cirnogodot/Scripts/Weapons/LaserBullet3D.cs

using Cirno.Scripts.Actors._3D;
using Cirno.Scripts.Components;
using Cirno.Scripts.Controllers;
using Cirno.Scripts.Utils;
using Godot;

namespace Cirno.Scripts.Weapons;

/// <summary>
/// Laser implementation that conforms to the IBullet interface.
/// Wraps the Laser class functionality to integrate with the bullet system.
/// </summary>
public partial class LaserBullet3D : Area3D, IBullet
{
    private BulletInfo _bulletInfo;
    
    public float Speed { get; set; }
    public BulletOwner BulletOwner => _bulletInfo?.Owner ?? BulletOwner.None;
    public float Damage => _bulletInfo?.Damage ?? 1;
    public DamageType DamageType => _bulletInfo?.DamageType ?? DamageType.Neutral;
    public BulletInfo BulletInfo => _bulletInfo;
    public bool IsGrazed { get; set; }
    public bool IsFrozen { get; private set; }
    public bool Enabled { get; private set; }

    private Vector2 _direction = Vector2.Right;
    private double _elapsedTime;
    
    private MeshInstance3D _mesh;
    private CollisionShape3D _collision;
    private RayCast3D _ray;
    private ShaderMaterial _beamMaterial;
    private float _currentRadius;
    private Laser.LaserState _state = Laser.LaserState.Inactive;
    private float _stateTimer;
    private Vector3 _origin;
    private Vector3 _laserDirection;
    private float _currentLength;
    
    [Signal]
    public delegate void OnDestroyEventHandler();

    [Signal]
    public delegate void InitializedEventHandler();

    public override void _Ready()
    {
        _mesh = GetNode<MeshInstance3D>("MeshInstance3D");
        _collision = GetNode<CollisionShape3D>("CollisionShape3D");
        _ray = GetNode<RayCast3D>("RayCast3D");
        _beamMaterial = _mesh.MaterialOverride as ShaderMaterial;
    }

    public void Initialize(BulletInfo bulletInfo)
    {
        _bulletInfo = bulletInfo;
        _elapsedTime = 0f;
        _direction = bulletInfo.Direction.Normalized();
        
        IsGrazed = false;
        IsFrozen = false;
        
        // Setup laser from direction
        _origin = GlobalPosition;
        _laserDirection = new Vector3(_direction.X, 0, _direction.Y).Normalized();
        
        if (_bulletInfo.LaserConfig != null)
        {
            _ray.CollisionMask = _bulletInfo.LaserConfig.GeometryLayer;
        }
        
        ChangeCollisionStateDeferred(true);
        
        StartLaser();
        EmitSignal(SignalName.Initialized);
    }

    private void StartLaser()
    {
        _mesh.Scale = Vector3.One;
        _collision.Scale = Vector3.One;
        
        _stateTimer = 0f;
        _state = _bulletInfo.LaserConfig.WarningDuration > 0
            ? Laser.LaserState.Warning
            : Laser.LaserState.Expanding;
        
        UpdateVisualOrientation();
        SetRadius(_bulletInfo.LaserConfig.WarningRadius);
    }

    public void Enable()
    {
        Enabled = true;
        Show();
        if (_collision != null)
        {
            _collision.SetDeferred(CollisionShape3D.PropertyName.Disabled, false);
        }
    }

    public void Disable(bool hideSprite = true)
    {
        Enabled = false;
        if (hideSprite)
        {
            Hide();
        }
        if (_collision != null)
        {
            _collision.SetDeferred(CollisionShape3D.PropertyName.Disabled, true);
        }
    }

    public void Graze()
    {
        if (!Enabled) return;
        IsGrazed = true;
    }

    public void RotateBullet(float degrees)
    {
        float radians = Mathf.DegToRad(degrees);
        _direction = _direction.Rotated(radians).Normalized();
        _laserDirection = new Vector3(_direction.X, 0, _direction.Y).Normalized();
        UpdateVisualOrientation();
    }

