/*
 * Copyright 2013 Google Inc. All rights reserved.
 *
 * 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.errorprone.refaster;

import com.google.auto.value.AutoValue;

import com.sun.tools.javac.code.BoundKind;
import com.sun.tools.javac.code.Type;
import com.sun.tools.javac.code.Type.WildcardType;

import javax.annotation.Nullable;

/**
 * {@link UType} version of {@link WildcardType}.
 *
 * @author [email protected] (Louis Wasserman)
 */
@AutoValue
abstract class UWildcardType extends UType {
  public static UWildcardType create(BoundKind boundKind, UType bound) {
    return new AutoValue_UWildcardType(boundKind, bound);
  }
  
  /**
   * This corresponds to a plain ? wildcard.
   */
  public static UWildcardType create() {
    return create(BoundKind.UNBOUND, UClassType.create("java.lang.Object"));
  }
  
  abstract BoundKind boundKind();
  
  abstract UType bound();

  @Override
  @Nullable
  public Unifier visitWildcardType(WildcardType wildcard, @Nullable Unifier unifier) {
    unifier = boundKind().equals(wildcard.kind) ? unifier : null;
    return bound().unify(wildcard.type, unifier);
  }

  @Override
  public Type inline(Inliner inliner) throws CouldNotResolveImportException {
    return new WildcardType(
        bound().inline(inliner),
        boundKind(),
        inliner.symtab().boundClass);
  }
}