/*
 * Copyright 2013-present Facebook, 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 com.facebook.buck.rules;

import static org.junit.Assert.assertEquals;

import com.facebook.buck.io.ProjectFilesystem;
import com.facebook.buck.parser.BuildTargetParser;
import com.facebook.buck.rules.coercer.TypeCoercerFactory;
import com.facebook.buck.testutil.FakeProjectFilesystem;
import com.google.common.base.Optional;

import org.junit.Test;

import java.lang.reflect.Field;
import java.nio.file.Path;
import java.nio.file.Paths;

public class ParamInfoTest {

  private Path path = Paths.get("path");
  private TypeCoercerFactory typeCoercerFactory = new TypeCoercerFactory();

  @Test
  public void shouldReportWildcardsWithUpperBoundsAsUpperBound() throws NoSuchFieldException {
    class Example<X extends SourcePath> {
      @SuppressWarnings("unused")
      public X path;
    }

    Field field = Example.class.getField("path");
    ParamInfo<?> info = new ParamInfo<Object>(typeCoercerFactory, field);

    Class<?> type = info.getResultClass();
    assertEquals(SourcePath.class, type);
  }

  @Test
  public void anOptionalFieldMayBeWildcardedWithAnUpperBound() throws NoSuchFieldException {
    class Example {
      @SuppressWarnings("unused")
      public Optional<? extends SourcePath> path;
    }

    Field field = Example.class.getField("path");
    ParamInfo<?> info = new ParamInfo<Object>(typeCoercerFactory, field);

    Class<?> type = info.getResultClass();
    assertEquals(SourcePath.class, type);
  }

  @Test(expected = IllegalArgumentException.class)
  public void wildcardedFieldsWithNoUpperBoundAreNotAllowed() throws NoSuchFieldException {
    class Example {
      @SuppressWarnings("unused")
      public Optional<?> bad;
    }

    Field field = Example.class.getField("bad");
    new ParamInfo<Object>(typeCoercerFactory, field);
  }

  @Test(expected = IllegalArgumentException.class)
  public void superTypesForGenericsAreNotAllowedEither() throws NoSuchFieldException {
    class Example {
      @SuppressWarnings("unused")
      public Optional<? super SourcePath> bad;
    }

    Field field = Example.class.getField("bad");
    new ParamInfo<Object>(typeCoercerFactory, field);
  }

  @Test
  public void pythonNamesShouldBeCorrectlyGenerated() throws NoSuchFieldException {
    @SuppressWarnings("unused")
    class Example {
      public String isDefaultName;

      @Hint(name = "not_the_default_name_123")
      public String notDefaultName;
    }

    ParamInfo<?> info;

    info = new ParamInfo<Object>(typeCoercerFactory, Example.class.getField("isDefaultName"));
    assertEquals("is_default_name", info.getPythonName());

    info = new ParamInfo<Object>(typeCoercerFactory, Example.class.getField("notDefaultName"));
    assertEquals("not_the_default_name_123", info.getPythonName());
  }

  @Test
  public void fieldSetForOptionalFields() throws NoSuchFieldException, ParamInfoException {
    class Example {
      public Optional<String> field;
    }
    Example example = new Example();

    BuildTargetParser buildTargetParser = new BuildTargetParser();
    ProjectFilesystem filesystem = new FakeProjectFilesystem();

    ParamInfo<?> info = new ParamInfo<Object>(typeCoercerFactory, Example.class.getField("field"));

    info.set(buildTargetParser, filesystem, path, example, null);
    assertEquals(Optional.<String>absent(), example.field);

    info.set(buildTargetParser, filesystem, path, example, "");
    assertEquals(Optional.of(""), example.field);

    info.set(buildTargetParser, filesystem, path, example, "foo");
    assertEquals(Optional.of("foo"), example.field);
  }
}