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

namespace BF
{
    //只有纵向拉伸, 后续完善
    public class RawImageGrid : RawImage
    {
        private const int POINT_NUM = 8;
        private const int RECT_NUM = 3;
        private const float MAX_PADDING = 1f;

        //保证在初始时候设置好比例
        public float paddingTopSlice = 0.5f;
        public float paddingBottomSlice = 0.5f;
        
//        private List<Vector2> gridSlicePositions = new List<Vector2>();
//        private List<Vector2> rectPositions = new List<Vector2>();
        private float paddingTopDistance;
        private float paddingBottomDistance;
        
        private Vector3[] corners = new Vector3[4];

        protected override void Awake()
        {
            base.Awake();
            
//            gridSlicePositions.Add(new Vector2(0f, 0f));
//            gridSlicePositions.Add(new Vector2(0f, paddingBottomSlice));
//            gridSlicePositions.Add(new Vector2(0f, paddingTopSlice));
//            gridSlicePositions.Add(new Vector2(0f, 1f));
//            gridSlicePositions.Add(new Vector2(1f, 1f));
//            gridSlicePositions.Add(new Vector2(1f, paddingTopSlice));
//            gridSlicePositions.Add(new Vector2(1f, paddingBottomSlice));
//            gridSlicePositions.Add(new Vector2(1f, 0f));
            CalculateRectPos();
        }

        private void GetRectTransformBounds()
        {
            this.rectTransform.GetLocalCorners(corners);
        }

        private void CalculateRectPos()
        {
            if(paddingBottomSlice < paddingTopSlice)
                return;

//            rectPositions.Clear();
            GetRectTransformBounds();
            var rectWidth = corners[3].x - corners[0].x;
            var rectHeight = corners[1].y - corners[0].y;
            paddingTopDistance = Mathf.Min(MAX_PADDING, paddingTopSlice) * rectHeight;
            paddingBottomDistance = Mathf.Min(MAX_PADDING, paddingBottomSlice) * rectHeight;
//            var count = POINT_NUM;
//            for (int i = 0; i < count; i++)
//            {
//                var slicePos = gridSlicePositions[i];
//                var rectPosX = corners[0].x + slicePos.x * rectWidth;
//                var rectPosY = corners[0].y + slicePos.y * rectHeight;
//                rectPositions.Add(new Vector2(rectPosX, rectPosY));
//            }
        }

        private void GetVertPosAndUV(VertexHelper vh, Vector4 vector4, int gridIdx, Vector2 uv)
        {
////            var gridPos = Vector2.zero;//gridSlicePositions[gridIdx];
//            float gridX = gridIdx < POINT_NUM / 2 ? corners[0].x : corners[3].x; //gridPos.x;
//            float gridY = gridIdx < POINT_NUM / 2 ? corners[0].x : corners[3].x;
//            
//            Vector3 vert = new Vector3(vector4.x + (vector4.z - vector4.x) * gridX,
//                                        vector4.y + (vector4.w - vector4.y) * gridY);
//            uv.x *= (uvRect.xMin + (uvRect.xMax - uvRect.xMin) * gridX);
//            uv.y *= (uvRect.yMin + (uvRect.yMax - uvRect.yMin) * gridY);
//            vh.AddVert(vert, (Color32) this.color, uv);
            
            
//            vertexHelper.AddVert(new Vector3(posMin.x, posMin.y, 0.0f), color, new Vector2(uvMin.x, uvMin.y));
//            vertexHelper.AddVert(new Vector3(posMin.x, posMax.y, 0.0f), color, new Vector2(uvMin.x, uvMax.y));
//            vertexHelper.AddVert(new Vector3(posMax.x, posMax.y, 0.0f), color, new Vector2(uvMax.x, uvMax.y));
//            vertexHelper.AddVert(new Vector3(posMax.x, posMin.y, 0.0f), color, new Vector2(uvMax.x, uvMin.y));
//            vertexHelper.AddTriangle(currentVertCount, currentVertCount + 1, currentVertCount + 2);
//            vertexHelper.AddTriangle(currentVertCount + 2, currentVertCount + 3, currentVertCount);
        }

        private void AddQuad(VertexHelper vh, Vector2 posMin, Vector2 posMax, Color32 color, Vector2 uvMin, Vector2 uvMax)
        {
            vh.AddVert(new Vector3(posMin.x, posMin.y, 0.0f), color, new Vector2(uvMin.x, uvMin.y));
            vh.AddVert(new Vector3(posMin.x, posMax.y, 0.0f), color, new Vector2(uvMin.x, uvMax.y));
            vh.AddVert(new Vector3(posMax.x, posMax.y, 0.0f), color, new Vector2(uvMax.x, uvMax.y));
            vh.AddVert(new Vector3(posMax.x, posMin.y, 0.0f), color, new Vector2(uvMax.x, uvMin.y));
//            vh.AddTriangle(currentVertCount, currentVertCount + 1, currentVertCount + 2);
//            vh.AddTriangle(currentVertCount + 2, currentVertCount + 3, currentVertCount);
        }

