// Copyright 2014 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.exec;

import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import com.google.devtools.build.lib.actions.ActionExecutionContext;
import com.google.devtools.build.lib.actions.Artifact;
import com.google.devtools.build.lib.actions.EnvironmentalExecException;
import com.google.devtools.build.lib.actions.ExecException;
import com.google.devtools.build.lib.actions.ExecutionStrategy;
import com.google.devtools.build.lib.actions.Executor;
import com.google.devtools.build.lib.actions.SimpleSpawn;
import com.google.devtools.build.lib.actions.Spawn;
import com.google.devtools.build.lib.actions.SpawnActionContext;
import com.google.devtools.build.lib.actions.TestExecException;
import com.google.devtools.build.lib.analysis.RunfilesSupplierImpl;
import com.google.devtools.build.lib.analysis.config.BinTools;
import com.google.devtools.build.lib.events.Event;
import com.google.devtools.build.lib.events.EventKind;
import com.google.devtools.build.lib.events.Reporter;
import com.google.devtools.build.lib.rules.test.TestActionContext;
import com.google.devtools.build.lib.rules.test.TestAttempt;
import com.google.devtools.build.lib.rules.test.TestResult;
import com.google.devtools.build.lib.rules.test.TestRunnerAction;
import com.google.devtools.build.lib.rules.test.TestRunnerAction.ResolvedPaths;
import com.google.devtools.build.lib.util.Pair;
import com.google.devtools.build.lib.util.io.FileOutErr;
import com.google.devtools.build.lib.vfs.FileSystemUtils;
import com.google.devtools.build.lib.vfs.Path;
import com.google.devtools.build.lib.vfs.PathFragment;
import com.google.devtools.build.lib.view.test.TestStatus.BlazeTestStatus;
import com.google.devtools.build.lib.view.test.TestStatus.TestCase;
import com.google.devtools.build.lib.view.test.TestStatus.TestResultData;
import com.google.devtools.build.lib.view.test.TestStatus.TestResultData.Builder;
import com.google.devtools.common.options.OptionsClassProvider;
import java.io.Closeable;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

/** Runs TestRunnerAction actions. */
@ExecutionStrategy(
  contextType = TestActionContext.class,
  name = {"standalone"}
)
public class StandaloneTestStrategy extends TestStrategy {
  // TODO(bazel-team) - add tests for this strategy.
  public static final String COLLECT_COVERAGE =
      "external/bazel_tools/tools/test/collect_coverage.sh";

  private static final ImmutableMap<String, String> ENV_VARS =
      ImmutableMap.<String, String>builder()
          .put("TZ", "UTC")
          .put("USER", TestPolicy.SYSTEM_USER_NAME)
          .put("TEST_SRCDIR", TestPolicy.RUNFILES_DIR)
          // TODO(lberki): Remove JAVA_RUNFILES and PYTHON_RUNFILES.
          .put("JAVA_RUNFILES", TestPolicy.RUNFILES_DIR)
          .put("PYTHON_RUNFILES", TestPolicy.RUNFILES_DIR)
          .put("RUNFILES_DIR", TestPolicy.RUNFILES_DIR)
          .put("TEST_TMPDIR", TestPolicy.TEST_TMP_DIR)
          .build();

  public static final TestPolicy DEFAULT_LOCAL_POLICY = new TestPolicy(ENV_VARS);

  protected final Path tmpDirRoot;

  public StandaloneTestStrategy(
      OptionsClassProvider requestOptions,
      BinTools binTools,
      Map<String, String> clientEnv,
      Path tmpDirRoot) {
    super(requestOptions, binTools, clientEnv);
    this.tmpDirRoot = tmpDirRoot;
  }

  @Override
  public void exec(TestRunnerAction action, ActionExecutionContext actionExecutionContext)
      throws ExecException, InterruptedException {
    Path execRoot = actionExecutionContext.getExecutor().getExecRoot();
    Path coverageDir = execRoot.getRelative(action.getCoverageDirectory());
    Path runfilesDir =
        getLocalRunfilesDirectory(
            action,
            actionExecutionContext,
            binTools,
            action.getLocalShellEnvironment(),
            action.isEnableRunfiles());
    Path tmpDir =
        tmpDirRoot.getChild(
            getTmpDirName(action.getExecutionSettings().getExecutable().getExecPath()));
    Map<String, String> env = setupEnvironment(action, execRoot, runfilesDir, tmpDir);
    Path workingDirectory = runfilesDir.getRelative(action.getRunfilesPrefix());

