/*
    * 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.io.File;
  import java.lang.reflect.Constructor;
  import java.net.URI;
  import java.net.URL;
  import java.net.URLStreamHandlerFactory;
  import java.nio.file.Path;
  import java.util.Collection;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.vfs2.operations.FileOperationProvider;
  
  /**
   * A FileSystemManager manages a set of file systems. This interface is used to locate a {@link FileObject} by name from
   * one of those file systems.
   * <p>
   * To locate a {@link FileObject}, use one of the {@code resolveFile()} methods.
   * </p>
   *
   * <h2><a id="naming">File Naming</a></h2>
   * <p>
   * A file system manager can recognize several types of file names:
   * </p>
   * <ul>
   * <li>Absolute URI. These must start with a scheme, such as {@code file:} or {@code ftp:}, followed by a scheme
   * dependent file name. Some examples: {@code file:/c:/somefile} or {@code ftp://somewhere.org/somefile}.</li>
   * <li>Absolute local file name. For example, {@code /home/someuser/a-file} or {@code c:\dir\somefile.html}. Elements in
   * the name can be separated using any of the following characters: {@code /}, {@code \}, or the native file separator
   * character. For example, the following file names are the same: {@code c:\somedir\somefile.xml} and
   * {@code c:/somedir/somefile.xml}.</li>
   * <li>Relative path. For example: {@code ../somefile} or {@code somedir/file.txt}. The file system manager resolves
   * relative paths against its <em>base file</em>. Elements in the relative path can be separated using {@code /},
   * {@code \}, or file system specific separator characters. Relative paths may also contain {@code ..} and {@code .}
   * elements. See {@link FileObject#resolveFile} for more details.</li>
   * </ul>
   */
  public interface FileSystemManager extends AutoCloseable {
  
      /**
       * Adds the specified FileOperationProvider for the specified scheme.
       * <p>
       * Several FileOperationProvider's might be registered for the same scheme. For example, for {@code "file"} scheme
       * we can register {@code SvnWsOperationProvider} and {@code CvsOperationProvider.}
       * </p>
       *
       * @param scheme The scheme associated with this provider.
       * @param operationProvider The FileOperationProvider to add.
       * @throws FileSystemException if an error occurs.
       */
      void addOperationProvider(String scheme, FileOperationProvider operationProvider) throws FileSystemException;
  
      /**
       * Adds an operation provider.
       *
       * @see FileSystemManager#addOperationProvider(String, org.apache.commons.vfs2.operations.FileOperationProvider)
       * @param schemes The schemes that will be associated with the provider.
       * @param operationProvider The FileOperationProvider to add.
       * @throws FileSystemException if an error occurs.
       */
      void addOperationProvider(String[] schemes, FileOperationProvider operationProvider) throws FileSystemException;
  
      /**
       * Determines if a layered file system can be created for a given file.
       *
       * @param file The file to check for.
       * @return true if the FileSystem can be created.
       * @throws FileSystemException if an error occurs.
       */
      boolean canCreateFileSystem(FileObject file) throws FileSystemException;
  
      /**
       * Closes this file system manager.
       *
       * @since 2.5.0
       */
      @Override
      default void close() {
          // noop
      }
  
      /**
       * Closes the given file system.
      * <p>
      * If you use VFS as singleton it is VERY dangerous to call this method.
      * </p>
      *
      * @param fileSystem The FileSystem to close.
      */
     void closeFileSystem(FileSystem fileSystem);
 
     /**
      * Creates a layered file system. A layered file system is a file system that is created from the contents of a
      * file, such as a ZIP or tar file.
      *
      * @param file The file to use to create the file system.
      * @return The root file of the new file system.
      * @throws FileSystemException On error creating the file system.
      */
     FileObject createFileSystem(FileObject file) throws FileSystemException;
 
     /**
      * Creates a layered file system. A layered file system is a file system that is created from the contents of a
      * file, such as a ZIP or tar file.
      *
      * @param provider The name of the file system provider to use. This name is the same as the scheme used in URI to
      *            identify the provider.
      * @param file The file to use to create the file system.
      * @return The root file of the new file system.
      * @throws FileSystemException On error creating the file system.
      */
     FileObject createFileSystem(String provider, FileObject file) throws FileSystemException;
 
