ReportSourceLocator.java

/*
 * Copyright 2015 Jason Fehr
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and limitations under the License.
 */
package org.pitest.maven.report;

import java.io.File;
import java.io.FileFilter;
import java.util.Arrays;

import org.apache.commons.io.comparator.LastModifiedFileComparator;
import org.apache.commons.io.filefilter.AndFileFilter;
import org.apache.commons.io.filefilter.CanWriteFileFilter;
import org.apache.commons.io.filefilter.DirectoryFileFilter;
import org.apache.commons.io.filefilter.RegexFileFilter;
import org.apache.maven.plugin.logging.Log;
import org.pitest.util.PitError;

/**
 * Determines the directory where the most recent PIT reports are actually
 * located since the value of the timestamedReports parameter could impact where
 * the reports are stored.
 * 
 * @author jasonmfehr
 */
public class ReportSourceLocator {

  // a java.io.File object is considered to be representing a directory where a
  // timestamped pit report is located if
  // 1.) the java.io.File is a directory
  // 2.) the directory name contains only numbers
  // 3.) the directory is readable
  static final FileFilter TIMESTAMPED_REPORTS_FILE_FILTER = 
      new AndFileFilter(Arrays.asList(DirectoryFileFilter.DIRECTORY,
                                      new RegexFileFilter(
                                        "^\\d+$"),
                                        CanWriteFileFilter.CAN_WRITE));

  /**
   * Determines the directory where the most recent PIT reports are located. If
   * timestampedReports is set to true, then the latest reports directory is
   * located and returned. If timestampedReports is set to false, then the
   * provided reportsDirectory parameter is returned. If multiple runs of the
   * plugin have resulted in a combination of a non-timestamped report directory
   * and timestamped reports directories, then the latest of all those
   * directories is returned.
   * 
   * See {@link ReportSourceLocator#TIMESTAMPED_REPORTS_FILE_FILTER} for an
   * explanation of what constitutes a timestamped reports directory;
   * 
   * @param reportsDirectory
   *          {@link File} representing the directory where non-timestamped
   *          reports were written if the plugin's configuration has
   *          timestampedReports set to true;
   * @param log
   *          {@link Log} plugin logger for logging debug messages
   * 
   * @return {@link File} representing the directory where the latest PIT
   *         reports are located
   */
  public File locate(File reportsDirectory, Log log) {
    if (!reportsDirectory.exists()) {
      throw new PitError("could not find reports directory ["
          + reportsDirectory + "]");
    }

    if (!reportsDirectory.canRead()) {
      throw new PitError("reports directory [" + reportsDirectory
          + "] not readable");
    }

    if (!reportsDirectory.isDirectory()) {
      throw new PitError("reports directory [" + reportsDirectory
          + "] is actually a file, it must be a directory");
    }

    return executeLocator(reportsDirectory, log);
  }

  private File executeLocator(File reportsDirectory, Log log) {
    File[] subdirectories = reportsDirectory
        .listFiles(TIMESTAMPED_REPORTS_FILE_FILTER);
    File latest = reportsDirectory;

    log.debug("ReportSourceLocator starting search in directory ["
        + reportsDirectory.getAbsolutePath() + "]");

    if (subdirectories != null) {
      LastModifiedFileComparator c = new LastModifiedFileComparator();

      for (File f : subdirectories) {
        log.debug("comparing directory [" + f.getAbsolutePath()
            + "] with the current latest directory of ["
            + latest.getAbsolutePath() + "]");
        if (c.compare(latest, f) < 0) {
          latest = f;
          log.debug("directory [" + f.getAbsolutePath() + "] is now the latest");
        }
      }
    } else {
      throw new PitError("could not list files in directory ["
          + reportsDirectory.getAbsolutePath()
          + "] because of an unknown I/O error");
    }

    log.debug("ReportSourceLocator determined directory ["
        + latest.getAbsolutePath()
        + "] is the directory containing the latest pit reports");
    return latest;
  }

}