/**
 *
 * 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.regionserver;

import java.util.Iterator;
import java.util.SortedSet;

import org.apache.hadoop.hbase.KeyValue;
import org.apache.hadoop.hbase.SmallTests;
import org.apache.hadoop.hbase.util.Bytes;

import junit.framework.TestCase;
import org.junit.experimental.categories.Category;

@Category(SmallTests.class)
public class TestKeyValueSkipListSet extends TestCase {
  private final KeyValueSkipListSet kvsls =
    new KeyValueSkipListSet(KeyValue.COMPARATOR);

  protected void setUp() throws Exception {
    super.setUp();
    this.kvsls.clear();
  }

  public void testAdd() throws Exception {
    byte [] bytes = Bytes.toBytes(getName());
    KeyValue kv = new KeyValue(bytes, bytes, bytes, bytes);
    this.kvsls.add(kv);
    assertTrue(this.kvsls.contains(kv));
    assertEquals(1, this.kvsls.size());
    KeyValue first = this.kvsls.first();
    assertTrue(kv.equals(first));
    assertTrue(Bytes.equals(kv.getValue(), first.getValue()));
    // Now try overwritting
    byte [] overwriteValue = Bytes.toBytes("overwrite");
    KeyValue overwrite = new KeyValue(bytes, bytes, bytes, overwriteValue);
    this.kvsls.add(overwrite);
    assertEquals(1, this.kvsls.size());
    first = this.kvsls.first();
    assertTrue(Bytes.equals(overwrite.getValue(), first.getValue()));
    assertFalse(Bytes.equals(overwrite.getValue(), kv.getValue()));
  }

  public void testIterator() throws Exception {
    byte [] bytes = Bytes.toBytes(getName());
    byte [] value1 = Bytes.toBytes("1");
    byte [] value2 = Bytes.toBytes("2");
    final int total = 3;
    for (int i = 0; i < total; i++) {
      this.kvsls.add(new KeyValue(bytes, bytes, Bytes.toBytes("" + i), value1));
    }
    // Assert that we added 'total' values and that they are in order
    int count = 0;
    for (KeyValue kv: this.kvsls) {
      assertEquals("" + count, Bytes.toString(kv.getQualifier()));
      assertTrue(Bytes.equals(kv.getValue(), value1));
      count++;
    }
    assertEquals(total, count);
    // Now overwrite with a new value.
    for (int i = 0; i < total; i++) {
      this.kvsls.add(new KeyValue(bytes, bytes, Bytes.toBytes("" + i), value2));
    }
    // Assert that we added 'total' values and that they are in order and that
    // we are getting back value2
    count = 0;
    for (KeyValue kv: this.kvsls) {
      assertEquals("" + count, Bytes.toString(kv.getQualifier()));
      assertTrue(Bytes.equals(kv.getValue(), value2));
      count++;
    }
    assertEquals(total, count);
  }

  public void testDescendingIterator() throws Exception {
    byte [] bytes = Bytes.toBytes(getName());
    byte [] value1 = Bytes.toBytes("1");
    byte [] value2 = Bytes.toBytes("2");
    final int total = 3;
    for (int i = 0; i < total; i++) {
      this.kvsls.add(new KeyValue(bytes, bytes, Bytes.toBytes("" + i), value1));
    }
    // Assert that we added 'total' values and that they are in order
    int count = 0;
    for (Iterator<KeyValue> i = this.kvsls.descendingIterator(); i.hasNext();) {
      KeyValue kv = i.next();
      assertEquals("" + (total - (count + 1)), Bytes.toString(kv.getQualifier()));
      assertTrue(Bytes.equals(kv.getValue(), value1));
      count++;
    }
    assertEquals(total, count);
    // Now overwrite with a new value.
    for (int i = 0; i < total; i++) {
      this.kvsls.add(new KeyValue(bytes, bytes, Bytes.toBytes("" + i), value2));
    }
    // Assert that we added 'total' values and that they are in order and that
    // we are getting back value2
    count = 0;
    for (Iterator<KeyValue> i = this.kvsls.descendingIterator(); i.hasNext();) {
      KeyValue kv = i.next();
      assertEquals("" + (total - (count + 1)), Bytes.toString(kv.getQualifier()));
      assertTrue(Bytes.equals(kv.getValue(), value2));
      count++;
    }
    assertEquals(total, count);
  }

  public void testHeadTail() throws Exception {
    byte [] bytes = Bytes.toBytes(getName());
    byte [] value1 = Bytes.toBytes("1");
    byte [] value2 = Bytes.toBytes("2");
    final int total = 3;
    KeyValue splitter = null;
    for (int i = 0; i < total; i++) {
      KeyValue kv = new KeyValue(bytes, bytes, Bytes.toBytes("" + i), value1);
      if (i == 1) splitter = kv;
      this.kvsls.add(kv);
    }
    SortedSet<KeyValue> tail = this.kvsls.tailSet(splitter);
    assertEquals(2, tail.size());
    SortedSet<KeyValue> head = this.kvsls.headSet(splitter);
    assertEquals(1, head.size());
    // Now ensure that we get back right answer even when we do tail or head.
    // Now overwrite with a new value.
    for (int i = 0; i < total; i++) {
      this.kvsls.add(new KeyValue(bytes, bytes, Bytes.toBytes("" + i), value2));
    }
    tail = this.kvsls.tailSet(splitter);
    assertTrue(Bytes.equals(tail.first().getValue(), value2));
    head = this.kvsls.headSet(splitter);
    assertTrue(Bytes.equals(head.first().getValue(), value2));
  }

}