/*
 * SonarQube
 * Copyright (C) 2009-2022 SonarSource SA
 * mailto:info AT sonarsource DOT com
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 3 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */
package org.sonar.application;

import com.google.common.net.HostAndPort;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.StandardCopyOption;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.function.Supplier;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.sonar.application.command.AbstractCommand;
import org.sonar.application.command.EsScriptCommand;
import org.sonar.application.command.JavaCommand;
import org.sonar.application.command.JvmOptions;
import org.sonar.application.es.EsConnectorImpl;
import org.sonar.application.es.EsInstallation;
import org.sonar.application.es.EsKeyStoreCli;
import org.sonar.application.process.EsManagedProcess;
import org.sonar.application.process.ManagedProcess;
import org.sonar.application.process.ProcessCommandsManagedProcess;
import org.sonar.process.FileUtils2;
import org.sonar.process.ProcessId;
import org.sonar.process.sharedmemoryfile.AllProcessesCommands;
import org.sonar.process.sharedmemoryfile.ProcessCommands;

import static com.google.common.base.Preconditions.checkArgument;
import static java.lang.String.format;
import static java.util.Collections.singleton;
import static java.util.Objects.requireNonNull;
import static org.sonar.application.es.EsKeyStoreCli.BOOTSTRAP_PASSWORD_PROPERTY_KEY;
import static org.sonar.application.es.EsKeyStoreCli.KEYSTORE_PASSWORD_PROPERTY_KEY;
import static org.sonar.application.es.EsKeyStoreCli.TRUSTSTORE_PASSWORD_PROPERTY_KEY;
import static org.sonar.process.ProcessEntryPoint.PROPERTY_GRACEFUL_STOP_TIMEOUT_MS;
import static org.sonar.process.ProcessEntryPoint.PROPERTY_PROCESS_INDEX;
import static org.sonar.process.ProcessEntryPoint.PROPERTY_PROCESS_KEY;
import static org.sonar.process.ProcessEntryPoint.PROPERTY_SHARED_PATH;

public class ProcessLauncherImpl implements ProcessLauncher {
  private static final Logger LOG = LoggerFactory.getLogger(ProcessLauncherImpl.class);

  private final File tempDir;
  private final AllProcessesCommands allProcessesCommands;
  private final Supplier<ProcessBuilder> processBuilderSupplier;

  public ProcessLauncherImpl(File tempDir) {
    this(tempDir, new AllProcessesCommands(tempDir), JavaLangProcessBuilder::new);
  }

  ProcessLauncherImpl(File tempDir, AllProcessesCommands allProcessesCommands, Supplier<ProcessBuilder> processBuilderSupplier) {
    this.tempDir = tempDir;
    this.allProcessesCommands = allProcessesCommands;
    this.processBuilderSupplier = processBuilderSupplier;
  }

  @Override
  public void close() {
    allProcessesCommands.close();
  }

  public ManagedProcess launch(AbstractCommand command) {
    EsInstallation esInstallation = command.getEsInstallation();
    if (esInstallation != null) {
      cleanupOutdatedEsData(esInstallation);
      writeConfFiles(esInstallation);
    }

    Process process;
    if (command instanceof EsScriptCommand) {
      process = launchExternal((EsScriptCommand) command);
    } else if (command instanceof JavaCommand) {
      process = launchJava((JavaCommand<?>) command);
    } else {
      throw new IllegalStateException("Unexpected type of command: " + command.getClass());
    }

    ProcessId processId = command.getProcessId();
    try {
      if (processId == ProcessId.ELASTICSEARCH) {
        checkArgument(esInstallation != null, "Incorrect configuration EsInstallation is null");
        EsConnectorImpl esConnector = new EsConnectorImpl(singleton(HostAndPort.fromParts(esInstallation.getHost(),
          esInstallation.getHttpPort())), esInstallation.getBootstrapPassword());
        return new EsManagedProcess(process, processId, esConnector);
      } else {
        ProcessCommands commands = allProcessesCommands.createAfterClean(processId.getIpcIndex());
        return new ProcessCommandsManagedProcess(process, processId, commands);
      }
    } catch (Exception e) {
      // just in case
      if (process != null) {
        process.destroyForcibly();
      }
      throw new IllegalStateException(format("Fail to launch monitor of process [%s]", processId.getKey()), e);
    }
  }

  private Process launchExternal(EsScriptCommand esScriptCommand) {
    try {
      ProcessBuilder processBuilder = create(esScriptCommand);
      logLaunchedCommand(esScriptCommand, processBuilder);
      return processBuilder.start();
    } catch (Exception e) {
      throw new IllegalStateException(format("Fail to launch process [%s]", esScriptCommand.getProcessId().getKey()), e);
    }
  }

