using DG.Tweening;
using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.UI;
using XRTool.Util;

namespace XRTool.WorldUI
{
    public class XRText : Text
    {
        [Range(-10f,100f)]
        public float textSpacing = 0f;
        protected override void OnPopulateMesh(VertexHelper vh)
        {
            base.OnPopulateMesh(vh);
            if (!IsActive() || vh.currentVertCount == 0)
            {
                return;
            }

            Text text = GetComponent<Text>();
            if (text == null)
            {
                Debug.LogError("Missing Text component");
                return;
            }

            List<UIVertex> vertexs = new List<UIVertex>();
            vh.GetUIVertexStream(vertexs);
            int indexCount = vh.currentIndexCount;

            string[] lineTexts = text.text.Split('\n');

            Line[] lines = new Line[lineTexts.Length];

            //根据lines数组中各个元素的长度计算每一行中第一个点的索引，每个字、字母、空母均占6个点
            for (int i = 0; i < lines.Length; i++)
            {
                //除最后一行外，vertexs对于前面几行都有回车符占了6个点
                if (i == 0)
                {
                    lines[i] = new Line(0, lineTexts[i].Length + 1);
                }
                else if (i > 0 && i < lines.Length - 1)
                {
                    lines[i] = new Line(lines[i - 1].EndVertexIndex + 1, lineTexts[i].Length + 1);
                }
                else
                {
                    lines[i] = new Line(lines[i - 1].EndVertexIndex + 1, lineTexts[i].Length);
                }
            }

            UIVertex vt;

            for (int i = 0; i < lines.Length; i++)
            {
                for (int j = lines[i].StartVertexIndex + 6; j <= lines[i].EndVertexIndex; j++)
                {
                    if (j < 0 || j >= vertexs.Count)
                    {
                        continue;
                    }
                    vt = vertexs[j];
                    vt.position += new Vector3(textSpacing * ((j - lines[i].StartVertexIndex) / 6), 0, 0);
                    vertexs[j] = vt;
                    //以下注意点与索引的对应关系
                    if (j % 6 <= 2)
                    {
                        vh.SetUIVertex(vt, (j / 6) * 4 + j % 6);
                    }
                    if (j % 6 == 4)
                    {
                        vh.SetUIVertex(vt, (j / 6) * 4 + j % 6 - 1);
                    }
                }
            }
        }
    }
}