cirnogodot/Scripts/Enemy.cs

using Cirno.Scripts;
using Godot;
using System;
using System.Diagnostics;

public partial class Enemy : Area2D, IDestructible
{
	private InteractionController _cachedPlayer;
	private EnemyState _currentState = EnemyState.Idle;

	[Export]
	public PackedScene BulletScene { get; set; }

	[Export] public float Health = 4f;

	[Export] public double RateOfFire = 0.4f;

	[Export] public float BulletSpeed = 100f;

	private float _currentHealth = 0f;

	private bool _isDestroyed = false;

	private Timer _cooldownTimer;

	// Called when the node enters the scene tree for the first time.
	public override void _Ready()
	{
		_currentHealth = Health;
		_cooldownTimer = GetNode<Timer>("./ShootTimer");
	}

	// Called every frame. 'delta' is the elapsed time since the previous frame.
	public override void _Process(double delta)
	{
		switch (_currentState)
		{
			case EnemyState.Idle:

				break;

			case EnemyState.Primed:
				// Have the raycast follow the player and shoot if visible
				//HandlePlayerDetection();
				break;

			//case EnemyState.Shooting:
			// Shoot
			//break;
			default:
				break;
		}
	}

	public override void _PhysicsProcess(double delta)
	{
		HandlePlayerDetection();
	}

	private void HandlePlayerDetection()
	{
		if (_cachedPlayer == null || _currentState is not EnemyState.Primed)
		{
			return;
		}

		if (_cooldownTimer.IsStopped() && IsPlayerInSight())
		{
			// SHOOT
			var bullet = this.CreateChild<Bullet>(BulletScene);
			// var bullet = BulletScene.Instantiate<Bullet>();
			// Owner.AddChild(bullet);
			// bullet.Transform = this.GlobalTransform;
			// bullet.Position = this.Position;
			bullet.SetDirection((_cachedPlayer.GlobalPosition - this.GlobalPosition).Normalized());
			bullet.Speed = BulletSpeed;
			_cooldownTimer.Start(RateOfFire);
		}
	}

	private bool IsPlayerInSight()
	{
		var spaceState = GetWorld2D().DirectSpaceState;
		var query = PhysicsRayQueryParameters2D.Create(this.GlobalPosition, _cachedPlayer.GlobalPosition, CollisionMask, new Godot.Collections.Array<Rid> { GetRid() });
		var result = spaceState.IntersectRay(query);

		// If count is 0 then the player is in sight, otherwise there is level geometry in the way
		return result.Count == 0;

		// if (result.Count > 0)
		//     GD.Print("Hit at point: ", result["position"]);
	}

	private void _on_player_detection_area_entered(Area2D area)
	{
		// Assume area is player for now
		if (area is InteractionController player)
		{
			Debug.WriteLine("Enemy detection area Entered by interaction controller");

			_cachedPlayer = player;
			if (_currentState is EnemyState.Idle)
			{
				_currentState = EnemyState.Primed;
			}
		}
	}

	private void _on_player_detection_area_exited(Area2D area)
	{
		if (_currentState is EnemyState.Primed)
		{
			_currentState = EnemyState.Idle;
		}
	}

	// Bullets collision
	private void _on_area_entered(Area2D area)
	{
		
	}

	private void Explode()
	{
		Debug.WriteLine("Ded");
		//CreateParticles();
		//CreateDebris();
		QueueFree();
	}

	public void Hit(float damage)
	{
		if (_isDestroyed) return;
		
		_currentHealth -= damage;
		if (!(_currentHealth <= 0)) return;
		_isDestroyed = true;
		Explode();
	}

	public bool IsDestroyed()
	{
		return _isDestroyed;
	}

	private enum EnemyState
	{
		Idle,
		Primed
	}
}