// Copyright (c) 2018, the R8 project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
package com.android.tools.r8.resolution;

import static org.junit.Assert.assertTrue;

import com.android.tools.r8.AsmTestBase;
import com.android.tools.r8.dex.ApplicationReader;
import com.android.tools.r8.graph.AppInfo;
import com.android.tools.r8.graph.AppInfoWithSubtyping;
import com.android.tools.r8.graph.AppServices;
import com.android.tools.r8.graph.AppView;
import com.android.tools.r8.graph.DexApplication;
import com.android.tools.r8.graph.DexEncodedMethod;
import com.android.tools.r8.graph.DexItemFactory;
import com.android.tools.r8.graph.DexMethod;
import com.android.tools.r8.graph.DexType;
import com.android.tools.r8.graph.ResolutionResult;
import com.android.tools.r8.resolution.singletarget.Main;
import com.android.tools.r8.resolution.singletarget.one.AbstractSubClass;
import com.android.tools.r8.resolution.singletarget.one.AbstractTopClass;
import com.android.tools.r8.resolution.singletarget.one.InterfaceWithDefault;
import com.android.tools.r8.resolution.singletarget.one.IrrelevantInterfaceWithDefault;
import com.android.tools.r8.resolution.singletarget.one.IrrelevantInterfaceWithDefaultDump;
import com.android.tools.r8.resolution.singletarget.one.SubSubClassOne;
import com.android.tools.r8.resolution.singletarget.one.SubSubClassThree;
import com.android.tools.r8.resolution.singletarget.one.SubSubClassTwo;
import com.android.tools.r8.resolution.singletarget.three.ThirdAbstractTopClass;
import com.android.tools.r8.resolution.singletarget.three.ThirdSubClassOne;
import com.android.tools.r8.resolution.singletarget.three.ThirdSubClassTwoDump;
import com.android.tools.r8.resolution.singletarget.two.OtherAbstractSubClassOne;
import com.android.tools.r8.resolution.singletarget.two.OtherAbstractSubClassTwo;
import com.android.tools.r8.resolution.singletarget.two.OtherAbstractTopClass;
import com.android.tools.r8.resolution.singletarget.two.OtherSubSubClassOne;
import com.android.tools.r8.resolution.singletarget.two.OtherSubSubClassTwo;
import com.android.tools.r8.shaking.AppInfoWithLiveness;
import com.android.tools.r8.shaking.EnqueuerFactory;
import com.android.tools.r8.shaking.ProguardClassFilter;
import com.android.tools.r8.shaking.ProguardClassNameList;
import com.android.tools.r8.shaking.ProguardConfigurationRule;
import com.android.tools.r8.shaking.ProguardKeepRule;
import com.android.tools.r8.shaking.ProguardKeepRule.Builder;
import com.android.tools.r8.shaking.ProguardKeepRuleType;
import com.android.tools.r8.shaking.ProguardTypeMatcher;
import com.android.tools.r8.shaking.RootSetBuilder;
import com.android.tools.r8.shaking.RootSetBuilder.RootSet;
import com.android.tools.r8.utils.AndroidApp;
import com.android.tools.r8.utils.DescriptorUtils;
import com.android.tools.r8.utils.InternalOptions;
import com.android.tools.r8.utils.Timing;
import com.google.common.collect.ImmutableList;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.stream.Collectors;
import org.junit.Assert;
import org.junit.BeforeClass;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;
import org.junit.runners.Parameterized.Parameters;

@RunWith(Parameterized.class)
public class SingleTargetLookupTest extends AsmTestBase {

  /**
   * Initialized in @Before rule.
   */
  public static AppInfoWithLiveness appInfo;

  public static List<Class<?>> CLASSES =
      ImmutableList.of(
          InterfaceWithDefault.class,
          AbstractTopClass.class,
          AbstractSubClass.class,
          SubSubClassOne.class,
          SubSubClassTwo.class,
          SubSubClassThree.class,
          OtherAbstractTopClass.class,
          OtherAbstractSubClassOne.class,
          OtherAbstractSubClassTwo.class,
          OtherSubSubClassOne.class,
          OtherSubSubClassTwo.class,
          ThirdAbstractTopClass.class,
          ThirdSubClassOne.class,
          Main.class);

  public static List<byte[]> ASM_CLASSES = ImmutableList.of(
      getBytesFromAsmClass(IrrelevantInterfaceWithDefaultDump::dump),
      getBytesFromAsmClass(ThirdSubClassTwoDump::dump)
  );

