package com.mojang.blaze3d.opengl;

import com.mojang.blaze3d.systems.GpuQueryPool;
import java.util.OptionalLong;
import org.lwjgl.opengl.GL33C;

public class GlQueryPool implements GpuQueryPool {
	private final int[] handles;
	private boolean closed;

	public GlQueryPool(final int size) {
		this.handles = new int[size];
		GL33C.glGenQueries(this.handles);
	}

	@Override
	public int size() {
		return this.handles.length;
	}

	@Override
	public OptionalLong getValue(final int index) {
		int handle = this.handles[index];
		return GL33C.glGetQueryObjecti(handle, 34919) == 0 ? OptionalLong.empty() : OptionalLong.of(GL33C.glGetQueryObjectui64(handle, 34918));
	}

	@Override
	public OptionalLong[] getValues(final int index, final int count) {
		if (index + count > this.handles.length) {
			throw new IndexOutOfBoundsException(
				"getValues would read out-of-bounds for an array of " + count + " starting at " + index + ", when total size is " + this.handles.length
			);
		} else {
			OptionalLong[] result = new OptionalLong[count];

			for (int i = 0; i < count; i++) {
				result[i] = this.getValue(index + i);
			}

			return result;
		}
	}

	protected void writeTimestamp(final int index) {
		GL33C.glQueryCounter(this.handles[index], 36392);
	}

	@Override
	public void close() {
		if (!this.closed) {
			this.closed = true;
			GL33C.glDeleteQueries(this.handles);
		}
	}
}