// 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.shaking;

import static com.android.tools.r8.ToolHelper.EXAMPLES_BUILD_DIR;
import static com.android.tools.r8.ToolHelper.EXAMPLES_DIR;

import com.android.tools.r8.CompilationFailedException;
import com.android.tools.r8.Diagnostic;
import com.android.tools.r8.DiagnosticsHandler;
import com.android.tools.r8.OutputMode;
import com.android.tools.r8.R8;
import com.android.tools.r8.R8Command;
import com.android.tools.r8.TestBase.Backend;
import com.android.tools.r8.ToolHelper;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.PrintStream;
import java.io.StringReader;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Arrays;
import java.util.Collection;
import java.util.stream.Collectors;
import java.util.stream.Stream;
import org.junit.Assert;
import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.ExpectedException;
import org.junit.rules.TemporaryFolder;
import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;
import org.junit.runners.Parameterized.Parameters;

@RunWith(Parameterized.class)
public class TreeShakingSpecificTest {

  private Backend backend;

  @Parameters(name = "Backend: {0}")
  public static Collection<Backend> data() {
    return Arrays.asList(Backend.values());
  }

  public TreeShakingSpecificTest(Backend backend) {
    this.backend = backend;
  }

  private static final String VALID_PROGUARD_DIR = "src/test/proguard/valid/";

  @Rule
  public TemporaryFolder temp = ToolHelper.getTemporaryFolderForTest();

  @Rule
  public ExpectedException thrown = ExpectedException.none();

  private void finishBuild(R8Command.Builder builder, Path out, String test) throws IOException {
    Path input;
    if (backend == Backend.DEX) {
      builder.setOutput(out, OutputMode.DexIndexed);
      input = Paths.get(EXAMPLES_BUILD_DIR, test, "classes.dex");
    } else {
      builder.setOutput(out, OutputMode.ClassFile);
      input = Paths.get(EXAMPLES_BUILD_DIR, test + ".jar");
    }
    ToolHelper.getAppBuilder(builder).addProgramFiles(input);
  }

  @Test
  public void testIgnoreWarnings() throws Exception {
    // Generate R8 processed version without library option.
    Path out = temp.getRoot().toPath();
    String test = "shaking2";
    Path keepRules = Paths.get(EXAMPLES_DIR, test, "keep-rules.txt");
    Path ignoreWarnings = Paths.get(VALID_PROGUARD_DIR, "ignorewarnings.flags");
    R8Command.Builder builder = R8Command.builder()
        .addProguardConfigurationFiles(keepRules, ignoreWarnings);
    finishBuild(builder, out, test);
    R8.run(builder.build());
  }

  @Test(expected = CompilationFailedException.class)
  public void testMissingLibrary() throws Exception {
    // Generate R8 processed version without library option.
    Path out = temp.getRoot().toPath();
    String test = "shaking2";
    Path keepRules = Paths.get(EXAMPLES_DIR, test, "keep-rules.txt");
    DiagnosticsHandler handler =
        new DiagnosticsHandler() {
          @Override
          public void error(Diagnostic error) {
            String expectedErrorMessage =
                "Compilation can't be completed because the class `java.lang.Object` is missing";
            if (error.getDiagnosticMessage().contains(expectedErrorMessage)) {
              return;
            }
            throw new RuntimeException("Unexpected compilation error");
          }
        };
    R8Command.Builder builder = R8Command.builder(handler)
        .addProguardConfigurationFiles(keepRules);
    finishBuild(builder, out, test);
    R8.run(builder.build());
  }

  @Test
  public void testPrintMapping() throws Exception {
    // Generate R8 processed version without library option.
    String test = "shaking1";
    Path out = temp.getRoot().toPath();
    Path keepRules = Paths.get(EXAMPLES_DIR, test, "keep-rules.txt");

    // Create a flags file in temp dir requesting dump of the mapping.
    // The mapping file will be created alongside the flags file in temp dir.
    Path printMapping = out.resolve("printmapping.flags");
    try (PrintStream mapping = new PrintStream(printMapping.toFile())) {
      mapping.println("-printmapping mapping.txt");
    }

    R8Command.Builder builder = R8Command.builder()
        .addProguardConfigurationFiles(keepRules, printMapping);
    // Turn off inlining, as we want the mapping that is printed to be stable.
    finishBuild(builder, out, test);
    if (backend == Backend.DEX) {
      builder.addLibraryFiles(ToolHelper.getDefaultAndroidJar());
    } else {
      assert backend == Backend.CF;
      builder.addLibraryFiles(ToolHelper.getJava8RuntimeJar());
    }
    ToolHelper.runR8(builder.build(), options -> options.enableInlining = false);

    Path outputmapping = out.resolve("mapping.txt");
    // Remove comments.
    String actualMapping =
        Stream.of(new String(Files.readAllBytes(outputmapping), StandardCharsets.UTF_8).split("\n"))
            .filter(line -> !line.startsWith("#"))
            .collect(Collectors.joining("\n"));
    String refMapping =
        new String(
            Files.readAllBytes(
                Paths.get(
                    EXAMPLES_DIR,
                    "shaking1",
                    "print-mapping-" + backend.name().toLowerCase() + ".ref")),
            StandardCharsets.UTF_8);
    Assert.assertEquals(sorted(refMapping), sorted(actualMapping));
  }

  private static String sorted(String str) {
    return new BufferedReader(new StringReader(str))
        .lines().sorted().filter(s -> !s.isEmpty()).collect(Collectors.joining("\n"));
  }
}