// 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.classlookup;

import static com.android.tools.r8.utils.codeinspector.Matchers.isPresent;
import static org.hamcrest.MatcherAssert.assertThat;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.fail;
import static org.junit.Assume.assumeTrue;

import com.android.tools.r8.CompilationFailedException;
import com.android.tools.r8.Diagnostic;
import com.android.tools.r8.R8FullTestBuilder;
import com.android.tools.r8.TestBase;
import com.android.tools.r8.TestParameters;
import com.android.tools.r8.TestParametersCollection;
import com.android.tools.r8.jasmin.JasminBuilder;
import com.android.tools.r8.utils.AndroidApiLevel;
import com.android.tools.r8.utils.codeinspector.CodeInspector;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.ImmutableSet.Builder;
import java.util.List;
import java.util.Set;
import org.hamcrest.CoreMatchers;
import org.junit.BeforeClass;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;

// This test used to test R8 errors/warnings when library class extends program class. Before
// the change fixing b/120884788, that could easily happen as lookup would lookup in program
// classes before library classes, and the Android library included parts of JUnit, which could
// also easily end up as program classes when JUnit was used by a program.
//
// Now that library classes are looked up before program classes these JUnit classes will be
// found in the library and the ones in program will be ignored and not end up in the output.
//
// For a D8 compilation any class passed as input will end up in the output.
@RunWith(Parameterized.class)
public class LibraryClassExtendsProgramClassTest extends TestBase {

  private static String[] libraryClassesExtendingTestCase =
      new String[] {
        "android.test.InstrumentationTestCase",
        "android.test.AndroidTestCase",
        "android.test.suitebuilder.TestSuiteBuilder$FailedToCreateTests"
      };

  private static List<byte[]> junitClasses;

  @BeforeClass
  public static void setUp() throws Exception {
    JasminBuilder builder = new JasminBuilder();
    builder.addClass("junit.framework.TestCase");
    junitClasses = builder.buildClasses();
  }

  private final TestParameters parameters;

  @Parameterized.Parameters(name = "{0}")
  public static TestParametersCollection data() {
    return getTestParameters().withAllRuntimes().withAllApiLevels().build();
  }

  public LibraryClassExtendsProgramClassTest(TestParameters parameters) {
    this.parameters = parameters;
  }

  // The default library in the test runner is chosen to be the first one with at least the API
  // level. The junit testing framework was removed in P.
  private boolean libraryContainsJUnit() {
    return parameters.isDexRuntime()
        && parameters.getApiLevel().getLevel() < AndroidApiLevel.P.getLevel();
  }

  private void checkClassesInResult(CodeInspector inspector) {
    if (libraryContainsJUnit()) {
      noClassesInResult(inspector);
    } else {
      testCaseClassInResult(inspector);
    }
  }

  private void noClassesInResult(CodeInspector inspector) {
    assertEquals(1, inspector.allClasses().size());
    assertThat(inspector.clazz(TestClass.class), isPresent());
  }

  private void testCaseClassInResult(CodeInspector inspector) {
    assertEquals(2, inspector.allClasses().size());
    assertThat(inspector.clazz("junit.framework.TestCase"), isPresent());
    assertThat(inspector.clazz(TestClass.class), isPresent());
  }

  private void checkDiagnostics(List<Diagnostic> diagnostics) {
    Builder<String> builder = ImmutableSet.builder();
    for (String libraryClass : libraryClassesExtendingTestCase) {
      builder.add(
          "Library class " + libraryClass + " extends program class junit.framework.TestCase");
    }
    Set<String> expected = builder.build();
    for (Diagnostic diagnostic : diagnostics) {
      assertThat(expected, CoreMatchers.hasItem(diagnostic.getDiagnosticMessage()));
    }
    assertEquals(expected.size(), diagnostics.size());
  }

  @Test
  public void testFullMode() throws Exception {
    testForR8(parameters.getBackend())
        .setMinApi(parameters.getApiLevel())
        .addProgramClasses(TestClass.class)
        .addProgramClassFileData(junitClasses)
        .addKeepAllClassesRule()
        // TODO(120884788): Remove when this is the default.
        .addOptionsModification(options -> options.lookupLibraryBeforeProgram = true)
        .compile()
        .inspect(this::checkClassesInResult)
        .assertNoMessages();
  }

  @Test
  public void testCompatibilityMode() throws Exception {
    testForR8Compat(parameters.getBackend())
        .setMinApi(parameters.getApiLevel())
        .addProgramClasses(TestClass.class)
        .addProgramClassFileData(junitClasses)
        .addKeepAllClassesRule()
        // TODO(120884788): Remove when this is the default.
        .addOptionsModification(options -> options.lookupLibraryBeforeProgram = true)
        .compile()
        .inspect(this::checkClassesInResult)
        .assertNoMessages();
  }

  @Test
  public void testD8() throws Exception {
    assumeTrue("Only run D8 for Dex backend", parameters.isDexRuntime());
    testForD8()
        .setMinApi(parameters.getApiLevel())
        .addProgramClasses(TestClass.class)
        .addProgramClassFileData(junitClasses)
        .compile()
        .inspect(this::testCaseClassInResult)
        .assertNoMessages();
  }

  @Test
  public void testFullModeError() throws Exception {
    R8FullTestBuilder builder =
        testForR8(parameters.getBackend())
            .setMinApi(parameters.getApiLevel())
            .addProgramClasses(TestClass.class)
            .addProgramClassFileData(junitClasses)
            .addKeepAllClassesRule()
            .addOptionsModification(options -> options.lookupLibraryBeforeProgram = false);
    if (!libraryContainsJUnit()) {
      builder.compile().inspect(this::testCaseClassInResult).assertNoMessages();
      return;
    }
    try {
      builder.compileWithExpectedDiagnostics(
          diagnostics -> {
            diagnostics.assertOnlyErrors();
            checkDiagnostics(diagnostics.getErrors());
          });
      fail("Expected compilation failure");
    } catch (CompilationFailedException e) {
      // Expected exception.
    }
  }

  @Test
  public void testCompatibilityModeWarning() throws Exception {
    testForR8Compat(parameters.getBackend())
        .setMinApi(parameters.getApiLevel())
        .addProgramClasses(TestClass.class)
        .addProgramClassFileData(junitClasses)
        .addKeepAllClassesRule()
        .addOptionsModification(options -> options.lookupLibraryBeforeProgram = false)
        .compileWithExpectedDiagnostics(
            diagnostics -> {
              if (libraryContainsJUnit()) {
                diagnostics.assertOnlyWarnings();
                checkDiagnostics(diagnostics.getWarnings());
              } else {
                diagnostics.assertNoMessages();
              }
            })
        .inspect(this::testCaseClassInResult);
  }

  @Test
  public void testWithDontWarn() throws Exception {
    testForR8(parameters.getBackend())
        .setMinApi(parameters.getApiLevel())
        .addProgramClassFileData(junitClasses)
        .addKeepAllClassesRule()
        .addKeepRules("-dontwarn android.test.**")
        .addOptionsModification(options -> options.lookupLibraryBeforeProgram = false)
        .compile()
        .assertNoMessages();
  }

  static class TestClass {

    public static void main(String[] args) throws Exception {
      // Ensure that the problematic library types are actually live.
      Class.forName("android.test.InstrumentationTestCase").getDeclaredConstructor().newInstance();
      Class.forName("android.test.AndroidTestCase").getDeclaredConstructor().newInstance();
      Class.forName("android.test.suitebuilder.TestSuiteBuilder$FailedToCreateTests")
          .getDeclaredConstructor()
          .newInstance();
    }
  }
}