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

namespace G.UI
{
	public class RadarChart : Image
	{
		// Start is called before the first frame update
		[SerializeField]
		public int _pointCount;
		[SerializeField]
		public List<RectTransform> _points = new List<RectTransform>();
		[SerializeField]
		private Vector2 _pointSize = new Vector2(10, 10);
		[SerializeField]
		private Sprite _pointSprite;
		[SerializeField]
		private Color _pointColor = Color.white;
		[SerializeField]
		public List<RadarChartHandler> _handlers = new List<RadarChartHandler>();
		[SerializeField]
		private float[] _handlerRadio;

		public float[] radio
		{
			get { return _handlerRadio; }
		}

		private void Update()
		{
			SetVerticesDirty();         //实时对顶点数据刷新
		}

		protected override void OnPopulateMesh(VertexHelper vertexHelper)
		{
			vertexHelper.Clear();

			if (_handlers != null && _handlers.Count > 0)
				if (!_handlers[0])
					_handlers.Clear();
			if (_handlers != null && _handlers.Count == 0)
				return;

			AddVerts(vertexHelper);       //添加全部顶点信息
										  //AddVertsPlate(vertexHelper);
			AddTriangles(vertexHelper); //添加全部面信息
		}

		/// <summary>
		/// 添加顶点
		/// </summary>
		/// <param name="vh"></param>
		private void AddVerts(VertexHelper vh)
		{
			vh.AddVert(transform.localPosition, color, Vector2.one);
			foreach (var handler in _handlers)
			{
				vh.AddVert(handler.transform.localPosition, color, Vector2.zero);
			}
		}

		/// <summary>
		/// 添加顶点模板 （制作带sprite的雷达图效果）
		/// </summary>
		/// <param name="vh"></param>
		private void AddVertsPlate(VertexHelper vh)
		{
			if (_handlers != null && _handlers.Count > 0)
			{
				if (!_handlers[0])
				{
					_handlers.Clear();
					return;
				}
				vh.AddVert(_handlers[0].transform.localPosition, color, new Vector2(0.5f, 1.0f));
				vh.AddVert(_handlers[1].transform.localPosition, color, new Vector2(0f, 1.0f));
				vh.AddVert(_handlers[2].transform.localPosition, color, new Vector2(0f, 0f));
				vh.AddVert(_handlers[3].transform.localPosition, color, new Vector2(1.0f, 0f));
				vh.AddVert(_handlers[4].transform.localPosition, color, new Vector2(1.0f, 1.0f));
			}
		}

		private void AddTriangles(VertexHelper vh)      //UI.Default.shader 默认剔除是关闭的,模型黑面,很奇怪（法向量搞反）
		{
			for (int i = 1; i <= _pointCount - 1; i++)
			{
				vh.AddTriangle(0, i + 1, i);
			}
			vh.AddTriangle(0, 1, 5);
		}

		public void InitPoints()
		{
			ClearPoints();
			_points = new List<RectTransform>();
			_handlers = new List<RadarChartHandler>();
			SpawnPoints();
			SetPointPos();
		}

		private void SpawnPoints()  //生成 point
		{
			for (var i = 0; i < _pointCount; i++)
			{
				var point = new GameObject("Point" + i);
				point.transform.SetParent(transform);
				_points.Add(point.AddComponent<RectTransform>());
			}
		}
		private void ClearPoints()
		{
			if (_points == null) return;
			foreach (var point in _points.Where(point => point != null))
			{
				DestroyImmediate(point);         //在编译时也能进行
			}
		}
		private void ClearHandles()
		{
			if (_handlers == null) return;
			for (int i = _handlers.Count - 1; i >= 0; i--)
			{
				if (_handlers[i])
				{
					DestroyImmediate(_handlers[i].gameObject);
				}
			}
			_handlers.Clear();
		}

		private void SetPointPos()          //设置点坐标
		{
			float radian = 2 * Mathf.PI / _pointCount;  //计算出当前多边形的每一段对应填充圆的弧长
			float radius = 130; //暂定当前正多边形的所填充圆的半径为100.
			float curRadian = 2 * Mathf.PI / 4.0f;     //计算出初始弧度位置 为正五边形的正上方  （起点选择与坐标轴延伸线相接的地方）
			for (int i = 0; i < _pointCount; i++)
			{
				float x = Mathf.Cos(curRadian) * radius;
				float y = Mathf.Sin(curRadian) * radius;
				curRadian += radian;
				_points[i].anchoredPosition = new Vector2(x, y);
			}
		}
		public void InitHandlers()
		{
			ClearHandles();
			SpawnHandlers();
			SetHandlerPos();
		}
		private void SpawnHandlers()
		{
			for (int i = 0; i < _pointCount; i++)
			{
				if (i < _handlers.Count)
				{
					continue;
				}
				var go = new GameObject("Handler" + i);
				go.AddComponent<RectTransform>();
				go.AddComponent<Image>();
				var handler = go.AddComponent<RadarChartHandler>();
				handler.transform.SetParent(transform, false);
				handler.ChangeColor(_pointColor);
				handler.ChangeSprite(_pointSprite);
				handler.SetSize(_pointSize);
				_handlers.Add(handler);

			}
		}
		private void SetHandlerPos()
		{
			if (_handlerRadio == null || _handlerRadio.Length != _pointCount)
			{
				for (var i = 0; i < _pointCount; i++)
				{
					if (_handlers[i])
						_handlers[i].SetPos(_points[i].anchoredPosition);
				}
			}
			else
			{
				for (var i = 0; i < _pointCount; i++)
				{
					if (_handlers[i])
						_handlers[i].SetPos(_points[i].anchoredPosition * _handlerRadio[i]);
				}
			}
		}
	}
}