package org.webslinger.commons.vfs.operations;

 import java.util.Collection;

 import org.apache.commons.vfs.FileObject;

 import org.apache.commons.vfs.FileSystemException;

 import org.apache.commons.vfs.FileSystemManager;

 import org.apache.commons.vfs.operations.FileOperation;

 import org.apache.commons.vfs.operations.FileOperationProvider;

 public abstract class RealFileOperationProvider<T extends FileObject> implements FileOperationProvider {

     protected final Class<T> fileClass;

     protected RealFileOperationProvider(Class<T> fileClass) {

         this.fileClass = fileClass;

     }

     public void collectOperations(Collection operationsList, FileObject file) throws FileSystemException {

         collectRealOperations((Collection<Class<? extends FileOperation>>) operationsList, fileClass.cast(file));

     }

     public FileOperation getOperation(FileObject file, Class operationClass) throws FileSystemException {

         return getRealOperation(fileClass.cast(file), operationClass.asSubclass(FileOperation.class));

     }

     protected void collectOperationsWorker(Collection<Class<? extends FileOperation>> operationsList, FileObject file) throws FileSystemException {

         if (file == null) return;

         String scheme = file.getURL().getProtocol();

         FileOperationProvider[] providers = file.getFileSystem().getFileSystemManager().getOperationProviders(scheme);

         if (providers == null) return;

         for (FileOperationProvider provider: providers) {

             provider.collectOperations(operationsList, file);

         }

     }

     protected FileOperation getOperationWorker(FileObject file, Class<? extends FileOperation> operationClass) throws FileSystemException {

         if (file == null) return null;

         String scheme = file.getURL().getProtocol();

         FileOperationProvider[] providers = file.getFileSystem().getFileSystemManager().getOperationProviders(scheme);

         if (providers == null) return null;

         for (FileOperationProvider provider: providers) {

             FileOperation operation = provider.getOperation(file, operationClass);

             if (operation != null) return operation;

         }

         return null;

     }

     protected abstract void collectRealOperations(Collection<Class<? extends FileOperation>> operationsList, T file) throws FileSystemException;

     protected abstract FileOperation getRealOperation(T file, Class<? extends FileOperation> operationClass) throws FileSystemException;

 }