/*
    * 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.commons.vfs2;
  
  import java.util.Arrays;
  import java.util.Iterator;
  import java.util.Map;
  import java.util.SortedMap;
  import java.util.TreeMap;
  
  /**
   * Configures file systems individually with these options.
   * <p>
   * To configure a file system, you set properties on a {@link FileSystemOptions} object. Most file systems provide a
   * {@link FileSystemConfigBuilder} with specific options for that file system.
   * </p>
   * <p>
   * To use the options, pass them to {@link FileSystemManager#resolveFile(String,FileSystemOptions)}. From there, the
   * options apply to all files that are resolved relative to that file.
   * </p>
   *
   * @see org.apache.commons.vfs2.impl.DefaultFileSystemConfigBuilder
   * @see org.apache.commons.vfs2.provider.ftp.FtpFileSystemConfigBuilder
   * @see org.apache.commons.vfs2.provider.ftps.FtpsFileSystemConfigBuilder
   * @see org.apache.commons.vfs2.provider.http.HttpFileSystemConfigBuilder
   * @see org.apache.commons.vfs2.provider.ram.RamFileSystemConfigBuilder
   * @see org.apache.commons.vfs2.provider.res.ResourceFileSystemConfigBuilder
   * @see org.apache.commons.vfs2.provider.sftp.SftpFileSystemConfigBuilder
   * @see org.apache.commons.vfs2.provider.zip.ZipFileSystemConfigBuilder
   */
  public final class FileSystemOptions implements Cloneable, Comparable<FileSystemOptions> {
  
      /**
       * Keys in the options Map.
       */
      private static final class FileSystemOptionKey implements Comparable<FileSystemOptionKey> {
          /** Constant used to create hash code */
          private static final int HASH = 29;
  
          /** The FileSystem class */
          private final Class<? extends FileSystem> fileSystemClass;
  
          /** The option name */
          private final String name;
  
          // TODO: the parameter name suggests that the class should only be a
          // a FileSystem, however some of the tests pass in DefaultFileSystemConfigBuilder
          private FileSystemOptionKey(final Class<? extends FileSystem> fileSystemClass, final String name) {
              this.fileSystemClass = fileSystemClass;
              this.name = name;
          }
  
          @Override
          public int compareTo(final FileSystemOptionKey o) {
              final int ret = fileSystemClass.getName().compareTo(o.fileSystemClass.getName());
              if (ret != 0) {
                  return ret;
              }
              return name.compareTo(o.name);
          }
  
          @Override
          public boolean equals(final Object o) {
              if (this == o) {
                  return true;
              }
              if (o == null || getClass() != o.getClass()) {
                  return false;
              }
  
              final FileSystemOptionKey that = (FileSystemOptionKey) o;
  
              if (!fileSystemClass.equals(that.fileSystemClass)) {
                  return false;
              }
              return name.equals(that.name);
          }
  
          @Override
          public int hashCode() {
              int result;
              result = fileSystemClass.hashCode();
              return HASH * result + name.hashCode();
          }
  
         @Override
         public String toString() {
             return fileSystemClass.getName() + "." + name;
         }
     }
 
     /** The options */
     private final Map<FileSystemOptionKey, Object> options;
 
     /**
      * Constructs a new instance.
      */
     public FileSystemOptions() {
         this(new TreeMap<>());
     }
 
     /**
      * Constructs a new instance with the given options.
      *
      * @param options the options.
      * @since 2.10.0
      */
     public FileSystemOptions(final Map<FileSystemOptionKey, Object> options) {
         this.options = options;
     }
 
     /**
      * {@inheritDoc}
      *
      * @since 2.0
      */
     @Override
     public Object clone() {
         return new FileSystemOptions(new TreeMap<>(options));
     }
 
     @Override
     public int compareTo(final FileSystemOptions other) {
         if (this == other) {
             // the same instance
             return 0;
         }
 
         final int propsSz = options == null ? 0 : options.size();
         final int propsFkSz = other.options == null ? 0 : other.options.size();
         if (propsSz < propsFkSz) {
             return -1;
         }
         if (propsSz > propsFkSz) {
             return 1;
         }
         if (propsSz == 0) {
             // props empty
             return 0;
         }
 
         // ensure proper sequence of options
         final SortedMap<FileSystemOptionKey, Object> myOptions = options instanceof SortedMap
                 ? (SortedMap<FileSystemOptionKey, Object>) options
                 : new TreeMap<>(options);
         final SortedMap<FileSystemOptionKey, Object> theirOptions = other.options instanceof SortedMap
                 ? (SortedMap<FileSystemOptionKey, Object>) other.options
                 : new TreeMap<>(other.options);
         final Iterator<FileSystemOptionKey> optKeysIter = myOptions.keySet().iterator();
         final Iterator<FileSystemOptionKey> otherKeysIter = theirOptions.keySet().iterator();
         while (optKeysIter.hasNext()) {
             final int comp = optKeysIter.next().compareTo(otherKeysIter.next());
             if (comp != 0) {
                 return comp;
             }
         }
 
         final int hash = Arrays.deepHashCode(myOptions.values().toArray());
         final int hashFk = Arrays.deepHashCode(theirOptions.values().toArray());
         return Integer.compare(hash, hashFk);
 
         // TODO: compare Entry by Entry ??
     }
 
     @Override
     public boolean equals(final Object obj) {
         if (this == obj) {
             return true;
         }
         if (obj == null) {
             return false;
         }
         if (getClass() != obj.getClass()) {
             return false;
         }
         final FileSystemOptions other = (FileSystemOptions) obj;
         return compareTo(other) == 0;
     }
 
     <T> T getOption(final Class<? extends FileSystem> fileSystemClass, final String name) {
         return getOptionOrDefault(fileSystemClass, name, null);
     }
 
     <T> T getOptionOrDefault(final Class<? extends FileSystem> fileSystemClass, final String name, final T defaultValue) {
         final T value = (T) options.getOrDefault(new FileSystemOptionKey(fileSystemClass, name), defaultValue);
         return value != null ? value : defaultValue;
     }
 
     @Override
     public int hashCode() {
         final int prime = 31;
         int result = 1;
         if (options == null) {
             result = prime * result;
         } else {
             final SortedMap<FileSystemOptionKey, Object> myOptions = options instanceof SortedMap
                     ? (SortedMap<FileSystemOptionKey, Object>) options
                     : new TreeMap<>(options);
             result = prime * result + myOptions.keySet().hashCode();
             result = prime * result + Arrays.deepHashCode(myOptions.values().toArray());
         }
         return result;
     }
 
     boolean hasOption(final Class<? extends FileSystem> fileSystemClass, final String name) {
         return options.containsKey(new FileSystemOptionKey(fileSystemClass, name));
     }
 
     void setOption(final Class<? extends FileSystem> fileSystemClass, final String name, final Object value) {
         options.put(new FileSystemOptionKey(fileSystemClass, name), value);
     }
 
     int size() {
         return options.size();
     }
 
      @Override
     public String toString() {
         return options.toString();
     }
 }