    ResolvedPaths resolvedPaths = action.resolve(execRoot);

    Map<String, String> info = new HashMap<>();
    // This key is only understood by StandaloneSpawnStrategy.
    info.put("timeout", "" + getTimeout(action));
    info.putAll(action.getTestProperties().getExecutionInfo());

    Spawn spawn =
        new SimpleSpawn(
            action,
            getArgs(COLLECT_COVERAGE, action),
            ImmutableMap.copyOf(env),
            ImmutableMap.copyOf(info),
            new RunfilesSupplierImpl(
                runfilesDir.relativeTo(execRoot), action.getExecutionSettings().getRunfiles()),
            /*inputs=*/ImmutableList.copyOf(action.getInputs()),
            /*tools=*/ImmutableList.<Artifact>of(),
            /*filesetManifests=*/ImmutableList.<Artifact>of(),
            ImmutableList.copyOf(action.getSpawnOutputs()),
            action
                .getTestProperties()
                .getLocalResourceUsage(executionOptions.usingLocalTestJobs()));

    Executor executor = actionExecutionContext.getExecutor();

    TestResultData.Builder dataBuilder = TestResultData.newBuilder();

    try {
      int maxAttempts = getTestAttempts(action);
      TestResultData data =
          executeTestAttempt(
              action,
              spawn,
              actionExecutionContext,
              execRoot,
              coverageDir,
              tmpDir,
              workingDirectory);
      int attempt;
      for (attempt = 1;
          data.getStatus() != BlazeTestStatus.PASSED && attempt < maxAttempts;
          attempt++) {
        processFailedTestAttempt(
            attempt, executor, action, dataBuilder, data, actionExecutionContext.getFileOutErr());
        data =
            executeTestAttempt(
                action,
                spawn,
                actionExecutionContext,
                execRoot,
                coverageDir,
                tmpDir,
                workingDirectory);
      }
      processLastTestAttempt(attempt, dataBuilder, data);
      ImmutableList.Builder<Pair<String, Path>> testOutputsBuilder = new ImmutableList.Builder<>();
      if (action.getTestLog().getPath().exists()) {
        testOutputsBuilder.add(Pair.of("test.log", action.getTestLog().getPath()));
      }
      if (resolvedPaths.getXmlOutputPath().exists()) {
        testOutputsBuilder.add(Pair.of("test.xml", resolvedPaths.getXmlOutputPath()));
      }
      executor
          .getEventBus()
          .post(
              new TestAttempt(
                  action,
                  attempt,
                  data.getStatus(),
                  data.getRunDurationMillis(),
                  testOutputsBuilder.build(),
                  true));
      finalizeTest(actionExecutionContext, action, dataBuilder.build());
    } catch (IOException e) {
      executor.getEventHandler().handle(Event.error("Caught I/O exception: " + e));
      throw new EnvironmentalExecException("unexpected I/O exception", e);
    }
  }

