/*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you 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 org.apache.maven.shared.filtering;
  
  import java.io.ByteArrayOutputStream;
  import java.io.IOException;
  import java.io.OutputStream;
  import java.io.PrintStream;
  
  /**
   * Helping class to capture console input and output for tests.
   *
   * @author abelsromero
   * @since 3.3.2
   */
  class ConsoleHolder {
  
      private PrintStream originalOut;
      private PrintStream originalErr;
  
      private ByteArrayOutputStream newOut;
      private ByteArrayOutputStream newErr;
  
      private ConsoleHolder() {}
  
      static ConsoleHolder start() {
          final ConsoleHolder holder = new ConsoleHolder();
  
          holder.originalOut = System.out;
          holder.originalErr = System.err;
  
          holder.newOut = new DoubleOutputStream(holder.originalOut);
          holder.newErr = new DoubleOutputStream(holder.originalErr);
  
          System.setOut(new PrintStream(holder.newOut));
          System.setErr(new PrintStream(holder.newErr));
  
          return holder;
      }
  
      void release() {
          System.setOut(originalOut);
          System.setOut(originalErr);
      }
  
      String getOutput() {
          return new String(newOut.toByteArray());
      }
  
      String getError() {
          return new String(newErr.toByteArray());
      }
  
      static class DoubleOutputStream extends ByteArrayOutputStream {
  
          final OutputStream other;
  
          DoubleOutputStream(final OutputStream os) {
              other = os;
          }
  
          @Override
          public synchronized void write(final byte[] b, final int off, final int len) {
              try {
                  other.write(b, off, len);
              } catch (IOException e) {
                  throw new RuntimeException(e);
              }
              super.write(b, off, len);
          }
      }
  }