using Godot.NativeInterop;

public partial class Item : RigidBody3D
{
	public MultiplayerSynchronizer Sync { get; internal set; }
	public ItemManager Manager { get; internal set; } = null; // TODO: Replace with Owner?
	public uint TrackingId { get; internal set; }

	/// <summary> Child node representing the 3D model of this item. </summary>
	public virtual Node3D Model => GetNode<Node3D>("Model");

	/// <summary> Whether this item is attached to a grid. </summary>
	public bool IsAttached => GetParent() is Grid;

	/// <summary> Size of the item in grid spaces. </summary>
	[Export] public Vector3I Size { get; set; }

	public override void _Ready()
	{
		// Set the collision properties here so we don't have to specify them in each item scene separately.
		CollisionLayer = (uint)(PhysicsLayer.Item | PhysicsLayer.Pickup);
		CollisionMask  = (uint)(PhysicsLayer.Static | PhysicsLayer.Dynamic | PhysicsLayer.Player | PhysicsLayer.Item);

		// TODO: Find a better way to better import models with colliders.
		// TODO: Import items dynamically at runtime?
		// TODO: Use PostImport tool script?
		foreach (var body in FindChildren("*", "StaticBody3D").Cast<StaticBody3D>()) {
			foreach (var shape in body.GetChildren().OfType<CollisionShape3D>())
				shape.Reparent(this);
			body.GetParent().RemoveChild(body);
		}

		// Set up syncronization for this item when its physics are enabled.
		// Sync = new() { RootPath = ".." };
		// var config = Sync.ReplicationConfig = new();
		// config.AddProperty(":position");
		// config.AddProperty(":rotation");
		// config.AddProperty(":linear_velocity");
		// config.AddProperty(":angular_velocity");
		// AddChild(Sync);

		UpdatePhysicsState();
	}

	public override void _Notification(int what)
	{
		switch ((long)what) {
			case NotificationParented:
				if (IsInsideTree())
					UpdatePhysicsState();
				break;
		}
	}

	void UpdatePhysicsState()
	{
		Freeze = IsAttached;
		// Sync.PublicVisibility = !IsAttached;
	}


	public void TryPickup()
	{
		if (this.IsAuthority())
			RPC.ToAll().Send(Manager.RelayAccept, GetPath(),
				ItemManager.AcceptFunc.AcceptPickup,
				new Godot.Collections.Array { Multiplayer.GetUniqueId() });
			// RPC.ToAll().Send(AcceptPickup, Multiplayer.GetUniqueId());
		else
			RPC.To(GetMultiplayerAuthority()).Send(Manager.RelayRequest, GetPath(),
				ItemManager.RequestFunc.RequestPickup,
				new Godot.Collections.Array());
			// RPC.To(GetMultiplayerAuthority()).Send(RequestPickup);
	}

	[Rpc(RpcMode.AnyPeer)]
	void RequestPickup()
	{
		// Pickup will be requested by any player to the owner of the item.
		// If this message is received by anyone else, ignore it (for now).
		if (!IsMultiplayerAuthority()) return;

		var player = Multiplayer.GetRemoteSenderPlayer();
		if (player.Pickup.HasItemsHeld) return;
		// TODO: Check if player is in range.

		RPC.ToAll().Send(Manager.RelayAccept, GetPath(),
			ItemManager.AcceptFunc.AcceptPickup,
			new Godot.Collections.Array { player.PeerId });
		// RPC.ToAll().Send(AcceptPickup, player.PeerId);
	}

	[Rpc(CallLocal = true)]
	void AcceptPickup(int peerId)
	{
		var player = Game.Players.ByPeerId(peerId);
		Reparent(player.Pickup);
		Transform = Transform3D.Identity; // TODO: Rotate item?
	}


	public void TryPlace(Grid grid, Transform3D localTransform)
	{
		if (this.IsAuthority())
			RPC.ToAll().Send(Manager.RelayAccept, GetPath(),
				ItemManager.AcceptFunc.AcceptPlace,
				new Godot.Collections.Array { grid.GetPath(), localTransform });
			// RPC.ToAll().Send(AcceptPlace, grid.GetPath(), localTransform);
		else
			RPC.To(GetMultiplayerAuthority()).Send(Manager.RelayRequest, GetPath(),
				ItemManager.RequestFunc.RequestPlace,
				new Godot.Collections.Array { grid.GetPath(), localTransform });
			// RPC.To(GetMultiplayerAuthority()).Send(RequestPlace, grid.GetPath(), localTransform);
	}

	[Rpc(RpcMode.AnyPeer)]
	void RequestPlace(NodePath gridPath, Transform3D localTransform)
	{
		// Must be received by the owner of this item.
		if (!IsMultiplayerAuthority()) return;

		if (GetNodeOrNull(gridPath) is not Grid grid) return;
		// Item and Grid must be owned by the same peer.
		if (!grid.IsMultiplayerAuthority()) return;
		if (!grid.CanPlaceAt(this, localTransform)) return;

		RPC.ToAll().Send(Manager.RelayAccept, GetPath(),
			ItemManager.AcceptFunc.AcceptPlace,
			new Godot.Collections.Array { gridPath, localTransform });
		// RPC.ToAll().Send(AcceptPlace, gridPath, localTransform);
	}

	[Rpc(CallLocal = true)]
	void AcceptPlace(NodePath gridPath, Transform3D localTransform)
	{
		if (GetNodeOrNull(gridPath) is not Grid grid) return;
		// Item and Grid must be owned by the same peer.
		if (grid.GetMultiplayerAuthority() != GetMultiplayerAuthority()) return;

		Reparent(grid);
		Transform = localTransform;
	}


	public void TryThrow()
	{
		if (this.IsAuthority())
			RPC.ToAll().Send(Manager.RelayAccept, GetPath(),
				ItemManager.AcceptFunc.AcceptThrow,
				new Godot.Collections.Array());
			// RPC.ToAll().Send(AcceptThrow);
		else
			RPC.To(GetMultiplayerAuthority()).Send(Manager.RelayRequest, GetPath(),
				ItemManager.RequestFunc.RequestThrow,
				new Godot.Collections.Array());
			// RPC.To(GetMultiplayerAuthority()).Send(RequestThrow);
	}

	[Rpc(RpcMode.AnyPeer)]
	void RequestThrow()
	{
		if (!IsMultiplayerAuthority()) return;

		var player = Multiplayer.GetRemoteSenderPlayer();
		if (this.FindParentOrNull<Player>() != player) return;

		RPC.ToAll().Send(Manager.RelayAccept, GetPath(),
			ItemManager.AcceptFunc.AcceptThrow,
			new Godot.Collections.Array());
		// RPC.ToAll().Send(AcceptThrow);
	}

	[Rpc(CallLocal = true)]
	void AcceptThrow()
	{
		var player = this.FindParentOrThrow<Player>();
		var world  = Manager.GetParent<Node3D>();

		Reparent(world, true);

		// Throw item forward and up a bit.
		var basis     = player.Camera.Camera.GlobalBasis;
		var direction = -basis.Z + basis.Y;
		ApplyImpulse(direction * 2);
	}
}