// 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.analysis;

import static com.google.common.truth.Truth.assertThat;
import static org.junit.Assert.assertNotNull;

import com.google.common.collect.ImmutableSet;
import com.google.common.collect.ListMultimap;
import com.google.devtools.build.lib.analysis.config.ConfigMatchingProvider;
import com.google.devtools.build.lib.analysis.util.AnalysisTestCase;
import com.google.devtools.build.lib.analysis.util.TestAspects;
import com.google.devtools.build.lib.analysis.util.TestAspects.AspectRequiringRule;
import com.google.devtools.build.lib.cmdline.Label;
import com.google.devtools.build.lib.collect.nestedset.NestedSetBuilder;
import com.google.devtools.build.lib.packages.Aspect;
import com.google.devtools.build.lib.packages.Attribute;
import com.google.devtools.build.lib.packages.NativeAspectClass;
import com.google.devtools.build.lib.packages.NoSuchPackageException;
import com.google.devtools.build.lib.packages.NoSuchTargetException;
import com.google.devtools.build.lib.packages.NoSuchThingException;
import com.google.devtools.build.lib.packages.Target;
import com.google.devtools.build.lib.testutil.TestRuleClassProvider;

import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;

import javax.annotation.Nullable;

/**
 * Tests for {@link DependencyResolver}.
 *
 * <p>These use custom rules so that all usual and unusual cases related to aspect processing can
 * be tested.
 *
 * <p>It would be nicer is we didn't have a Skyframe executor, if we didn't have that, we'd need a
 * way to create a configuration, a package manager and a whole lot of other things, so it's just
 * easier this way.
 */
@RunWith(JUnit4.class)
public class DependencyResolverTest extends AnalysisTestCase {
  private DependencyResolver dependencyResolver;

  @Before
  public final void createResolver() throws Exception {
    dependencyResolver = new DependencyResolver() {
      @Override
      protected void invalidVisibilityReferenceHook(TargetAndConfiguration node, Label label) {
        throw new IllegalStateException();
      }

      @Override
      protected void invalidPackageGroupReferenceHook(TargetAndConfiguration node, Label label) {
        throw new IllegalStateException();
      }

      @Override
      protected void missingEdgeHook(Target from, Label to, NoSuchThingException e) {
        throw new IllegalStateException(e);
      }

      @Nullable
      @Override
      protected Target getTarget(Target from, Label label, NestedSetBuilder<Label> rootCauses) {
        try {
          return packageManager.getTarget(reporter, label);
        } catch (NoSuchPackageException | NoSuchTargetException | InterruptedException e) {
          throw new IllegalStateException(e);
        }
      }
    };
  }

  private void pkg(String name, String... contents) throws Exception {
    scratch.file("" + name + "/BUILD", contents);
  }

  @SafeVarargs
  private final void setRules(RuleDefinition... rules) throws Exception {
    ConfiguredRuleClassProvider.Builder builder =
        new ConfiguredRuleClassProvider.Builder();
    TestRuleClassProvider.addStandardRules(builder);
    for (RuleDefinition rule : rules) {
      builder.addRuleDefinition(rule);
    }

    useRuleClassProvider(builder.build());
    update();
  }

  private <T extends ConfiguredNativeAspectFactory>
    ListMultimap<Attribute, Dependency> dependentNodeMap(
      String targetName, Class<T> aspect) throws Exception {
    Target target = packageManager.getTarget(reporter, Label.parseAbsolute(targetName));
    return dependencyResolver.dependentNodeMap(
        new TargetAndConfiguration(target, getTargetConfiguration()),
        getHostConfiguration(),
        aspect != null ? Aspect.forNative(new NativeAspectClass<T>(aspect)) : null,
        ImmutableSet.<ConfigMatchingProvider>of());
  }

  @SafeVarargs
  private final void assertDep(
      ListMultimap<Attribute, Dependency> dependentNodeMap,
      String attrName,
      String dep,
      AspectDescriptor... aspects) {
    Attribute attr = null;
    for (Attribute candidate : dependentNodeMap.keySet()) {
      if (candidate.getName().equals(attrName)) {
        attr = candidate;
        break;
      }
    }

    assertNotNull("Attribute '" + attrName + "' not found", attr);
    Dependency dependency = null;
    for (Dependency candidate : dependentNodeMap.get(attr)) {
      if (candidate.getLabel().toString().equals(dep)) {
        dependency = candidate;
        break;
      }
    }

    assertNotNull("Dependency '" + dep + "' on attribute '" + attrName + "' not found", dependency);
    assertThat(dependency.getAspects()).containsExactly((Object[]) aspects);
  }

  @Test
  public void hasAspectsRequiredByRule() throws Exception {
    setRules(new AspectRequiringRule(), new TestAspects.BaseRule());
    pkg("a",
        "aspect(name='a', foo=[':b'])",
        "aspect(name='b', foo=[])");
    ListMultimap<Attribute, Dependency> map = dependentNodeMap("//a:a", null);
    assertDep(
        map, "foo", "//a:b",
        new AspectDescriptor(new NativeAspectClass<>(TestAspects.SimpleAspect.class)));
  }

  @Test
  public void hasAspectsRequiredByAspect() throws Exception {
    setRules(new TestAspects.BaseRule(), new TestAspects.SimpleRule());
    pkg("a",
        "simple(name='a', foo=[':b'])",
        "simple(name='b', foo=[])");
    ListMultimap<Attribute, Dependency> map =
        dependentNodeMap("//a:a", TestAspects.AttributeAspect.class);
    assertDep(
        map, "foo", "//a:b",
        new AspectDescriptor(new NativeAspectClass<>(TestAspects.AttributeAspect.class)));
  }

  @Test
  public void hasAspectDependencies() throws Exception {
    setRules(new TestAspects.BaseRule());
    pkg("a", "base(name='a')");
    pkg("extra", "base(name='extra')");
    ListMultimap<Attribute, Dependency> map =
        dependentNodeMap("//a:a", TestAspects.ExtraAttributeAspect.class);
    assertDep(map, "$dep", "//extra:extra");
  }
}