/*
    * Copyright (C) 2011 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.base;
  
  import com.google.common.annotations.GwtCompatible;
  import com.google.common.testing.SerializableTester;
  
  import junit.framework.TestCase;
  
  import java.lang.annotation.Retention;
  import java.lang.annotation.RetentionPolicy;
  
  /**
   * Tests for {@link Enums}.
   *
   * @author Steve McKay
   */
  @GwtCompatible(emulated = true)
  public class EnumsTest extends TestCase {
  
    private enum TestEnum {
      CHEETO,
      HONDA,
      POODLE,
    }
  
    private enum OtherEnum {}
  
    public void testGetIfPresent() {
      assertEquals(Optional.of(TestEnum.CHEETO), Enums.getIfPresent(TestEnum.class, "CHEETO"));
      assertEquals(Optional.of(TestEnum.HONDA), Enums.getIfPresent(TestEnum.class, "HONDA"));
      assertEquals(Optional.of(TestEnum.POODLE), Enums.getIfPresent(TestEnum.class, "POODLE"));
  
      assertTrue(Enums.getIfPresent(TestEnum.class, "CHEETO").isPresent());
      assertTrue(Enums.getIfPresent(TestEnum.class, "HONDA").isPresent());
      assertTrue(Enums.getIfPresent(TestEnum.class, "POODLE").isPresent());
  
      assertEquals(TestEnum.CHEETO, Enums.getIfPresent(TestEnum.class, "CHEETO").get());
      assertEquals(TestEnum.HONDA, Enums.getIfPresent(TestEnum.class, "HONDA").get());
      assertEquals(TestEnum.POODLE, Enums.getIfPresent(TestEnum.class, "POODLE").get());
    }
  
    public void testGetIfPresent_caseSensitive() {
      assertFalse(Enums.getIfPresent(TestEnum.class, "cHEETO").isPresent());
      assertFalse(Enums.getIfPresent(TestEnum.class, "Honda").isPresent());
      assertFalse(Enums.getIfPresent(TestEnum.class, "poodlE").isPresent());
    }
  
    public void testGetIfPresent_whenNoMatchingConstant() {
      assertEquals(Optional.absent(), Enums.getIfPresent(TestEnum.class, "WOMBAT"));
    }
  
    // Create a second ClassLoader and use it to get a second version of the TestEnum class.
    // Run Enums.getIfPresent on that other TestEnum and then return a WeakReference containing the
    // new ClassLoader. If Enums.getIfPresent does caching that prevents the shadow TestEnum
    // (and therefore its ClassLoader) from being unloaded, then this WeakReference will never be
    // cleared.
  
    public void testStringConverter_convert() {
      Converter<String, TestEnum> converter = Enums.stringConverter(TestEnum.class);
      assertEquals(TestEnum.CHEETO, converter.convert("CHEETO"));
      assertEquals(TestEnum.HONDA, converter.convert("HONDA"));
      assertEquals(TestEnum.POODLE, converter.convert("POODLE"));
      assertNull(converter.convert(null));
      assertNull(converter.reverse().convert(null));
    }
  
    public void testStringConverter_convertError() {
      Converter<String, TestEnum> converter = Enums.stringConverter(TestEnum.class);
      try {
        converter.convert("xxx");
        fail();
      } catch (IllegalArgumentException expected) {
      }
    }
  
    public void testStringConverter_reverse() {
      Converter<String, TestEnum> converter = Enums.stringConverter(TestEnum.class);
      assertEquals("CHEETO", converter.reverse().convert(TestEnum.CHEETO));
      assertEquals("HONDA", converter.reverse().convert(TestEnum.HONDA));
      assertEquals("POODLE", converter.reverse().convert(TestEnum.POODLE));
    }
  
    public void testStringConverter_nullConversions() {
      Converter<String, TestEnum> converter = Enums.stringConverter(TestEnum.class);
     assertNull(converter.convert(null));
     assertNull(converter.reverse().convert(null));
   }
 
   public void testStringConverter_serialization() {
     SerializableTester.reserializeAndAssert(Enums.stringConverter(TestEnum.class));
   }
 
   @Retention(RetentionPolicy.RUNTIME)
   private @interface ExampleAnnotation {}
 
   private enum AnEnum {
     @ExampleAnnotation FOO,
     BAR
   }
 }