/*
    * 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.commons.io.input;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  
  import java.io.IOException;
  import java.io.StringReader;
  import java.util.function.IntPredicate;
  
  import org.apache.commons.io.IOUtils;
  import org.apache.commons.io.output.StringBuilderWriter;
  import org.apache.commons.lang3.StringUtils;
  import org.junit.jupiter.api.Test;
  
  /**
   * Tests {@link CharacterFilterReader} with an {@link IntPredicate}.
   */
  public class CharacterFilterReaderIntPredicateTest {
  
      @Test
      public void testInputSize0FilterAll() throws IOException {
          final StringReader input = new StringReader(StringUtils.EMPTY);
          try (CharacterFilterReader reader = new CharacterFilterReader(input, ch -> true)) {
              assertEquals(-1, reader.read());
          }
      }
  
      @Test
      public void testInputSize1FilterAll() throws IOException {
          try (StringReader input = new StringReader("a");
                  CharacterFilterReader reader = new CharacterFilterReader(input, ch -> true)) {
              assertEquals(-1, reader.read());
          }
      }
  
      @Test
      public void testInputSize2FilterAll() throws IOException {
          final StringReader input = new StringReader("aa");
          try (CharacterFilterReader reader = new CharacterFilterReader(input, ch -> true)) {
              assertEquals(-1, reader.read());
          }
      }
  
      @Test
      public void testInputSize2FilterFirst() throws IOException {
          final StringReader input = new StringReader("ab");
          try (CharacterFilterReader reader = new CharacterFilterReader(input, ch -> ch == 'a')) {
              assertEquals('b', reader.read());
              assertEquals(-1, reader.read());
          }
      }
  
      @Test
      public void testInputSize2FilterLast() throws IOException {
          final StringReader input = new StringReader("ab");
          try (CharacterFilterReader reader = new CharacterFilterReader(input, ch -> ch == 'b')) {
              assertEquals('a', reader.read());
              assertEquals(-1, reader.read());
          }
      }
  
      @Test
      public void testInputSize5FilterWhitespace() throws IOException {
          final StringReader input = new StringReader(" a b ");
          try (CharacterFilterReader reader = new CharacterFilterReader(input, Character::isWhitespace)) {
              assertEquals('a', reader.read());
              assertEquals('b', reader.read());
              assertEquals(-1, reader.read());
          }
      }
  
      @Test
      public void testReadIntoBuffer() throws IOException {
          final StringReader input = new StringReader("ababcabcd");
          try (CharacterFilterReader reader = new CharacterFilterReader(input, ch -> ch == 'b')) {
              final char[] buff = new char[9];
              final int charCount = reader.read(buff);
              assertEquals(6, charCount);
              assertEquals("aacacd", new String(buff, 0, charCount));
          }
      }
  
      @Test
      public void testReadIntoBufferFilterWhitespace() throws IOException {
         final StringReader input = new StringReader(" a b a b c a b c d ");
         try (CharacterFilterReader reader = new CharacterFilterReader(input, Character::isWhitespace)) {
             final char[] buff = new char[19];
             final int charCount = reader.read(buff);
             assertEquals(9, charCount);
             assertEquals("ababcabcd", new String(buff, 0, charCount));
         }
     }
 
     @Test
     public void testReadUsingReader() throws IOException {
         final StringReader input = new StringReader("ababcabcd");
         try (StringBuilderWriter output = new StringBuilderWriter();
                 CharacterFilterReader reader = new CharacterFilterReader(input, ch -> ch == 'b')) {
             IOUtils.copy(reader, output);
             assertEquals("aacacd", output.toString());
         }
     }
 
     @Test
     public void testReadUsingReaderFilterWhitespace() throws IOException {
         final StringReader input = new StringReader(" a b a b c a b c d ");
         try (StringBuilderWriter output = new StringBuilderWriter();
                 CharacterFilterReader reader = new CharacterFilterReader(input, Character::isWhitespace)) {
             IOUtils.copy(reader, output);
             assertEquals("ababcabcd", output.toString());
         }
     }
 
 }