/*
    * 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.operations;
  
  import java.util.ArrayList;
  import java.util.List;
  
  import org.apache.commons.lang3.ArrayUtils;
  import org.apache.commons.vfs2.FileObject;
  import org.apache.commons.vfs2.FileSystemException;
  import org.apache.commons.vfs2.FileSystemManager;
  
  /**
   * The default implementations for {@link FileOperations}.
   *
   * @since 0.1
   */
  public class DefaultFileOperations implements FileOperations {
  
      /**
       */
      private final FileSystemManager fsmanager;
  
      /**
       */
      private final FileObject fileObject;
  
      /**
       * Constructs a new instance.
       *
       * @param file The file.
       */
      public DefaultFileOperations(final FileObject file) {
          fileObject = file;
  
          fsmanager = file.getFileSystem().getFileSystemManager();
      }
  
      /**
       * @param operationClass The Class that performs the operation.
       * @return The FileOperation.
       * @throws FileSystemException if an error occurs.
       */
      @Override
      public FileOperation getOperation(final Class<? extends FileOperation> operationClass) throws FileSystemException {
  
          final String scheme = fileObject.getURL().getProtocol();
          final FileOperationProvider[] providers = fsmanager.getOperationProviders(scheme);
  
          FileSystemException.requireNonNull(providers, "vfs.operation/operation-not-supported.error", operationClass);
  
          FileOperation resultOperation = null;
  
          for (final FileOperationProvider provider : providers) {
              resultOperation = provider.getOperation(fileObject, operationClass);
  
              if (resultOperation != null) {
                  break;
              }
          }
  
          return FileSystemException.requireNonNull(resultOperation, "vfs.operation/operation-not-supported.error", operationClass);
      }
  
      /**
       * @return The operation classes.
       * @throws FileSystemException If an error occurs.
       */
      @Override
      public Class<? extends FileOperation>[] getOperations() throws FileSystemException {
  
          final String scheme = fileObject.getURL().getProtocol();
          final FileOperationProvider[] providers = fsmanager.getOperationProviders(scheme);
  
          if (providers == null) {
              return null;
          }
  
          final List<Class<? extends FileOperation>> operations = new ArrayList<>();
  
          for (final FileOperationProvider provider : providers) {
              provider.collectOperations(operations, fileObject);
          }
  
          @SuppressWarnings("unchecked")
         final Class<? extends FileOperation>[] array = (Class<? extends FileOperation>[]) operations
                 .toArray(ArrayUtils.EMPTY_CLASS_ARRAY);
         return array;
     }
 
     /**
      * @param operationClass the operation's class.
      * @return true if the operation of specified class is supported for current FileObject and false otherwise.
      * @throws FileSystemException if an error occurs.
      */
     @Override
     public boolean hasOperation(final Class<? extends FileOperation> operationClass) throws FileSystemException {
         final Class<? extends FileOperation>[] operations = getOperations();
         if (operations == null) {
             return false;
         }
 
         for (final Class<? extends FileOperation> operation : operations) {
             if (operationClass.isAssignableFrom(operation)) {
                 return true;
             }
         }
         return false;
     }
 }