/*
 * 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.hadoop.fs.contract;

import static org.apache.hadoop.fs.CommonPathCapabilities.FS_CONCAT;
import static org.apache.hadoop.fs.contract.ContractTestUtils.assertFileHasLength;
import static org.apache.hadoop.fs.contract.ContractTestUtils.assertHasPathCapabilities;
import static org.apache.hadoop.fs.contract.ContractTestUtils.createFile;
import static org.apache.hadoop.fs.contract.ContractTestUtils.dataset;
import static org.apache.hadoop.fs.contract.ContractTestUtils.touch;
import static org.junit.jupiter.api.Assertions.assertThrows;

import org.apache.hadoop.fs.Path;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;

/**
 * Test concat -if supported.
 */
public abstract class AbstractContractConcatTest extends AbstractFSContractTestBase {

  private Path srcFile;
  private Path zeroByteFile;
  private Path target;

  @BeforeEach
  @Override
  public void setup() throws Exception {
    super.setup();
    skipIfUnsupported(SUPPORTS_CONCAT);

    //delete the test directory
    Path testPath = path("test");
    srcFile = new Path(testPath, "small.txt");
    zeroByteFile = new Path(testPath, "zero.txt");
    target = new Path(testPath, "target");

    byte[] block = dataset(TEST_FILE_LEN, 0, 255);
    createFile(getFileSystem(), srcFile, true, block);
    touch(getFileSystem(), zeroByteFile);
  }

  @Test
  public void testConcatEmptyFiles() throws Throwable {
    touch(getFileSystem(), target);
    handleExpectedException(assertThrows(Exception.class,
        () -> getFileSystem().concat(target, new Path[0])));
  }

  @Test
  public void testConcatMissingTarget() throws Throwable {
    handleExpectedException(
        assertThrows(Exception.class,
            () -> getFileSystem().concat(target, new Path[]{zeroByteFile})));
  }

  @Test
  public void testConcatFileOnFile() throws Throwable {
    byte[] block = dataset(TEST_FILE_LEN, 0, 255);
    createFile(getFileSystem(), target, false, block);
    getFileSystem().concat(target,
                           new Path[] {srcFile});
    assertFileHasLength(getFileSystem(), target, TEST_FILE_LEN * 2);
    ContractTestUtils.validateFileContent(
        ContractTestUtils.readDataset(getFileSystem(), target, TEST_FILE_LEN * 2),
        new byte[][]{block, block});
  }

  @Test
  public void testConcatOnSelf() throws Throwable {
    byte[] block = dataset(TEST_FILE_LEN, 0, 255);
    createFile(getFileSystem(), target, false, block);
    handleExpectedException(assertThrows(Exception.class,
        () -> getFileSystem().concat(target, new Path[]{target})));
  }

  @Test
  public void testFileSystemDeclaresCapability() throws Throwable {
    assertHasPathCapabilities(getFileSystem(), target, FS_CONCAT);
  }

}
