/*
 * 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.provider.sftp;

import java.io.File;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;

import org.apache.commons.vfs2.AbstractProviderTestCase;
import org.apache.commons.vfs2.Capability;
import org.apache.commons.vfs2.FileObject;
import org.apache.commons.vfs2.Selectors;
import org.apache.commons.vfs2.VFS;
import org.junit.Test;

/**
 * MultiThread tests for writing with SFTP provider.
 */
public class SftpMultiThreadWriteTests extends AbstractProviderTestCase {

    /**
     * Sets up a scratch folder for the test to use.
     */
    protected FileObject createScratchFolder() throws Exception {
        final FileObject scratchFolder = getWriteFolder();

        // Make sure the test folder is empty
        scratchFolder.delete(Selectors.EXCLUDE_SELF);
        scratchFolder.createFolder();

        return scratchFolder;
    }

    /**
     * Returns the capabilities required by the tests of this test case.
     */
    @Override
    protected Capability[] getRequiredCapabilities() {
        return new Capability[] {Capability.CREATE, Capability.DELETE, Capability.GET_TYPE, Capability.LIST_CHILDREN,
            Capability.READ_CONTENT, Capability.WRITE_CONTENT};
    }

    /**
     * Tests file copy from local file system in parallel mode. This was a problem with SFTP channels.
     */
    @Test
    public void testParallelCopyFromLocalFileSystem() throws Exception {
        final File localFile = new File("src/test/resources/test-data/test.zip");

        final FileObject localFileObject = VFS.getManager().toFileObject(localFile);

        final FileObject scratchFolder = createScratchFolder();

        final List<Callable<Boolean>> tasks = new ArrayList<>();
        for (int i = 0; i < 100; i++) {
            final String fileName = "file" + i + "copy.txt";
            tasks.add(() -> {
                try {
                    final FileObject fileCopy = scratchFolder.resolveFile(fileName);

                    assertFalse(fileCopy.exists());
                    fileCopy.copyFrom(localFileObject, Selectors.SELECT_SELF);
                } catch (final Throwable e) {
                    return false;
                }
                return true;
            });
        }

        final ExecutorService service = Executors.newFixedThreadPool(10);
        try {
            final List<Future<Boolean>> futures = service.invokeAll(tasks);
            assertTrue(futures.stream().allMatch(future -> {
                try {
                    return future.get(5, TimeUnit.SECONDS);
                } catch (final Exception e) {
                    return false;
                }
            }));
        } finally {
            service.shutdown();
        }
    }
}