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

public class TestWaspRobot : MonoBehaviour
{
	[SerializeField] private TopDownTransform m_Follow;

	[SerializeField] private float m_MoveSpeed;

	private SpriteRenderer m_SpriteRenderer;
	private TopDownTransform m_Coords;

	// wasp»·ÈÆ
	[SerializeField] private float m_Radius;

	[SerializeField] private List<Sprite> m_Sprites;

	private bool m_Following;

	private float m_Angle;

	private float m_OrbitSpeed = 3f;

	enum State
	{
		None,
		Move, 
		Orbit,
	}

	private State m_State = State.None;

	private Coroutine m_Coroutine;

	private void Start()
	{
		m_SpriteRenderer = GetComponent<SpriteRenderer>();
		m_Coords = GetComponent<TopDownTransform>();

		m_Following = false;
		m_Angle = 0;

		ChangeState(State.Move);
	}

	private void ChangeState(State state)
	{
		if(m_State != state)
		{
			//Debug.Log(m_State.ToString() + "->" + state.ToString());

			if(m_Coroutine != null)
			{
				StopCoroutine(m_Coroutine);
			}
			m_State = state;
			m_Coroutine = StartCoroutine("co" + m_State.ToString());
		}
	}

	void Update()
    {

		float distance = (m_Follow.positionOnGround - m_Coords.positionOnGround).magnitude;
		m_Following = distance > m_Radius + 0.1f;

		if(m_Following)
		{
			ChangeState(State.Move);
		}
		else
		{
			ChangeState(State.Orbit);
		}

	}

	IEnumerator coMove()
	{
		while (true)
		{
			if (m_Following)
			{
				Vector2 dir = (m_Follow.positionOnGround - m_Coords.positionOnGround).normalized;

				Vector2 posOnGround = m_Coords.positionOnGround;
				posOnGround.x += m_MoveSpeed * Time.deltaTime * dir.x;
				posOnGround.y += m_MoveSpeed * Time.deltaTime * dir.y;

				m_Coords.positionOnGround = posOnGround;

				float rad = GetAngleToTarget();

				int index = GetSpriteIndex(rad);
				SetSprite(index);
			}

			yield return null;
		}
	}

	IEnumerator coOrbit()
	{
		m_Angle = GetAngleToTarget();

		while (true)
		{
			m_Angle += Time.deltaTime * m_OrbitSpeed;

			Vector2 centre = m_Follow.positionOnGround;
			centre += new Vector2(Mathf.Cos(m_Angle), Mathf.Sin(m_Angle)).normalized * m_Radius;
			m_Coords.positionOnGround = Vector2.Lerp(m_Coords.positionOnGround, centre, 0.25f);

			int index = GetSpriteIndex(m_Angle); 
			SetSprite(index);

			yield return null;
		}
	}

	float GetAngleToTarget()
	{
		Vector2 posOnGround = m_Coords.positionOnGround;
		Vector2 target = m_Follow.positionOnGround;

		Vector2 dir = (posOnGround - target).normalized;

		return Mathf.Atan2(dir.y, dir.x) + 2 * Mathf.PI * TestMathHelper.Check(dir.y < 0);
	}

	// angle rad
	int GetSpriteIndex(float rad) 
	{
		int index = ((int)Mathf.Floor(((rad * Mathf.Rad2Deg) % 360) / 30)) % 12;
		index = Mathf.Clamp(index, 0, m_Sprites.Count - 1);
		return index;
	}

	void SetSprite(int index)
	{
		m_SpriteRenderer.sprite = m_Sprites[index];
	}

}