// Copyright (c) 2017, 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.ir.optimize;

import static com.android.tools.r8.utils.codeinspector.Matchers.isAbsent;
import static org.hamcrest.MatcherAssert.assertThat;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertTrue;
import static org.junit.Assume.assumeFalse;

import com.android.tools.r8.TestBase;
import com.android.tools.r8.TestParameters;
import com.android.tools.r8.ToolHelper;
import com.android.tools.r8.ToolHelper.DexVm.Version;
import com.android.tools.r8.ToolHelper.ProcessResult;
import com.android.tools.r8.graph.AppView;
import com.android.tools.r8.graph.DexEncodedMethod;
import com.android.tools.r8.graph.DexMethod;
import com.android.tools.r8.graph.DexProgramClass;
import com.android.tools.r8.graph.DexType;
import com.android.tools.r8.horizontalclassmerging.HorizontallyMergedClasses;
import com.android.tools.r8.synthesis.SyntheticItemsTestUtils;
import com.android.tools.r8.utils.BooleanUtils;
import com.android.tools.r8.utils.DescriptorUtils;
import com.android.tools.r8.utils.FileUtils;
import com.android.tools.r8.utils.IntBox;
import com.android.tools.r8.utils.ZipUtils;
import com.android.tools.r8.utils.codeinspector.ClassSubject;
import com.android.tools.r8.utils.codeinspector.CodeInspector;
import com.android.tools.r8.utils.codeinspector.InstructionSubject;
import com.android.tools.r8.utils.codeinspector.InvokeInstructionSubject;
import com.android.tools.r8.utils.codeinspector.MethodSubject;
import com.google.common.collect.ImmutableList;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import org.junit.Before;
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 R8InliningTest extends TestBase {

  private static final String DEFAULT_DEX_FILENAME = "classes.dex";
  private static final String DEFAULT_JAR_FILENAME = "out.jar";
  private static final String DEFAULT_MAP_FILENAME = "proguard.map";
  private static final String NAME = "inlining";
  private static final String KEEP_RULES_FILE = ToolHelper.EXAMPLES_DIR + NAME + "/keep-rules.txt";

  @Parameters(name = "{1}, allow access modification: {0}")
  public static Collection<Object[]> data() {
    return buildParameters(
        BooleanUtils.values(), getTestParameters().withAllRuntimesAndApiLevels().build());
  }

  private final boolean allowAccessModification;
  private final TestParameters parameters;
  private Path outputDir = null;
  private String nullabilityClass = "inlining.Nullability";

  public R8InliningTest(boolean allowAccessModification, TestParameters parameters) {
    this.allowAccessModification = allowAccessModification;
    this.parameters = parameters;
  }

  private Path getInputFile() {
    return Paths.get(ToolHelper.EXAMPLES_BUILD_DIR, NAME + FileUtils.JAR_EXTENSION);
  }

  private Path getGeneratedDexFile() {
    return outputDir.resolve(DEFAULT_DEX_FILENAME);
  }

  private Path getGeneratedFile(Path dir) {
    if (parameters.isDexRuntime()) {
      return dir.resolve(DEFAULT_DEX_FILENAME);
    } else {
      assert parameters.isCfRuntime();
      return dir.resolve(DEFAULT_JAR_FILENAME);
    }
  }

  private Path getGeneratedFile() {
    return getGeneratedFile(outputDir);
  }

  private String getGeneratedProguardMap() {
    Path mapFile = outputDir.resolve(DEFAULT_MAP_FILENAME);
    if (Files.exists(mapFile)) {
      return mapFile.toAbsolutePath().toString();
    }
    return null;
  }

  private void fixInliningNullabilityClass(
      AppView<?> appView, HorizontallyMergedClasses horizontallyMergedClasses) {
    DexType originalType =
        appView
            .dexItemFactory()
            .createType(DescriptorUtils.javaTypeToDescriptor("inlining.Nullability"));
    nullabilityClass =
        horizontallyMergedClasses
            .getMergeTargetOrDefault(originalType, originalType)
            .toSourceString();
  }

