package org.apache.archiva.repository.storage;
   
   /*
    * 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.
   */
  
  import org.apache.archiva.common.filelock.FileLockException;
  import org.apache.archiva.common.filelock.FileLockManager;
  import org.apache.archiva.common.filelock.FileLockTimeoutException;
  import org.apache.archiva.common.filelock.Lock;
  import org.apache.archiva.common.utils.PathUtil;
  import org.apache.commons.io.FileUtils;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.io.FileNotFoundException;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.net.URI;
  import java.nio.channels.FileChannel;
  import java.nio.channels.ReadableByteChannel;
  import java.nio.channels.WritableByteChannel;
  import java.nio.file.*;
  import java.util.function.Consumer;
  
  /**
   * Implementation of <code>{@link RepositoryStorage}</code> where data is stored in the filesystem.
   *
   * All files are relative to a given base path. Path values are separated by '/', '..' is allowed to navigate
   * to a parent directory, but navigation out of the base path will lead to a exception.
   */
  public class FilesystemStorage implements RepositoryStorage {
  
      private static final Logger log = LoggerFactory.getLogger(FilesystemStorage.class);
  
      private Path basePath;
      private final FileLockManager fileLockManager;
  
      public FilesystemStorage(Path basePath, FileLockManager fileLockManager) throws IOException {
          if (!Files.exists(basePath)) {
              Files.createDirectories(basePath);
          }
          this.basePath = basePath.normalize().toRealPath();
          this.fileLockManager = fileLockManager;
      }
  
      private Path normalize(final String path) {
          String nPath = path;
          while (nPath.startsWith("/")) {
              nPath = nPath.substring(1);
          }
          return Paths.get(nPath);
      }
  
      private Path getAssetPath(String path) throws IOException {
          Path assetPath = basePath.resolve(normalize(path)).normalize();
          if (!assetPath.startsWith(basePath))
          {
              throw new IOException("Path navigation out of allowed scope: "+path);
          }
          return assetPath;
      }
  
      @Override
      public void consumeData(StorageAsset asset, Consumer<InputStream> consumerFunction, boolean readLock ) throws IOException
      {
          final Path path = asset.getFilePath();
          try {
              if (readLock) {
                  consumeDataLocked( path, consumerFunction );
              } else
              {
                  try ( InputStream is = Files.newInputStream( path ) )
                  {
                      consumerFunction.accept( is );
                  }
                  catch ( IOException e )
                  {
                      log.error("Could not read the input stream from file {}", path);
                      throw e;
                  }
              }
          } catch (RuntimeException e)
         {
             log.error( "Runtime exception during data consume from artifact {}. Error: {}", path, e.getMessage() );
             throw new IOException( e );
         }
 
     }
 
     @Override
     public void consumeDataFromChannel( StorageAsset asset, Consumer<ReadableByteChannel> consumerFunction, boolean readLock ) throws IOException
     {
         final Path path = asset.getFilePath();
         try {
             if (readLock) {
                 consumeDataFromChannelLocked( path, consumerFunction );
             } else
             {
                 try ( FileChannel is = FileChannel.open( path, StandardOpenOption.READ ) )
                 {
                     consumerFunction.accept( is );
                 }
                 catch ( IOException e )
                 {
                     log.error("Could not read the input stream from file {}", path);
                     throw e;
                 }
             }
         } catch (RuntimeException e)
         {
             log.error( "Runtime exception during data consume from artifact {}. Error: {}", path, e.getMessage() );
             throw new IOException( e );
         }
     }
 
     @Override
     public void writeData( StorageAsset asset, Consumer<OutputStream> consumerFunction, boolean writeLock ) throws IOException
     {
         final Path path = asset.getFilePath();
         try {
             if (writeLock) {
                 writeDataLocked( path, consumerFunction );
             } else
             {
                 try ( OutputStream is = Files.newOutputStream( path ) )
                 {
                     consumerFunction.accept( is );
                 }
                 catch ( IOException e )
                 {
                     log.error("Could not write the output stream to file {}", path);
                     throw e;
                 }
             }
         } catch (RuntimeException e)
         {
             log.error( "Runtime exception during data consume from artifact {}. Error: {}", path, e.getMessage() );
             throw new IOException( e );
         }
 
