using System;
using System.Collections.Generic;
using Godot;

public abstract class GameObject
{
	[Flags]
	public enum DirtyFlags : ulong
	{
		None = 0,
		UUID = 1UL << 0,
		Sector = 1UL << 1,
		LocalCoordinates = 1UL << 2,
		Rotation = 1UL << 3,
		Velocity = 1UL << 4,
		AngularVelocity = 1UL << 5
	}
	public DirtyFlags DirtyBits { get; protected set; } = DirtyFlags.None;

	protected Guid _uuid;
	public Guid UUID
	{
		get => _uuid;
		set
		{
			if (_uuid != value)
			{
				_uuid = value;
				DirtyBits |= DirtyFlags.UUID;
			}
		}
	}

	protected Vector3I _currentSectorCoordinates;
	protected Sector _currentSector;
	public Sector CurrentSector
	{
		get => _currentSector;
		protected set
		{
			if (_currentSector != value)
			{
				_currentSector = value;
				_currentSectorCoordinates = value.Coordinates;
				DirtyBits |= DirtyFlags.Sector;
			}
		}
	}

	protected Vector3 _localCoordinates;
	public Vector3 LocalCoordinates
	{
		get => _localCoordinates;
		protected set
		{
			if (_localCoordinates != value)
			{
				_localCoordinates = value;
				DirtyBits |= DirtyFlags.LocalCoordinates;
			}
		}
	}

	protected Vector3 _rotation;
	public Vector3 Rotation
	{
		get => _rotation;
		protected set
		{
			if (_rotation != value)
			{
				_rotation = value;
				DirtyBits |= DirtyFlags.Rotation;
			}
		}
	}

	protected Vector3 _velocity;
	public Vector3 Velocity
	{
		get => _velocity;
		protected set
		{
			if (_velocity != value)
			{
				_velocity = value;
				DirtyBits |= DirtyFlags.Velocity;
			}
		}
	}

	protected Vector3 _angularVelocity;
	public Vector3 AngularVelocity
	{
		get => _angularVelocity;
		protected set
		{
			if (_angularVelocity != value)
			{
				_angularVelocity = value;
				DirtyBits |= DirtyFlags.AngularVelocity;
			}
		}
	}

	public Vector3Dec GlobalCoordinates { get; protected set; }
	public Vector3 SectorOffset { get; protected set; }

	protected bool reassigning = false;

	public GameObject(Sector sector, Vector3 localCoordinates)
	{
		UUID = Guid.NewGuid();

		CurrentSector = sector;
		LocalCoordinates = localCoordinates;

		Velocity = new(0, 0, 1);
		AngularVelocity = Vector3.Zero;
		Rotation = Vector3.Zero;

		GlobalCoordinates = CalculateGlobalCoordinates(sector.GlobalCenterCoordinates, localCoordinates);
	}

	public GameObject(Vector3Dec coordinates)
	{
		GlobalCoordinates = coordinates;
		UpdateSector();
	}

	public GameObject(decimal x, decimal y, decimal z)
	{
		GlobalCoordinates = new(x, y, z);
		UpdateSector();
	}

	public Vector3Dec CalculateGlobalCoordinates(Vector3Dec sectorCenter, Vector3 local)
	{
		return new
		(
			sectorCenter.X + (decimal)local.X,
			sectorCenter.Y + (decimal)local.Y,
			sectorCenter.Z + (decimal)local.Z
		);
	}

	public void ApplyVelocity(double delta)
	{
		SetCoordinatesFromLocal(LocalCoordinates + Velocity * delta);
		Rotation += AngularVelocity * delta;
	}

	public bool IsInCurrentSector()
	{
		return Helpers.IsInsideArea(CurrentSector.Size / 2, LocalCoordinates);
	}

	public void UpdateSector()
	{
		List<Sector> neighbours = CurrentSector.GetNeighbouringSectors();
		foreach (Sector sector in neighbours)
		{
			if (sector.IsObjectInSector(this))
			{
				reassigning = true;
				sector.AssignObject(this);
				return;
			}
		}

		if (!GameManager.GameUniverse.IsInside(CurrentSector.Coordinates, LocalCoordinates))
		{
			return;
		}

		foreach (Sector sector in GameManager.GameUniverse.Sectors)
		{
			if (sector.IsObjectInSector(this))
			{
				reassigning = true;
				sector.AssignObject(this);
				return;
			}
		}
	}

	public virtual void AssignSector(Sector sector)
	{
		CurrentSector = sector;
		ResetLocalCoordinates();

