// 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.analysis;

import static com.google.devtools.build.lib.packages.Attribute.ConfigurationTransition.DATA;
import static com.google.devtools.build.lib.packages.Attribute.ConfigurationTransition.HOST;
import static com.google.devtools.build.lib.packages.Attribute.attr;
import static com.google.devtools.build.lib.packages.BuildType.DISTRIBUTIONS;
import static com.google.devtools.build.lib.packages.BuildType.LABEL;
import static com.google.devtools.build.lib.packages.BuildType.LABEL_LIST;
import static com.google.devtools.build.lib.packages.BuildType.LICENSE;
import static com.google.devtools.build.lib.packages.BuildType.NODEP_LABEL_LIST;
import static com.google.devtools.build.lib.syntax.Type.BOOLEAN;
import static com.google.devtools.build.lib.syntax.Type.INTEGER;
import static com.google.devtools.build.lib.syntax.Type.STRING;
import static com.google.devtools.build.lib.syntax.Type.STRING_LIST;

import com.google.common.annotations.VisibleForTesting;
import com.google.common.collect.ImmutableList;
import com.google.devtools.build.lib.analysis.config.BuildConfiguration;
import com.google.devtools.build.lib.analysis.config.RunUnder;
import com.google.devtools.build.lib.analysis.constraints.EnvironmentRule;
import com.google.devtools.build.lib.cmdline.Label;
import com.google.devtools.build.lib.packages.Attribute;
import com.google.devtools.build.lib.packages.Attribute.LateBoundLabel;
import com.google.devtools.build.lib.packages.Attribute.LateBoundLabelList;
import com.google.devtools.build.lib.packages.AttributeMap;
import com.google.devtools.build.lib.packages.Rule;
import com.google.devtools.build.lib.packages.RuleClass;
import com.google.devtools.build.lib.packages.RuleClass.Builder;
import com.google.devtools.build.lib.packages.RuleClass.Builder.RuleClassType;
import com.google.devtools.build.lib.packages.TestSize;
import com.google.devtools.build.lib.syntax.Type;
import com.google.devtools.build.lib.util.FileTypeSet;

import java.util.List;

/**
 * Rule class definitions used by (almost) every rule.
 */
public class BaseRuleClasses {
  /**
   * Label of the pseudo-filegroup that contains all the targets that are needed
   * for running tests in coverage mode.
   */
  private static final Label COVERAGE_SUPPORT_LABEL =
      Label.parseAbsoluteUnchecked("//tools/defaults:coverage");

  private static final Attribute.ComputedDefault testonlyDefault =
      new Attribute.ComputedDefault() {
        @Override
        public Object getDefault(AttributeMap rule) {
          return rule.getPackageDefaultTestOnly();
        }
      };

  private static final Attribute.ComputedDefault deprecationDefault =
      new Attribute.ComputedDefault() {
        @Override
        public Object getDefault(AttributeMap rule) {
          return rule.getPackageDefaultDeprecation();
        }
      };

  /**
   * Implementation for the :action_listener attribute.
   */
  @VisibleForTesting
  static final LateBoundLabelList<BuildConfiguration> ACTION_LISTENER =
      new LateBoundLabelList<BuildConfiguration>() {
    @Override
    public List<Label> resolve(Rule rule, AttributeMap attributes,
        BuildConfiguration configuration) {
      // action_listeners are special rules; they tell the build system to add extra_actions to
      // existing rules. As such they need an edge to every ConfiguredTarget with the limitation
      // that they only run on the target configuration and should not operate on action_listeners
      // and extra_actions themselves (to avoid cycles).
      return configuration.getActionListeners();
    }
  };

  private static final LateBoundLabelList<BuildConfiguration> COVERAGE_SUPPORT =
      new LateBoundLabelList<BuildConfiguration>(ImmutableList.of(COVERAGE_SUPPORT_LABEL)) {
        @Override
        public List<Label> resolve(Rule rule, AttributeMap attributes,
            BuildConfiguration configuration) {
          return configuration.isCodeCoverageEnabled()
              ? ImmutableList.copyOf(configuration.getCoverageLabels())
              : ImmutableList.<Label>of();
        }
      };