     }
 
     @Override
     public void writeDataToChannel( StorageAsset asset, Consumer<WritableByteChannel> consumerFunction, boolean writeLock ) throws IOException
     {
         final Path path = asset.getFilePath();
         try {
             if (writeLock) {
                 writeDataToChannelLocked( path, consumerFunction );
             } else
             {
                 try ( FileChannel os = FileChannel.open( path, StandardOpenOption.WRITE, StandardOpenOption.TRUNCATE_EXISTING, StandardOpenOption.CREATE ))
                 {
                     consumerFunction.accept( os );
                 }
                 catch ( IOException e )
                 {
                     log.error("Could not write the data to file {}", path);
                     throw e;
                 }
             }
         } catch (RuntimeException e)
         {
             log.error( "Runtime exception during data consume from artifact {}. Error: {}", path, e.getMessage() );
             throw new IOException( e );
         }
     }
 
     private void consumeDataLocked( Path file, Consumer<InputStream> consumerFunction) throws IOException
     {
 
         final Lock lock;
         try
         {
             lock = fileLockManager.readFileLock( file );
             try ( InputStream is = Files.newInputStream( lock.getFile()))
             {
                 consumerFunction.accept( is );
             }
             catch ( IOException e )
             {
                 log.error("Could not read the input stream from file {}", file);
                 throw e;
             } finally
             {
                 fileLockManager.release( lock );
             }
         }
         catch ( FileLockException | FileNotFoundException | FileLockTimeoutException e)
         {
             log.error("Locking error on file {}", file);
             throw new IOException(e);
         }
     }
 
     private void consumeDataFromChannelLocked( Path file, Consumer<ReadableByteChannel> consumerFunction) throws IOException
     {
 
         final Lock lock;
         try
         {
             lock = fileLockManager.readFileLock( file );
             try ( FileChannel is = FileChannel.open( lock.getFile( ), StandardOpenOption.READ ))
             {
                 consumerFunction.accept( is );
             }
             catch ( IOException e )
             {
                 log.error("Could not read the input stream from file {}", file);
                 throw e;
             } finally
             {
                 fileLockManager.release( lock );
             }
         }
         catch ( FileLockException | FileNotFoundException | FileLockTimeoutException e)
         {
             log.error("Locking error on file {}", file);
             throw new IOException(e);
         }
     }
 
 
     private void writeDataLocked( Path file, Consumer<OutputStream> consumerFunction) throws IOException
     {
 
         final Lock lock;
         try
         {
             lock = fileLockManager.writeFileLock( file );
             try ( OutputStream is = Files.newOutputStream( lock.getFile()))
             {
                 consumerFunction.accept( is );
             }
             catch ( IOException e )
             {
                 log.error("Could not write the output stream to file {}", file);
                 throw e;
             } finally
             {
                 fileLockManager.release( lock );
             }
         }
         catch ( FileLockException | FileNotFoundException | FileLockTimeoutException e)
         {
             log.error("Locking error on file {}", file);
             throw new IOException(e);
         }
     }
 
     private void writeDataToChannelLocked( Path file, Consumer<WritableByteChannel> consumerFunction) throws IOException
     {
 
         final Lock lock;
         try
         {
             lock = fileLockManager.writeFileLock( file );
             try ( FileChannel is = FileChannel.open( lock.getFile( ), StandardOpenOption.WRITE, StandardOpenOption.TRUNCATE_EXISTING, StandardOpenOption.CREATE ))
             {
                 consumerFunction.accept( is );
             }
             catch ( IOException e )
             {
                 log.error("Could not write to file {}", file);
                 throw e;
             } finally
             {
                 fileLockManager.release( lock );
             }
         }
         catch ( FileLockException | FileNotFoundException | FileLockTimeoutException e)
         {
             log.error("Locking error on file {}", file);
             throw new IOException(e);
         }
     }
 
     @Override
     public URI getLocation() {
         return basePath.toUri();
     }
 
