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

public class CircleMoveTo : MonoBehaviour
{
    public float circleTime = 1f;
    public float duration = 2f;
    public float ratio = 3;
    public float accelerate = 0.2f;

    [SerializeField]
    Vector3 m_Desitination = Vector3.zero;
    public Vector3 destination {
        get { return m_Desitination; }
        private set {
            m_Desitination = value;
        }
    }

    Vector3 forward = Vector3.zero;
    float timer = 0f;
    float endTime = 0f;
    float velocity = 0f;

    bool windUp = false;
    Vector3 refPosition = Vector3.zero;
    Action onReach;
    bool beginMove = false;

    public void MoveTo(Vector3 _destination, Action _callBack = null)
    {
        this.SetActive(true);
        windUp = false;
        velocity = 0f;
        destination = _destination;
        beginMove = true;
        endTime = Time.time + duration;
        refPosition = Vector3.zero;
        onReach = _callBack;
    }

    void FixedUpdate()
    {
        if (!beginMove)
        {
            return;
        }

        if (Time.time > endTime && !windUp)
        {
            var normalize1 = Vector3.Normalize(destination.SetZ(0));
            var normalize2 = Vector3.Normalize(this.transform.position.SetZ(0));
            var dot = Vector3.Dot(normalize1, normalize1 - normalize2);
            if (dot > -0.15f && dot < 0.15f)
            {
                windUp = true;
            }
        }

        if (windUp)
        {
            var newPosition = Vector3.SmoothDamp(this.transform.position, destination, ref refPosition, 0.25f);
            this.transform.position = newPosition;
            this.transform.localPosition = this.transform.localPosition.SetZ(0);
            if (Vector3.Distance(this.transform.position.SetZ(0), destination.SetZ(0)) < 0.01f)
            {
                if (onReach != null)
                {
                    onReach();
                    onReach = null;
                }

                beginMove = false;
                this.SetActive(false);
            }
        }
        else
        {
            velocity += Time.deltaTime * accelerate;
            timer += Time.deltaTime;
            if (timer > circleTime)
            {
                timer = timer - circleTime;
            }

            var t = Mathf.Clamp01(timer / circleTime);
            forward = new Vector3(Mathf.Sin(2 * t * Mathf.PI), Mathf.Cos(2 * t * Mathf.PI), 0f);
            this.transform.position += Vector3.Normalize(forward) * Mathf.Pow(velocity, ratio);
        }

    }


}