  private void generateR8Version(Path out, Path mapFile, boolean inlining) throws Exception {
    assert parameters.isDexRuntime() || parameters.isCfRuntime();
    testForR8(parameters.getBackend())
        .addProgramFiles(getInputFile())
        .addLibraryFiles(ToolHelper.getMostRecentAndroidJar())
        .addKeepRuleFiles(Paths.get(KEEP_RULES_FILE))
        .addOptionsModification(
            o -> {
              // Disable class inlining to prevent that the instantiation of Nullability is removed,
              // and that the class is therefore made abstract.
              o.enableClassInlining = false;
              o.inlinerOptions().enableInlining = inlining;
              o.inlinerOptions().enableInliningOfInvokesWithNullableReceivers = false;
              o.inlinerOptions().simpleInliningInstructionLimit = 7;
              o.testing.horizontallyMergedClassesConsumer = this::fixInliningNullabilityClass;
              o.testing.horizontalClassMergingTarget =
                  (appView, candidates, target) -> {
                    for (DexProgramClass candidate : candidates) {
                      if (SyntheticItemsTestUtils.isEnumUnboxingSharedUtilityClass(
                          candidate.getClassReference())) {
                        return candidate;
                      }
                    }
                    return target;
                  };
            })
        .allowAccessModification(allowAccessModification)
        .enableProguardTestOptions()
        .addDontObfuscate()
        .setMinApi(parameters)
        .compile()
        .applyIf(
            parameters.isCfRuntime(),
            result -> result.writeToZip(out.resolve(DEFAULT_JAR_FILENAME)),
            result -> result.writeSingleDexOutputToFile(out.resolve(DEFAULT_DEX_FILENAME)))
        .applyIf(mapFile != null, result -> result.writeProguardMap(mapFile));
  }

  @Before
  public void generateR8Version() throws Exception {
    // Triggers ART failure. See also b/205481246.
    assumeFalse(parameters.isDexRuntimeVersion(Version.V6_0_1));
    outputDir = temp.newFolder().toPath();
    Path mapFile = outputDir.resolve(DEFAULT_MAP_FILENAME);
    generateR8Version(outputDir, mapFile, true);
    String output;
    if (parameters.isDexRuntime()) {
      output =
          ToolHelper.runArtNoVerificationErrors(
              Collections.singletonList(outputDir.resolve(DEFAULT_DEX_FILENAME).toString()),
              "inlining.Inlining",
              builder -> {},
              parameters.getRuntime().asDex().getVm());
    } else {
      assert parameters.isCfRuntime();
      output =
          ToolHelper.runJava(
                  parameters.getRuntime().asCf(),
                  Collections.singletonList("-noverify"),
                  Collections.singletonList(outputDir.resolve(DEFAULT_JAR_FILENAME)),
                  "inlining.Inlining")
              .stdout;
    }

    // Compare result with Java to make sure we have the same behavior.
    ProcessResult javaResult = ToolHelper.runJava(getInputFile(), "inlining.Inlining");
    assertEquals(0, javaResult.exitCode);
    assertEquals(javaResult.stdout, output);
  }

  private void checkAbsentBooleanMethod(ClassSubject clazz, String name) {
    checkAbsent(clazz, "boolean", name, Collections.emptyList());
  }

  private void checkAbsent(ClassSubject clazz, String returnType, String name, List<String> args) {
    assertTrue(clazz.isPresent());
    MethodSubject method = clazz.method(returnType, name, args);
    assertFalse(method.isPresent());
  }

  private void dump(DexEncodedMethod method) {
    System.out.println(method);
    System.out.println(method.codeToString());
  }

  private void dump(Path path, String title) throws Throwable {
    System.out.println(title + ":");
    CodeInspector inspector = new CodeInspector(path.toAbsolutePath());
    inspector.clazz("inlining.Inlining").forAllMethods(m -> dump(m.getMethod()));
    System.out.println(title + " size: " + Files.size(path));
  }

