/*
    * 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.assertArrayEquals;
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertNotEquals;
  import static org.junit.jupiter.api.Assertions.assertThrows;
  import static org.junit.jupiter.api.Assertions.assertThrowsExactly;
  import static org.junit.jupiter.api.Assertions.assertTrue;
  
  import java.io.ByteArrayInputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.nio.file.Files;
  import java.nio.file.Paths;
  import java.security.MessageDigest;
  import java.security.NoSuchAlgorithmException;
  import java.util.Random;
  import java.util.concurrent.atomic.AtomicBoolean;
  
  import org.apache.commons.codec.digest.DigestUtils;
  import org.apache.commons.codec.digest.MessageDigestAlgorithms;
  import org.apache.commons.io.IOExceptionList;
  import org.apache.commons.io.IOUtils;
  import org.apache.commons.io.test.CustomIOException;
  import org.junit.jupiter.api.Test;
  
  /**
   * Tests {@link MessageDigestInputStream}.
   */
  class MessageDigestInputStreamTest {
  
      static byte[] generateRandomByteStream(final int size) {
          final byte[] buffer = new byte[size];
          final Random rnd = new Random();
          rnd.nextBytes(buffer);
          return buffer;
      }
  
      private InputStream createInputStream() throws IOException, NoSuchAlgorithmException {
          return createInputStream(new ByteArrayInputStream(MessageDigestInputStreamTest.generateRandomByteStream(256)));
      }
  
      private InputStream createInputStream(final InputStream origin) throws IOException, NoSuchAlgorithmException {
          // @formatter:off
          return MessageDigestInputStream.builder()
                  .setMessageDigest(MessageDigest.getInstance(MessageDigestAlgorithms.SHA_512))
                  .setInputStream(origin)
                  .get();
          // @formatter:on
      }
  
      @Test
      void testAfterReadConsumer() throws Exception {
          final AtomicBoolean boolRef = new AtomicBoolean();
          // @formatter:off
          try (InputStream bounded = MessageDigestInputStream.builder()
                  .setMessageDigest(MessageDigest.getInstance(MessageDigestAlgorithms.SHA_512))
                  .setCharSequence("Hi")
                  .setAfterRead(i -> boolRef.set(true))
                  .get()) {
              IOUtils.consume(bounded);
          }
          // @formatter:on
          assertTrue(boolRef.get());
          // Throwing
          final String message = "test exception message";
          // @formatter:off
          try (InputStream bounded = MessageDigestInputStream.builder()
                  .setMessageDigest(MessageDigest.getInstance(MessageDigestAlgorithms.SHA_512))
                  .setCharSequence("Hi")
                  .setAfterRead(i -> {
                      throw new CustomIOException(message);
                  })
                  .get()) {
              assertTrue(assertThrowsExactly(IOExceptionList.class, () -> IOUtils.consume(bounded)).getMessage().contains(message));
          }
          // @formatter:on
      }
  
      @SuppressWarnings("resource")
      @Test
      void testAvailableAfterClose() throws Exception {
          final InputStream shadow;
         try (InputStream in = createInputStream()) {
             assertTrue(in.available() > 0);
             shadow = in;
         }
         assertEquals(0, shadow.available());
     }
 
     @Test
     void testAvailableAfterOpen() throws Exception {
         try (InputStream in = createInputStream()) {
             assertTrue(in.available() > 0);
             assertNotEquals(IOUtils.EOF, in.read());
             assertTrue(in.available() > 0);
         }
     }
 
     @Test
     void testNoDefault() throws Exception {
         // No default by design, call MUST set a message digest
         // Fail-fast, no need to try to process any input origin
         assertThrows(NullPointerException.class, () -> MessageDigestInputStream.builder().get());
         assertThrows(NullPointerException.class, () -> MessageDigestInputStream.builder().setInputStream(new ByteArrayInputStream(new byte[] { 1 })).get());
     }
 
     @Test
     void testNormalUse() throws Exception {
         for (int i = 256; i < 8192; i *= 2) {
             final byte[] buffer = generateRandomByteStream(i);
             final byte[] expect = DigestUtils.sha512(buffer);
             try (MessageDigestInputStream messageDigestInputStream = MessageDigestInputStream.builder().setMessageDigest(MessageDigestAlgorithms.SHA_512)
                     .setInputStream(new ByteArrayInputStream(buffer)).get()) {
                 messageDigestInputStream.consume();
                 assertArrayEquals(expect, messageDigestInputStream.getMessageDigest().digest());
             }
             try (MessageDigestInputStream messageDigestInputStream = MessageDigestInputStream.builder().setByteArray(buffer)
                     .setMessageDigest(DigestUtils.getSha512Digest()).get()) {
                 messageDigestInputStream.consume();
                 assertArrayEquals(expect, messageDigestInputStream.getMessageDigest().digest());
             }
         }
     }
 
     @Test
     void testReadAfterClose_ByteArrayInputStream() throws Exception {
         try (InputStream in = createInputStream()) {
             in.close();
             assertNotEquals(IOUtils.EOF, in.read());
         }
     }
 
     @SuppressWarnings("resource")
     @Test
     void testReadAfterClose_ChannelInputStream() throws Exception {
         try (InputStream in = createInputStream(Files.newInputStream(Paths.get("src/test/resources/org/apache/commons/io/abitmorethan16k.txt")))) {
             in.close();
             // ChannelInputStream throws when closed
             assertThrows(IOException.class, in::read);
         }
     }
 
 }