// Copyright 2015 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.android;

import com.google.common.collect.ImmutableList;
import com.google.devtools.build.lib.analysis.ConfiguredAspect;
import com.google.devtools.build.lib.analysis.ConfiguredAspectFactory;
import com.google.devtools.build.lib.analysis.ConfiguredTarget;
import com.google.devtools.build.lib.analysis.RuleConfiguredTarget.Mode;
import com.google.devtools.build.lib.analysis.RuleContext;
import com.google.devtools.build.lib.analysis.TransitiveInfoCollection;
import com.google.devtools.build.lib.packages.AspectDefinition;
import com.google.devtools.build.lib.packages.AspectParameters;
import com.google.devtools.build.lib.packages.BuildType;
import com.google.devtools.build.lib.packages.NativeAspectClass;
import com.google.devtools.build.lib.rules.java.JavaCommon;
import com.google.devtools.build.lib.rules.java.JavaCompilationArgsProvider;
import com.google.devtools.build.lib.rules.java.JavaRuntimeJarProvider;
import java.util.ArrayList;
import java.util.List;

/**
 * An aspect that collects neverlink libraries in the transitive closure.
 *
 * <p>Used for determining the -libraryjars argument of the Proguard invocation in Android binaries.
 *
 * <p>One would think that using the compile time classpath would be enough, but alas, those are
 * ijars,
 */
public class AndroidNeverlinkAspect extends NativeAspectClass implements ConfiguredAspectFactory {
  public static final String NAME = "AndroidNeverlinkAspect";
  private static final ImmutableList<String> ATTRIBUTES =
      ImmutableList.of(
          "deps", "exports", "runtime_deps", "binary_under_test", "$instrumentation_test_runner");

  @Override
  public ConfiguredAspect create(
      ConfiguredTarget base, RuleContext ruleContext, AspectParameters parameters) {
    if (!JavaCommon.getConstraints(ruleContext).contains("android")
        && !ruleContext.getRule().getRuleClass().startsWith("android_")) {
      return new ConfiguredAspect.Builder(NAME, ruleContext).build();
    }

    List<TransitiveInfoCollection> deps = new ArrayList<>();

    // This is probably an overestimate, but it's fine -- Proguard doesn't care if there are more
    // jars in -libraryjars than is required. The alternative would be somehow getting
    // JavaCommon.getDependencies() here, which would be fugly.
    for (String attribute : ATTRIBUTES) {
      if (!ruleContext.getRule().getRuleClassObject().hasAttr(attribute, BuildType.LABEL_LIST)) {
        continue;
      }

      deps.addAll(ruleContext.getPrerequisites(attribute, Mode.TARGET));
    }

    return new ConfiguredAspect.Builder(NAME, ruleContext)
        .addProvider(
            AndroidNeverLinkLibrariesProvider.create(
                AndroidCommon.collectTransitiveNeverlinkLibraries(
                    ruleContext,
                    deps,
                    base.getProvider(JavaRuntimeJarProvider.class).getRuntimeJars())))
        .build();
  }

  @Override
  public AspectDefinition getDefinition(AspectParameters aspectParameters) {
    AspectDefinition.Builder builder = new AspectDefinition.Builder("AndroidNeverlinkAspect");
    for (String attribute : ATTRIBUTES) {
      builder.attributeAspect(attribute, this);
    }

    return builder
        .requireProvider(JavaCompilationArgsProvider.class)
        .requiresConfigurationFragments()
        .build();
  }
}