  @Test
  public void checkNoInvokes() throws Throwable {
    CodeInspector inspector =
        new CodeInspector(ImmutableList.of(getGeneratedFile()), getGeneratedProguardMap(), null);
    ClassSubject clazz = inspector.clazz("inlining.Inlining");

    // Simple constant inlining.
    checkAbsentBooleanMethod(clazz, "longExpression");
    checkAbsentBooleanMethod(clazz, "intExpression");
    checkAbsentBooleanMethod(clazz, "doubleExpression");
    checkAbsentBooleanMethod(clazz, "floatExpression");
    // Simple return argument inlining.
    checkAbsentBooleanMethod(clazz, "longArgumentExpression");
    checkAbsentBooleanMethod(clazz, "intArgumentExpression");
    checkAbsentBooleanMethod(clazz, "doubleArgumentExpression");
    checkAbsentBooleanMethod(clazz, "floatArgumentExpression");
    // Static method calling interface method. The interface method implementation is in
    // a private class in another package.
    checkAbsent(clazz, "int", "callInterfaceMethod", ImmutableList.of("inlining.IFace"));

    clazz = inspector.clazz(nullabilityClass);
    checkAbsentBooleanMethod(clazz, "inlinableWithPublicField");
    checkAbsentBooleanMethod(clazz, "inlinableWithControlFlow");
  }

  private long sumOfClassFileSizes(Path dir) throws IOException {
    IntBox size = new IntBox();
    ZipUtils.iter(getGeneratedFile(dir), (a, b) -> size.increment((int) a.getSize()));
    return size.get();
  }

  @Test
  public void processedFileIsSmaller() throws Throwable {
    Path nonInlinedOutputDir = temp.newFolder().toPath();
    generateR8Version(nonInlinedOutputDir, null, false);

    long nonInlinedSize, inlinedSize;
    if (parameters.isDexRuntime()) {
      Path nonInlinedDexFile = nonInlinedOutputDir.resolve(DEFAULT_DEX_FILENAME);
      nonInlinedSize = Files.size(nonInlinedDexFile);
      inlinedSize = Files.size(getGeneratedDexFile());
    } else {
      assert parameters.isCfRuntime();
      nonInlinedSize = sumOfClassFileSizes(nonInlinedOutputDir);
      inlinedSize = sumOfClassFileSizes(outputDir);
    }
    assertTrue("Inlining failed to reduce size", nonInlinedSize > inlinedSize);
  }

  // Count invokes of callee in two code sections in Inlining.main(). The section boundaries are
  // marked with a bunch of calls to the marker0(), marker1() and marker2() methods.
  private static int[] countInvokes(CodeInspector inspector, MethodSubject callee) {
    // 'counters' counts the number of calls (invoke) to callee between marker0/1 and between
    // marker1/2.
    int[] counters = {0, 0};

    if (!callee.isPresent()) {
      // Method is not present, no invokes, only inlined uses possible.
      return counters;
    }

    ClassSubject clazz = inspector.clazz("inlining.Inlining");
    MethodSubject m = clazz.method("void", "main", ImmutableList.of("java.lang.String[]"));
    assertTrue(m.isPresent());

    // Find DexMethods for the marker0, marker1, marker2 methods.
    DexMethod[] markers = new DexMethod[3];
    for (int i = 0; i < 3; ++i) {
      MethodSubject markerSubject = clazz.method("void", "marker" + i, Collections.emptyList());
      assertTrue(markerSubject.isPresent());
      markers[i] = markerSubject.getMethod().getReference();
    }

    // Count invokes to callee between markers.
    Iterator<InstructionSubject> iterator = m.iterateInstructions();
    int phase = -1;
    while (iterator.hasNext()) {
      InstructionSubject instruction = iterator.next();
      if (!instruction.isInvoke()) {
        continue;
      }

