cirnogodot/Scripts/Resources/BossPhase.cs

using Cirno.Scripts.Actors;
using Cirno.Scripts.AttackPatterns;
using Cirno.Scripts.Resources.BulletScripts;
using Godot;
using Godot.Collections;

namespace Cirno.Scripts.Resources;

[GlobalClass]
[Tool]
public partial class BossPhase : Resource
{
    [Export] public string PhaseName = string.Empty;
    [Export] public int Threshold;
    [Export] public bool PlayAnimation;
    [Export] public BulletScript3D BulletScript3D;

    // Legacy path kept for backwards compatibility with existing phase compositions.
    // TODO: Migrate compositions to BulletScript3D-first workflows where possible.
    [Export] public Array<AttackPattern> Patterns;

    private int currentPatternIndex = 0;
    private double patternTimer;
    private bool _useBulletScript3D;

    private IPatternMachine _patternMachine;
    private BulletScript3D.BulletScriptMachine _bulletScriptMachine;

    public void Start(Node boss)
    {
        _useBulletScript3D = BulletScript3D is not null;
        patternTimer = 0;

        if (_useBulletScript3D)
        {
            _bulletScriptMachine = BulletScript3D.Make(boss);
            _bulletScriptMachine.Start();
            _patternMachine = null;
            return;
        }

        if (Patterns is null || Patterns.Count == 0)
        {
            GD.PushWarning($"BossPhase '{PhaseName}' has no legacy Patterns and no BulletScript3D assigned.");
            _patternMachine = null;
            return;
        }

        currentPatternIndex = 0;
        _patternMachine = Patterns[currentPatternIndex].MakeMachine(boss);
        _patternMachine.Start();
    }

    public void UpdatePhase(double delta)
    {
        if (_useBulletScript3D)
        {
            _bulletScriptMachine?.UpdatePhase(delta);
            return;
        }

        if (_patternMachine is null || Patterns is null || Patterns.Count == 0)
        {
            return;
        }

        patternTimer += delta;
        var currentPattern = Patterns[currentPatternIndex];

        _patternMachine.UpdatePattern(delta);

        if (!currentPattern.WaitForCompletion || _patternMachine.IsComplete())
        {
            currentPatternIndex = (currentPatternIndex + 1) % Patterns.Count;
            var oldParent = _patternMachine.Parent;
            _patternMachine = Patterns[currentPatternIndex].MakeMachine(oldParent);
            _patternMachine.Start();
        }
    }
}