cirnogodot/Scripts/Components/FSM/Elevator/ElevatorMovementState.cs

using System.Threading;
using System.Threading.Tasks;
using Cirno.Scripts.Enums;
using Godot;
using GTweens.Builders;
using GTweens.Tweens;
using GTweensGodot.Extensions;

namespace Cirno.Scripts.Components.FSM.Elevator;

public abstract partial class ElevatorMovementState : BaseState<ElevatorState, ElevatorProxy>
{
    
    protected GTween Tween;
    protected Node2D OldPlayerParent;
    
    protected abstract Vector2 StartingPosition { get; }
    protected abstract Vector2 EndingPosition { get; }
    
    protected abstract ElevatorState EndState { get; }

    protected CharacterBody2D PlayerBody => MainObject.CachedPlayer?.StateMachine.MainObject;
    
    public override void EnterState()
    {
        Tween?.Kill();
        MainObject.SetPosition(StartingPosition);
        Move();
    }

    public override void ExitState()
    {
        Tween?.Kill();
       RestorePlayerParent();
    }

    private void RestorePlayerParent()
    {
        if (PlayerBody is null) return;
        PlayerBody.Reparent(OldPlayerParent);
        OldPlayerParent = null;
        MainObject.CachedPlayer?.StateMachine.SetState(PlayerState.Active);
    }

    private void CatchPlayer()
    {
        if (PlayerBody is null) return;
        OldPlayerParent = PlayerBody.GetParent<Node2D>();
        MainObject.CachedPlayer.StateMachine.SetState(PlayerState.Cutscene);
        PlayerBody.Reparent(MainObject);
    }

    private void Move()
    {
        // Grab player if in range
        CatchPlayer();

        //Ascend
        _ = PlayAnimation();
    }

    private async Task PlayAnimation()
    {
        Tween = GTweenSequenceBuilder.New()
            .Append(MainObject.TweenPosition(EndingPosition, MainObject.MovementTime))
            .Build();

        await Tween.PlayAsync(CancellationToken.None);
        
        StateMachine.SetState(EndState);
    }
}