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

public class JiugongGridSegmentation : MonoBehaviour {

	/// <summary>
	/// 地形
	/// </summary>
	public Terrain Terrain;
	/// <summary>
	/// 角色Transform
	/// </summary>
	public Transform Target;
	/// <summary>
	/// 角色位置
	/// </summary>
	public Vector2 PlayerPos;
	/// <summary>
	/// 当前实时位置标号
	/// </summary>
	public Vector2 CalPos;

	/// <summary>
	/// 格子尺寸
	/// </summary>
	public Vector2 GridSize = new Vector2(10, 10);
    /// <summary>
    /// 当前所在标号
    /// </summary>
    public byte[] CenterIndex = new byte[2];
	/// <summary>
	/// 当前所在格子
	/// </summary>
	public Rect CurrentRect;
	/// <summary>
	/// 格子列表
	/// </summary>
	public List<Rect> GridRects = new List<Rect>();
	/// <summary>
	/// 格子标号与位置信息
	/// </summary>
	public Dictionary<byte[],Rect> CellRects = new Dictionary<byte[], Rect>();

	
	private Coroutine SelfInfoCoroutine; //更新坐标协程
	private Vector2 TerrainPosition; //地形坐标
	private float XCount; //X方向格子数量
	private float ZCount; //Z方向格子数量
	// Use this for initialization
	void Start () {
		Terrain = FindObjectOfType<Terrain>();
		TerrainPosition = new Vector2(Terrain.GetPosition().x, Terrain.GetPosition().z);
		Generate();
		SelfInfoCoroutine = StartCoroutine(UpdateSelfPosInfo());
	}

	// Update is called once per frame
	void Update()
	{
		if (Target != null) {
			PlayerPos = new Vector2(Target.position.x, Target.position.z);
			CalPos = new Vector2(Mathf.FloorToInt((PlayerPos.x - TerrainPosition.x) / 10), Mathf.FloorToInt((PlayerPos.y - TerrainPosition.y) / 10));
		}
	}

	void OnDestroy()	{
		StopCoroutine(SelfInfoCoroutine);
	}
	/// <summary>
	/// 生成格子
	/// </summary>
	public void Generate()
	{
		float xwidth = Terrain.terrainData.size.x;
		float zwidth = Terrain.terrainData.size.z;
		Vector2 terrainPosxz = new Vector2(TerrainPosition.x, TerrainPosition.y); //起始位置

		XCount = xwidth / GridSize.x;
		ZCount = zwidth / GridSize.y;

		for (int i = 0; i < ZCount; i++)
		{
			for (int j = 0; j < XCount; j++)
			{
				Vector2 pos = new Vector2(terrainPosxz.x + GridSize.x * j, terrainPosxz.y + GridSize.y * i);
				Rect rect = new Rect(pos, GridSize);
				GridRects.Add(rect);
				CellRects.Add(new byte[2] { ((byte)j), ((byte)i) }, rect);
#if UNITY_EDITOR
				TestCube(pos);
#endif
			}
		}
	}

	/// <summary>
	/// 生成测试方块
	/// </summary>
	/// <param name="pos"></param>
	private void TestCube(Vector2 pos)
    {
		GameObject cube = GameObject.CreatePrimitive(PrimitiveType.Cube);
		Vector3 position = new Vector3(pos.x, 0, pos.y);
		position.y = Terrain.activeTerrain.SampleHeight(position);
		cube.transform.position = position;
		cube.transform.localScale = Vector3.one;
		cube.transform.SetParent(this.transform);
	}

	/// <summary>
	/// 获取自身位置信息
	/// </summary>
	public void GetSelfPosInfo()
	{
		if (Target == null) return;
		Vector2 currentPos = new Vector2(Target.position.x, Target.position.z);

		for (int i = 0; i < GridRects.Count; i++)
		{
			//得到当前Rect
			if (GridRects[i].Contains(currentPos))
			{
				CurrentRect = GridRects[i];
				//找到当前Rect对应的序号
				var current = CellRects.FirstOrDefault(rect => rect.Value.Equals(CurrentRect));
				CenterIndex = current.Key;
				break;
			}
		}
	}

	public float GetTerrainHeight(Vector3 pos)
    {
		return Terrain.SampleHeight(pos);
    }

	/// <summary>
	/// 更新位置协程
	/// </summary>
	/// <returns></returns>
	IEnumerator UpdateSelfPosInfo()
    {
		while (true)
        {
			yield return new WaitForSeconds(1);
			GetSelfPosInfo();
		}
    }
}