MovementTests/scenes/enemies/Enemy.cs

using System;
using System.Collections.Generic;
using Chickensoft.AutoInject;
using Chickensoft.Introspection;
using Gamesmiths.Forge.Abilities;
using Gamesmiths.Forge.Attributes;
using Gamesmiths.Forge.Core;
using Gamesmiths.Forge.Cues;
using Gamesmiths.Forge.Effects;
using Gamesmiths.Forge.Events;
using Gamesmiths.Forge.Godot.Resources.Abilities;
using Gamesmiths.Forge.Statescript;
using Gamesmiths.Forge.Tags;
using Godot;
using Movementtests.interfaces;
using Movementtests.systems;
using Movementtests.tools;
using Node = Godot.Node;

[GlobalClass, Icon("res://assets/ui/IconGodotNode/node_3D/icon_beetle.png"), Meta(typeof(IAutoNode))]
public partial class Enemy : CharacterBody3D, 
	IDamageable, 
	IHealthable, 
	IKillable, 
	IMoveable, 
	ISpawnable,
	IKnockbackable,
	ITargetable,
	IStunnable,
	IForgeEntity
{
    public override void _Notification(int what) => this.Notify(what);
    
    #region Dependencies 
    
    [Dependency]
    public TagsManager TagsManager => this.DependOn<TagsManager>();
    [Dependency]
    public CuesManager CuesManager => this.DependOn<CuesManager>();
    
    #endregion

    #region Signals

    // Signals and events
    public event Action<IDamageable, DamageRecord> DamageTaken = null!;
    public event Action<IHealthable, HealthChangedRecord> HealthChanged = null!;
    public event Action<IHealthable> HealthDepleted = null!;
    
    #endregion

	#region Inspector

	// Public export components
	[Export]
	public Node3D? Target { get; set; }
	[Export] public required ForgeAbilityData HitAbility { get; set; }

	[Export]
	public float EnemyHeight { get; set; } = 1f;
	
	[ExportGroup("Health")]
	[Export]
	public RHealth RHealth { get; set; } = null!;
	[Export]
	public RDeathEffect[] DeathEffects { get; set; } = null!;
	public IHealthable CHealth { get; set; } = null!;
	
	[ExportGroup("Damage")]
	[Export]
	public RDamage? RDamage { get; set; }
	public IDamageable CDamageable { get; set; } = null!;
	
	[Export]
	public RKnockback? RKnockback { get; set; }
	public IKnockbackable CKnockback { get; set; } = null!;
	
	[ExportGroup("Movement")]
	[Export]
	public required RMovement RMovement { get; set; }
	public required IMoveable CMovement { get; set; }

	#endregion
	
	// Public stuff
	public float CurrentHealth
	{
		get => CHealth.CurrentHealth; 
		set => CHealth.CurrentHealth = value;
	}

	#region IForgeEntity

	// Perfectly forward the IForgeEntity interface to the ForgeEntity component
	public EntityAttributes Attributes
	{
		get => ForgeEntity.Attributes;
		set => ForgeEntity.Attributes = value;
	}
	public EntityTags Tags
	{
		get => ForgeEntity.Tags;
		set => ForgeEntity.Tags = value;
	}
	public EffectsManager EffectsManager
	{
		get => ForgeEntity.EffectsManager;
		set => ForgeEntity.EffectsManager = value;
	}
	public EntityAbilities Abilities
	{
		get => ForgeEntity.Abilities;
		set => ForgeEntity.Abilities = value;
	}
	public EventManager Events
	{
		get => ForgeEntity.Events;
		set => ForgeEntity.Events = value;
	}

	public Variables SharedVariables
	{
		get => ForgeEntity.SharedVariables;
		set => ForgeEntity.SharedVariables = value; 
	}

	#endregion

	// Private stuff
	[Node("DamageBox")] public required Area3D DamageBox { get; set;}
	[Node("CTarget")] public required Node3D TargetComponent { get; set;}
	[Node("CHealthBar")] public required CHealthbar HealthBarWrapper { get; set;}
	[Node("ForgeEntityNode")] public required ForgeEntityNode ForgeEntity { get; set;}
	
	private AbilityHandle? _hitAbilityHandle;
	private EntityAttribute _healthAttribute;
	
	public void OnReady()
	{
		Init();
		SetupSignals();
	}

	public void Init()
	{
		CMovement = GetNode<Node>("CMovement") as IMoveable ?? throw new Exception("Movement component not found");
		CMovement.RMovement = RMovement;
		_healthAttribute = Attributes["EnemyAttributeSet.Health"];
		
		CDamageable = (GetNode<Node>("CDamageable") as IDamageable)!;
		CHealth = (GetNode<Node>("CHealth") as IHealthable)!;
		CKnockback = (GetNode<Node>("CKnockback") as IKnockbackable)!;
		
		CHealth.RHealth = RHealth;
		CHealth.CurrentHealth = RHealth.StartingHealth;
		CKnockback.RKnockback = RKnockback;

		_hitAbilityHandle = Abilities.GrantAbilityPermanently(HitAbility.GetAbilityData(), 1, LevelComparison.None, this);
	}

	public void OnResolved()
	{
		HealthBarWrapper.ResourceBar.Init(_healthAttribute);
		// CuesManager.RegisterCue(Tag.RequestTag(TagsManager, "cues.enemy.health"), HealthBarWrapper.ResourceBar);
		
