/*
    * Licensed to the Apache Software Foundation (ASF) under one   *
    * or more contributor license agreements.  See the NOTICE file *
    * distributed with this work for additional information        *
    * regarding copyright ownership.  The ASF licenses this file   *
    * to you 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.apache.rat.walker;
  
  import java.io.File;
  import java.io.IOException;
  import java.io.Reader;
  import java.util.Objects;
  
  import org.apache.commons.io.IOUtils;
  import org.apache.rat.api.RatException;
  import org.apache.rat.commandline.Arg;
  import org.apache.rat.config.exclusion.ExclusionUtils;
  import org.apache.rat.document.DocumentName;
  import org.apache.rat.document.DocumentNameMatcher;
  import org.apache.rat.document.FileDocument;
  import org.apache.rat.report.RatReport;
  import org.apache.rat.report.Reportable;
  import org.apache.rat.utils.DefaultLog;
  
  /**
   * Implementation of Reportable that traverses over a resource collection
   * internally.
   */
  public class FileListWalker implements Reportable {
      /** The source document name. */
      private final FileDocument source;
      /** The root document name. */
      private final DocumentName rootDoc;
      /** The base directory for the source document. */
      private final DocumentName baseDoc;
  
      /**
       * Constructor.
       * @param source the file document that is the source from which this walker will read.
       */
      public FileListWalker(final FileDocument source) {
          this.source = source;
          File baseDir = source.getFile().getParentFile().getAbsoluteFile();
          this.baseDoc = DocumentName.builder(baseDir).build();
          File p = baseDir;
          while (p.getParentFile() != null) {
              p = p.getParentFile();
          }
          this.rootDoc = DocumentName.builder(p).build();
      }
  
      private FileDocument createDocument(final String unixFileName) {
          Objects.requireNonNull(unixFileName, "unixFileName may not be null");
          DocumentName sourceName = source.getName();
          String finalName = ExclusionUtils.convertSeparator(unixFileName, "/", sourceName.getDirectorySeparator());
          DocumentName documentBase = unixFileName.startsWith("/") ? rootDoc : baseDoc;
          DocumentName documentName = documentBase.resolve(finalName);
          File documentFile = documentName.asFile();
          return new FileDocument(documentBase, documentFile, DocumentNameMatcher.MATCHES_ALL);
      }
  
      @Override
      public void run(final RatReport report) throws RatException {
          DefaultLog.getInstance().debug(String.format("Reading file name: %s due to option %s", source, Arg.SOURCE.option()));
          DocumentName sourceName = name();
          try (Reader reader = source.reader()) {
              for (String docName : IOUtils.readLines(reader)) {
                  try {
                      DefaultLog.getInstance().debug("Reading file name: " + docName);
                      FileDocument document = createDocument(docName);
                      if (document.isDirectory()) {
                          new DirectoryWalker(document).run(report);
                      } else {
                          report.report(document);
                      }
                  } catch (RatException e) {
                      throw new RatException(String.format("Error reading file `%s` read from `%s`", docName, sourceName), e);
                  }
              }
          }  catch (IOException e) {
              throw new RatException("can not read " + sourceName.getName(), e);
          }
      }
  
      @Override
      public DocumentName name() {
          return source.getName();
     }
 }