/*
    * 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.codec.binary;
  
  import static org.junit.jupiter.api.Assertions.assertArrayEquals;
  import static org.junit.jupiter.api.Assertions.assertNotNull;
  import static org.junit.jupiter.api.Assertions.assertThrows;
  
  import java.io.ByteArrayOutputStream;
  import java.io.IOException;
  import java.io.OutputStream;
  
  import org.junit.jupiter.api.Test;
  
  /**
   * Tests {@link Base16OutputStream}.
   */
  class Base16OutputStreamTest {
  
      private static final String STRING_FIXTURE = "Hello World";
  
      /**
       * Test the Base16OutputStream implementation against empty input.
       *
       * @throws IOException for some failure scenarios.
       */
      @Test
      void testBase16EmptyOutputStream() throws IOException {
          final byte[] emptyEncoded = {};
          final byte[] emptyDecoded = {};
          testByteByByte(emptyEncoded, emptyDecoded);
          testByChunk(emptyEncoded, emptyDecoded);
      }
  
      /**
       * Test the Base16OutputStream implementation
       *
       * @throws IOException for some failure scenarios.
       */
      @Test
      void testBase16OutputStreamByChunk() throws IOException {
          // Hello World test.
          byte[] encoded = StringUtils.getBytesUtf8("48656C6C6F20576F726C64");
          byte[] decoded = StringUtils.getBytesUtf8(STRING_FIXTURE);
          testByChunk(encoded, decoded);
  
          // Single Byte test.
          encoded = StringUtils.getBytesUtf8("41");
          decoded = new byte[]{(byte) 0x41};
          testByChunk(encoded, decoded);
  
          // test random data of sizes 0 through 150
          final BaseNCodec codec = Base16.builder().setLowerCase(true).get();
          for (int i = 0; i <= 150; i++) {
              final byte[][] randomData = BaseNTestData.randomData(codec, i);
              encoded = randomData[1];
              decoded = randomData[0];
              testByChunk(encoded, decoded, true);
          }
      }
  
      /**
       * Test the Base16OutputStream implementation
       *
       * @throws IOException for some failure scenarios.
       */
      @Test
      void testBase16OutputStreamByteByByte() throws IOException {
          // Hello World test.
          byte[] encoded = StringUtils.getBytesUtf8("48656C6C6F20576F726C64");
          byte[] decoded = StringUtils.getBytesUtf8(STRING_FIXTURE);
          testByteByByte(encoded, decoded);
          // Single Byte test.
          encoded = StringUtils.getBytesUtf8("41");
          decoded = new byte[] { (byte) 0x41 };
          testByteByByte(encoded, decoded);
          // test random data of sizes 0 through 150
          final BaseNCodec codec = Base16.builder().setLowerCase(true).get();
          for (int i = 0; i <= 150; i++) {
              final byte[][] randomData = BaseNTestData.randomData(codec, i);
              encoded = randomData[1];
              decoded = randomData[0];
              testByteByByte(encoded, decoded, true);
          }
     }
 
     @Test
     void testBuilder() {
         assertNotNull(Base16OutputStream.builder().getBaseNCodec());
     }
 
     /**
      * Test method does three tests on the supplied data: 1. encoded ---[DECODE]--> decoded 2. decoded ---[ENCODE]-->
      * encoded 3. decoded ---[WRAP-WRAP-WRAP-etc...] --> decoded
      * <p/>
      * By "[WRAP-WRAP-WRAP-etc...]" we mean situation where the Base16OutputStream wraps itself in encode and decode
      * mode over and over again.
      *
      * @param encoded base16 encoded data
      * @param decoded the data from above, but decoded
      * @throws IOException Usually signifies a bug in the Base16 commons-codec implementation.
      */
     private void testByChunk(final byte[] encoded, final byte[] decoded) throws IOException {
         testByChunk(encoded, decoded, false);
     }
 
     /**
      * Test method does three tests on the supplied data: 1. encoded ---[DECODE]--> decoded 2. decoded ---[ENCODE]-->
      * encoded 3. decoded ---[WRAP-WRAP-WRAP-etc...] --> decoded
      * <p/>
      * By "[WRAP-WRAP-WRAP-etc...]" we mean situation where the Base16OutputStream wraps itself in encode and decode
      * mode over and over again.
      *
      * @param encoded base16 encoded data
      * @param decoded the data from above, but decoded
      * @param lowerCase if {@code true} then use a lower-case Base16 alphabet
      * @throws IOException Usually signifies a bug in the Base16 commons-codec implementation.
      */
     private void testByChunk(final byte[] encoded, final byte[] decoded, final boolean lowerCase) throws IOException {
 
         // Start with encode.
         try (ByteArrayOutputStream byteOut = new ByteArrayOutputStream();
                 OutputStream out = new Base16OutputStream(byteOut, true, lowerCase)) {
             out.write(decoded);
             final byte[] output = byteOut.toByteArray();
             assertArrayEquals(encoded, output, "Streaming chunked base16 encode");
         }
 
         // Now let's try to decode.
         try (ByteArrayOutputStream byteOut = new ByteArrayOutputStream();
                 OutputStream out = new Base16OutputStream(byteOut, false, lowerCase)) {
             out.write(encoded);
             final byte[] output = byteOut.toByteArray();
             assertArrayEquals(decoded, output, "Streaming chunked base16 decode");
         }
 
