/*
    * Copyright (C) 2008 The Guava Authors
    *
    * Licensed 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 com.google.common.testing;
  
  import com.google.common.annotations.GwtCompatible;
  
  import junit.framework.TestCase;
  
  import java.util.EnumSet;
  import java.util.concurrent.TimeUnit;
  
  /**
   * Unit test for {@link FakeTicker}.
   *
   * @author Jige Yu
   */
  @GwtCompatible(emulated = true)
  public class FakeTickerTest extends TestCase {
  
    public void testAdvance() {
      FakeTicker ticker = new FakeTicker();
      assertEquals(0, ticker.read());
      assertSame(ticker, ticker.advance(10));
      assertEquals(10, ticker.read());
      ticker.advance(1, TimeUnit.MILLISECONDS);
      assertEquals(1000010L, ticker.read());
    }
  
    public void testAutoIncrementStep_returnsSameInstance() {
      FakeTicker ticker = new FakeTicker();
      assertSame(ticker, ticker.setAutoIncrementStep(10, TimeUnit.NANOSECONDS));
    }
  
    public void testAutoIncrementStep_nanos() {
      FakeTicker ticker = new FakeTicker().setAutoIncrementStep(10, TimeUnit.NANOSECONDS);
      assertEquals(0, ticker.read());
      assertEquals(10, ticker.read());
      assertEquals(20, ticker.read());
    }
  
    public void testAutoIncrementStep_millis() {
      FakeTicker ticker = new FakeTicker().setAutoIncrementStep(1, TimeUnit.MILLISECONDS);
      assertEquals(0, ticker.read());
      assertEquals(1000000, ticker.read());
      assertEquals(2000000, ticker.read());
    }
  
    public void testAutoIncrementStep_seconds() {
      FakeTicker ticker = new FakeTicker().setAutoIncrementStep(3, TimeUnit.SECONDS);
      assertEquals(0, ticker.read());
      assertEquals(3000000000L, ticker.read());
      assertEquals(6000000000L, ticker.read());
    }
  
    public void testAutoIncrementStep_resetToZero() {
      FakeTicker ticker = new FakeTicker().setAutoIncrementStep(10, TimeUnit.NANOSECONDS);
      assertEquals(0, ticker.read());
      assertEquals(10, ticker.read());
      assertEquals(20, ticker.read());
  
      for (TimeUnit timeUnit : EnumSet.allOf(TimeUnit.class)) {
        ticker.setAutoIncrementStep(0, timeUnit);
        assertEquals(
            "Expected no auto-increment when setting autoIncrementStep to 0 " + timeUnit,
            30, ticker.read());
      }
    }
  
    public void testAutoIncrement_negative() {
      FakeTicker ticker = new FakeTicker();
      try {
        ticker.setAutoIncrementStep(-1, TimeUnit.NANOSECONDS);
        fail("Expected IllegalArgumentException");
      } catch (IllegalArgumentException expected) {
      }
    }
  }