     /**
      * Creates a virtual file system. The file system will contain a junction at the fs root to the supplied root file.
      *
      * @param rootFile The root file to backs the file system.
      * @return The root of the new file system.
      * @throws FileSystemException if an error occurs creating the VirtualFileSystem.
      */
     FileObject createVirtualFileSystem(FileObject rootFile) throws FileSystemException;
 
     /**
      * Creates an empty virtual file system. Can be populated by adding junctions to it.
      *
      * @param rootUri The root URI to use for the new file system. Can be null.
      * @return The root file of the new file system.
      * @throws FileSystemException if an error occurs creating the VirtualFileSystem.
      */
     FileObject createVirtualFileSystem(String rootUri) throws FileSystemException;
 
     /**
      * Returns the base file used to resolve relative paths.
      *
      * @return The base FileObject.
      * @throws FileSystemException if an error occurs.
      */
     FileObject getBaseFile() throws FileSystemException;
 
     /**
      * Gets the cache strategy used.
      *
      * @return the CacheStrategy.
      */
     CacheStrategy getCacheStrategy();
 
     /**
      * Gets the class to use to determine the content-type (mime-type).
      *
      * @return the FileContentInfoFactory.
      */
     FileContentInfoFactory getFileContentInfoFactory();
 
     /**
      * Gets the file object decorator used.
      *
      * @return the file object decorator Class.
      */
     Class<?> getFileObjectDecorator();
 
     /**
      * Gets the constructor associated to the fileObjectDecorator. We cache it here for performance reasons.
      *
      * @return the Constructor associated with the FileObjectDecorator.
      */
     Constructor<?> getFileObjectDecoratorConst();
 
     /**
      * Gets the cache used to cache file objects.
      *
      * @return The FilesCache.
      */
     FilesCache getFilesCache();
 
     /**
      * Gets the configuration builder for the given scheme.
      *
      * @param scheme The scheme to use to obtain the FileSystemConfigBuilder.
      * @return A FileSystemConfigBuilder appropriate for the given scheme.
      * @throws FileSystemException if the given scheme is not known.
      */
     FileSystemConfigBuilder getFileSystemConfigBuilder(String scheme) throws FileSystemException;
 
     /**
      * Gets Providers for file operations.
      *
      * @param scheme the scheme for which we want to get the list af registered providers.
      * @return the registered FileOperationProviders for the specified scheme. If there were no providers registered for
      *         the scheme, it returns null.
      *
      * @throws FileSystemException if an error occurs.
      */
     FileOperationProvider[] getOperationProviders(String scheme) throws FileSystemException;
 
     /**
      * Gets the capabilities for a given scheme.
      *
      * @param scheme The scheme to use to locate the provider's capabilities.
      * @return A Collection of the various capabilities.
      * @throws FileSystemException if the given scheme is not known.
      */
     Collection<Capability> getProviderCapabilities(String scheme) throws FileSystemException;
 
     /**
      * Gets the schemes currently available.
      *
      * @return An array of available scheme names that are supported.
      */
     String[] getSchemes();
 
     /**
      * Returns a stream handler factory to enable URL lookup using this FileSystemManager.
      *
      * @return the URLStreamHandlerFactory.
      */
     URLStreamHandlerFactory getURLStreamHandlerFactory();
 
     /**
      * Returns true if this manager has a provider for a particular scheme.
      *
      * @param scheme The scheme for which a provider should be checked.
      * @return true if a provider for the scheme is available.
      */
     boolean hasProvider(String scheme);
 
     /**
      * Locates a file by name. See {@link #resolveFile(FileObject, String)} for details.
      *
      * @param baseFile The base file to use to resolve relative paths. Must not be {@code null}, not even if the
      *            <em>name</em> is absolute.
      * @param name The name of the file.
      * @return The file. Never returns null.
      * @throws FileSystemException On error parsing the file name.
      */
     FileObject resolveFile(File baseFile, String name) throws FileSystemException;
 