  private static void cleanupOutdatedEsData(EsInstallation esInstallation) {
    esInstallation.getOutdatedSearchDirectories()
      .forEach(outdatedDir -> {
        if (outdatedDir.exists()) {
          LOG.info("Deleting outdated search index data directory {}", outdatedDir.getAbsolutePath());
          try {
            FileUtils2.deleteDirectory(outdatedDir);

            if (outdatedDir.exists()) {
              LOG.info("Failed to delete outdated search index data directory {}", outdatedDir);
            }
          } catch (IOException e) {
            LOG.info("Failed to delete outdated search index data directory {}", outdatedDir.getAbsolutePath(), e);
          }
        }
      });
  }

  private void writeConfFiles(EsInstallation esInstallation) {
    File confDir = esInstallation.getConfDirectory();

    pruneElasticsearchConfDirectory(confDir);
    createElasticsearchConfDirectory(confDir);
    setupElasticsearchAuthentication(esInstallation);

    esInstallation.getEsYmlSettings().writeToYmlSettingsFile(esInstallation.getElasticsearchYml());
    esInstallation.getEsJvmOptions().writeToJvmOptionFile(esInstallation.getJvmOptions());
    storeElasticsearchLog4j2Properties(esInstallation);
  }

  private static void pruneElasticsearchConfDirectory(File confDir) {
    try {
      Files.deleteIfExists(confDir.toPath());
    } catch (IOException e) {
      throw new IllegalStateException("Could not delete Elasticsearch temporary conf directory", e);
    }
  }

  private static void createElasticsearchConfDirectory(File confDir) {
    if (!confDir.mkdirs()) {
      String error = format("Failed to create temporary configuration directory [%s]", confDir.getAbsolutePath());
      LOG.error(error);
      throw new IllegalStateException(error);
    }
  }

  private void setupElasticsearchAuthentication(EsInstallation esInstallation) {
    if (esInstallation.isSecurityEnabled()) {
      EsKeyStoreCli keyStoreCli = EsKeyStoreCli.getInstance(esInstallation)
        .store(BOOTSTRAP_PASSWORD_PROPERTY_KEY, esInstallation.getBootstrapPassword());

      String esConfPath = esInstallation.getConfDirectory().getAbsolutePath();

      Path trustStoreLocation = esInstallation.getTrustStoreLocation();
      Path keyStoreLocation = esInstallation.getKeyStoreLocation();
      if (trustStoreLocation.equals(keyStoreLocation)) {
        copyFile(trustStoreLocation, Paths.get(esConfPath, trustStoreLocation.toFile().getName()));
      } else {
        copyFile(trustStoreLocation, Paths.get(esConfPath, trustStoreLocation.toFile().getName()));
        copyFile(keyStoreLocation, Paths.get(esConfPath, keyStoreLocation.toFile().getName()));
      }

      esInstallation.getTrustStorePassword().ifPresent(s -> keyStoreCli.store(TRUSTSTORE_PASSWORD_PROPERTY_KEY, s));
      esInstallation.getKeyStorePassword().ifPresent(s -> keyStoreCli.store(KEYSTORE_PASSWORD_PROPERTY_KEY, s));

      keyStoreCli.executeWith(this::launchJava);
    }
  }

  private static void copyFile(Path from, Path to) {
    try {
      Files.copy(from, to, StandardCopyOption.REPLACE_EXISTING);
    } catch (IOException e) {
      throw new IllegalStateException("Could not copy file: " + from.toString(), e);
    }
  }

  private static void storeElasticsearchLog4j2Properties(EsInstallation esInstallation) {
    try (FileOutputStream fileOutputStream = new FileOutputStream(esInstallation.getLog4j2PropertiesLocation())) {
      esInstallation.getLog4j2Properties().store(fileOutputStream, "log4j2 properties file for ES bundled in SonarQube");
    } catch (IOException e) {
      throw new IllegalStateException("Failed to write ES configuration files", e);
    }
  }

  private <T extends JvmOptions> Process launchJava(JavaCommand<T> javaCommand) {
    ProcessId processId = javaCommand.getProcessId();
    try {
      ProcessBuilder processBuilder = create(javaCommand);
      logLaunchedCommand(javaCommand, processBuilder);
      return processBuilder.start();
    } catch (Exception e) {
      throw new IllegalStateException(format("Fail to launch process [%s]", processId.getKey()), e);
    }
  }

  private static <T extends AbstractCommand> void logLaunchedCommand(AbstractCommand<T> command, ProcessBuilder processBuilder) {
    if (LOG.isInfoEnabled()) {
      LOG.info("Launch process[{}] from [{}]: {}",
        command.getProcessId(),
        command.getWorkDir().getAbsolutePath(),
        String.join(" ", processBuilder.command()));
    }
  }