  public SingleTargetLookupTest(
      String methodName,
      Class invokeReceiver,
      Class singleTargetHolderOrNull,
      List<Class> allTargetHolders) {
    this.methodName = methodName;
    this.invokeReceiver = invokeReceiver;
    this.singleTargetHolderOrNull = singleTargetHolderOrNull;
    this.allTargetHolders = allTargetHolders;
  }

  public static AppInfoWithLiveness createAppInfoWithLiveness(AndroidApp app, Class<?> mainClass)
      throws Exception {
    // Run the tree shaker to compute an instance of AppInfoWithLiveness.
    Timing timing = new Timing();
    InternalOptions options = new InternalOptions();
    DexApplication application = new ApplicationReader(app, options, timing).read().toDirect();
    AppView<? extends AppInfoWithSubtyping> appView =
        AppView.createForR8(new AppInfoWithSubtyping(application), options);
    appView.setAppServices(AppServices.builder(appView).build());

    ExecutorService executor = Executors.newSingleThreadExecutor();
    RootSet rootSet =
        new RootSetBuilder(
                appView, application, buildKeepRuleForClass(mainClass, application.dexItemFactory))
            .run(executor);
    return EnqueuerFactory.createForInitialTreeShaking(appView)
        .traceApplication(rootSet, ProguardClassFilter.empty(), executor, timing);
    // We do not run the tree pruner to ensure that the hierarchy is as designed and not modified
    // due to liveness.
  }

  @BeforeClass
  public static void computeAppInfo() throws Exception {
    appInfo = createAppInfoWithLiveness(readClassesAndAsmDump(CLASSES, ASM_CLASSES), Main.class);
  }

  private static List<ProguardConfigurationRule> buildKeepRuleForClass(Class clazz,
      DexItemFactory factory) {
    Builder keepRuleBuilder = ProguardKeepRule.builder();
    keepRuleBuilder.setSource("buildKeepRuleForClass " + clazz.getTypeName());
    keepRuleBuilder.setType(ProguardKeepRuleType.KEEP);
    keepRuleBuilder.setClassNames(
        ProguardClassNameList.singletonList(
            ProguardTypeMatcher.create(
                factory.createType(DescriptorUtils.javaTypeToDescriptor(clazz.getTypeName())))));
    return Collections.singletonList(keepRuleBuilder.build());
  }

  private static Object[] singleTarget(String name, Class<?> receiverAndTarget) {
    return new Object[]{name, receiverAndTarget, receiverAndTarget,
        Collections.singletonList(receiverAndTarget)};
  }

  private static Object[] singleTarget(String name, Class<?> receiver, Class<?> target) {
    return new Object[]{name, receiver, target, Collections.singletonList(target)};
  }

  private static Object[] singleTargetWithAbstracts(String name, Class<?> receiver,
      Class<?> target, Class<?>... extras) {
    return new Object[]{name, receiver, target,
        ImmutableList.builder().add(target).add((Object[]) extras).build()};
  }

  private static Object[] manyTargets(String name, Class<?> receiver, Class<?>... targets) {
    return new Object[]{name, receiver, null, ImmutableList.copyOf(targets)};
  }

  private static Object[] onlyUnreachableTargets(String name, Class<?> receiver,
      Class<?>... targets) {
    return new Object[]{name, receiver, null, ImmutableList.copyOf(targets)};
  }

