package com.mojang.blaze3d.systems;

import com.mojang.jtracy.GpuApi;
import com.mojang.jtracy.GpuContext;
import com.mojang.jtracy.TracyClient;
import java.util.OptionalLong;

public class TracyGpuProfiler {
	private static final int MAX_QUERIES = 1024;
	private final GpuQueryPool queries;
	private final GpuContext context;
	private int head = 0;
	private int tail = 0;

	public TracyGpuProfiler(final GpuDevice device) {
		this.queries = device.createTimestampQueryPool(1024);
		float period = device.getDeviceInfo().timestampPeriod();
		this.context = TracyClient.createGpuContext(GpuApi.OPENGL, device.getTimestampNow(), period);
	}

	public void close() {
		this.queries.close();
	}

	public void pushZone(final CommandEncoder encoder, final String name) {
		int queryId = this.nextQueryId();
		encoder.writeTimestamp(this.queries, queryId);
		this.context.beginZone(queryId, name, "", "", 0);
	}

	public void popZone(final CommandEncoder encoder) {
		int queryId = this.nextQueryId();
		encoder.writeTimestamp(this.queries, queryId);
		this.context.endZone(queryId);
	}

	public void endFrame() {
		if (this.head < this.tail) {
			OptionalLong[] timestamps = this.queries.getValues(this.tail, 1024 - this.tail);

			for (int i = 0; i < timestamps.length; i++) {
				OptionalLong timestamp = timestamps[i];
				if (!timestamp.isPresent()) {
					return;
				}

				this.context.submitQueryTimestamp(this.tail, timestamp.getAsLong());
				this.tail = (this.tail + 1) % 1024;
			}
		}

		if (this.tail < this.head) {
			OptionalLong[] timestamps = this.queries.getValues(this.tail, this.head - this.tail);

			for (int i = 0; i < timestamps.length; i++) {
				OptionalLong timestamp = timestamps[i];
				if (!timestamp.isPresent()) {
					return;
				}

				this.context.submitQueryTimestamp(this.tail, timestamp.getAsLong());
				this.tail = (this.tail + 1) % 1024;
			}
		}
	}

	private int nextQueryId() {
		int id = this.head;
		this.head = (this.head + 1) % 1024;
		return id;
	}
}