		UpdateSectorOffsetToMainPlayer();

		List<Sector> neighbours = GameManager.Instance.GetCurrentSector().GetNeighbouringSectors();

		if (neighbours.Contains(sector))
		{
			GameManager.Instance.Spawn(this);
		}
		else
		{
			GameManager.Instance.Despawn(this);
		}

		reassigning = false;
	}

	public Vector3 GetSectorOffset(Sector sector)
	{
		Vector3Dec relative = CurrentSector.GlobalCenterCoordinates - sector.GlobalCenterCoordinates;
		return relative.ToVector3();
	}

	public void UpdateSectorOffset(Sector sector)
	{
		SectorOffset = GetSectorOffset(sector);
	}

	public void UpdateSectorOffsetToMainPlayer()
	{
		UpdateSectorOffset(GameManager.Instance.GetCurrentSector());
	}

	public void SetCoordinatesFromGlobal(Vector3Dec globalCoordinates)
	{
		GlobalCoordinates = globalCoordinates;
		LocalCoordinates = (globalCoordinates - CurrentSector.GlobalCenterCoordinates).ToVector3();

		UpdateNodePosition();
	}

	public void SetCoordinatesFromLocal(Vector3 localCoordinates)
	{
		LocalCoordinates = localCoordinates;
		GlobalCoordinates = Vector3Dec.FromVector3(localCoordinates) + CurrentSector.GlobalCenterCoordinates;

		UpdateNodePosition();
	}

	public void ResetLocalCoordinates()
	{
		SetCoordinatesFromGlobal(GlobalCoordinates);
	}

	public virtual void UpdateNodePosition() { }

	public virtual void Simulate(double delta)
	{
		ApplyVelocity(delta);

		if (!reassigning && !IsInCurrentSector())
		{
			UpdateSector();
		}
	}

	public virtual Node3D Instantiate(Sector sector)
	{
		PackedScene modulePrefab = ResourceLoader.Load<PackedScene>("res://prefabs/gameObjects/node.tscn");
		Node3D instance = modulePrefab.Instantiate<Node3D>();

		instance.Name = $"GameObject-{UUID}";

		return instance;
	}

	public virtual Godot.Collections.Dictionary NetworkWrite(long id, bool full)
	{
		Godot.Collections.Dictionary gameObjectData = [];

		if (full)
			gameObjectData.Add("type", GetType().ToString());

		if (DirtyBits.HasFlag(DirtyFlags.Sector) || full)
			gameObjectData.Add("sectorCoordinates", _currentSectorCoordinates);

		if (DirtyBits.HasFlag(DirtyFlags.LocalCoordinates) || full)
			gameObjectData.Add("localCoordinates", _localCoordinates);

		if (DirtyBits.HasFlag(DirtyFlags.Rotation) || full)
			gameObjectData.Add("rotation", _rotation);

		if (DirtyBits.HasFlag(DirtyFlags.Velocity) || full)
			gameObjectData.Add("velocity", _velocity);

		if (DirtyBits.HasFlag(DirtyFlags.AngularVelocity) || full)
			gameObjectData.Add("angularVelocity", _angularVelocity);

		if (gameObjectData.Count > 0)
		{
			gameObjectData.Add("uuid", UUID.ToString());
			return gameObjectData;
		}

		return null;
	}

	public virtual void NetworkRead(Godot.Collections.Dictionary gameObjectData)
	{
		if (gameObjectData.TryGetValue("sectorCoordinates", out var sectorCoordinatesData))
		{
			Sector newSector = GameManager.GameUniverse.GetSector((Vector3I)sectorCoordinatesData);
			CurrentSector.GameObjects.Remove(this);
			newSector.GameObjects.Add(this);

			AssignSector(newSector);
		}

		if (gameObjectData.TryGetValue("localCoordinates", out var localCoordinatesData))
			LocalCoordinates = (Vector3)localCoordinatesData;

		if (gameObjectData.TryGetValue("rotation", out var rotationData))
			Rotation = (Vector3)rotationData;

		if (gameObjectData.TryGetValue("velocity", out var velocityData))
			Velocity = (Vector3)velocityData;

		if (gameObjectData.TryGetValue("angularVelocity", out var angularVelocityData))
			AngularVelocity = (Vector3)angularVelocityData;
	}

	public override bool Equals(object obj)
	{
		GameObject gameObj = (GameObject)obj;
		return gameObj.UUID == UUID;
	}

	public override int GetHashCode()
	{
		return UUID.GetHashCode();
	}
}