    public void RotateSpriteDegrees(float degrees)
    {
        // Lasers don't rotate sprite independently
        RotateBullet(degrees);
    }

    public void RotateSprite(float radians)
    {
        // Lasers don't rotate sprite independently
        RotateBullet(Mathf.RadToDeg(radians));
    }

    public void FacePlayer()
    {
        if (GameController.Instance.PlayerPosition.HasValue)
        {
            _direction = (GameController.Instance.PlayerPosition.Value.ToVector2() - GlobalPosition.ToVector2()).Normalized();
            _laserDirection = new Vector3(_direction.X, 0, _direction.Y).Normalized();
            UpdateVisualOrientation();
        }
    }

    public void SetDirection(Vector2 direction)
    {
        _direction = direction.Normalized();
        _laserDirection = new Vector3(_direction.X, 0, _direction.Y).Normalized();
        UpdateVisualOrientation();
    }

    public bool CanHit(BulletOwner bulletOwner, BulletOwner targetGroup)
    {
        if (bulletOwner == BulletOwner.None || targetGroup == BulletOwner.None)
        {
            return true;
        }
        return bulletOwner != targetGroup;
    }

    public void RequestCollisionDestruction()
    {
        // Lasers typically don't get destroyed on collision
        if (_bulletInfo.DestroyOnCollision)
        {
            Destroy();
        }
    }

    public void Freeze()
    {
        IsFrozen = true;
        EmitSignal(SignalName.OnDestroy);
        PoolingManager.Instance.DisableBullet(this);
    }

    public override void _Process(double delta)
    {
        if (!Enabled) return;
        
        _elapsedTime += delta;

        if (_elapsedTime >= _bulletInfo.LifeTime)
        {
            Destroy();
            return;
        }

        if (_state == Laser.LaserState.Finished)
            return;

        _stateTimer += (float)delta;

        UpdateRaycast();
        UpdateBeam();

        switch (_state)
        {
            case Laser.LaserState.Warning:
                if (_stateTimer >= _bulletInfo.LaserConfig.WarningDuration)
                    TransitionTo(Laser.LaserState.Expanding);
                break;

            case Laser.LaserState.Expanding:
                HandleExpansion();
                break;

            case Laser.LaserState.Active:
                if (_bulletInfo.LaserConfig.ActiveDuration >= 0 &&
                    _stateTimer >= _bulletInfo.LaserConfig.ActiveDuration)
                    TransitionTo(Laser.LaserState.Finished);
                break;
        }
    }

    private void TransitionTo(Laser.LaserState next)
    {
        _state = next;
        _stateTimer = 0f;

        switch (next)
        {
            case Laser.LaserState.Expanding:
                if (_bulletInfo.LaserConfig.ExpansionDuration <= 0f)
                {
                    SetRadius(_bulletInfo.LaserConfig.DamageRadius);
                    EnableCollision();
                    TransitionTo(Laser.LaserState.Active);
                }
                break;

            case Laser.LaserState.Active:
                EnableCollision();
                SetRadius(_bulletInfo.LaserConfig.DamageRadius);
                break;

            case Laser.LaserState.Finished:
                Destroy();
                break;
        }
    }

    private void HandleExpansion()
    {
        if (_stateTimer < _bulletInfo.LaserConfig.ExpansionDelay)
            return;

        var t = Mathf.Clamp(
            (_stateTimer - _bulletInfo.LaserConfig.ExpansionDelay) / 
            Mathf.Max(_bulletInfo.LaserConfig.ExpansionDuration, 0.001f),
            0f, 1f
        );

        var radius = Mathf.Lerp(_bulletInfo.LaserConfig.WarningRadius, 
                                _bulletInfo.LaserConfig.DamageRadius, t);
        SetRadius(radius);

        if (t >= 1f)
            TransitionTo(Laser.LaserState.Active);
    }

    private void UpdateRaycast()
    {
        _ray.TargetPosition = _laserDirection * _bulletInfo.LaserConfig.MaxLength;
        _ray.ForceRaycastUpdate();

