/*
    * 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
    *
    *      https://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.commons.io.input;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  
  import java.io.ByteArrayInputStream;
  import java.io.IOException;
  import java.nio.charset.StandardCharsets;
  
  import org.junit.jupiter.api.Test;
  
  class UnixLineEndingInputStreamTest {
  
      private String roundtrip(final String msg) throws IOException {
          return roundtrip(msg, true, 0);
      }
  
      private String roundtrip(final String msg, final boolean ensureLineFeedAtEndOfFile, final int minBufferLen) throws IOException {
          final String string;
          // read(byte[])
          try (ByteArrayInputStream baos = new ByteArrayInputStream(msg.getBytes(StandardCharsets.UTF_8));
                  UnixLineEndingInputStream in = new UnixLineEndingInputStream(baos, ensureLineFeedAtEndOfFile)) {
              // read into a buffer larger than the fixture.
              final byte[] buf = new byte[minBufferLen + msg.length() * 10];
              string = new String(buf, 0, in.read(buf), StandardCharsets.UTF_8);
          }
          // read(byte[], int, int)
          try (ByteArrayInputStream baos = new ByteArrayInputStream(msg.getBytes(StandardCharsets.UTF_8));
                  UnixLineEndingInputStream in = new UnixLineEndingInputStream(baos, ensureLineFeedAtEndOfFile)) {
              // read into a buffer larger than the fixture.
              final byte[] buf = new byte[minBufferLen + msg.length() * 10];
              assertEquals(string, new String(buf, 0, in.read(buf, 0, buf.length), StandardCharsets.UTF_8));
          }
          // read
          try (ByteArrayInputStream baos = new ByteArrayInputStream(msg.getBytes(StandardCharsets.UTF_8));
                  UnixLineEndingInputStream in = new UnixLineEndingInputStream(baos, ensureLineFeedAtEndOfFile)) {
              // read into a buffer larger than the fixture.
              final int[] buf = new int[minBufferLen + msg.length() * 10];
              if (buf.length > 0) {
                  int b;
                  int i = 0;
                  while ((b = in.read()) != -1) {
                      buf[i++] = b;
                  }
                  assertEquals(string, new String(buf, 0, i));
              }
          }
          return string;
      }
  
      @Test
      void testCrAtEnd() throws Exception {
          assertEquals("a\n", roundtrip("a\r"));
      }
  
      @Test
      void testCrOnlyEnsureAtEof() throws Exception {
          assertEquals("a\nb\n", roundtrip("a\rb"));
      }
  
      @Test
      void testCrOnlyNotAtEof() throws Exception {
          assertEquals("a\nb", roundtrip("a\rb", false, 0));
      }
  
      @Test
      void testEmpty() throws Exception {
          assertEquals("", roundtrip(""));
      }
  
      @Test
      void testInTheMiddleOfTheLine() throws Exception {
          assertEquals("a\nbc\n", roundtrip("a\r\nbc"));
      }
  
      @Test
      void testMultipleBlankLines() throws Exception {
          assertEquals("a\n\nbc\n", roundtrip("a\r\n\r\nbc"));
      }
  
      @Test
      void testRetainLineFeed() throws Exception {
          assertEquals("a\n\n", roundtrip("a\r\n\r\n", false, 0));
          assertEquals("a", roundtrip("a", false, 0));
     }
 
     @Test
     void testSimpleString() throws Exception {
         assertEquals("abc\n", roundtrip("abc"));
     }
 
     @Test
     void testTwoLinesAtEnd() throws Exception {
         assertEquals("a\n\n", roundtrip("a\r\n\r\n"));
     }
 
 }