/*
    * 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.apache.commons.io.IOUtils.EOF;
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertSame;
  
  import java.io.InputStream;
  
  import org.junit.jupiter.api.Test;
  
  /**
   * Tests {@link ClosedInputStream}.
   */
  class ClosedInputStreamTest {
  
      private void assertEof(final ClosedInputStream cis) {
          assertEquals(EOF, cis.read(), "read()");
      }
  
      @Test
      void testAvailableAfterClose() throws Exception {
          assertEquals(0, ClosedInputStream.INSTANCE.available());
          assertEquals(0, ClosedInputStream.INSTANCE.available());
          final InputStream shadow;
          try (InputStream in = new ClosedInputStream()) {
              assertEquals(0, in.available());
              shadow = in;
          }
          assertEquals(0, shadow.available());
      }
  
      @Test
      void testAvailableAfterOpen() throws Exception {
          assertEquals(0, ClosedInputStream.INSTANCE.available());
          assertEquals(0, ClosedInputStream.INSTANCE.available());
          try (ClosedInputStream cis = new ClosedInputStream()) {
              assertEquals(0, cis.available());
          }
      }
  
      @SuppressWarnings("resource")
      @Test
      void testNonNull() throws Exception {
          assertSame(ClosedInputStream.INSTANCE, ClosedInputStream.ifNull(null));
          assertSame(ClosedInputStream.INSTANCE, ClosedInputStream.ifNull(ClosedInputStream.INSTANCE));
          assertSame(System.in, ClosedInputStream.ifNull(System.in));
      }
  
      @Test
      void testRead() throws Exception {
          try (ClosedInputStream cis = new ClosedInputStream()) {
              assertEof(cis);
          }
      }
  
      @Test
      void testReadAfterCose() throws Exception {
          assertEquals(0, ClosedInputStream.INSTANCE.available());
          assertEquals(0, ClosedInputStream.INSTANCE.available());
          final InputStream shadow;
          try (InputStream in = new ClosedInputStream()) {
              assertEquals(0, in.available());
              shadow = in;
          }
          assertEquals(EOF, shadow.read());
      }
  
      @Test
      void testReadArray() throws Exception {
          try (ClosedInputStream cis = new ClosedInputStream()) {
              assertEquals(EOF, cis.read(new byte[4096]));
              assertEquals(EOF, cis.read(new byte[1]));
              assertEquals(EOF, cis.read(new byte[0]));
          }
      }
  
      @Test
      void testReadArrayIndex() throws Exception {
          try (ClosedInputStream cis = new ClosedInputStream()) {
              assertEquals(EOF, cis.read(new byte[4096], 0, 1));
              assertEquals(EOF, cis.read(new byte[1], 0, 1));
              assertEquals(EOF, cis.read(new byte[0], 0, 0));
          }
     }
 
     @Test
     void testSingleton() throws Exception {
         try (@SuppressWarnings("deprecation")
         ClosedInputStream cis = ClosedInputStream.CLOSED_INPUT_STREAM) {
             assertEof(cis);
         }
         try (ClosedInputStream cis = ClosedInputStream.INSTANCE) {
             assertEof(cis);
         }
     }
 
 }