  @Parameters(name = "{1}.{0} -> {2}")
  public static List<Object[]> getData() {
    return ImmutableList.copyOf(
        new Object[][] {
          singleTarget("singleTargetAtTop", AbstractTopClass.class),
          singleTargetWithAbstracts(
              "singleShadowingOverride",
              AbstractTopClass.class,
              AbstractSubClass.class,
              AbstractTopClass.class),
          manyTargets(
              "abstractTargetAtTop",
              AbstractTopClass.class,
              AbstractTopClass.class,
              SubSubClassOne.class,
              SubSubClassTwo.class),
          singleTargetWithAbstracts(
              "overridenInAbstractClassOnly",
              AbstractTopClass.class,
              AbstractTopClass.class,
              SubSubClassThree.class),
          onlyUnreachableTargets(
              "overridenInAbstractClassOnly", SubSubClassThree.class, SubSubClassThree.class),
          manyTargets(
              "overriddenInTwoSubTypes",
              AbstractTopClass.class,
              AbstractTopClass.class,
              SubSubClassOne.class,
              SubSubClassTwo.class),
          manyTargets(
              "definedInTwoSubTypes",
              AbstractTopClass.class,
              AbstractTopClass.class,
              SubSubClassOne.class,
              SubSubClassTwo.class),
          onlyUnreachableTargets("staticMethod", AbstractTopClass.class),
          manyTargets(
              "overriddenInTwoSubTypes",
              OtherAbstractTopClass.class,
              OtherAbstractTopClass.class,
              OtherSubSubClassOne.class,
              OtherSubSubClassTwo.class),
          manyTargets(
              "abstractOverriddenInTwoSubTypes",
              OtherAbstractTopClass.class,
              OtherAbstractTopClass.class,
              OtherSubSubClassOne.class,
              OtherSubSubClassTwo.class),
          manyTargets(
              "overridesOnDifferentLevels",
              OtherAbstractTopClass.class,
              OtherAbstractTopClass.class,
              OtherSubSubClassOne.class,
              OtherAbstractSubClassTwo.class),
          singleTarget("defaultMethod", AbstractTopClass.class, InterfaceWithDefault.class),
          manyTargets(
              "overriddenDefault",
              AbstractTopClass.class,
              InterfaceWithDefault.class,
              SubSubClassTwo.class),
          singleTarget("overriddenDefault", SubSubClassTwo.class),
          singleTarget("overriddenByIrrelevantInterface", AbstractTopClass.class),
          singleTarget(
              "overriddenByIrrelevantInterface", SubSubClassOne.class, AbstractTopClass.class),
          manyTargets(
              "overriddenInOtherInterface",
              AbstractTopClass.class,
              InterfaceWithDefault.class,
              IrrelevantInterfaceWithDefault.class),
          manyTargets(
              "overriddenInOtherInterface",
              SubSubClassOne.class,
              InterfaceWithDefault.class,
              IrrelevantInterfaceWithDefault.class),
          manyTargets(
              "abstractMethod",
              ThirdAbstractTopClass.class,
              ThirdAbstractTopClass.class,
              ThirdSubClassOne.class),
          singleTarget("instanceMethod", ThirdAbstractTopClass.class, ThirdAbstractTopClass.class),
          singleTarget(
              "otherInstanceMethod", ThirdAbstractTopClass.class, ThirdAbstractTopClass.class),
        });
  }

  public static DexMethod buildMethod(Class clazz, String name, AppInfo appInfo) {
    return appInfo
        .dexItemFactory()
        .createMethod(
            toType(clazz, appInfo),
            appInfo.dexItemFactory().createProto(appInfo.dexItemFactory().voidType),
            name);
  }

  public static DexType toType(Class clazz, AppInfo appInfo) {
    return appInfo
        .dexItemFactory()
        .createType(DescriptorUtils.javaTypeToDescriptor(clazz.getTypeName()));
  }

  private final String methodName;
  private final Class invokeReceiver;
  private final Class singleTargetHolderOrNull;
  private final List<Class> allTargetHolders;

  @Test
  public void lookupSingleTarget() {
    DexMethod method = buildMethod(invokeReceiver, methodName, appInfo);
    Assert.assertNotNull(
        appInfo.resolveMethod(toType(invokeReceiver, appInfo), method).asResultOfResolve());
    DexEncodedMethod singleVirtualTarget = appInfo.lookupSingleVirtualTarget(method, method.holder);
    if (singleTargetHolderOrNull == null) {
      Assert.assertNull(singleVirtualTarget);
    } else {
      Assert.assertNotNull(singleVirtualTarget);
      Assert.assertEquals(
          toType(singleTargetHolderOrNull, appInfo), singleVirtualTarget.method.holder);
    }
  }

  @Test
  public void lookupVirtualTargets() {
    DexMethod method = buildMethod(invokeReceiver, methodName, appInfo);
    Assert.assertNotNull(
        appInfo.resolveMethod(toType(invokeReceiver, appInfo), method).asResultOfResolve());
    ResolutionResult resolutionResult = appInfo.resolveMethod(method.holder, method);
    if (resolutionResult.isValidVirtualTarget(appInfo.app().options)) {
      Set<DexEncodedMethod> targets = resolutionResult.lookupVirtualTargets(appInfo);
      Set<DexType> targetHolders =
          targets.stream().map(m -> m.method.holder).collect(Collectors.toSet());
      Assert.assertEquals(allTargetHolders.size(), targetHolders.size());
      assertTrue(
          allTargetHolders.stream().map(t -> toType(t, appInfo)).allMatch(targetHolders::contains));
    } else {
      assertTrue(allTargetHolders.isEmpty());
    }
  }
}