     /**
      * Updates the location and releases all locks.
      *
      * @param newLocation The URI to the new location
      *
      * @throws IOException If the directory cannot be created.
      */
     @Override
     public void updateLocation(URI newLocation) throws IOException {
         Path newPath = PathUtil.getPathFromUri(newLocation).toAbsolutePath();
         if (!Files.exists(newPath)) {
             Files.createDirectories(newPath);
         }
         basePath = newPath;
         if (fileLockManager!=null) {
             fileLockManager.clearLockFiles();
         }
     }
 
     @Override
     public StorageAsset getAsset( String path )
     {
         try {
             return new FilesystemAsset(this, path, getAssetPath(path));
         } catch (IOException e) {
             throw new IllegalArgumentException("Path navigates outside of base directory "+path);
         }
     }
 
     @Override
     public StorageAsset addAsset( String path, boolean container )
     {
         try {
             return new FilesystemAsset(this, path, getAssetPath(path), basePath, container);
         } catch (IOException e) {
             throw new IllegalArgumentException("Path navigates outside of base directory "+path);
         }
     }
 
     @Override
     public void removeAsset( StorageAsset asset ) throws IOException
     {
         Files.delete(asset.getFilePath());
     }
 
     @Override
     public StorageAsset./../../org/apache/archiva/repository/storage/StorageAsset.html#StorageAsset">StorageAsset moveAsset( StorageAsset origin, String destination, CopyOption... copyOptions ) throws IOException
     {
         boolean container = origin.isContainer();
         FilesystemAssete/FilesystemAsset.html#FilesystemAsset">FilesystemAsset newAsset = new FilesystemAsset(this, destination, getAssetPath(destination), basePath, container );
         moveAsset( origin, newAsset, copyOptions );
         return newAsset;
     }
 
     @Override
     public void moveAsset( StorageAsset./../../../org/apache/archiva/repository/storage/StorageAsset.html#StorageAsset">StorageAsset origin, StorageAsset destination, CopyOption... copyOptions ) throws IOException
     {
         if (origin.getStorage()!=this) {
             throw new IOException("The origin asset does not belong to this storage instance. Cannot copy between different storage instances.");
         }
         if (destination.getStorage()!=this) {
             throw new IOException("The destination asset does not belong to this storage instance. Cannot copy between different storage instances.");
         }
         Files.move(origin.getFilePath(), destination.getFilePath(), copyOptions);
     }
 
     @Override
     public StorageAsset./../../org/apache/archiva/repository/storage/StorageAsset.html#StorageAsset">StorageAsset copyAsset( StorageAsset origin, String destination, CopyOption... copyOptions ) throws IOException
     {
         boolean container = origin.isContainer();
         FilesystemAssete/FilesystemAsset.html#FilesystemAsset">FilesystemAsset newAsset = new FilesystemAsset(this, destination, getAssetPath(destination), basePath, container );
         copyAsset( origin, newAsset, copyOptions );
         return newAsset;
     }
 
     @Override
     public void copyAsset( StorageAsset./../../../org/apache/archiva/repository/storage/StorageAsset.html#StorageAsset">StorageAsset origin, StorageAsset destination, CopyOption... copyOptions ) throws IOException
     {
         if (origin.getStorage()!=this) {
             throw new IOException("The origin asset does not belong to this storage instance. Cannot copy between different storage instances.");
         }
         if (destination.getStorage()!=this) {
             throw new IOException("The destination asset does not belong to this storage instance. Cannot copy between different storage instances.");
         }
         Path destinationPath = destination.getFilePath();
         boolean overwrite = false;
         for (int i=0; i<copyOptions.length; i++) {
             if (copyOptions[i].equals( StandardCopyOption.REPLACE_EXISTING )) {
                 overwrite=true;
             }
         }
         if (Files.exists(destinationPath) && !overwrite) {
             throw new IOException("Destination file exists already "+ destinationPath);
         }
         if (Files.isDirectory( origin.getFilePath() ))
         {
             FileUtils.copyDirectory(origin.getFilePath( ).toFile(), destinationPath.toFile() );
         } else if (Files.isRegularFile( origin.getFilePath() )) {
             if (!Files.exists( destinationPath )) {
                 Files.createDirectories( destinationPath );
             }
             Files.copy( origin.getFilePath( ), destinationPath, copyOptions );
         }
     }
 
     public FileLockManager getFileLockManager() {
         return fileLockManager;
     }
 
 }