  private static final LateBoundLabelList<BuildConfiguration> GCOV =
      new LateBoundLabelList<BuildConfiguration>(ImmutableList.of(COVERAGE_SUPPORT_LABEL)) {
        @Override
        public List<Label> resolve(Rule rule, AttributeMap attributes,
            BuildConfiguration configuration) {
          return configuration.isCodeCoverageEnabled()
              ? ImmutableList.copyOf(configuration.getGcovLabels())
              : ImmutableList.<Label>of();
        }
      };

  private static final LateBoundLabelList<BuildConfiguration> COVERAGE_REPORT_GENERATOR =
      new LateBoundLabelList<BuildConfiguration>(ImmutableList.of(COVERAGE_SUPPORT_LABEL)) {
        @Override
        public List<Label> resolve(Rule rule, AttributeMap attributes,
            BuildConfiguration configuration) {
          return configuration.isCodeCoverageEnabled()
              ? ImmutableList.copyOf(configuration.getCoverageReportGeneratorLabels())
              : ImmutableList.<Label>of();
        }
      };

  /**
   * Implementation for the :run_under attribute.
   */
  private static final LateBoundLabel<BuildConfiguration> RUN_UNDER =
      new LateBoundLabel<BuildConfiguration>() {
        @Override
        public Label resolve(Rule rule, AttributeMap attributes,
            BuildConfiguration configuration) {
          RunUnder runUnder = configuration.getRunUnder();
          return runUnder == null ? null : runUnder.getLabel();
        }
      };

  /**
   * A base rule for all test rules.
   */
  public static final class TestBaseRule implements RuleDefinition {
    @Override
    public RuleClass build(Builder builder, RuleDefinitionEnvironment env) {
      return builder
          .add(attr("size", STRING).value("medium").taggable()
              .nonconfigurable("policy decision: should be consistent across configurations"))
          .add(attr("timeout", STRING).taggable()
              .nonconfigurable("policy decision: should be consistent across configurations")
              .value(new Attribute.ComputedDefault() {
                @Override
                public Object getDefault(AttributeMap rule) {
                  TestSize size = TestSize.getTestSize(rule.get("size", Type.STRING));
                  if (size != null) {
                    String timeout = size.getDefaultTimeout().toString();
                    if (timeout != null) {
                      return timeout;
                    }
                  }
                  return "illegal";
                }
              }))
          .add(attr("flaky", BOOLEAN).value(false).taggable()
              .nonconfigurable("policy decision: should be consistent across configurations"))
          .add(attr("shard_count", INTEGER).value(-1))
          .add(attr("local", BOOLEAN).value(false).taggable()
              .nonconfigurable("policy decision: should be consistent across configurations"))
          .add(attr("args", STRING_LIST)
              .nonconfigurable("policy decision: should be consistent across configurations"))
          .add(attr("$test_runtime", LABEL_LIST).cfg(HOST).value(ImmutableList.of(
              env.getToolsLabel("//tools/test:runtime"))))

          // TODO(bazel-team): TestActions may need to be run with coverage, so all tests
          // implicitly depend on crosstool, which provides gcov.  We could add gcov to
          // InstrumentedFilesProvider.getInstrumentationMetadataFiles() (or a new method) for
          // all the test rules that have C++ in their transitive closure. Then this could go.
          .add(attr(":gcov", LABEL_LIST).cfg(HOST).value(GCOV))
          .add(attr(":coverage_support", LABEL_LIST).cfg(HOST).value(COVERAGE_SUPPORT))
          .add(attr(":coverage_report_generator", LABEL_LIST).cfg(HOST)
              .value(COVERAGE_REPORT_GENERATOR))

          // The target itself and run_under both run on the same machine. We use the DATA config
          // here because the run_under acts like a data dependency (e.g. no LIPO optimization).
          .add(attr(":run_under", LABEL).cfg(DATA).value(RUN_UNDER)
              .skipPrereqValidatorCheck())
          .build();
    }

    @Override
    public Metadata getMetadata() {
      return RuleDefinition.Metadata.builder()
          .name("$test_base_rule")
          .type(RuleClassType.ABSTRACT)
          .build();
    }
  }

