using Godot;
using System;
using Djup.Native;

public partial class World : Node2D
{
	private IntPtr context;
	private IntPtr currentSnapshot;
	public const double Tps = 1d/60d;

	public unsafe override void _Ready()
	{
		context = LibDjup.physics_context_create(2);
		currentSnapshot = LibDjup.physics_context_get_snapshot(context);
	}

	public override void _ExitTree()
	{
		LibDjup.physics_context_free(context);
	}

	public unsafe void PutPlayer(uint id, Djup.Native.Player player)
	{
		if (LibDjup.snapshot_put_player(currentSnapshot, id, &player) != 0)
		{
			throw new Exception($"Failed to put player {id}");
		}
	}

	public void SetPlayerInput(uint playerId, byte input)
	{
		int ret = LibDjup.snapshot_set_player_input(currentSnapshot, playerId, input);
		if (ret != 0)
		{
			throw new Exception($"Failed to set input of player {playerId}: {ret}");
		}
	}

	private unsafe void DrawPlayer(Djup.Native.Player player)
	{
		float radius = 50f;
		this.DrawCircle(new Vector2(player.Position.X, player.Position.Y), radius, Colors.DarkBlue, antialiased: true);
		this.DrawCircle(new Vector2(player.Position.X, player.Position.Y), radius * 0.90f, Colors.Blue, antialiased: true);
	}

	public unsafe override void _Draw()
	{
		Snapshot *s = (Snapshot *)currentSnapshot;

		for (int i = 0; i < Constants.WorldMaxPlayers; i++)
		{
			var p = s->Players[i];
			if (p.State == EntityState.Active)
			{
				DrawPlayer(p);
			}
		}
	}

	public override void _Process(double delta)
	{
		this.QueueRedraw();
	}

	public override void _PhysicsProcess(double delta)
	{
		IntPtr next = LibDjup.physics_context_get_snapshot(context);
		if (LibDjup.physics_tick(currentSnapshot, Tps, next) != 0)
		{
			throw new Exception("World tick failed");
		}
		LibDjup.physics_context_return_snapshot(context, currentSnapshot);
		currentSnapshot = next;
	}
}