/*
 * Copyright 2009 The Apache Software Foundation
 *
 * 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.hbase.filter;

import junit.framework.TestCase;
import org.apache.hadoop.hbase.HConstants;
import org.apache.hadoop.hbase.util.Bytes;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.UnsupportedEncodingException;

public class TestPrefixFilter extends TestCase {
  Filter mainFilter;
  static final char FIRST_CHAR = 'a';
  static final char LAST_CHAR = 'e';
  static final String HOST_PREFIX = "org.apache.site-";
  static byte [] GOOD_BYTES = null;

  static {
    try {
      GOOD_BYTES = "abc".getBytes(HConstants.UTF8_ENCODING);
    } catch (UnsupportedEncodingException e) {
      fail();
    }
  }

  protected void setUp() throws Exception {
    super.setUp();
    this.mainFilter = new PrefixFilter(Bytes.toBytes(HOST_PREFIX));
  }

  public void testPrefixOnRow() throws Exception {
    prefixRowTests(mainFilter);
  }

  public void testPrefixOnRowInsideWhileMatchRow() throws Exception {
    prefixRowTests(new WhileMatchFilter(this.mainFilter), true);
  }

  public void testSerialization() throws Exception {
    // Decompose mainFilter to bytes.
    ByteArrayOutputStream stream = new ByteArrayOutputStream();
    DataOutputStream out = new DataOutputStream(stream);
    mainFilter.write(out);
    out.close();
    byte[] buffer = stream.toByteArray();

    // Recompose filter.
    DataInputStream in = new DataInputStream(new ByteArrayInputStream(buffer));
    Filter newFilter = new PrefixFilter();
    newFilter.readFields(in);

    // Ensure the serialization preserved the filter by running all test.
    prefixRowTests(newFilter);
  }

  private void prefixRowTests(Filter filter) throws Exception {
    prefixRowTests(filter, false);
  }

  private void prefixRowTests(Filter filter, boolean lastFilterAllRemaining)
  throws Exception {
    for (char c = FIRST_CHAR; c <= LAST_CHAR; c++) {
      byte [] t = createRow(c);
      assertFalse("Failed with character " + c,
        filter.filterRowKey(t, 0, t.length));
      assertFalse(filter.filterAllRemaining());
    }
    String yahooSite = "com.yahoo.www";
    byte [] yahooSiteBytes = Bytes.toBytes(yahooSite);
    assertTrue("Failed with character " +
      yahooSite, filter.filterRowKey(yahooSiteBytes, 0, yahooSiteBytes.length));
    assertEquals(filter.filterAllRemaining(), lastFilterAllRemaining);
  }

  private byte [] createRow(final char c) {
    return Bytes.toBytes(HOST_PREFIX + Character.toString(c));
  }
}