package io.prometheus.client.benchmark;

import com.codahale.metrics.MetricRegistry;
import java.util.concurrent.TimeUnit;
import org.openjdk.jmh.annotations.Benchmark;
import org.openjdk.jmh.annotations.BenchmarkMode;
import org.openjdk.jmh.annotations.Mode;
import org.openjdk.jmh.annotations.OutputTimeUnit;
import org.openjdk.jmh.annotations.Scope;
import org.openjdk.jmh.annotations.Setup;
import org.openjdk.jmh.annotations.State;
import org.openjdk.jmh.runner.Runner;
import org.openjdk.jmh.runner.RunnerException;
import org.openjdk.jmh.runner.options.Options;
import org.openjdk.jmh.runner.options.OptionsBuilder;

@State(Scope.Benchmark)
public class GaugeBenchmark {

  MetricRegistry registry;
  com.codahale.metrics.Counter codahaleCounter;

  io.prometheus.client.Gauge prometheusSimpleGauge;
  io.prometheus.client.Gauge.Child prometheusSimpleGaugeChild;
  io.prometheus.client.Gauge prometheusSimpleGaugeNoLabels;

  @Setup
  public void setup() {
    prometheusSimpleGauge =
        io.prometheus.client.Gauge.build()
            .name("name")
            .help("some description..")
            .labelNames("some", "group")
            .create();
    prometheusSimpleGaugeChild = prometheusSimpleGauge.labels("test", "group");

    prometheusSimpleGaugeNoLabels =
        io.prometheus.client.Gauge.build().name("name").help("some description..").create();

    registry = new MetricRegistry();
    codahaleCounter = registry.counter("name");
  }

  // Increment.
  @Benchmark
  @BenchmarkMode({Mode.AverageTime})
  @OutputTimeUnit(TimeUnit.NANOSECONDS)
  public void prometheusSimpleGaugeIncBenchmark() {
    prometheusSimpleGauge.labels("test", "group").inc();
  }

  @Benchmark
  @BenchmarkMode({Mode.AverageTime})
  @OutputTimeUnit(TimeUnit.NANOSECONDS)
  public void prometheusSimpleGaugeChildIncBenchmark() {
    prometheusSimpleGaugeChild.inc();
  }

  @Benchmark
  @BenchmarkMode({Mode.AverageTime})
  @OutputTimeUnit(TimeUnit.NANOSECONDS)
  public void prometheusSimpleGaugeNoLabelsIncBenchmark() {
    prometheusSimpleGaugeNoLabels.inc();
  }

  @Benchmark
  @BenchmarkMode({Mode.AverageTime})
  @OutputTimeUnit(TimeUnit.NANOSECONDS)
  public void codahaleCounterIncBenchmark() {
    codahaleCounter.inc();
  }

  // Decrement.
  @Benchmark
  @BenchmarkMode({Mode.AverageTime})
  @OutputTimeUnit(TimeUnit.NANOSECONDS)
  public void prometheusSimpleGaugeDecBenchmark() {
    prometheusSimpleGauge.labels("test", "group").dec();
  }

  @Benchmark
  @BenchmarkMode({Mode.AverageTime})
  @OutputTimeUnit(TimeUnit.NANOSECONDS)
  public void prometheusSimpleGaugeChildDecBenchmark() {
    prometheusSimpleGaugeChild.dec();
  }

  @Benchmark
  @BenchmarkMode({Mode.AverageTime})
  @OutputTimeUnit(TimeUnit.NANOSECONDS)
  public void prometheusSimpleGaugeNoLabelsDecBenchmark() {
    prometheusSimpleGaugeNoLabels.dec();
  }

  @Benchmark
  @BenchmarkMode({Mode.AverageTime})
  @OutputTimeUnit(TimeUnit.NANOSECONDS)
  public void codahaleCounterDecBenchmark() {
    codahaleCounter.dec();
  }

  // Set.
  @Benchmark
  @BenchmarkMode({Mode.AverageTime})
  @OutputTimeUnit(TimeUnit.NANOSECONDS)
  public void prometheusSimpleGaugeSetBenchmark() {
    prometheusSimpleGauge.labels("test", "group").set(42);
  }

  @Benchmark
  @BenchmarkMode({Mode.AverageTime})
  @OutputTimeUnit(TimeUnit.NANOSECONDS)
  public void prometheusSimpleGaugeChildSetBenchmark() {
    prometheusSimpleGaugeChild.set(42);
  }

  @Benchmark
  @BenchmarkMode({Mode.AverageTime})
  @OutputTimeUnit(TimeUnit.NANOSECONDS)
  public void prometheusSimpleGaugeNoLabelsSetBenchmark() {
    prometheusSimpleGaugeNoLabels.set(42);
  }

  public static void main(String[] args) throws RunnerException {

    Options opt =
        new OptionsBuilder()
            .include(GaugeBenchmark.class.getSimpleName())
            .warmupIterations(5)
            .measurementIterations(4)
            .threads(4)
            .forks(1)
            .build();

    new Runner(opt).run();
  }
}