  /**
   * Share common attributes across both base and Skylark base rules.
   */
  public static RuleClass.Builder commonCoreAndSkylarkAttributes(RuleClass.Builder builder) {
    return builder
        // The visibility attribute is special: it is a nodep label, and loading the
        // necessary package groups is handled by {@link LabelVisitor#visitTargetVisibility}.
        // Package groups always have the null configuration so that they are not duplicated
        // needlessly.
        .add(attr("visibility", NODEP_LABEL_LIST).orderIndependent().cfg(HOST)
            .nonconfigurable("special attribute integrated more deeply into Bazel's core logic"))
        .add(attr("deprecation", STRING).value(deprecationDefault)
            .nonconfigurable("Used in core loading phase logic with no access to configs"))
        .add(attr("tags", STRING_LIST).orderIndependent().taggable()
            .nonconfigurable("low-level attribute, used in TargetUtils without configurations"))
        .add(attr("generator_name", STRING).undocumented("internal")
            .nonconfigurable("static structure of a rule"))
        .add(attr("generator_function", STRING).undocumented("internal")
            .nonconfigurable("static structure of a rule"))
        .add(attr("generator_location", STRING).undocumented("internal")
            .nonconfigurable("static structure of a rule"))
        .add(attr("testonly", BOOLEAN).value(testonlyDefault)
            .nonconfigurable("policy decision: rules testability should be consistent"))
        .add(attr("features", STRING_LIST).orderIndependent())
        .add(attr(":action_listener", LABEL_LIST).cfg(HOST).value(ACTION_LISTENER))
        .add(attr(RuleClass.COMPATIBLE_ENVIRONMENT_ATTR, LABEL_LIST)
            .allowedRuleClasses(EnvironmentRule.RULE_NAME)
            .cfg(Attribute.ConfigurationTransition.HOST)
            .allowedFileTypes(FileTypeSet.NO_FILE))
        .add(attr(RuleClass.RESTRICTED_ENVIRONMENT_ATTR, LABEL_LIST)
            .allowedRuleClasses(EnvironmentRule.RULE_NAME)
            .cfg(Attribute.ConfigurationTransition.HOST)
            .allowedFileTypes(FileTypeSet.NO_FILE));
  }

  /**
   * Common parts of rules.
   */
  public static final class BaseRule implements RuleDefinition {
    @Override
    public RuleClass build(RuleClass.Builder builder, RuleDefinitionEnvironment env) {
      return commonCoreAndSkylarkAttributes(builder)
          // The name attribute is handled specially, so it does not appear here.
          //
          // Aggregates the labels of all {@link ConfigRuleClasses} rules this rule uses (e.g.
          // keys for configurable attributes). This is specially populated in
          // {@RuleClass#populateRuleAttributeValues}.
          //
          // This attribute is not needed for actual builds. Its main purpose is so query's
          // proto/XML output includes the labels of config dependencies, so, e.g., depserver
          // reverse dependency lookups remain accurate. These can't just be added to the
          // attribute definitions proto/XML queries already output because not all attributes
          // contain labels.
          //
          // Builds and Blaze-interactive queries don't need this because they find dependencies
          // through direct Rule label visitation, which already factors these in.
          .add(attr("$config_dependencies", LABEL_LIST)
              .nonconfigurable("not intended for actual builds"))
          .add(attr("licenses", LICENSE)
              .nonconfigurable("Used in core loading phase logic with no access to configs"))
          .add(attr("distribs", DISTRIBUTIONS)
              .nonconfigurable("Used in core loading phase logic with no access to configs"))
          .build();
    }

    @Override
    public Metadata getMetadata() {
      return RuleDefinition.Metadata.builder()
          .name("$base_rule")
          .type(RuleClassType.ABSTRACT)
          .build();
    }
  }

  /**
   * Common ancestor class for all rules.
   */
  public static final class RuleBase implements RuleDefinition {
    @Override
    public RuleClass build(Builder builder, RuleDefinitionEnvironment env) {
      return builder
          .add(attr("deps", LABEL_LIST).legacyAllowAnyFileType())
          .add(attr("data", LABEL_LIST).cfg(DATA).allowedFileTypes(FileTypeSet.ANY_FILE))
          .build();
    }

    @Override
    public Metadata getMetadata() {
      return RuleDefinition.Metadata.builder()
          .name("$rule")
          .type(RuleClassType.ABSTRACT)
          .ancestors(BaseRule.class)
          .build();
    }
  }
}