godot-host-test/Game/Target/Target.cs

using Godot;
using GodotHostTest.Interfaces;
using OwofGames.AetherBind;
using R3;

namespace GodotHostTest.Game.Target;

public partial class Target : Node2D, ITarget
{
    private readonly Subject<Unit> _hit = new();
    private readonly Subject<Unit> _timedOut = new();

    [Export] public required Area2D CollisionArea;
    [Export] public required Sprite2D Image;
    [Export] public required Timer TimeOutTimer;
    [Export] private PackedScene _explosionPackedScene = null!;

    [Inject] private ILevel _level = null!;
    [Inject] private ITargetCollector _targetCollector = null!;

    public Observable<Unit> TimedOut => _timedOut.AsObservable();

    public Observable<Unit> Hit => _hit.AsObservable();

    public void Enable()
    {
        Image.Visible = true;
        CollisionArea.Monitoring = true;
        CollisionArea.Monitorable = true;
        TimeOutTimer.Start(_level.SpawnDuration.TotalSeconds);
    }

    private void Disable()
    {
        Image.Visible = false;
        // can't set monitoring/monitorable when inside collision code, like during OnHit, so let's call them deferred
        CollisionArea.SetDeferred(Area2D.PropertyName.Monitoring, false);
        CollisionArea.SetDeferred(Area2D.PropertyName.Monitorable, false);
        TimeOutTimer.Stop();
    }

    public override void _Ready()
    {
        _targetCollector.NewTarget(this);
    }

    protected override void Dispose(bool disposing)
    {
        base.Dispose(disposing);
        _timedOut.Dispose();
        _hit.Dispose();
    }

    private void OnAreaEntered(Area2D _)
    {
        Disable();
        _hit.OnNext(Unit.Default);

        var explosion = (GpuParticles2D)_explosionPackedScene.Instantiate();
        explosion.GlobalPosition = GlobalPosition;
        explosion.Emitting = true;
        GetTree().CurrentScene.AddChild(explosion);
    }

    private void OnTimeout()
    {
        Disable();
        _timedOut.OnNext(Unit.Default);
    }
}