/*
 * Copyright 2016 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.idea.blaze.android.run.test;

import com.android.ddmlib.IDevice;
import com.android.tools.idea.run.ConsolePrinter;
import com.android.tools.idea.run.tasks.LaunchTask;
import com.android.tools.idea.run.tasks.LaunchTaskDurations;
import com.android.tools.idea.run.util.LaunchStatus;
import com.android.tools.idea.run.util.ProcessHandlerLaunchStatus;
import com.google.common.util.concurrent.ListenableFuture;
import com.google.idea.blaze.base.async.executor.BlazeExecutor;
import com.google.idea.blaze.base.async.process.ExternalTask;
import com.google.idea.blaze.base.async.process.LineProcessingOutputStream;
import com.google.idea.blaze.base.command.BlazeCommand;
import com.google.idea.blaze.base.command.BlazeCommandName;
import com.google.idea.blaze.base.command.BlazeFlags;
import com.google.idea.blaze.base.model.primitives.Label;
import com.google.idea.blaze.base.model.primitives.WorkspaceRoot;
import com.google.idea.blaze.base.projectview.ProjectViewManager;
import com.google.idea.blaze.base.projectview.ProjectViewSet;
import com.google.idea.blaze.base.scope.BlazeContext;
import com.google.idea.blaze.base.scope.Scope;
import com.google.idea.blaze.base.scope.ScopedFunction;
import com.google.idea.blaze.base.scope.output.IssueOutput;
import com.google.idea.blaze.base.settings.Blaze;
import com.intellij.execution.process.ProcessAdapter;
import com.intellij.execution.process.ProcessEvent;
import com.intellij.execution.process.ProcessHandler;
import com.intellij.openapi.diagnostic.Logger;
import com.intellij.openapi.project.Project;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.ide.PooledThreadExecutor;

import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.CancellationException;
import java.util.concurrent.ExecutionException;

/**
 * An Android application launcher that invokes `blaze test` on an android_test target, and sets
 * up process handling and debugging for the test run.
 */
class BlazeAndroidTestLaunchTask implements LaunchTask {
  // Uses a local device/emulator attached to adb to run an android_test.
  public static final String TEST_LOCAL_DEVICE = BlazeFlags.TEST_ARG + "--device_broker_type=LOCAL_ADB_SERVER";
  // Uses a local device/emulator attached to adb to run an android_test.
  public static final String TEST_DEBUG = BlazeFlags.TEST_ARG + "--enable_debug";
  // Specifies the serial number for a local test device.
  private static final String TEST_DEVICE_SERIAL = "--device_serial_number=";
  private static final Logger LOG = Logger.getInstance(BlazeAndroidTestLaunchTask.class);

  private final Project project;
  private final Label target;
  private final List<String> buildFlags;
  private final BlazeAndroidTestFilter testFilter;

  private ListenableFuture<Boolean> blazeResult;

  private final BlazeAndroidTestRunContext runContext;

  private final boolean debug;

  public BlazeAndroidTestLaunchTask(
    Project project,
    Label target,
    List<String> buildFlags,
    BlazeAndroidTestFilter testFilter,
    BlazeAndroidTestRunContext runContext,
    boolean debug
  ) {
    this.project = project;
    this.target = target;
    this.buildFlags = buildFlags;
    this.testFilter = testFilter;
    this.runContext = runContext;
    this.debug = debug;
  }

  @NotNull
  @Override
  public String getDescription() {
    return String.format("Running %s tests", Blaze.buildSystemName(project));
  }

  @Override
  public int getDuration() {
    return LaunchTaskDurations.LAUNCH_ACTIVITY;
  }

  @Override
  public boolean perform(@NotNull IDevice device, @NotNull LaunchStatus launchStatus, @NotNull ConsolePrinter printer) {
    BlazeExecutor executor = BlazeExecutor.getInstance();

