content: /*
   * Copyright 2002-2019 Drew Noakes and contributors
   *
   *    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
   *
   *        https://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.
   *
   * More information about this project is available at:
   *
   *    https://drewnoakes.com/code/exif/
   *    https://github.com/drewnoakes/metadata-extractor
   */
  package com.drew.metadata;
  
  import com.drew.lang.annotations.NotNull;
  import com.drew.lang.annotations.Nullable;
  
  import java.util.*;
  
  /**
   * A top-level object that holds the metadata values extracted from an image.
   * <p>
   * Metadata objects may contain zero or more {@link Directory} objects.  Each directory may contain zero or more tags
   * with corresponding values.
   *
   * @author Drew Noakes https://drewnoakes.com
   */
  public final class Metadata
  {
      /**
       * The list of {@link Directory} instances in this container, in the order they were added.
       */
      @NotNull
      private final List<Directory> _directories = new ArrayList<Directory>();
  
      /**
       * Returns an iterable set of the {@link Directory} instances contained in this metadata collection.
       *
       * @return an iterable set of directories
       */
      @NotNull
      public Iterable<Directory> getDirectories()
      {
          return _directories;
      }
  
      @NotNull
      @SuppressWarnings("unchecked")
      public <T extends Directory> Collection<T> getDirectoriesOfType(Class<T> type)
      {
          List<T> directories = new ArrayList<T>();
          for (Directory dir : _directories) {
              if (type.isAssignableFrom(dir.getClass())) {
                  directories.add((T)dir);
              }
          }
          return directories;
      }
  
      /**
       * Returns the count of directories in this metadata collection.
       *
       * @return the number of unique directory types set for this metadata collection
       */
      public int getDirectoryCount()
      {
          return _directories.size();
      }
  
      /**
       * Adds a directory to this metadata collection.
       *
       * @param directory the {@link Directory} to add into this metadata collection.
       */
      public <T extends Directory> void addDirectory(@NotNull T directory)
      {
          if (directory == null) {
              throw new IllegalArgumentException("Directory may not be null.");
          }
  
          _directories.add(directory);
      }
  
      /**
       * Gets the first {@link Directory} of the specified type contained within this metadata collection.
       * If no instances of this type are present, <code>null</code> is returned.
       *
       * @param type the Directory type
       * @param <T> the Directory type
       * @return the first Directory of type T in this metadata collection, or <code>null</code> if none exist
       */
      @Nullable
      @SuppressWarnings("unchecked")
      public <T extends Directory> T getFirstDirectoryOfType(@NotNull Class<T> type)
      {
          for (Directory dir : _directories) {
              if (type.isAssignableFrom(dir.getClass()))
                  return (T)dir;
          }
          return null;
      }
  
      /**
       * Indicates whether an instance of the given directory type exists in this Metadata instance.
       *
       * @param type the {@link Directory} type
       * @return <code>true</code> if a {@link Directory} of the specified type exists, otherwise <code>false</code>
       */
      public boolean containsDirectoryOfType(Class<? extends Directory> type)
      {
          for (Directory dir : _directories) {
              if (type.isAssignableFrom(dir.getClass()))
                  return true;
          }
          return false;
      }
  
      /**
       * Indicates whether any errors were reported during the reading of metadata values.
       * This value will be true if Directory.hasErrors() is true for one of the contained {@link Directory} objects.
       *
       * @return whether one of the contained directories has an error
       */
      public boolean hasErrors()
      {
          for (Directory directory : getDirectories()) {
              if (directory.hasErrors())
                  return true;
          }
          return false;
      }
  
      @Override
      public String toString()
      {
          int count = getDirectoryCount();
          return String.format("Metadata (%d %s)",
              count,
              count == 1
                  ? "directory"
                  : "directories");
      }
  }
  