package com.databricks.unsafe.util.benchmark;

import org.openjdk.jmh.annotations.Benchmark;
import org.openjdk.jmh.annotations.Param;
import org.openjdk.jmh.annotations.Scope;
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 BinarySearch {

  @Param({"1", "10", "50", "100", "200", "250", "273", "365"})
  public int dayInYear;

  private static final int[] arr = {0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365};

  @Benchmark
  public long linearSearch() {
    if (dayInYear <= 31) {
      return 1;
    } else if (dayInYear <= 59) {
      return 2;
    } else if (dayInYear <= 90) {
      return 3;
    } else if (dayInYear <= 120) {
      return 4;
    } else if (dayInYear <= 151) {
      return 5;
    } else if (dayInYear <= 181) {
      return 6;
    } else if (dayInYear <= 212) {
      return 7;
    } else if (dayInYear <= 243) {
      return 8;
    } else if (dayInYear <= 273) {
      return 9;
    } else if (dayInYear <= 304) {
      return 10;
    } else if (dayInYear <= 334) {
      return 11;
    } else {
      return 12;
    }
  }

  @Benchmark
  public long binarySearch() {
    int index = java.util.Arrays.binarySearch(arr, dayInYear);
    return index > 0 ? index - 1 : - index - 2;  // zero based
  }

  public static void main(String[] args) throws RunnerException {
    Options opt = new OptionsBuilder()
      .include(BinarySearch.class.getSimpleName())
      .warmupIterations(5)
      .measurementIterations(5)
      .forks(2)
      .jvmArgs("-ea")
      .build();

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