    ProcessHandlerLaunchStatus processHandlerLaunchStatus = (ProcessHandlerLaunchStatus)launchStatus;
    final ProcessHandler processHandler = processHandlerLaunchStatus.getProcessHandler();

    blazeResult = executor.submit(new Callable<Boolean>() {
      @Override
      public Boolean call() throws Exception {
        return Scope.root(new ScopedFunction<Boolean>() {
          @Override
          public Boolean execute(@NotNull BlazeContext context) {
            ProjectViewSet projectViewSet = ProjectViewManager.getInstance(project).getProjectViewSet();
            if (projectViewSet == null) {
              IssueOutput.error("Could not load project view. Please resync project.").submit(context);
              return false;
            }

            BlazeCommand.Builder commandBuilder = BlazeCommand.builder(Blaze.getBuildSystem(project), BlazeCommandName.TEST)
              .addTargets(target);
            // Build flags must match BlazeBeforeRunTask.
            commandBuilder
              .addBlazeFlags(buildFlags);
            // Run the test on the selected local device/emulator.
            commandBuilder
              .addBlazeFlags(TEST_LOCAL_DEVICE, BlazeFlags.TEST_OUTPUT_STREAMED)
              .addBlazeFlags(testDeviceSerialFlags(device.getSerialNumber()))
              .addBlazeFlags(testFilter.getBlazeFlags());
            if (debug) {
              commandBuilder.addBlazeFlags(TEST_DEBUG, BlazeFlags.NO_CACHE_TEST_RESULTS);
            }
            BlazeCommand command = commandBuilder.build();

            printer.stdout(String.format("Starting %s test...\n", Blaze.buildSystemName(project)));
            printer.stdout(command + "\n");
            LineProcessingOutputStream.LineProcessor stdoutLineProcessor = line -> {
              printer.stdout(line);
              return true;
            };
            LineProcessingOutputStream.LineProcessor stderrLineProcessor = line -> {
              printer.stderr(line);
              return true;
            };
            int retVal = ExternalTask.builder(WorkspaceRoot.fromProject(project), command)
              .context(context)
              .stdout(LineProcessingOutputStream.of(stdoutLineProcessor))
              .stderr(LineProcessingOutputStream.of(stderrLineProcessor))
              .build()
              .run();

            if (retVal != 0) {
              context.setHasError();
            }

            return !context.hasErrors();
          }
        });
      }
    });

    blazeResult.addListener(runContext::onLaunchTaskComplete, PooledThreadExecutor.INSTANCE);

    // The debug case is set up in ConnectBlazeTestDebuggerTask
    if (!debug) {
      waitAndSetUpForKillingBlazeOnStop(processHandler, launchStatus);
    }
    return true;
  }

  /**
   *  Hooks up the Blaze process to be killed if the user hits the 'Stop' button, then waits for
   *  the Blaze process to stop.
   *  In non-debug mode, we wait for test execution to finish before returning from launch()
   *  (this matches the behavior of the stock ddmlib runner).
   */
  private void waitAndSetUpForKillingBlazeOnStop(@NotNull final ProcessHandler processHandler, @NotNull LaunchStatus launchStatus) {
    processHandler.addProcessListener(new ProcessAdapter() {
      @Override
      public void processWillTerminate(ProcessEvent event, boolean willBeDestroyed) {
        blazeResult.cancel(true /* mayInterruptIfRunning */);
        launchStatus.terminateLaunch("Test run stopped.\n");
      }
    });

    try {
      blazeResult.get();
      launchStatus.terminateLaunch("Tests ran to completion.\n");
    }
    catch (CancellationException e) {
      // The user has canceled the test.
      launchStatus.terminateLaunch("Test run stopped.\n");
    }
    catch (InterruptedException e) {
      // We've been interrupted - cancel the underlying Blaze process.
      blazeResult.cancel(true /* mayInterruptIfRunning */);
      launchStatus.terminateLaunch("Test run stopped.\n");
    }
    catch (ExecutionException e) {
      LOG.error(e);
      launchStatus.terminateLaunch("Test run stopped due to internal exception. Please file a bug report.\n");
    }
  }

  @NotNull
  private static String testDeviceSerialFlags(@NotNull String serial) {
    return BlazeFlags.TEST_ARG + TEST_DEVICE_SERIAL + serial;
  }
}