/*
    * 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 de.softwareforge.testing.postgres.embedded;
  
  import java.io.BufferedReader;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.io.UncheckedIOException;
  import java.nio.charset.StandardCharsets;
  
  import org.slf4j.Logger;
  
  /**
   * Read standard output of process and write lines to given {@link Logger} as INFO; depends on {@link ProcessBuilder#redirectErrorStream(boolean)} being set to
   * {@code true} (since only stdout is read).
   *
   * <p>
   * The use of the input stream is thread safe since it's used only in a single thread&mdash;the one launched by this code.
   */
  final class ProcessOutputLogger implements Runnable {
  
      private final Logger logger;
      private final BufferedReader reader;
  
      private ProcessOutputLogger(final Logger logger, final Process process) {
          this.logger = logger;
          this.reader = new BufferedReader(new InputStreamReader(process.getInputStream(), StandardCharsets.UTF_8));
      }
  
      @Override
      public void run() {
          try {
              try {
                  reader.lines().forEach(logger::debug);
              } catch (final UncheckedIOException e) {
                  logger.error("while reading output:", e);
              }
          } finally {
              try {
                  reader.close();
              } catch (final IOException e) {
                  logger.trace("while closing reader:", e);
              }
          }
      }
  
      static void logOutput(final Logger logger, final String name, final Process process) {
          final Thread t = new Thread(new ProcessOutputLogger(logger, process));
          t.setName(name);
          t.setDaemon(true);
          t.start();
      }
  }