using System;
using UnityEngine;

public class MerchantMove : State<Character>
{
    Transform start;
    Transform destination;
    float duration;
    Func<float> getCurrentElapsedTime;

    public bool HasDestination => destination != null;

    public void Setup(Transform start, Transform destination, float duration, Func<float> getCurrentElapsedTime)
    {
        Debug.Assert(start != null && destination != null && duration > 0, "arguments are not valid");

        this.start = start;
        this.destination = destination;
        this.duration = duration;
        this.getCurrentElapsedTime = getCurrentElapsedTime;
    }

    public override void Enter()
    {
        Debug.Assert(Owner.Excutor.SkeletonAnimation.TryGetAnimation("move", out Spine.Animation _), "move animation not exist");
        Owner.Excutor.SkeletonAnimation.AnimationState.SetAnimation(0, "move", true);
    }

    public override void Excute()
    {
        float elapsedTime = getCurrentElapsedTime();

        if (elapsedTime >= duration)
        {
            Owner.ChangeState<MerchantIdle>();
        }
        else
        {
            Owner.Excutor.Position = Vector2.Lerp(start.position, destination.position, elapsedTime / duration);
        }
    }

    public override void Exit()
    {
        start = null;
        destination = null;
        duration = 0;
    }
}