package org.wikimedia.search.extra.regex;
   
   import static org.junit.Assert.assertFalse;
   import static org.junit.Assert.assertTrue;
   
   import java.io.IOException;
   import java.util.Locale;
   
   import org.apache.logging.log4j.LogManager;
  import org.apache.logging.log4j.Logger;
  import org.junit.Test;
  import org.wikimedia.search.extra.regex.SourceRegexQuery.NonBacktrackingOnTheFlyCaseConvertingRechecker;
  import org.wikimedia.search.extra.regex.SourceRegexQuery.NonBacktrackingRechecker;
  import org.wikimedia.search.extra.regex.SourceRegexQuery.Rechecker;
  import org.wikimedia.search.extra.regex.SourceRegexQuery.SlowRechecker;
  import org.wikimedia.search.extra.regex.SourceRegexQueryBuilder.Settings;
  
  import com.google.common.base.Charsets;
  import com.google.common.collect.ImmutableList;
  import com.google.common.io.Resources;
  
  public class SourceRegexQueryRecheckTest {
      private static final Logger LOG = LogManager.getLogger(SourceRegexQueryRecheckTest.class.getPackage().getName());
  
      private final String rashidun;
      private final String obama;
  
      public SourceRegexQueryRecheckTest() throws IOException {
          rashidun = Resources.toString(Resources.getResource("Rashidun Caliphate.txt"), Charsets.UTF_8);
          obama = Resources.toString(Resources.getResource("Barack Obama.txt"), Charsets.UTF_8);
      }
  
      @Test
      public void insensitiveNoMatch() {
          Settings settings = new Settings();
          // This was a pathological case, taking more than a minute for a single iteration.
          // Solved by prefixing .* to all regex's and making a single pass through the source.
          many("case insensitive", ".*does not match anything", settings, 1000, false);
      }
  
      @Test
      public void sensitiveNoMatch() {
          Settings settings = new Settings();
          settings.caseSensitive(true);
          many("case sensitive", ".*does not match anything", settings, 1000, false);
      }
  
      @Test
      public void insensitiveShortRegex() {
          Settings settings = new Settings();
          many("case insensitive", "cat", settings, 1000, true);
      }
  
      @Test
      public void sensitiveShortRegex() {
          Settings settings = new Settings();
          settings.caseSensitive(true);
          many("case sensitive", "cat", settings, 1000, true);
      }
  
      @Test
      public void insensitiveLongerRegex() {
          Settings settings = new Settings();
          many("case insensitive", "\\[\\[Category:", settings, 1000, true);
      }
  
      @Test
      public void sensitiveLongerRegex() {
          Settings settings = new Settings();
          settings.caseSensitive(true);
          many("case sensitive", "\\[\\[Category:", settings, 1000, true);
      }
  
      @Test
      public void insensitiveBacktrackyRegex() {
          Settings settings = new Settings();
          settings.caseSensitive(true);
          many("case sensitive", "days.+and", settings, 1000, true);
      }
  
      @Test
      public void sensitiveBacktrackyRegex() {
          Settings settings = new Settings();
          many("case sensitive", "days.+and", settings, 1000, true);
      }
  
      private void many(String name, String regex, Settings settings, int times, boolean isMatching) {
          long slow = manyTestCase(new SlowRechecker(regex, settings), "slow", name, settings, times, regex, isMatching);
          long nonBacktracking = manyTestCase(new NonBacktrackingRechecker(regex, settings), "non backtracking", name, settings, times, regex, isMatching);
          if (!settings.caseSensitive()) {
              long nonBacktrackingCaseConverting = manyTestCase(new NonBacktrackingOnTheFlyCaseConvertingRechecker(regex, settings),
                      "case converting", name, settings, times, regex, isMatching);
          }
      }
  
      private long manyTestCase(Rechecker rechecker, String recheckerName, String name, Settings settings, int times, String regex, boolean isMatching) {
          long start = System.currentTimeMillis();
          for (int i = 0; i < times; i++) {
              if (isMatching) {
                 assertTrue(rechecker.recheck(ImmutableList.of(rashidun)));
                 assertTrue(rechecker.recheck(ImmutableList.of(obama)));
             } else {
                 assertFalse(rechecker.recheck(ImmutableList.of(rashidun)));
                 assertFalse(rechecker.recheck(ImmutableList.of(obama)));
             }
         }
         long took = System.currentTimeMillis() - start;
         LOG.info("{} took {} millis to match /{}/", String.format(Locale.ROOT, "%20s %10s", recheckerName, name), took, regex);
         return took;
     }
 }