// Copyright 2018 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.query2;

import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableSet;
import com.google.common.util.concurrent.AsyncFunction;
import com.google.common.util.concurrent.Futures;
import com.google.common.util.concurrent.MoreExecutors;
import com.google.devtools.build.lib.analysis.ConfiguredTarget;
import com.google.devtools.build.lib.analysis.config.BuildConfiguration;
import com.google.devtools.build.lib.analysis.configuredtargets.RuleConfiguredTarget;
import com.google.devtools.build.lib.cmdline.Label;
import com.google.devtools.build.lib.cmdline.TargetParsingException;
import com.google.devtools.build.lib.cmdline.TargetPattern;
import com.google.devtools.build.lib.events.ExtendedEventHandler;
import com.google.devtools.build.lib.events.Reporter;
import com.google.devtools.build.lib.packages.RuleTransitionFactory;
import com.google.devtools.build.lib.packages.Target;
import com.google.devtools.build.lib.pkgcache.PackageManager;
import com.google.devtools.build.lib.pkgcache.PathPackageLocator;
import com.google.devtools.build.lib.query2.engine.Callback;
import com.google.devtools.build.lib.query2.engine.KeyExtractor;
import com.google.devtools.build.lib.query2.engine.QueryEnvironment;
import com.google.devtools.build.lib.query2.engine.QueryException;
import com.google.devtools.build.lib.query2.engine.QueryExpression;
import com.google.devtools.build.lib.query2.engine.QueryUtil.ThreadSafeMutableKeyExtractorBackedSetImpl;
import com.google.devtools.build.lib.query2.output.AqueryOptions;
import com.google.devtools.build.lib.rules.AliasConfiguredTarget;
import com.google.devtools.build.lib.skyframe.BuildConfigurationValue;
import com.google.devtools.build.lib.skyframe.ConfiguredTargetKey;
import com.google.devtools.build.lib.skyframe.ConfiguredTargetValue;
import com.google.devtools.build.lib.skyframe.SkyframeExecutor;
import com.google.devtools.build.skyframe.SkyKey;
import com.google.devtools.build.skyframe.WalkableGraph;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.List;
import java.util.Set;
import java.util.function.Supplier;
import javax.annotation.Nullable;

/**
 * {@link QueryEnvironment} that is specialized for running action graph queries over the configured
 * target graph.
 */
public class ActionGraphQueryEnvironment
    extends PostAnalysisQueryEnvironment<ConfiguredTargetValue> {

  public static final ImmutableList<QueryFunction> AQUERY_FUNCTIONS = ImmutableList.of();
  public static final ImmutableList<QueryFunction> FUNCTIONS = populateFunctions();
  AqueryOptions aqueryOptions;
  private final KeyExtractor<ConfiguredTargetValue, ConfiguredTargetKey>
      configuredTargetKeyExtractor;
  private final ConfiguredTargetValueAccessor accessor;

  public ActionGraphQueryEnvironment(
      boolean keepGoing,
      ExtendedEventHandler eventHandler,
      Iterable<QueryFunction> extraFunctions,
      BuildConfiguration defaultTargetConfiguration,
      BuildConfiguration hostConfiguration,
      String parserPrefix,
      PathPackageLocator pkgPath,
      Supplier<WalkableGraph> walkableGraphSupplier,
      Set<Setting> settings) {
    super(
        keepGoing,
        eventHandler,
        extraFunctions,
        defaultTargetConfiguration,
        hostConfiguration,
        parserPrefix,
        pkgPath,
        walkableGraphSupplier,
        settings);
    this.configuredTargetKeyExtractor =
        configuredTargetValue -> {
          try {
            ConfiguredTarget element = configuredTargetValue.getConfiguredTarget();
            return ConfiguredTargetKey.of(
                element,
                element.getConfigurationKey() == null
                    ? null
                    : ((BuildConfigurationValue) graph.getValue(element.getConfigurationKey()))
                        .getConfiguration());
          } catch (InterruptedException e) {
            throw new IllegalStateException("Interruption unexpected in configured query");
          }
        };
    this.accessor =
        new ConfiguredTargetValueAccessor(
            walkableGraphSupplier.get(), this.configuredTargetKeyExtractor);
  }

  public ActionGraphQueryEnvironment(
      boolean keepGoing,
      ExtendedEventHandler eventHandler,
      Iterable<QueryFunction> extraFunctions,
      BuildConfiguration defaultTargetConfiguration,
      BuildConfiguration hostConfiguration,
      String parserPrefix,
      PathPackageLocator pkgPath,
      Supplier<WalkableGraph> walkableGraphSupplier,
      AqueryOptions aqueryOptions) {
    this(
        keepGoing,
        eventHandler,
        extraFunctions,
        defaultTargetConfiguration,
        hostConfiguration,
        parserPrefix,
        pkgPath,
        walkableGraphSupplier,
        aqueryOptions.toSettings());
    this.aqueryOptions = aqueryOptions;
  }

  private static ImmutableList<QueryFunction> populateFunctions() {
    return ImmutableList.copyOf(QueryEnvironment.DEFAULT_QUERY_FUNCTIONS);
  }

  @Override
  public ConfiguredTargetValueAccessor getAccessor() {
    return accessor;
  }

  @Override
  public ImmutableList<NamedThreadSafeOutputFormatterCallback<ConfiguredTargetValue>>
      getDefaultOutputFormatters(
          TargetAccessor<ConfiguredTargetValue> accessor,
          Reporter reporter,
          SkyframeExecutor skyframeExecutor,
          BuildConfiguration hostConfiguration,
          @Nullable RuleTransitionFactory trimmingTransitionFactory,
          PackageManager packageManager) {
    OutputStream out = reporter.getOutErr().getOutputStream();
    return ImmutableList.of(
        new ActionGraphProtoOutputFormatterCallback(
            reporter, aqueryOptions, out, skyframeExecutor, accessor),
        new ActionGraphTextOutputFormatterCallback(
            reporter, aqueryOptions, out, skyframeExecutor, accessor));
  }