      DexMethod target = ((InvokeInstructionSubject) instruction).invokedMethod();

      if (target == callee.getMethod().getReference()) {
        assertTrue(phase == 0 || phase == 1);
        ++counters[phase];
        continue;
      }

      for (int i = 0; i <= 2; ++i) {
        if (target == markers[i]) {
          assertTrue(phase == i - 1 || phase == i); // Make sure markers found in order.
          phase = i;
          break;
        }
      }
    }
    assertEquals(2, phase);
    return counters;
  }

  private static void assertCounters(int expected0, int expected1, int[] counters) {
    assert counters.length == 2;
    assertEquals(expected0, counters[0]);
    assertEquals(expected1, counters[1]);
  }

  @Test
  public void invokeOnNullableReceiver() throws Exception {
    CodeInspector inspector =
        new CodeInspector(ImmutableList.of(getGeneratedFile()), getGeneratedProguardMap(), null);

    // These constants describe the expected number of invoke instructions calling a possibly
    // inlined method.
    int ALWAYS_INLINABLE = 0;
    int INLINABLE_WHEN_DISABLED = allowAccessModification && parameters.isDexRuntime() ? 1 : 0;
    int NEVER_INLINABLE = 1;

    ClassSubject clazz = inspector.clazz(nullabilityClass);
    MethodSubject m;

    m = clazz.method("int", "inlinable", ImmutableList.of("inlining.A"));
    assertCounters(ALWAYS_INLINABLE, ALWAYS_INLINABLE, countInvokes(inspector, m));

    m =
        clazz.method(
            allowAccessModification ? "void" : "int",
            "notInlinable",
            ImmutableList.of("inlining." + (allowAccessModification ? "B" : "A")));
    assertCounters(ALWAYS_INLINABLE, INLINABLE_WHEN_DISABLED, countInvokes(inspector, m));

    m = clazz.method("int", "notInlinableDueToMissingNpe", ImmutableList.of("inlining.A"));
    assertCounters(ALWAYS_INLINABLE, ALWAYS_INLINABLE, countInvokes(inspector, m));

    m = clazz.method("int", "notInlinableDueToSideEffect", ImmutableList.of("inlining.A"));
    assertCounters(
        parameters.isCfRuntime() ? ALWAYS_INLINABLE : NEVER_INLINABLE,
        NEVER_INLINABLE,
        countInvokes(inspector, m));

    m =
        clazz.method(
            "void", "notInlinableOnThrow", ImmutableList.of("java.lang.IllegalArgumentException"));
    assertCounters(ALWAYS_INLINABLE, NEVER_INLINABLE, countInvokes(inspector, m));

    m =
        clazz.method(
            "void",
            "notInlinableDueToMissingNpeBeforeThrow",
            ImmutableList.of("java.lang.IllegalArgumentException"));
    assertCounters(ALWAYS_INLINABLE, NEVER_INLINABLE * 2, countInvokes(inspector, m));
  }

  @Test
  public void invokeOnNonNullReceiver() throws Exception {
    CodeInspector inspector =
        new CodeInspector(ImmutableList.of(getGeneratedFile()), getGeneratedProguardMap(), null);
    ClassSubject clazz = inspector.clazz(nullabilityClass);
    assertThat(clazz.uniqueMethodWithOriginalName("conditionalOperator"), isAbsent());

    // The enum parameter is unboxed.
    MethodSubject m = clazz.uniqueMethodWithOriginalName("moreControlFlows");
    assertTrue(m.isPresent());

    // Verify that a.b() is resolved to an inline instance-get.
    Iterator<InstructionSubject> iterator = m.iterateInstructions();
    int instanceGetCount = 0;
    int invokeCount = 0;
    while (iterator.hasNext()) {
      InstructionSubject instruction = iterator.next();
      if (instruction.isInstanceGet()) {
        ++instanceGetCount;
      } else if (instruction.isInvoke()) {
        ++invokeCount;
      }
    }
    assertEquals(1, instanceGetCount);
    assertEquals(0, invokeCount);
  }
}