/**
 * 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.oncrpc;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertNull;
import static org.junit.Assert.assertTrue;

import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.Iterator;
import java.util.Map.Entry;

import org.apache.hadoop.oncrpc.RpcCallCache.CacheEntry;
import org.apache.hadoop.oncrpc.RpcCallCache.ClientRequest;
import org.junit.Test;

import static org.mockito.Mockito.*;

/**
 * Unit tests for {@link RpcCallCache}
 */
public class TestRpcCallCache {
  
  @Test(expected=IllegalArgumentException.class)
  public void testRpcCallCacheConstructorIllegalArgument0(){
    new RpcCallCache("test", 0);
  }
  
  @Test(expected=IllegalArgumentException.class)
  public void testRpcCallCacheConstructorIllegalArgumentNegative(){
    new RpcCallCache("test", -1);
  }
  
  @Test
  public void testRpcCallCacheConstructor(){
    RpcCallCache cache = new RpcCallCache("test", 100);
    assertEquals("test", cache.getProgram());
  }
  
  @Test
  public void testAddRemoveEntries() throws UnknownHostException {
    RpcCallCache cache = new RpcCallCache("test", 100);
    InetAddress clientIp = InetAddress.getByName("1.1.1.1");
    int xid = 100;
    
    // Ensure null is returned when there is no entry in the cache
    // An entry is added to indicate the request is in progress
    CacheEntry e = cache.checkOrAddToCache(clientIp, xid);
    assertNull(e);
    e = cache.checkOrAddToCache(clientIp, xid);
    validateInprogressCacheEntry(e);
    
    // Set call as completed
    RpcResponse response = mock(RpcResponse.class);
    cache.callCompleted(clientIp, xid, response);
    e = cache.checkOrAddToCache(clientIp, xid);
    validateCompletedCacheEntry(e, response);
  }
  
  private void validateInprogressCacheEntry(CacheEntry c) {
    assertTrue(c.isInProgress());
    assertFalse(c.isCompleted());
    assertNull(c.getResponse());
  }
  
  private void validateCompletedCacheEntry(CacheEntry c, RpcResponse response) {
    assertFalse(c.isInProgress());
    assertTrue(c.isCompleted());
    assertEquals(response, c.getResponse());
  }
  
  @Test
  public void testCacheEntry() {
    CacheEntry c = new CacheEntry();
    validateInprogressCacheEntry(c);
    assertTrue(c.isInProgress());
    assertFalse(c.isCompleted());
    assertNull(c.getResponse());
    
    RpcResponse response = mock(RpcResponse.class);
    c.setResponse(response);
    validateCompletedCacheEntry(c, response);
  }
  
  @Test
  public void testCacheFunctionality() throws UnknownHostException {
    RpcCallCache cache = new RpcCallCache("Test", 10);
    
    // Add 20 entries to the cache and only last 10 should be retained
    int size = 0;
    for (int clientId = 0; clientId < 20; clientId++) {
      InetAddress clientIp = InetAddress.getByName("1.1.1."+clientId);
      System.out.println("Adding " + clientIp);
      cache.checkOrAddToCache(clientIp, 0);
      size = Math.min(++size, 10);
      System.out.println("Cache size " + cache.size());
      assertEquals(size, cache.size()); // Ensure the cache size is correct
      
      // Ensure the cache entries are correct
      int startEntry = Math.max(clientId - 10 + 1, 0);
      Iterator<Entry<ClientRequest, CacheEntry>> iterator = cache.iterator();
      for (int i = 0; i < size; i++) {
        ClientRequest key = iterator.next().getKey();
        System.out.println("Entry " + key.getClientId());
        assertEquals(InetAddress.getByName("1.1.1." + (startEntry + i)),
            key.getClientId());
      }
      
      // Ensure cache entries are returned as in progress.
      for (int i = 0; i < size; i++) {
        CacheEntry e = cache.checkOrAddToCache(
            InetAddress.getByName("1.1.1." + (startEntry + i)), 0);
        assertNotNull(e);
        assertTrue(e.isInProgress());
        assertFalse(e.isCompleted());
      }
    }
  }
}