  @Override
  public String getOutputFormat() {
    return aqueryOptions.outputFormat;
  }

  @Override
  protected KeyExtractor<ConfiguredTargetValue, ConfiguredTargetKey>
      getConfiguredTargetKeyExtractor() {
    return configuredTargetKeyExtractor;
  }

  @Override
  public Label getCorrectLabel(ConfiguredTargetValue configuredTargetValue) {
    ConfiguredTarget target = configuredTargetValue.getConfiguredTarget();
    if (target instanceof AliasConfiguredTarget) {
      return ((AliasConfiguredTarget) target).getOriginalLabel();
    }
    return target.getLabel();
  }

  @Nullable
  @Override
  protected ConfiguredTargetValue getHostConfiguredTarget(Label label) throws InterruptedException {
    return this.getConfiguredTargetValue(ConfiguredTargetValue.key(label, hostConfiguration));
  }

  @Nullable
  @Override
  protected ConfiguredTargetValue getTargetConfiguredTarget(Label label)
      throws InterruptedException {
    return this.getConfiguredTargetValue(
        ConfiguredTargetValue.key(label, defaultTargetConfiguration));
  }

  @Nullable
  @Override
  protected ConfiguredTargetValue getNullConfiguredTarget(Label label) throws InterruptedException {
    return this.getConfiguredTargetValue(
        ConfiguredTargetValue.key(label, /* configuration= */ null));
  }

  @Nullable
  @Override
  protected ConfiguredTargetValue getValueFromKey(SkyKey key) throws InterruptedException {
    return getConfiguredTargetValue(key);
  }

  @Nullable
  @Override
  protected RuleConfiguredTarget getRuleConfiguredTarget(
      ConfiguredTargetValue configuredTargetValue) {
    ConfiguredTarget configuredTarget = configuredTargetValue.getConfiguredTarget();
    if (configuredTarget instanceof RuleConfiguredTarget) {
      return (RuleConfiguredTarget) configuredTarget;
    }
    return null;
  }

  @Nullable
  @Override
  protected BuildConfiguration getConfiguration(ConfiguredTargetValue configuredTargetValue) {
    ConfiguredTarget target = configuredTargetValue.getConfiguredTarget();
    try {
      return target.getConfigurationKey() == null
          ? null
          : ((BuildConfigurationValue) graph.getValue(target.getConfigurationKey()))
              .getConfiguration();
    } catch (InterruptedException e) {
      throw new IllegalStateException("Unexpected interruption during aquery");
    }
  }

  @Override
  protected ConfiguredTargetKey getSkyKey(ConfiguredTargetValue configuredTargetValue) {
    ConfiguredTarget target = configuredTargetValue.getConfiguredTarget();
    return ConfiguredTargetKey.of(target, getConfiguration(configuredTargetValue));
  }

  @Override
  public QueryTaskFuture<Void> getTargetsMatchingPattern(
      QueryExpression owner, String pattern, Callback<ConfiguredTargetValue> callback) {
    TargetPattern patternToEval;
    try {
      patternToEval = getPattern(pattern);
    } catch (TargetParsingException tpe) {
      try {
        reportBuildFileError(owner, tpe.getMessage());
      } catch (QueryException qe) {
        return immediateFailedFuture(qe);
      }
      return immediateSuccessfulFuture(null);
    }
    AsyncFunction<TargetParsingException, Void> reportBuildFileErrorAsyncFunction =
        exn -> {
          reportBuildFileError(owner, exn.getMessage());
          return Futures.immediateFuture(null);
        };
    return QueryTaskFutureImpl.ofDelegate(
        Futures.catchingAsync(
            patternToEval.evalAdaptedForAsync(
                resolver,
                ImmutableSet.of(),
                ImmutableSet.of(),
                (Callback<Target>)
                    partialResult -> {
                      List<ConfiguredTargetValue> transformedResult = new ArrayList<>();
                      for (Target target : partialResult) {
                        ConfiguredTargetValue configuredTargetValue =
                            getConfiguredTargetValue(target.getLabel());
                        if (configuredTargetValue != null) {
                          transformedResult.add(configuredTargetValue);
                        }
                      }
                      callback.process(transformedResult);
                    },
                QueryException.class),
            TargetParsingException.class,
            reportBuildFileErrorAsyncFunction,
            MoreExecutors.directExecutor()));
  }

  private ConfiguredTargetValue getConfiguredTargetValue(Label label) throws InterruptedException {
    // Try with target configuration.
    ConfiguredTargetValue configuredTargetValue = getTargetConfiguredTarget(label);
    if (configuredTargetValue != null) {
      return configuredTargetValue;
    }
    // Try with host configuration (even when --nohost_deps is set in the case that top-level
    // targets are configured in the host configuration so we are doing a host-configuration-only
    // query).
    configuredTargetValue = getHostConfiguredTarget(label);
    if (configuredTargetValue != null) {
      return configuredTargetValue;
    }
    // Last chance: source file.
    return getNullConfiguredTarget(label);
  }

  @Override
  public ThreadSafeMutableSet<ConfiguredTargetValue> createThreadSafeMutableSet() {
    return new ThreadSafeMutableKeyExtractorBackedSetImpl<>(
        configuredTargetKeyExtractor,
        ConfiguredTargetValue.class,
        SkyQueryEnvironment.DEFAULT_THREAD_COUNT);
  }
}