// Copyright 2017 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.devtools.build.lib.analysis.ConfiguredTarget;
import com.google.devtools.build.lib.cmdline.Label;
import com.google.devtools.build.lib.packages.NoSuchTargetException;
import com.google.devtools.build.lib.packages.Rule;
import com.google.devtools.build.lib.packages.Target;
import com.google.devtools.build.lib.packages.TargetUtils;
import com.google.devtools.build.lib.query2.engine.QueryEnvironment.TargetAccessor;
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.QueryVisibility;
import com.google.devtools.build.lib.rules.AliasConfiguredTarget;
import com.google.devtools.build.lib.skyframe.PackageValue;
import com.google.devtools.build.skyframe.WalkableGraph;
import java.util.List;
import java.util.Set;

/** A {@link TargetAccessor} for {@link ConfiguredTarget} objects.
 *
 * Incomplete; we'll implement getLabelListAttr and getVisibility when needed.
 */
class ConfiguredTargetAccessor implements TargetAccessor<ConfiguredTarget> {

  private final WalkableGraph walkableGraph;

  ConfiguredTargetAccessor(WalkableGraph walkableGraph) {
    this.walkableGraph = walkableGraph;
  }

  @Override
  public String getTargetKind(ConfiguredTarget target) {
    Target actualTarget = getTargetFromConfiguredTarget(target);
    return actualTarget.getTargetKind();
  }

  @Override
  public String getLabel(ConfiguredTarget target) {
    return target.getLabel().toString();
  }

  @Override
  public String getPackage(ConfiguredTarget target) {
    return target.getLabel().getPackageIdentifier().getPackageFragment().toString();
  }

  @Override
  public boolean isRule(ConfiguredTarget target) {
    Target actualTarget = getTargetFromConfiguredTarget(target);
    return actualTarget instanceof Rule;
  }

  @Override
  public boolean isTestRule(ConfiguredTarget target) {
    Target actualTarget = getTargetFromConfiguredTarget(target);
    return TargetUtils.isTestRule(actualTarget);
  }

  @Override
  public boolean isTestSuite(ConfiguredTarget target) {
    Target actualTarget = getTargetFromConfiguredTarget(target);
    return TargetUtils.isTestSuiteRule(actualTarget);
  }

  @Override
  public List<ConfiguredTarget> getLabelListAttr(
      QueryExpression caller,
      ConfiguredTarget configuredTarget,
      String attrName,
      String errorMsgPrefix)
      throws QueryException, InterruptedException {
    // TODO(bazel-team): implement this if needed.
    throw new UnsupportedOperationException();
  }

  @Override
  public List<String> getStringListAttr(ConfiguredTarget target, String attrName) {
    Target actualTarget = getTargetFromConfiguredTarget(target);
    return TargetUtils.getStringListAttr(actualTarget, attrName);
  }

  @Override
  public String getStringAttr(ConfiguredTarget target, String attrName) {
    Target actualTarget = getTargetFromConfiguredTarget(target);
    return TargetUtils.getStringAttr(actualTarget, attrName);
  }

  @Override
  public Iterable<String> getAttrAsString(ConfiguredTarget target, String attrName) {
    Target actualTarget = getTargetFromConfiguredTarget(target);
    return TargetUtils.getAttrAsString(actualTarget, attrName);
  }

  @Override
  public Set<QueryVisibility<ConfiguredTarget>> getVisibility(ConfiguredTarget from)
      throws QueryException, InterruptedException {
    // TODO(bazel-team): implement this if needed.
    throw new UnsupportedOperationException();
  }

  public Target getTargetFromConfiguredTarget(ConfiguredTarget configuredTarget) {
    return getTargetFromConfiguredTarget(configuredTarget, walkableGraph);
  }

  public static Target getTargetFromConfiguredTarget(
      ConfiguredTarget configuredTarget, WalkableGraph walkableGraph) {
    Target target = null;
    try {
      Label label =
          configuredTarget instanceof AliasConfiguredTarget
              ? ((AliasConfiguredTarget) configuredTarget).getOriginalLabel()
              : configuredTarget.getLabel();
      target =
          ((PackageValue) walkableGraph.getValue(PackageValue.key(label.getPackageIdentifier())))
              .getPackage()
              .getTarget(label.getName());
    } catch (NoSuchTargetException e) {
      throw new IllegalStateException("Unable to get target from package in accessor.");
    } catch (InterruptedException e2) {
      throw new IllegalStateException("Thread interrupted in the middle of getting a Target.");
    }
    return target;
  }
}