using UnityEngine;

using System;
using System.Collections;

public class TweenCG : Tween
{
    #region 变量

    public override bool InOrigin
    {
        get
        {
            if (Math.Abs(Target.alpha - Origin) < 0.0005f)
            {
                _InOrigin = true;
            }
            else
            {
                _InOrigin = false;
            }

            return _InOrigin;
        }

        set
        {
            _InOrigin = value;

            if (_InOrigin)
            {
                Target.alpha = Origin;
            }

            
        }
    }

    public override bool InDestination
    {
        get
        {
            if (Math.Abs(Target.alpha - Destination) < 0.0005f)
            {
                _InDestination = true;
            }
            else
            {
                _InDestination = false;
            }

            return _InDestination;
        }
        set
        {
            _InDestination = value;

            if (_InDestination)
            {
                Target.alpha = Destination;
            }
            
        }
    }

    protected float Delta;
    protected float Origin;
    protected float Destination;
    protected CanvasGroup Target;
    protected CurveFunctionF Func;

    #endregion

    public TweenCG(CanvasGroup target, float origin, float destination, float duration, bool originActive, bool destActive, Curve curve)
    {
        Func = ManaAnim.CurveFuncDicF[curve];
        Target = target;

        InForward = false;
        InBackward = false;

        Delta = destination - origin;
        Origin = origin;
        Duration = duration;
        DestActive = destActive;
        Destination = destination;
        OriginActive = originActive;

        OnForwardStart += () =>
        {
            
        };

        OnForwardFinish += () =>
        {
            
        };

        OnBackwardStart += () =>
        {
            
        };

        OnBackwardFinish += () =>
        {
            
        };
    }

    public override void StartForward()
    {
        base.StartForward();

        Target.SetActive(true);
        Target.interactable = false;

        if (InBackward)
        {
            Timer = Duration - Timer;
        }
        else
        {
            Target.alpha = Origin;
        }
    }

    public override void StartBackward()
    {
        base.StartBackward();

        Target.SetActive(true);
        Target.interactable = false;

        if (InForward)
        {
            Timer = Duration - Timer;
        }
        else
        {
            Target.alpha = Destination;
        }
    }

    public override bool DoForward()
    {
        Timer += Time.fixedDeltaTime;

        if (Timer > Duration)
        {
            Timer = 0;

            InForward = false;
            InDestination = true;

            Target.SetActive(DestActive);
            Target.interactable = DestActive;

            OnForwardFinish.Invoke();

            ManaAnim.TweenForList.Remove(this);

            return true;
        }
        else
        {
            Target.alpha = Func(Timer, Duration, Origin, Delta);

            return false;
        }
    }

    public override bool DoBackward()
    {
        Timer += Time.fixedDeltaTime;

        if (Timer > Duration)
        {
            Timer = 0;

            InBackward = false;
            InOrigin = true;

            Target.SetActive(OriginActive);
            Target.interactable = OriginActive;

            OnBackwardFinish.Invoke();

            ManaAnim.TweenBacList.Remove(this);

            return true;
        }
        else
        {
            Target.alpha = Func(Timer, Duration, Destination, -Delta);

            return false;
        }
    }
}