/*
 * Copyright 2013 Netflix, Inc.
 *
 * 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 feign;

import feign.codec.Decoder;
import org.testng.annotations.Test;

import java.io.Reader;
import java.lang.reflect.Type;
import java.util.List;

import static feign.Util.resolveLastTypeParameter;
import static org.testng.Assert.assertEquals;

@Test
public class UtilTest {

  interface LastTypeParameter {
    final List<String> LIST_STRING = null;
    final Parameterized<List<String>> PARAMETERIZED_LIST_STRING = null;
    final Parameterized<? extends List<String>> PARAMETERIZED_WILDCARD_LIST_STRING = null;
    final ParameterizedDecoder<List<String>> PARAMETERIZED_DECODER_LIST_STRING = null;
    final ParameterizedDecoder<?> PARAMETERIZED_DECODER_UNBOUND = null;
  }

  interface ParameterizedDecoder<T extends List<String>> extends Decoder {
  }

  interface Parameterized<T> {
  }

  static class ParameterizedSubtype implements Parameterized<String> {
  }

  @Test public void resolveLastTypeParameterWhenNotSubtype() throws Exception {
    Type context = LastTypeParameter.class.getDeclaredField("PARAMETERIZED_LIST_STRING").getGenericType();
    Type listStringType = LastTypeParameter.class.getDeclaredField("LIST_STRING").getGenericType();
    Type last = resolveLastTypeParameter(context, Parameterized.class);
    assertEquals(last, listStringType);
  }

  @Test public void lastTypeFromInstance() throws Exception {
    Parameterized instance = new ParameterizedSubtype();
    Type last = resolveLastTypeParameter(instance.getClass(), Parameterized.class);
    assertEquals(last, String.class);
  }

  @Test public void lastTypeFromAnonymous() throws Exception {
    Parameterized instance = new Parameterized<Reader>() {};
    Type last = resolveLastTypeParameter(instance.getClass(), Parameterized.class);
    assertEquals(last, Reader.class);
  }

  @Test public void resolveLastTypeParameterWhenWildcard() throws Exception {
    Type context = LastTypeParameter.class.getDeclaredField("PARAMETERIZED_WILDCARD_LIST_STRING").getGenericType();
    Type listStringType = LastTypeParameter.class.getDeclaredField("LIST_STRING").getGenericType();
    Type last = resolveLastTypeParameter(context, Parameterized.class);
    assertEquals(last, listStringType);
  }

  @Test public void resolveLastTypeParameterWhenParameterizedSubtype() throws Exception {
    Type context = LastTypeParameter.class.getDeclaredField("PARAMETERIZED_DECODER_LIST_STRING").getGenericType();
    Type listStringType = LastTypeParameter.class.getDeclaredField("LIST_STRING").getGenericType();
    Type last = resolveLastTypeParameter(context, ParameterizedDecoder.class);
    assertEquals(last, listStringType);
  }

  @Test public void unboundWildcardIsObject() throws Exception {
    Type context = LastTypeParameter.class.getDeclaredField("PARAMETERIZED_DECODER_UNBOUND").getGenericType();
    Type last = resolveLastTypeParameter(context, ParameterizedDecoder.class);
    assertEquals(last, Object.class);
  }
}