  private void processFailedTestAttempt(
      int attempt,
      Executor executor,
      TestRunnerAction action,
      Builder dataBuilder,
      TestResultData data,
      FileOutErr outErr)
      throws IOException {
    ImmutableList.Builder<Pair<String, Path>> testOutputsBuilder = new ImmutableList.Builder<>();
    // Rename outputs
    String namePrefix =
        FileSystemUtils.removeExtension(action.getTestLog().getExecPath().getBaseName());
    Path attemptsDir =
        action.getTestLog().getPath().getParentDirectory().getChild(namePrefix + "_attempts");
    attemptsDir.createDirectory();
    String attemptPrefix = "attempt_" + attempt;
    Path testLog = attemptsDir.getChild(attemptPrefix + ".log");
    if (action.getTestLog().getPath().exists()) {
      action.getTestLog().getPath().renameTo(testLog);
      testOutputsBuilder.add(Pair.of("test.log", testLog));
    }
    ResolvedPaths resolvedPaths = action.resolve(executor.getExecRoot());
    if (resolvedPaths.getXmlOutputPath().exists()) {
      Path destinationPath = attemptsDir.getChild(attemptPrefix + ".xml");
      resolvedPaths.getXmlOutputPath().renameTo(destinationPath);
      testOutputsBuilder.add(Pair.of("test.xml", destinationPath));
    }
    // Add the test log to the output
    dataBuilder.addFailedLogs(testLog.toString());
    dataBuilder.addTestTimes(data.getTestTimes(0));
    dataBuilder.addAllTestProcessTimes(data.getTestProcessTimesList());
    executor
        .getEventBus()
        .post(
            new TestAttempt(
                action,
                attempt,
                data.getStatus(),
                data.getRunDurationMillis(),
                testOutputsBuilder.build(),
                false));
    processTestOutput(executor, outErr, new TestResult(action, data, false), testLog);
  }

  private void processLastTestAttempt(int attempt, Builder dataBuilder, TestResultData data) {
    dataBuilder.setCachable(data.getCachable());
    dataBuilder.setHasCoverage(data.getHasCoverage());
    dataBuilder.setStatus(
        data.getStatus() == BlazeTestStatus.PASSED && attempt > 1
            ? BlazeTestStatus.FLAKY
            : data.getStatus());
    dataBuilder.setTestPassed(data.getTestPassed());
    dataBuilder.setCachable(data.getCachable());
    for (int i = 0; i < data.getFailedLogsCount(); i++) {
      dataBuilder.addFailedLogs(data.getFailedLogs(i));
    }
    if (data.hasTestPassed()) {
      dataBuilder.setPassedLog(data.getPassedLog());
    }
    dataBuilder.addTestTimes(data.getTestTimes(0));
    dataBuilder.addAllTestProcessTimes(data.getTestProcessTimesList());
    dataBuilder.setRunDurationMillis(data.getRunDurationMillis());
    if (data.hasTestCase()) {
      dataBuilder.setTestCase(data.getTestCase());
    }
  }

  private TestResultData executeTestAttempt(
      TestRunnerAction action,
      Spawn spawn,
      ActionExecutionContext actionExecutionContext,
      Path execRoot,
      Path coverageDir,
      Path tmpDir,
      Path workingDirectory)
      throws IOException, ExecException, InterruptedException {
    prepareFileSystem(action, tmpDir, coverageDir, workingDirectory);

    try (FileOutErr fileOutErr =
            new FileOutErr(
                action.getTestLog().getPath(), action.resolve(execRoot).getTestStderr())) {
      TestResultData data =
          executeTest(
              action,
              spawn,
              actionExecutionContext.withFileOutErr(fileOutErr));
      appendStderr(fileOutErr.getOutputPath(), fileOutErr.getErrorPath());
      return data;
    }
  }

  private Map<String, String> setupEnvironment(
      TestRunnerAction action, Path execRoot, Path runfilesDir, Path tmpDir) {
    PathFragment relativeTmpDir;
    if (tmpDir.startsWith(execRoot)) {
      relativeTmpDir = tmpDir.relativeTo(execRoot);
    } else {
      relativeTmpDir = tmpDir.asFragment();
    }
    return DEFAULT_LOCAL_POLICY.computeTestEnvironment(
        action,
        clientEnv,
        getTimeout(action),
        runfilesDir.relativeTo(execRoot),
        relativeTmpDir);
  }

  protected TestResultData executeTest(
      TestRunnerAction action,
      Spawn spawn,
      ActionExecutionContext actionExecutionContext)
          throws ExecException, InterruptedException, IOException {
    Executor executor = actionExecutionContext.getExecutor();
    Closeable streamed = null;
    Path testLogPath = action.getTestLog().getPath();
    TestResultData.Builder builder = TestResultData.newBuilder();

