//--------------------------------------------------------
//    [Author]:           第二世界
//    [  Date ]:           Thursday, September 07, 2017
//--------------------------------------------------------
using UnityEngine;
using System.Collections;
using UnityEngine.UI;
using System;

public class ScreenMoveTo : MonoBehaviour
{

    [SerializeField]
    LerpType m_LerpType = LerpType.Linear;

    [SerializeField]
    Vector2 m_Destination;
    public Vector2 destination {
        get { return m_Destination; }
        set { m_Destination = value; }
    }

    [SerializeField]
    float m_Duration = 0.5f;
    public float duration {
        get { return m_Duration; }
        set { m_Duration = value; }
    }

    [SerializeField]
    bool m_IsLocal = true;
    public bool isLocal {
        get { return m_IsLocal; }
    }

    bool disableOnEnd = true;
    float endTime = 0f;

    Vector3 startPosition = Vector3.zero;
    Vector3 startLocalPosition = Vector3.zero;
    Vector3 refPosition = Vector3.zero;

    bool end = false;
    Action endCallBack = null;

    public void Begin(bool _deActiveOnEnd = true)
    {
        endTime = Time.time + duration;
        end = false;
        disableOnEnd = _deActiveOnEnd;
        startPosition = this.transform.position;
        startLocalPosition = this.transform.localPosition;
        refPosition = Vector3.zero;
        endCallBack = null;

        this.enabled = true;
        if (!this.gameObject.activeInHierarchy)
        {
            this.SetActive(true);
        }
    }

    public void Begin(Action _callBack, bool _disableOnEnd = true)
    {
        endTime = Time.time + duration;
        end = false;
        disableOnEnd = _disableOnEnd;
        startPosition = this.transform.position;
        startLocalPosition = this.transform.localPosition;
        refPosition = Vector3.zero;
        endCallBack = _callBack;

        this.enabled = true;
        if (!this.gameObject.activeInHierarchy)
        {
            this.SetActive(true);
        }
    }

    private void LateUpdate()
    {
        switch (m_LerpType)
        {
            case LerpType.Linear:
                if (Time.time < endTime)
                {
                    var t = Mathf.Clamp01(1f - (endTime - Time.time) / m_Duration);
                    if (isLocal)
                    {
                        this.transform.localPosition = Vector3.Lerp(startLocalPosition, destination, t);
                    }
                    else
                    {
                        this.transform.position = Vector3.Lerp(startPosition, destination, t);
                    }
                }
                else
                {
                    end = true;
                    if (isLocal)
                    {
                        this.transform.localPosition = destination;
                    }
                    else
                    {
                        this.transform.position = destination;
                    }
                }
                break;
            case LerpType.Smooth:

                if (isLocal)
                {
                    if (Vector3.Distance(this.transform.localPosition, new Vector3(destination.x, destination.y)) > 1)
                    {
                        this.transform.localPosition = Vector3.SmoothDamp(this.transform.localPosition, destination, ref refPosition, duration);
                    }
                    else
                    {
                        this.transform.localPosition = destination;
                        end = true;
                    }
                }
                else
                {
                    if (Vector3.Distance(this.transform.position, new Vector3(destination.x, destination.y)) > 1)
                    {
                        this.transform.position = Vector3.SmoothDamp(this.transform.position, destination, ref refPosition, duration);
                    }
                    else
                    {
                        this.transform.position = destination;
                        end = true;
                    }
                }
                break;
        }

        if (end)
        {
            if (endCallBack != null)
            {
                endCallBack();
                endCallBack = null;
            }
        }

        if (end && disableOnEnd)
        {
            this.enabled = false;
        }

    }


    public enum LerpType
    {
        Linear,
        Smooth,
    }

}