using Godot;
using System;

public partial class Wretched : CharacterBody2D
{
	[Signal]
	public delegate void KilledEventHandler();
	
	public enum State
	{
		Waiting,
		Moving,
		Attack
	}
	
	public enum SideFace
	{
		Left,
		Up,
		Right,
		Down
	}
	
	[Export] public SideFace Facing = SideFace.Down;
	[Export] public float MovingSpeed = 32f;
	[Export] public bool IsAlive = true;
	
	
	public State CurrentState
	{
		get => _state;

		private set
		{
			_state = value;
			_timeSinceState = 0;

			switch (_state)
			{
				case State.Waiting:
					break;
				case State.Moving:
					break;
				case State.Attack:
					break;
			}
		}
	}

	private State _state;
	private float _timeSinceState;
	private AnimatedSprite2D _sprite;
	private NavigationAgent2D _nav;
	private bool _isActivated;
	
	public override void _Ready()
	{
		_sprite = (AnimatedSprite2D)FindChild("AnimatedSprite2D");
		_nav = (NavigationAgent2D)FindChild("NavigationAgent2D");
		_nav.VelocityComputed += OnNavVelocityCompute;
		CurrentState = State.Waiting;
		var animationName = "NonActivatedSide";
		switch (Facing)
		{
			case SideFace.Left:
				_sprite.FlipH = true;
				break;
			case SideFace.Right:
				break;
			case SideFace.Up:
				animationName = "NonActivatedUp";
				break;
			case SideFace.Down:
				animationName = "NonActivatedDown";
				break;
		}
		_sprite.Play(animationName);
		_sprite.Stop();
	}

	public override void _Process(double delta)
	{
	}

	public override void _PhysicsProcess(double delta)
	{
		if (!IsAlive)
			return;
		_timeSinceState += (float)delta;

		switch (_state)
		{
			case State.Attack:
				break;
			case State.Waiting:
				break;

			case State.Moving:
				_nav.TargetPosition = Player.Instance.Position;
				var direction = (_nav.GetNextPathPosition() - Position).Normalized();

				var animationName = "ActivatedSide";

				if (Velocity.Y > 0.001f)
					animationName = "ActivatedDown";
				else if (Velocity.Y < 0.001f)
					animationName = "ActivatedUp";

				if (Mathf.Abs(Velocity.X) >= Mathf.Abs(Velocity.Y))
					animationName = "ActivatedSide";

				_sprite.FlipH = Velocity.X < 0.001f && animationName == "ActivatedSide";
				_sprite.Play(animationName);
				_nav.Velocity = direction * MovingSpeed;
				MoveAndSlide();
				break;
		}
		CheckIfLitUp();
	}

	private void _OnLightEntered(Area2D area)
	{
		if (area.GetParentOrNull<GameCamera>() is null)
			return;

		_isActivated = true;
	}


	private void _OnPlayerCollision(Node2D body)
	{
		if (body is not Player player)
			return;

		if (CurrentState is State.Waiting)
			return;

		player.Kill(this);
	}

	void CheckIfLitUp()
	{
		if (!_isActivated)
		{
			CurrentState = State.Waiting;
			return;
		}
		
		if (CurrentState is State.Moving or State.Attack)
			return;

		CurrentState = State.Moving;
	}

	public void Kill(Node2D killer)
	{
		if (!IsAlive)
			return;
		
		GD.Print($"{this.Name} was killed by {killer.Name}");
		IsAlive = false;
		EmitSignal(SignalName.Killed);
		QueueFree(); // TODO
	}
	
	private void OnNavVelocityCompute(Vector2 safeVelocity)
	{
		Velocity = safeVelocity;
	}
}