        _currentLength = _ray.IsColliding()
            ? GlobalPosition.DistanceTo(_ray.GetCollisionPoint())
            : _bulletInfo.LaserConfig.MaxLength;
    }

    private void UpdateVisualOrientation()
    {
        Basis look = Basis.LookingAt(_laserDirection, Vector3.Up);
        Basis correction = new Basis(Vector3.Right, Mathf.Pi / 2f);
        Basis finalBasis = look * correction;

        _mesh.Basis = finalBasis;
        _collision.Basis = finalBasis;
    }

    private void UpdateBeam()
    {
        if (_mesh.Mesh is CylinderMesh cyl)
            cyl.Height = _currentLength;

        if (_collision.Shape is CapsuleShape3D capsule)
            capsule.Height = _currentLength;

        Vector3 center = _origin + _laserDirection * (_currentLength * 0.5f);

        Transform3D meshXform = _mesh.GlobalTransform;
        meshXform.Origin = center;
        _mesh.GlobalTransform = meshXform;

        Transform3D colXform = _collision.GlobalTransform;
        colXform.Origin = center;
        _collision.GlobalTransform = colXform;
    }

    private void SetRadius(float radius)
    {
        _currentRadius = radius;

        if (_mesh.Mesh is CylinderMesh cyl)
        {
            cyl.TopRadius = radius;
            cyl.BottomRadius = radius;
        }

        if (_collision.Shape is CapsuleShape3D capsule)
            capsule.Radius = radius;

        UpdateMaterial();
    }

    private void EnableCollision()
    {
        ChangeCollisionStateDeferred(false);
    }

    private void ChangeCollisionStateDeferred(bool value)
    {
        _collision.SetDeferred(CollisionShape3D.PropertyName.Disabled, value);
    }

    private void UpdateMaterial()
    {
        if (_beamMaterial == null)
            return;

        _beamMaterial.SetShaderParameter("beam_length", _currentLength);
        _beamMaterial.SetShaderParameter("beam_radius", _currentRadius);

        switch (_state)
        {
            case Laser.LaserState.Warning:
                _beamMaterial.SetShaderParameter("beam_color", new Color(1f, 1f, 0.2f));
                _beamMaterial.SetShaderParameter("intensity", 0.5f);
                break;

            case Laser.LaserState.Active:
                _beamMaterial.SetShaderParameter("beam_color", new Color(1f, 0.2f, 0.2f));
                _beamMaterial.SetShaderParameter("intensity", 1.0f);
                break;
        }
    }

    public bool IsPointInsideBeam(Vector3 worldPoint)
    {
        if (_state != Laser.LaserState.Active)
            return false;

        Vector3 local = worldPoint - _origin;
        float projection = local.Dot(_laserDirection);

        if (projection < 0 || projection > _currentLength)
            return false;

        Vector3 closestPoint = _origin + _laserDirection * projection;
        float distanceSq = worldPoint.DistanceSquaredTo(closestPoint);

        float radius = _bulletInfo.LaserConfig.DamageRadius;
        return distanceSq <= radius * radius;
    }

    private void _on_area_entered(Area3D area)
    {
        if (!Enabled || _state != Laser.LaserState.Active) return;
        
        if (area.IsInGroup("Destroyable") && area is IDestructible destructible &&
            CanHit(BulletOwner, destructible.BulletGroup))
        {
            destructible.Hit(Damage, DamageType);
            RequestCollisionDestruction();
        }
    }

    private void _on_body_entered(Node3D body)
    {
        if (!Enabled || _state != Laser.LaserState.Active) return;
        
        if (body.IsInGroup("Destroyable") && body is IDestructible destructible &&
            CanHit(BulletOwner, destructible.BulletGroup))
        {
            destructible.Hit(Damage, DamageType);
            RequestCollisionDestruction();
        }
    }

    private void Destroy()
    {
        EmitSignal(SignalName.OnDestroy);
        PoolingManager.Instance.DisableBullet(this);
    }
}