// Copyright 2014 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.devtools.build.lib.rules.cpp;

import com.google.common.base.Optional;
import com.google.devtools.build.lib.actions.Artifact;
import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec.VisibleForSerialization;

/** Structure for C++ module maps. Stores the name of the module and a .cppmap artifact. */
@Immutable
@AutoCodec
public final class CppModuleMap {
  // NOTE: If you add a field here, you'll likely need to update CppModuleMapAction.computeKey().
  private final Artifact artifact;
  private final String name;
  private final Optional<Artifact> umbrellaHeader;

  public CppModuleMap(Artifact artifact, String name) {
    this(artifact, Optional.absent(), name);
  }

  public CppModuleMap(Artifact artifact, Artifact umbrellaHeader, String name) {
    this(artifact, Optional.fromNullable(umbrellaHeader), name);
  }

  @AutoCodec.Instantiator
  @VisibleForSerialization
  CppModuleMap(Artifact artifact, Optional<Artifact> umbrellaHeader, String name) {
    this.artifact = artifact;
    this.umbrellaHeader = umbrellaHeader;
    this.name = name;
  }

  public Artifact getArtifact() {
    return artifact;
  }

  public String getName() {
    return name;
  }

  /**
   * Returns an optional umbrella header artifact. The headers declared in module maps are compiled
   * using the #import directives which are incompatible with J2ObjC segmented headers. The headers
   * generated by J2ObjC need to be compiled using the #include directives. We can #include all the
   * headers in an umbrella header and then declare the umbrella header in the module map.
   */
  public Optional<Artifact> getUmbrellaHeader() {
    return umbrellaHeader;
  }

  @Override
  public String toString() {
    return name + "@" + artifact;
  }

  /**
   * Specifies whether to generate an umbrella header.
   */
  public enum UmbrellaHeaderStrategy {
    /** Generate an umbrella header. */
    GENERATE,
    /** Do not generate an umbrella header. */
    DO_NOT_GENERATE 
  }
}

@@ -2462,16 +2462,681 @@
 r;%0A  %7D%0A%0A
+  @Override%0A  public int hashCode() %7B%0A    // It would be incorrect for two CppModuleMap instances in the same build graph to have the same%0A    // artifact but different names or umbrella headers. Since Artifacts' hash codes are cached, use%0A    // only it for efficiency.%0A    return artifact.hashCode();%0A  %7D%0A%0A  @Override%0A  public boolean equals(Object other) %7B%0A    if (this == other) %7B%0A      return true;%0A    %7D%0A    if (other instanceof CppModuleMap) %7B%0A      CppModuleMap that = (CppModuleMap) other;%0A      return artifact.equals(that.artifact)%0A          && umbrellaHeader.equals(that.umbrellaHeader)%0A          && name.equals(that.name);%0A    %7D%0A    return false;%0A  %7D%0A%0A
   @Overr
@@ -3164,24 +3164,24 @@
 oString() %7B%0A
-
     return n
@@ -3410,24 +3410,24 @@
  header. */%0A
+
     DO_NOT_G
@@ -3433,16 +3433,15 @@
 GENERATE
- 
 %0A  %7D%0A%7D%0A

Add proper `hashCode`/`equals` to `CppModuleMap`.