     /**
      * Locates a file by name. The name is resolved as described <a href="#naming">above</a>. That is, the name can be
      * either an absolute URI, an absolute file name, or a relative path to be resolved against {@code baseFile}.
      * <p>
      * Note that the file does not have to exist when this method is called.
      * </p>
      *
      * @param baseFile The base file to use to resolve relative paths. May be null if the name is an absolute file name.
      * @param name The name of the file.
      * @return The file. Never returns null.
      * @throws FileSystemException On error parsing the file name.
      */
     FileObject resolveFile(FileObject baseFile, String name) throws FileSystemException;
 
     /**
      * Locates a file by name. Equivalent to calling {@code resolveFile(getBaseFile(), name)}.
      *
      * @param name The name of the file.
      * @return The file. Never returns null.
      * @throws FileSystemException On error parsing the file name.
      */
     FileObject resolveFile(String name) throws FileSystemException;
 
     /**
      * Locates a file by name. Equivalent to calling {@code resolveFile(getBaseFile(), name)}.
      *
      * @param name The name of the file.
      * @param fileSystemOptions The FileSystemOptions used for FileSystem creation. All files that are later resolved
      *            relative to the returned {@code FileObject} share the options.
      * @return The file. Never returns null.
      * @throws FileSystemException On error parsing the file name.
      */
     FileObject resolveFile(String name, FileSystemOptions fileSystemOptions) throws FileSystemException;
 
     /**
      * Resolves a URI into a {@link FileObject}.
      *
      * @param uri The URI to convert.
      * @return The {@link FileObject} that represents the URI. Never returns null.
      * @throws FileSystemException On error converting the file.
      * @since 2.1
      */
     FileObject resolveFile(URI uri) throws FileSystemException;
 
     /**
      * Resolves a URL into a {@link FileObject}.
      *
      * @param url The URL to convert.
      * @return The {@link FileObject} that represents the URL. Never returns null.
      * @throws FileSystemException On error converting the file.
      * @since 2.1
      */
     FileObject resolveFile(URL url) throws FileSystemException;
 
     /**
      * Resolves a name, relative to this file name. Equivalent to calling
      * {@code resolveName( path, NameScope.FILE_SYSTEM )}.
      *
      * @param root the base file name
      * @param name The name to resolve.
      * @return A {@link FileName} object representing the resolved file name.
      * @throws FileSystemException If the name is invalid.
      */
     FileName resolveName(FileName root, String name) throws FileSystemException;
 
     /**
      * Resolves a name, relative to the "root" file name. Refer to {@link NameScope} for a description of how names are
      * resolved.
      *
      * @param root the base file name
      * @param name The name to resolve.
      * @param scope The {@link NameScope} to use when resolving the name.
      * @return A {@link FileName} object representing the resolved file name.
      * @throws FileSystemException If the name is invalid.
      */
     FileName resolveName(FileName root, String name, NameScope scope) throws FileSystemException;
 
     /**
      * Resolves the URI to a file name.
      *
      * @param uri The URI to resolve.
      * @return A FileName that matches the URI.
      * @throws FileSystemException if this is not possible.
      */
     FileName resolveURI(String uri) throws FileSystemException;
 
     /**
      * Sets the logger to use.
      *
      * @param log The logger to use.
      */
     void setLogger(Log log);
 
     /**
      * Converts a local file into a {@link FileObject}.
      *
      * @param file The file to convert.
      * @return The {@link FileObject} that represents the local file. Never returns null.
      * @throws FileSystemException On error converting the file.
      */
     FileObject toFileObject(File file) throws FileSystemException;
 
     /**
      * Converts a local path into a {@link FileObject}.
      *
      * @param path The path to convert.
      * @return The {@link FileObject} that represents the local file. Never returns null.
      * @throws FileSystemException On error converting the file.
      * @since 2.10.0
      */
     default FileObject toFileObject(final Path path) throws FileSystemException {
         return toFileObject(path.toFile());
     }
 
 }