cirnogodot/Scripts/Enemy.cs

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

public partial class Enemy : CharacterBody2D
{
	private InteractionController _cachedPlayer;
	private EnemyState _currentState = EnemyState.Idle;

	[Export] public float Health = 4f;

	[Export] public float WalkSpeed = 2500f;

	[Export] public float PlayerDisengageRange = 500f;

	[Export] public Weapon EquippedWeapon;

	private float _currentHealth = 0f;

	private bool _isDestroyed = false;
	
	private NavigationAgent2D _navigationAgent;
	
	private bool _isPlayerInRange = false;
	
	private Vector2? _lastPlayerPosition = null;
	
	[Export] public bool NavigationEnabled { get; set; } = false;

	// Called when the node enters the scene tree for the first time.
	public override void _Ready()
	{
		_currentHealth = Health;
		
		_navigationAgent = GetNode<NavigationAgent2D>("NavigationAgent2D");

		//CallDeferred("Setup");
	}

	// private void Setup()
	// {
	// 	
	// }
	
	// 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.Alert:
				break;

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

	public override void _PhysicsProcess(double delta)
	{
		switch (_currentState)
		{
			case EnemyState.Idle:
				HandlePlayerDetection();

				break;
			case EnemyState.Alert:

				// Update last known player position if it's in range
				if (_isPlayerInRange)
				{
					_lastPlayerPosition = _cachedPlayer.GlobalPosition;
				}

				if (_lastPlayerPosition.HasValue)
				{
					_navigationAgent.SetTargetPosition(_lastPlayerPosition.Value);
				}
				
				var currentAgentPosition = GlobalPosition;
			
				var nextPathPosition = _navigationAgent.GetNextPathPosition();
				
				var newVelocity = currentAgentPosition.DirectionTo(nextPathPosition) * (float)(WalkSpeed * delta);
				
				
				// Navigation is over, can do other things like shooting
				if (_navigationAgent.IsNavigationFinished())
				{
					// Shoot player
					Shoot();
					
					// TODO: If player totally left the max range it should stop shooting and go back to idle
					
					return;
				}
				
				if (_navigationAgent.AvoidanceEnabled)
				{
					_navigationAgent.SetVelocity(newVelocity);
			
				}
				else
				{
					_on_navigation_agent_2d_velocity_computed(newVelocity);
				}

				MoveAndSlide();
				
				break;
			case EnemyState.Patrolling:
				break;
			default:
				throw new ArgumentOutOfRangeException();
		}
	}
	
	public void _on_navigation_agent_2d_velocity_computed(Vector2 safeVelocity)
	{
		this.Velocity = safeVelocity; 
		
	}

	private void HandlePlayerDetection()
	{
		if (_cachedPlayer == null)
		{
			return;
		}

		if (IsPlayerInSight())
		{
			// Update player position only if player is in sight
			// if (NavigationEnabled)
			// {
			// 	_navigationAgent.SetTargetPosition(_cachedPlayer.GlobalPosition);
			// }
			//Shoot();
			
			_currentState = EnemyState.Alert;
		}
	}

	private void Shoot()
	{
		if (EquippedWeapon == null || !_lastPlayerPosition.HasValue) return;

		// Shoot at the player's last known position
		EquippedWeapon.ShootDirection = (_lastPlayerPosition.Value - this.GlobalPosition).Normalized();
		
		EquippedWeapon.Shoot();
		
			// // 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;
			//
			// _ammo -= 1;
			//
			// if (_ammo <= 0)
			// {
			// 	_ammo = BulletCount;
			// 	_cooldownTimer.Start(ReloadTime);
			// }
			// else
			// {
			// 	_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;

			_isPlayerInRange = true;
			// if (_currentState is EnemyState.Idle)
			// {
			// 	_currentState = EnemyState.Primed;
			// }
		}
	}

	private void _on_player_detection_area_exited(Area2D area)
	{
		_isPlayerInRange = false;

		// if (_currentState is EnemyState.Primed)
		// {
		// 	_currentState = EnemyState.Idle;
		// }
	}
	
	private void _on_damage_hitbox_area_entered(Area2D area)
	{
		if (area is not Bullet bullet) return;
		GD.Print("Enemy Received damage");
		this.Hit(bullet.Damage);
		bullet.QueueFree();
	}

	// 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,
		Alert,
		Patrolling
	}
}