		Events.Subscribe(Tag.RequestTag(TagsManager, "events.combat.hit"),
			data => {GD.Print("Hit!");});
		Events.Subscribe(Tag.RequestTag(TagsManager, "events.combat.damage"), OnDamageReceived);
		Events.Subscribe(Tag.RequestTag(TagsManager, "events.combat.death"), OnDeath);
	}

	public void SetupSignals()
	{
		// Anonymous function call to erase return values of ReduceHealth
		// CDamageable.DamageTaken += (source, record) => ReduceHealth(source, record);
		// CDamageable.DamageTaken += (_, record) => RegisterKnockback(new KnockbackRecord(record));
		// CHealth.HealthDepleted += Kill;
	}
	
	public override void _PhysicsProcess(double delta)
	{
		// Only trigger gameplay related effects on specific frames
		if(Engine.GetPhysicsFrames() % 10 == 0) ProcessGameplay(delta);
		
		var targetPlanar = new Vector3(Target.GlobalPosition.X, GlobalPosition.Y, Target.GlobalPosition.Z);
		LookAt(targetPlanar);
		
		var inputs = new MovementInputs(
			Velocity: Velocity,
			TargetLocation: Target.GlobalPosition,
			isOnFloor: IsOnFloor(),
			gravity: GetGravity(),
			delta: delta
		);
		Velocity = ComputeVelocity(inputs);
		Velocity += ComputeKnockback();
		MoveAndSlide();
	}

	public void ProcessGameplay(double delta)
	{
		if (IsStunned || _hitAbilityHandle == null) return;
		
		var bodies = DamageBox.GetOverlappingBodies();
		foreach (var body in bodies)
		{
			if (body is not IForgeEntity forgeEntity) continue;
			var canActivate = _hitAbilityHandle.CanActivate(out var _);
			if (!canActivate) return;
			
			_hitAbilityHandle.Activate(out var _, forgeEntity);
		}
	}
	
	public Vector3 ComputeVelocity(MovementInputs inputs)
	{
		return CMovement is null ? Vector3.Zero : CMovement.ComputeVelocity(inputs);
	}
	
	public void OnDamageReceived(EventData data)
	{
		var newHealth = _healthAttribute.CurrentValue + data.EventMagnitude;
		if (newHealth > _healthAttribute.Min) return;
		
		Events.Raise(new EventData
		{
			EventTags = Tag.RequestTag(TagsManager, "events.combat.death").GetSingleTagContainer()!,
			Source = data.Source,
			Target = data.Target
		});
	}

	public void OnDeath(EventData data)
	{
		// Remove weapon that might be planted there
		foreach (var child in GetChildren())
		{
			if (child is not WeaponSystem system) continue;
			CallDeferred(Node.MethodName.RemoveChild, system);
			GetTree().GetRoot().CallDeferred(Node.MethodName.AddChild, system);
			system.CallDeferred(Node3D.MethodName.SetGlobalPosition, GlobalPosition + Vector3.Up*EnemyHeight);
			system.CallDeferred(WeaponSystem.MethodName.RethrowWeapon);
		}
		
		CallDeferred(Node.MethodName.QueueFree);
	}

	public DamageRecord TakeDamage(DamageRecord damageRecord)
	{
		if (CDamageable is null)
			return damageRecord with { Damage = new RDamage(0, damageRecord.Damage.DamageType) };
		
		var finalDamage = CDamageable.TakeDamage(damageRecord);
		DamageTaken?.Invoke(this, finalDamage);
		return finalDamage;
	}

	public DamageRecord ComputeDamage(DamageRecord damageRecord)
	{
		if (CDamageable is null)
			return damageRecord with { Damage = new RDamage(0, damageRecord.Damage.DamageType) };
		
		return CDamageable.ComputeDamage(damageRecord);
	}

	public HealthChangedRecord ReduceHealth(IDamageable source, DamageRecord damageRecord)
	{
		if (CHealth is null) return new HealthChangedRecord(0, 0, 0);
		var record = CHealth.ReduceHealth(source, damageRecord);
		HealthChanged?.Invoke(this, record);
		return record;
	}

	public void Kill(IHealthable source)
	{
		// Remove weapon that might be planted there
		foreach (var child in GetChildren())
		{
			if (child is WeaponSystem system)
			{
				CallDeferred(Node.MethodName.RemoveChild, system);
				GetTree().GetRoot().CallDeferred(Node.MethodName.AddChild, system);
				system.CallDeferred(Node3D.MethodName.SetGlobalPosition, GlobalPosition + Vector3.Up*EnemyHeight);
				system.CallDeferred(WeaponSystem.MethodName.RethrowWeapon);
			}
		}
		
		foreach (var killable in DeathEffects.ToIKillables())
		{
			killable.Kill(source);
		}
		CallDeferred(Node.MethodName.QueueFree);
	}

	public void RegisterKnockback(KnockbackRecord knockbackRecord)
	{
		CKnockback.RegisterKnockback(knockbackRecord);
	}

	public Vector3 ComputeKnockback()
	{
		return CKnockback.ComputeKnockback();
	}

	public Vector3 GetTargetGlobalPosition()
	{
		return TargetComponent == null ? GlobalPosition : TargetComponent.GlobalPosition;
	}
	
	// Stun management
	public bool IsStunned { get; set; }

	[Export(PropertyHint.Range, "0.1, 2, 0.1, or_greater")]
	public float StunDuration { get; set; } = 1f;
	public void Stun()
	{
		IsStunned = true;
		GetTree().CreateTimer(StunDuration).Timeout += Unstun;
	}
	public void Unstun()
	{
		IsStunned = false;
	}
}