/*
 * Copyright 2016 The Bazel Authors. 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.idea.blaze.base.ideinfo;

import com.google.common.base.Joiner;
import com.google.common.base.Objects;
import com.google.common.collect.ComparisonChain;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Ordering;
import com.google.idea.blaze.base.model.primitives.Label;
import java.io.Serializable;
import java.util.List;

/** A key that uniquely idenfifies a target in the target map */
public class TargetKey implements Serializable, Comparable<TargetKey> {
  private static final long serialVersionUID = 3L;

  public final Label label;
  private final ImmutableList<String> aspectIds;

  private TargetKey(Label label, ImmutableList<String> aspectIds) {
    this.label = label;
    this.aspectIds = aspectIds;
  }

  /** Returns a key identifying a plain target */
  public static TargetKey forPlainTarget(Label label) {
    return new TargetKey(label, ImmutableList.of());
  }

  /** Returns a key identifying a general target */
  public static TargetKey forGeneralTarget(Label label, List<String> aspectIds) {
    if (aspectIds.isEmpty()) {
      return forPlainTarget(label);
    }
    return new TargetKey(label, ImmutableList.copyOf(aspectIds));
  }

  public boolean isPlainTarget() {
    return aspectIds.isEmpty();
  }

  @Override
  public boolean equals(Object o) {
    if (this == o) {
      return true;
    }
    if (o == null || getClass() != o.getClass()) {
      return false;
    }
    TargetKey key = (TargetKey) o;
    return Objects.equal(label, key.label) && Objects.equal(aspectIds, key.aspectIds);
  }

  @Override
  public int hashCode() {
    return Objects.hashCode(label, aspectIds);
  }

  @Override
  public String toString() {
    if (aspectIds.isEmpty()) {
      return label.toString();
    }
    return label.toString() + "#" + Joiner.on('#').join(aspectIds);
  }

  @Override
  public int compareTo(TargetKey o) {
    return ComparisonChain.start()
        .compare(label, o.label)
        .compare(aspectIds, o.aspectIds, Ordering.natural().lexicographical())
        .result();
  }
}