package org.codehaus.plexus.compiler.util.scan;
   
   /*
    * Copyright 2001-2005 The Apache Software Foundation.
    *
    * 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.
   */
  
  import java.io.File;
  import java.util.Collections;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Set;
  
  import org.codehaus.plexus.compiler.util.scan.mapping.SourceMapping;
  
  /**
   * @author jdcasey
   */
  public class StaleSourceScanner extends AbstractSourceInclusionScanner {
      private final long lastUpdatedWithinMsecs;
  
      private final Set<String> sourceIncludes;
  
      private final Set<String> sourceExcludes;
  
      // ----------------------------------------------------------------------
      //
      // ----------------------------------------------------------------------
  
      public StaleSourceScanner() {
          this(0, Collections.singleton("**/*"), Collections.emptySet());
      }
  
      public StaleSourceScanner(long lastUpdatedWithinMsecs) {
          this(lastUpdatedWithinMsecs, Collections.singleton("**/*"), Collections.emptySet());
      }
  
      public StaleSourceScanner(long lastUpdatedWithinMsecs, Set<String> sourceIncludes, Set<String> sourceExcludes) {
          this.lastUpdatedWithinMsecs = lastUpdatedWithinMsecs;
  
          this.sourceIncludes = sourceIncludes;
  
          this.sourceExcludes = sourceExcludes;
      }
  
      // ----------------------------------------------------------------------
      // SourceInclusionScanner Implementation
      // ----------------------------------------------------------------------
  
      public Set<File> getIncludedSources(File sourceDir, File targetDir) throws InclusionScanException {
          List<SourceMapping> srcMappings = getSourceMappings();
  
          if (srcMappings.isEmpty()) {
              return Collections.emptySet();
          }
  
          String[] potentialIncludes = scanForSources(sourceDir, sourceIncludes, sourceExcludes);
  
          Set<File> matchingSources = new HashSet<>();
  
          for (String path : potentialIncludes) {
              File sourceFile = new File(sourceDir, path);
  
              staleSourceFileTesting:
              for (SourceMapping mapping : srcMappings) {
                  Set<File> targetFiles = mapping.getTargetFiles(targetDir, path);
  
                  // never include files that don't have corresponding target mappings.
                  // the targets don't have to exist on the filesystem, but the
                  // mappers must tell us to look for them.
                  for (File targetFile : targetFiles) {
                      if (!targetFile.exists()
                              || (targetFile.lastModified() + lastUpdatedWithinMsecs < sourceFile.lastModified())) {
                          matchingSources.add(sourceFile);
                          break staleSourceFileTesting;
                      }
                  }
              }
          }
  
          return matchingSources;
      }
  }