using System.Collections;
using System.Collections.Generic;
using UnityEngine;
#if UNITY_EDITOR
using UnityEditor;
#endif

/// <summary>
/// 用于TopDown的Transform，支持模拟垂直高度
/// </summary>
[ExecuteInEditMode]
[RequireComponent(typeof(Transform))]
public class TopDownTransform : MonoBehaviour
{
	// 右手系
	//  z
	//  |
	//  |  /y
	//  | /
	//  |/______x

	// x, y, z ( z = height)
	[SerializeField] private Vector3 m_LocalPosition;

	// 只能绕一个虚拟轴旋转
	[SerializeField] private float m_LocalRotation;

	// x, z
	//[SerializeField] private Vector2 m_LocalScale;

	public Vector3 position
	{
		get
		{
			return m_LocalPosition;
		}
		set
		{
			m_LocalPosition = value;
			Project();
		}
	} 

	public float x
	{
		get
		{
			return m_LocalPosition.x;
		}
		set
		{
			m_LocalPosition.x = value;
			Project();
		}
	}
	public float y
	{
		get
		{
			return m_LocalPosition.y;
		}
		set
		{
			m_LocalPosition.y = value;
			Project();
		}
	}

	public float z
	{
		get
		{
			return m_LocalPosition.z;
		}
		set
		{
			m_LocalPosition.z = value;
			Project();
		}
	}

	public float height
	{
		get
		{
			return z;
		}
		set
		{
			z = value;
		}
	}

	// 地表坐标（Topdown空间）
	public Vector3 positionOnGround
	{
		set
		{
			Vector3 pos = position;
			pos.x = value.x;
			pos.y = value.y;
			position = pos;
			Project();
		}
		get
		{
			Vector3 pos = position;
			pos.z = 0;
			return pos;
		}
	}

	/// <summary>
	/// “投影”，把坐标转换到Transform上
	/// </summary>
	public void Project()
	{
		Vector3 pos = transform.localPosition;
		pos.x = m_LocalPosition.x;
		pos.y = m_LocalPosition.y + m_LocalPosition.z;

		transform.localPosition = pos;
	}

	private void Start()
	{
		SpriteRenderer sr = GetComponent<SpriteRenderer>();
		if (sr)
		{
			gameObject.AddOrGetComponent<TopDownSorting>();
			gameObject.AddOrGetComponent<TopDownShadowCaster>();
		}
	}

	private void Update()
	{
		Project();
	}

	#region 转换到3D笛卡尔空间
	public Vector3 Get3DPosition()
	{
		Vector3 pos = new Vector3();
		pos.x = m_LocalPosition.x;
		pos.y = m_LocalPosition.y + m_LocalPosition.z;
		pos.z = transform.localPosition.z;
		return pos;
	}

	/// <summary>
	/// 注意是在3D空间下
	/// </summary>
	/// <returns></returns>
	public Vector3 GetGround3DPosition()
	{
		Vector3 pos = new Vector3();
		pos.x = m_LocalPosition.x;
		pos.y = m_LocalPosition.y ;
		pos.z = transform.localPosition.z;
		return pos;
	}
	#endregion 

#if UNITY_EDITOR
	private void OnDrawGizmos()
	{
		// dash line 
		Vector3 start = transform.position;
		Vector3 end = start - new Vector3(0, m_LocalPosition.z, 0);

		Handles.DrawDottedLine(start, end, 1f);
		Handles.DrawWireCube(end, new Vector3(0.1f, 0.1f, 0f));
	}
#endif

}