/*
 * Copyright (C) 2008 Google 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.google.inject.internal;

import java.lang.annotation.Annotation;
import java.util.concurrent.atomic.AtomicInteger;

/** An implementation of Element. */
// TODO(cgruber): Use AutoAnnotation when available, here & wherever else is makes sense.
class RealElement implements Element {
  private static final AtomicInteger nextUniqueId = new AtomicInteger(1);

  private final int uniqueId;
  private final String setName;
  private final Element.Type type;
  private final String keyType;

  RealElement(String setName, Element.Type type, String keyType) {
    this(setName, type, keyType, nextUniqueId.incrementAndGet());
  }

  RealElement(String setName, Element.Type type, String keyType, int uniqueId) {
    this.uniqueId = uniqueId;
    this.setName = setName;
    this.type = type;
    this.keyType = keyType;
  }

  @Override
  public String setName() {
    return setName;
  }

  @Override
  public int uniqueId() {
    return uniqueId;
  }

  @Override
  public Element.Type type() {
    return type;
  }

  @Override
  public String keyType() {
    return keyType;
  }

  @Override
  public Class<? extends Annotation> annotationType() {
    return Element.class;
  }

  @Override
  public String toString() {
    return "@"
        + Element.class.getName()
        + "(setName="
        + setName
        + ",uniqueId="
        + uniqueId
        + ", type="
        + type
        + ", keyType="
        + keyType
        + ")";
  }

  @Override
  public boolean equals(Object o) {
    return o instanceof Element
        && ((Element) o).setName().equals(setName())
        && ((Element) o).uniqueId() == uniqueId()
        && ((Element) o).type() == type()
        && ((Element) o).keyType().equals(keyType());
  }

  @Override
  public int hashCode() {
    return ((127 * "setName".hashCode()) ^ setName.hashCode())
        + ((127 * "uniqueId".hashCode()) ^ uniqueId)
        + ((127 * "type".hashCode()) ^ type.hashCode())
        + ((127 * "keyType".hashCode()) ^ keyType.hashCode());
  }
}
