/*
    * 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.assertArrayEquals;
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertSame;
  
  import java.io.ByteArrayInputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.util.Arrays;
  
  import org.junit.jupiter.api.Test;
  
  /**
   * Tests {@link ProxyInputStream}.
   *
   * @param <T> The actual type tested.
   */
  public class ProxyInputStreamTest<T extends ProxyInputStream> {
  
      private static final class ProxyInputStreamFixture extends ProxyInputStream {
  
          public ProxyInputStreamFixture(final InputStream proxy) {
              super(proxy);
          }
  
      }
  
      @SuppressWarnings({ "resource", "unused" }) // For subclasses
      protected T createFixture() throws IOException {
          return (T) new ProxyInputStreamFixture(createProxySource());
      }
  
      protected InputStream createProxySource() {
          return CharSequenceInputStream.builder().setCharSequence("abc").get();
      }
  
      protected void testEos(final T inputStream) {
          // empty
      }
  
      @Test
      public void testRead() throws IOException {
          try (T inputStream = createFixture()) {
              int found = inputStream.read();
              assertEquals('a', found);
              found = inputStream.read();
              assertEquals('b', found);
              found = inputStream.read();
              assertEquals('c', found);
              found = inputStream.read();
              assertEquals(-1, found);
              testEos(inputStream);
          }
      }
  
      @Test
      public void testReadArrayAtMiddleFully() throws IOException {
          try (T inputStream = createFixture()) {
              final byte[] dest = new byte[5];
              int found = inputStream.read(dest, 2, 3);
              assertEquals(3, found);
              assertArrayEquals(new byte[] { 0, 0, 'a', 'b', 'c' }, dest);
              found = inputStream.read(dest, 2, 3);
              assertEquals(-1, found);
              testEos(inputStream);
          }
      }
  
      @Test
      public void testReadArrayAtStartFully() throws IOException {
          try (T inputStream = createFixture()) {
              final byte[] dest = new byte[5];
              int found = inputStream.read(dest, 0, 5);
              assertEquals(3, found);
              assertArrayEquals(new byte[] { 'a', 'b', 'c', 0, 0 }, dest);
              found = inputStream.read(dest, 0, 5);
              assertEquals(-1, found);
              testEos(inputStream);
          }
      }
  
     @Test
     public void testReadArrayAtStartPartial() throws IOException {
         try (T inputStream = createFixture()) {
             final byte[] dest = new byte[5];
             int found = inputStream.read(dest, 0, 2);
             assertEquals(2, found);
             assertArrayEquals(new byte[] { 'a', 'b', 0, 0, 0 }, dest);
             Arrays.fill(dest, (byte) 0);
             found = inputStream.read(dest, 0, 2);
             assertEquals(1, found);
             assertArrayEquals(new byte[] { 'c', 0, 0, 0, 0 }, dest);
             found = inputStream.read(dest, 0, 2);
             assertEquals(-1, found);
             testEos(inputStream);
         }
     }
 
     @Test
     public void testReadArrayFully() throws IOException {
         try (T inputStream = createFixture()) {
             final byte[] dest = new byte[5];
             int found = inputStream.read(dest);
             assertEquals(3, found);
             assertArrayEquals(new byte[] { 'a', 'b', 'c', 0, 0 }, dest);
             found = inputStream.read(dest);
             assertEquals(-1, found);
             testEos(inputStream);
         }
     }
 
     @Test
     public void testReadArrayPartial() throws IOException {
         try (T inputStream = createFixture()) {
             final byte[] dest = new byte[2];
             int found = inputStream.read(dest);
             assertEquals(2, found);
             assertArrayEquals(new byte[] { 'a', 'b' }, dest);
             Arrays.fill(dest, (byte) 0);
             found = inputStream.read(dest);
             assertEquals(1, found);
             assertArrayEquals(new byte[] { 'c', 0 }, dest);
             found = inputStream.read(dest);
             assertEquals(-1, found);
             testEos(inputStream);
         }
     }
 
     @Test
     public void testReadEof() throws Exception {
         final ByteArrayInputStream proxy = new ByteArrayInputStream(new byte[2]);
         try (ProxyInputStream inputStream = new ProxyInputStreamFixture(proxy)) {
             assertSame(proxy, inputStream.unwrap());
             int found = inputStream.read();
             assertEquals(0, found);
             found = inputStream.read();
             assertEquals(0, found);
             found = inputStream.read();
             assertEquals(-1, found);
         }
     }
 
 }