    long startTime = executor.getClock().currentTimeMillis();
    SpawnActionContext spawnActionContext = executor.getSpawnActionContext(action.getMnemonic());
    try {
      try {
        if (executionOptions.testOutput.equals(TestOutputFormat.STREAMED)) {
          streamed =
              new StreamedTestOutput(
                  Reporter.outErrForReporter(
                      actionExecutionContext.getExecutor().getEventHandler()),
                  testLogPath);
        }
        spawnActionContext.exec(spawn, actionExecutionContext);

        builder
            .setTestPassed(true)
            .setStatus(BlazeTestStatus.PASSED)
            .setCachable(true)
            .setPassedLog(testLogPath.getPathString());
      } catch (ExecException e) {
        // Execution failed, which we consider a test failure.

        // TODO(bazel-team): set cachable==true for relevant statuses (failure, but not for
        // timeout, etc.)
        builder
            .setTestPassed(false)
            .setStatus(e.hasTimedOut() ? BlazeTestStatus.TIMEOUT : BlazeTestStatus.FAILED)
            .addFailedLogs(testLogPath.getPathString());
        if (spawnActionContext.shouldPropagateExecException()) {
          throw e;
        }
      } finally {
        long duration = executor.getClock().currentTimeMillis() - startTime;
        builder.addTestTimes(duration);
        builder.addTestProcessTimes(duration);
        builder.setRunDurationMillis(duration);
        if (streamed != null) {
          streamed.close();
        }
      }

      TestCase details =
          parseTestResult(
              action
                  .resolve(actionExecutionContext.getExecutor().getExecRoot())
                  .getXmlOutputPath());
      if (details != null) {
        builder.setTestCase(details);
      }

      if (action.isCoverageMode()) {
        builder.setHasCoverage(true);
      }

      return builder.build();
    } catch (IOException e) {
      throw new TestExecException(e.getMessage());
    }
  }

  /**
   * Outputs test result to the stdout after test has finished (e.g. for --test_output=all or
   * --test_output=errors). Will also try to group output lines together (up to 10000 lines) so
   * parallel test outputs will not get interleaved.
   */
  protected void processTestOutput(
      Executor executor, FileOutErr outErr, TestResult result, Path testLogPath)
      throws IOException {
    Path testOutput = executor.getExecRoot().getRelative(testLogPath.asFragment());
    boolean isPassed = result.getData().getTestPassed();
    try {
      if (TestLogHelper.shouldOutputTestLog(executionOptions.testOutput, isPassed)) {
        TestLogHelper.writeTestLog(testOutput, result.getTestName(), outErr.getOutputStream());
      }
    } finally {
      if (isPassed) {
        executor.getEventHandler().handle(Event.of(EventKind.PASS, null, result.getTestName()));
      } else {
        if (result.getData().getStatus() == BlazeTestStatus.TIMEOUT) {
          executor
              .getEventHandler()
              .handle(
                  Event.of(
                      EventKind.TIMEOUT, null, result.getTestName() + " (see " + testOutput + ")"));
        } else {
          executor
              .getEventHandler()
              .handle(
                  Event.of(
                      EventKind.FAIL, null, result.getTestName() + " (see " + testOutput + ")"));
        }
      }
    }
  }

  private final void finalizeTest(
      ActionExecutionContext actionExecutionContext, TestRunnerAction action, TestResultData data)
      throws IOException, ExecException {
    TestResult result = new TestResult(action, data, false);
    postTestResult(actionExecutionContext.getExecutor(), result);

    processTestOutput(
        actionExecutionContext.getExecutor(),
        actionExecutionContext.getFileOutErr(),
        result,
        result.getTestLogPath());
    // TODO(bazel-team): handle --test_output=errors, --test_output=all.

    if (!executionOptions.testKeepGoing
        && data.getStatus() != BlazeTestStatus.FLAKY
        && data.getStatus() != BlazeTestStatus.PASSED) {
      throw new TestExecException("Test failed: aborting");
    }
  }

  @Override
  public TestResult newCachedTestResult(
      Path execRoot, TestRunnerAction action, TestResultData data) {
    return new TestResult(action, data, /*cached*/ true, execRoot);
  }
}