 - pos1;
                triY = pos3 - pos2;
                uvX = v2.uv0 - v1.uv0;
                uvY = v3.uv0 - v2.uv0;
            }
            else
            {
                triX = pos3 - pos2;
                triY = pos2 - pos1;
                uvX = v3.uv0 - v2.uv0;
                uvY = v2.uv0 - v1.uv0;
            }
            // 计算原始UV框
            var uvMin = _Min(v1.uv0, v2.uv0, v3.uv0);
            var uvMax = _Max(v1.uv0, v2.uv0, v3.uv0);
            //OutlineColor 和 OutlineWidth 也传入，避免出现不同的材质球
            var col_rg = new Vector2(OutlineColor.r, OutlineColor.g);       //描边颜色 用uv3 和 tangent的 zw传递
            var col_ba = new Vector4(0,0,OutlineColor.b, OutlineColor.a);   
            var normal = new Vector3(0, 0, OutlineWidth);                   //描边的宽度 用normal的z传递

            // 为每个顶点设置新的Position和UV，并传入原始UV框
            v1 = _SetNewPosAndUV(v1, this.OutlineWidth, posCenter, triX, triY, uvX, uvY, uvMin, uvMax);
            v1.uv3 = col_rg;
            v1.tangent = col_ba;
            v1.normal = normal;
            v2 = _SetNewPosAndUV(v2, this.OutlineWidth, posCenter, triX, triY, uvX, uvY, uvMin, uvMax);
            v2.uv3 = col_rg;
            v2.tangent = col_ba;
            v2.normal = normal;
            v3 = _SetNewPosAndUV(v3, this.OutlineWidth, posCenter, triX, triY, uvX, uvY, uvMin, uvMax);
            v3.uv3 = col_rg;
            v3.tangent = col_ba;
            v3.normal = normal;


            // 应用设置后的UIVertex
            //
            m_VetexList[i] = v1;
            m_VetexList[i + 1] = v2;
            m_VetexList[i + 2] = v3;
        }
    }


    private static UIVertex _SetNewPosAndUV(UIVertex pVertex, int pOutLineWidth,
        Vector2 pPosCenter,
        Vector2 pTriangleX, Vector2 pTriangleY,
        Vector2 pUVX, Vector2 pUVY,
        Vector2 pUVOriginMin, Vector2 pUVOriginMax)
    {
        // Position
        var pos = pVertex.position;
        var posXOffset = pos.x > pPosCenter.x ? pOutLineWidth : -pOutLineWidth;
        var posYOffset = pos.y > pPosCenter.y ? pOutLineWidth : -pOutLineWidth;
        pos.x += posXOffset;
        pos.y += posYOffset;
        pVertex.position = pos;
        // UV
        var uv = pVertex.uv0;


    uv += new Vector4((pUVX / pTriangleX.magnitude * posXOffset * (Vector2.Dot(pTriangleX, Vector2.right) > 0 ? 1 : -1)).x, (pUVX / pTriangleX.magnitude * posXOffset * (Vector2.Dot(pTriangleX, Vector2.right) > 0 ? 1 : -1)).y, 0, 0);
    uv += new Vector4((pUVY / pTriangleY.magnitude * posYOffset * (Vector2.Dot(pTriangleY, Vector2.up) > 0 ? 1 : -1)).x, (pUVY / pTriangleY.magnitude * posYOffset * (Vector2.Dot(pTriangleY, Vector2.up) > 0 ? 1 : -1)).y, 0, 0);
    
        pVertex.uv0 = uv;

        pVertex.uv1 = pUVOriginMin;     //uv1 uv2 可用  tangent  normal 在缩放情况 会有问题
        pVertex.uv2 = pUVOriginMax;

        return pVertex;
    }


    private static float _Min(float pA, float pB, float pC)
    {
        return Mathf.Min(Mathf.Min(pA, pB), pC);
    }


    private static float _Max(float pA, float pB, float pC)
    {
        return Mathf.Max(Mathf.Max(pA, pB), pC);
    }


    private static Vector2 _Min(Vector2 pA, Vector2 pB, Vector2 pC)
    {
        return new Vector2(_Min(pA.x, pB.x, pC.x), _Min(pA.y, pB.y, pC.y));
    }


    private static Vector2 _Max(Vector2 pA, Vector2 pB, Vector2 pC)
    {
        return new Vector2(_Max(pA.x, pB.x, pC.x), _Max(pA.y, pB.y, pC.y));
    }


}