package com.atlassian.scheduler.core.tests;
   
   import org.hamcrest.Matcher;
   import org.joda.time.DateTime;
   import org.joda.time.DateTimeZone;
   
   import java.util.ArrayList;
   import java.util.Date;
   import java.util.List;
  
  import static com.atlassian.scheduler.core.tests.CronFactory.CronExpressionAdapter;
  import static java.util.concurrent.TimeUnit.MILLISECONDS;
  import static org.hamcrest.Matchers.allOf;
  import static org.hamcrest.Matchers.contains;
  import static org.junit.Assert.assertThat;
  import static org.junit.Assert.fail;
  
  /**
   * @since v1.5
   */
  public abstract class AbstractCronExpressionTest {
      protected final CronFactory cronFactory;
  
      protected AbstractCronExpressionTest(final CronFactory cronFactory) {
          this.cronFactory = cronFactory;
      }
  
      @SuppressWarnings("unchecked")
      protected void assertCron(final String message, final String cronExpression, final Matcher... matchers) {
          assertThat(message, cronFactory.parse(cronExpression), allOf(matchers));
      }
  
      protected void assertQuartzBug(final String whyQuartzIsWrong, final String cronExpression, final Matcher<?> matcher) {
          final CronExpressionAdapter cron = cronFactory.parse(cronExpression);
          if (matcher.matches(cron)) {
              fail("Expected a Quartz bug to cause a mismatch between <" + cronExpression + "> and <" + matcher +
                      "> because " + whyQuartzIsWrong + " -- Maybe this bug has been fixed, now?");
          } else {
              System.err.println("Quartz failed to match <" + cronExpression + "> with <" + matcher +
                      "> due to known bug: " + whyQuartzIsWrong);
          }
      }
  
      protected void assertRunTimes(final String message, final String cronExpression, final DateTime startingAfter,
                                    final Matcher... matchers) {
          final CronExpressionAdapter cron = cronFactory.parse(cronExpression, startingAfter.getZone());
          assertRunTimes(message, cron, startingAfter, matchers);
      }
  
      protected void assertRunTimes(final String message, final CronExpressionAdapter cron, final DateTime startingAfter,
                                    final Matcher... matchers) {
          final List<Date> list = generateNextRunTimes(cron, startingAfter, matchers.length);
          boolean ok = false;
          try {
              assertThat(message, list, contains(matchers));
              ok = true;
          } finally {
              if (!ok) {
                  final DateTimeZone zone = startingAfter.getZone();
                  System.err.println("Debug info for run times of '" + cron + "':");
                  System.err.println("\t" + startingAfter.getMillis() + " = " + startingAfter + " (T = starting point)");
                  for (Date date : list) {
                      System.err.println("\t" + date.getTime() + " = " + new DateTime(date, zone) + " (T + " +
                              MILLISECONDS.toMinutes(date.getTime() - startingAfter.getMillis()) + " min)");
                  }
              }
          }
      }
  
      protected List<Date> generateNextRunTimes(final CronExpressionAdapter adapter,
                                                final DateTime startingAfter, final int maximumResults) {
          final List<Date> list = new ArrayList<Date>(maximumResults);
          Date current = startingAfter.toDate();
          for (int i = 0; i < maximumResults && current != null; ++i) {
              current = adapter.nextRunTime(current);
              list.add(current);
          }
          return list;
      }
  }