/*
 * 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.nifi.stateless.repository;

import org.apache.nifi.controller.repository.claim.ContentClaim;
import org.apache.nifi.controller.repository.claim.StandardResourceClaimManager;
import org.apache.nifi.stream.io.StreamUtils;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertThrows;

public class TestStatelessFileSystemContentRepository {
    private final File repoDirectory = new File("target/test-stateless-file-system-repository");
    private StatelessFileSystemContentRepository repository;

    @Before
    public void setup() throws IOException {
        repository = new StatelessFileSystemContentRepository(repoDirectory);
        repository.initialize(new StandardResourceClaimManager());
    }

    @After
    public void cleanup() {
        repository.cleanup();
    }

    @Test
    public void testWriteThenRead() throws IOException {
        final byte[] contents = "Hello, World!".getBytes();
        final ContentClaim claim = repository.create(true);
        try (final OutputStream out = repository.write(claim)) {
            out.write(contents);
        }

        assertEquals(contents.length, claim.getLength());

        // Ensure we can read multiple times.
        for (int i=0; i < 5; i++) {
            final byte[] bytesRead;
            try (final InputStream in = repository.read(claim);
                 final ByteArrayOutputStream baos = new ByteArrayOutputStream()) {
                StreamUtils.copy(in, baos);
                bytesRead = baos.toByteArray();
            }

            assertEquals(new String(contents), new String(bytesRead));
        }

        File[] files = repoDirectory.listFiles();
        assertNotNull(files);
        assertEquals(1, files.length);

        repository.purge();
        files = repoDirectory.listFiles();
        assertNotNull(files);
        assertEquals(0, files.length);
    }

    @Test
    public void testOverwriteFails() throws IOException {
        final byte[] contents = "Hello, World!".getBytes();
        final ContentClaim claim = repository.create(true);
        try (final OutputStream out = repository.write(claim)) {
            out.write(contents);
        }

        // An attempt to write to a content claim multiple times should fail
        assertThrows(IOException.class, () -> repository.write(claim));
    }

    @Test
    public void testOverwriteFailsBeforeClosingOutputStream() throws IOException {
        final byte[] contents = "Hello, World!".getBytes();
        final ContentClaim claim = repository.create(true);
        try (final OutputStream out = repository.write(claim)) {
            out.write(contents);

            // An attempt to write to a content claim multiple times should fail
            assertThrows(IOException.class, () -> repository.write(claim));
        }
    }

}