/*
 * 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.flume.test.agent;

import com.google.common.base.Charsets;
import com.google.common.io.Files;
import org.apache.flume.test.util.StagedInstall;
import org.apache.log4j.Logger;
import org.junit.After;
import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;

import java.io.File;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Properties;
import java.util.concurrent.TimeUnit;

public class TestFileChannel {

  private static final Logger LOGGER = Logger.getLogger(TestFileChannel.class);

  private static final Collection<File> tempResources = new ArrayList<File>();

  private Properties agentProps;
  private File sinkOutputDir;

  @Before
  public void setUp() throws Exception {
    /* Create 3 temp dirs, each used as value within agentProps */

    final File sinkOutputDir = Files.createTempDir();
    tempResources.add(sinkOutputDir);
    final String sinkOutputDirPath = sinkOutputDir.getCanonicalPath();
    LOGGER.info("Created rolling file sink's output dir: " + sinkOutputDirPath);

    final File channelCheckpointDir = Files.createTempDir();
    tempResources.add(channelCheckpointDir);
    final String channelCheckpointDirPath = channelCheckpointDir.getCanonicalPath();
    LOGGER.info("Created file channel's checkpoint dir: " + channelCheckpointDirPath);

    final File channelDataDir = Files.createTempDir();
    tempResources.add(channelDataDir);
    final String channelDataDirPath = channelDataDir.getCanonicalPath();
    LOGGER.info("Created file channel's data dir: " + channelDataDirPath);

    /* Build props to pass to flume agent */

    Properties agentProps = new Properties();

    // Active sets
    agentProps.put("a1.channels", "c1");
    agentProps.put("a1.sources", "r1");
    agentProps.put("a1.sinks", "k1");

    // c1
    agentProps.put("a1.channels.c1.type", "FILE");
    agentProps.put("a1.channels.c1.checkpointDir", channelCheckpointDirPath);
    agentProps.put("a1.channels.c1.dataDirs", channelDataDirPath);

    // r1
    agentProps.put("a1.sources.r1.channels", "c1");
    agentProps.put("a1.sources.r1.type", "EXEC");
    agentProps.put("a1.sources.r1.command", "seq 1 100");

    // k1
    agentProps.put("a1.sinks.k1.channel", "c1");
    agentProps.put("a1.sinks.k1.type", "FILE_ROLL");
    agentProps.put("a1.sinks.k1.sink.directory", sinkOutputDirPath);
    agentProps.put("a1.sinks.k1.sink.rollInterval", "0");

    this.agentProps = agentProps;
    this.sinkOutputDir = sinkOutputDir;
  }

  @After
  public void tearDown() throws Exception {
    StagedInstall.getInstance().stopAgent();
    for (File tempResource : tempResources) {
      tempResource.delete();
    }
    agentProps = null;
  }

  /**
   * File channel in/out test. Verifies that all events inserted into the
   * file channel are received by the sink in order.
   * <p>
   * The EXEC source creates 100 events where the event bodies have
   * sequential numbers. The source puts those events into the file channel,
   * and the FILE_ROLL The sink is expected to take all 100 events in FIFO
   * order.
   *
   * @throws Exception
   */
  @Test
  public void testInOut() throws Exception {
    LOGGER.debug("testInOut() started.");

    StagedInstall.getInstance().startAgent("a1", agentProps);
    TimeUnit.SECONDS.sleep(10); // Wait for source and sink to finish
    // TODO make this more deterministic

    /* Create expected output */
    StringBuffer sb = new StringBuffer();
    for (int i = 1; i <= 100; i++) {
      sb.append(i).append("\n");
    }
    String expectedOutput = sb.toString();
    LOGGER.info("Created expected output: " + expectedOutput);

    /* Create actual output file */

    File[] sinkOutputDirChildren = sinkOutputDir.listFiles();
    // Only 1 file should be in FILE_ROLL sink's dir (rolling is disabled)
    Assert.assertEquals("Expected FILE_ROLL sink's dir to have only 1 child," +
                        " but found " + sinkOutputDirChildren.length + " children.",
                        1, sinkOutputDirChildren.length);
    File actualOutput = sinkOutputDirChildren[0];

    if (!Files.toString(actualOutput, Charsets.UTF_8).equals(expectedOutput)) {
      LOGGER.error("Actual output doesn't match expected output.\n");
      throw new AssertionError("FILE_ROLL sink's actual output doesn't " +
                               "match expected output.");
    }

    LOGGER.debug("testInOut() ended.");
  }
}