  private ProcessBuilder create(EsScriptCommand esScriptCommand) {
    List<String> commands = new ArrayList<>();
    EsInstallation esInstallation = esScriptCommand.getEsInstallation();
    requireNonNull(esInstallation, () -> "No Elasticsearch installation configuration is available for the command of type " + esScriptCommand.getClass());
    commands.add(esInstallation.getExecutable().getAbsolutePath());
    commands.addAll(esScriptCommand.getOptions());

    return create(esScriptCommand, commands);
  }

  private <T extends JvmOptions> ProcessBuilder create(JavaCommand<T> javaCommand) {
    List<String> commands = new ArrayList<>();
    commands.add(buildJavaPath());
    commands.addAll(javaCommand.getJvmOptions().getAll());
    commands.addAll(buildClasspath(javaCommand));
    commands.add(javaCommand.getClassName());
    commands.addAll(javaCommand.getParameters());

    if (javaCommand.getReadsArgumentsFromFile()) {
      commands.add(buildPropertiesFile(javaCommand).getAbsolutePath());
    } else {
      javaCommand.getArguments().forEach((key, value) -> {
        if (value != null && !value.isEmpty()) {
          commands.add("-E" + key + "=" + value);
        }
      });
    }

    return create(javaCommand, commands);
  }

  private ProcessBuilder create(AbstractCommand<?> command, List<String> commands) {
    ProcessBuilder processBuilder = processBuilderSupplier.get();
    processBuilder.command(commands);
    processBuilder.directory(command.getWorkDir());
    Map<String, String> environment = processBuilder.environment();
    environment.putAll(command.getEnvVariables());
    command.getSuppressedEnvVariables().forEach(environment::remove);
    processBuilder.redirectErrorStream(true);
    return processBuilder;
  }

  private static String buildJavaPath() {
    String separator = System.getProperty("file.separator");
    return new File(new File(System.getProperty("java.home")), "bin" + separator + "java").getAbsolutePath();
  }

  private static <T extends JvmOptions> List<String> buildClasspath(JavaCommand<T> javaCommand) {
    String pathSeparator = System.getProperty("path.separator");
    return Arrays.asList("-cp", String.join(pathSeparator, javaCommand.getClasspath()));
  }

  private File buildPropertiesFile(JavaCommand javaCommand) {
    File propertiesFile = null;
    try {
      propertiesFile = File.createTempFile("sq-process", "properties", tempDir);
      Properties props = new Properties();
      props.putAll(javaCommand.getArguments());
      props.setProperty(PROPERTY_PROCESS_KEY, javaCommand.getProcessId().getKey());
      props.setProperty(PROPERTY_PROCESS_INDEX, Integer.toString(javaCommand.getProcessId().getIpcIndex()));
      props.setProperty(PROPERTY_GRACEFUL_STOP_TIMEOUT_MS, javaCommand.getGracefulStopTimeoutMs() + "");
      props.setProperty(PROPERTY_SHARED_PATH, tempDir.getAbsolutePath());
      try (OutputStream out = new FileOutputStream(propertiesFile)) {
        props.store(out, format("Temporary properties file for command [%s]", javaCommand.getProcessId().getKey()));
      }
      return propertiesFile;
    } catch (Exception e) {
      throw new IllegalStateException("Cannot write temporary settings to " + propertiesFile, e);
    }
  }

  /**
   * An interface of the methods of {@link java.lang.ProcessBuilder} that we use in {@link ProcessLauncherImpl}.
   * <p>Allows testing creating processes without actualling creating them at OS level</p>
   */
  public interface ProcessBuilder {
    List<String> command();

    ProcessBuilder command(List<String> commands);

    ProcessBuilder directory(File dir);

    Map<String, String> environment();

    ProcessBuilder redirectErrorStream(boolean b);

    Process start() throws IOException;
  }

  private static class JavaLangProcessBuilder implements ProcessBuilder {
    private final java.lang.ProcessBuilder builder = new java.lang.ProcessBuilder();

    /**
     * @see java.lang.ProcessBuilder#command()
     */
    @Override
    public List<String> command() {
      return builder.command();
    }

    /**
     * @see java.lang.ProcessBuilder#command(List)
     */
    @Override
    public ProcessBuilder command(List<String> commands) {
      builder.command(commands);
      return this;
    }

    /**
     * @see java.lang.ProcessBuilder#directory(File)
     */
    @Override
    public ProcessBuilder directory(File dir) {
      builder.directory(dir);
      return this;
    }

    /**
     * @see java.lang.ProcessBuilder#environment()
     */
    @Override
    public Map<String, String> environment() {
      return builder.environment();
    }

    /**
     * @see java.lang.ProcessBuilder#redirectErrorStream(boolean)
     */
    @Override
    public ProcessBuilder redirectErrorStream(boolean b) {
      builder.redirectErrorStream(b);
      return this;
    }

    /**
     * @see java.lang.ProcessBuilder#start()
     */
    @Override
    public Process start() throws IOException {
      return builder.start();
    }
  }
}