        protected override void OnPopulateMesh(VertexHelper vh)
        {
            Texture mainTexture = this.mainTexture;
            vh.Clear();
            if (!((Object) mainTexture != (Object) null))
                return;
            Rect pixelAdjustedRect = this.GetPixelAdjustedRect();
            Vector4 vector4 = new Vector4(pixelAdjustedRect.x, pixelAdjustedRect.y, pixelAdjustedRect.x + pixelAdjustedRect.width, pixelAdjustedRect.y + pixelAdjustedRect.height);
            float num1 = (float) mainTexture.width * mainTexture.texelSize.x;
            float num2 = (float) mainTexture.height * mainTexture.texelSize.y;

            GetRectTransformBounds();
            var count = RECT_NUM;
            var rectHeight = corners[1].y - corners[0].y;
            var rectBottomSlice = paddingBottomDistance / rectHeight;
            var rectTopSlice = (rectHeight - paddingTopDistance) / rectHeight;
//            for (int i = 0; i < count; i++)
//            {

            var posSize = vector4.w - vector4.y;
                Vector2 posMin = new Vector2(vector4.x, vector4.y);
                Vector2 posMax = new Vector2(vector4.z, vector4.y + posSize * rectBottomSlice);
                Vector2 uvMin = new Vector2(0, 0);
                Vector2 uvMax = new Vector2(0.5f, 0.5f);
                AddQuad(vh, posMin, posMax, color, uvMin, uvMax);
                
//                posMin = new Vector2(vector4.x, vector4.y + posSize * rectBottomSlice);
//                posMax = new Vector2(vector4.z, vector4.y + posSize * rectTopSlice);
//                uvMin = new Vector2(0.5f, 0.5f);
//                uvMax = new Vector2(0.5f, 0.5f);
//                AddQuad(vh, posMin, posMax, color, uvMin, uvMax);
                
                posMin = new Vector2(vector4.x, vector4.y + posSize * rectTopSlice);
                posMax = new Vector2(vector4.z, vector4.w);
                uvMin = new Vector2(0.5f, 0.5f);
                uvMax = new Vector2(1, 1);
                AddQuad(vh, posMin, posMax, color, uvMin, uvMax);
//            }
//            {
//                GetVertPosAndUV(vh, vector4, i, new Vector2(num1, num2));
//            }

            count = (count - 2) / 2;
//            for (int i = 0, j = 0; j < count; j++)
//            {
////                if (i == 0)
//                {
//                    vh.AddTriangle(i, i + 1, i + 3);
//                    vh.AddTriangle(i + 3, i + 1, i + 2);
//                    i++;
//                }
////                else if (i == 1)
////                {
////                    vh.AddTriangle(i, i + 3, i + 1);
////                    vh.AddTriangle(i + 1, i + 3, i + 4);
////                    i += 3;
////                }
////                else
////                {
////                    vh.AddTriangle(i, i + 2, i + 1);
////                    vh.AddTriangle(i + 1, i + 2, i + 3);
////                    i += 2;
////                }
//            }
//            vh.AddVert(new Vector3(vector4.x, vector4.y), (Color32) color, new Vector2(uvRect.xMin * num1, uvRect.yMin * num2));
//            vh.AddVert(new Vector3(vector4.x, vector4.w), (Color32) color, new Vector2(uvRect.xMin * num1, uvRect.yMax * num2));
//            vh.AddVert(new Vector3(vector4.z, vector4.w), (Color32) color, new Vector2(uvRect.xMax * num1, uvRect.yMax * num2));
//            vh.AddVert(new Vector3(vector4.z, vector4.y), (Color32) color, new Vector2(uvRect.xMax * num1, uvRect.yMin * num2));
            
//            vh.AddTriangle(0, 1, 6);
//            vh.AddTriangle(6, 7, 0);
//            vh.AddTriangle(1, 2, 5);
//            vh.AddTriangle(5, 6, 1);
//            vh.AddTriangle(2, 3, 4);
//            vh.AddTriangle(4, 5, 2);
            vh.AddTriangle(0, 1, 2);
            vh.AddTriangle(2, 3, 0);
            vh.AddTriangle(1, 2, 3);
            vh.AddTriangle(3, 2, 1);
        }
    }
}