         // wrap encoder with decoder
         try (ByteArrayOutputStream byteOut = new ByteArrayOutputStream();
              OutputStream decoderOut = new Base16OutputStream(byteOut, false, lowerCase);
              OutputStream encoderOut = new Base16OutputStream(decoderOut, true, lowerCase)) {
 
             encoderOut.write(decoded);
             final byte[] output = byteOut.toByteArray();
 
             assertArrayEquals(decoded, output, "Streaming chunked base16 wrap-wrap!");
         }
     }
 
     /**
      * Test method does three tests on the supplied data: 1. encoded ---[DECODE]--> decoded 2. decoded ---[ENCODE]-->
      * encoded 3. decoded ---[WRAP-WRAP-WRAP-etc...] --> decoded
      * <p/>
      * By "[WRAP-WRAP-WRAP-etc...]" we mean situation where the Base16OutputStream wraps itself in encode and decode
      * mode over and over again.
      *
      * @param encoded base16 encoded data
      * @param decoded the data from above, but decoded
      * @throws IOException Usually signifies a bug in the Base16 commons-codec implementation.
      */
     private void testByteByByte(final byte[] encoded, final byte[] decoded) throws IOException {
         testByteByByte(encoded, decoded, false);
     }
 
     /**
      * Test method does three tests on the supplied data: 1. encoded ---[DECODE]--> decoded 2. decoded ---[ENCODE]-->
      * encoded 3. decoded ---[WRAP-WRAP-WRAP-etc...] --> decoded
      * <p/>
      * By "[WRAP-WRAP-WRAP-etc...]" we mean situation where the Base16OutputStream wraps itself in encode and decode
      * mode over and over again.
      *
      * @param encoded base16 encoded data
      * @param decoded the data from above, but decoded
      * @throws IOException Usually signifies a bug in the Base16 commons-codec implementation.
      */
     private void testByteByByte(final byte[] encoded, final byte[] decoded, final boolean lowerCase) throws IOException {
         // Start with encode.
         try (ByteArrayOutputStream byteOut = new ByteArrayOutputStream();
                 OutputStream out = new Base16OutputStream(byteOut, true, lowerCase)) {
             for (final byte element : decoded) {
                 out.write(element);
             }
             final byte[] output = byteOut.toByteArray();
             assertArrayEquals(encoded, output, "Streaming byte-by-byte base16 encode");
         }
         try (ByteArrayOutputStream byteOut = new ByteArrayOutputStream();
                 OutputStream out = Base16OutputStream.builder()
                         .setOutputStream(byteOut).setEncode(true).setBaseNCodec(Base16.builder().setLowerCase(lowerCase).get())
                         .get()) {
             for (final byte element : decoded) {
                 out.write(element);
             }
             final byte[] output = byteOut.toByteArray();
             assertArrayEquals(encoded, output, "Streaming byte-by-byte base16 encode");
         }
         // Now let's try to decode.
         try (ByteArrayOutputStream byteOut = new ByteArrayOutputStream();
                 OutputStream out = new Base16OutputStream(byteOut, false, lowerCase)) {
             for (final byte element : encoded) {
                 out.write(element);
             }
             final byte[] output = byteOut.toByteArray();
             assertArrayEquals(decoded, output, "Streaming byte-by-byte base16 decode");
         }
         // Now let's try to decode with tonnes of flushes.
         try (ByteArrayOutputStream byteOut = new ByteArrayOutputStream();
                 OutputStream out = new Base16OutputStream(byteOut, false, lowerCase)) {
             for (final byte element : encoded) {
                 out.write(element);
                 out.flush();
             }
             final byte[] output = byteOut.toByteArray();
             assertArrayEquals(decoded, output, "Streaming byte-by-byte flush() base16 decode");
         }
         // wrap encoder with decoder
         try (ByteArrayOutputStream byteOut = new ByteArrayOutputStream();
                 OutputStream decoderOut = new Base16OutputStream(byteOut, false, lowerCase);
                 OutputStream encoderOut = new Base16OutputStream(decoderOut, true, lowerCase)) {
             for (final byte element : decoded) {
                 encoderOut.write(element);
             }
             final byte[] output = byteOut.toByteArray();
             assertArrayEquals(decoded, output, "Streaming byte-by-byte base16 wrap-wrap!");
         }
     }
 
     /**
      * Tests Base16OutputStream.write for expected IndexOutOfBoundsException conditions.
      *
      * @throws IOException for some failure scenarios.
      */
     @Test
     void testWriteOutOfBounds() throws IOException {
         final byte[] buf = new byte[1024];
         final ByteArrayOutputStream bout = new ByteArrayOutputStream();
         try (Base16OutputStream out = new Base16OutputStream(bout)) {
             assertThrows(IndexOutOfBoundsException.class, () -> out.write(buf, -1, 1), "Base16InputStream.write(buf, -1, 0)");
             assertThrows(IndexOutOfBoundsException.class, () -> out.write(buf, 1, -1), "Base16InputStream.write(buf, 1, -1)");
             assertThrows(IndexOutOfBoundsException.class, () -> out.write(buf, buf.length + 1, 0), "Base16InputStream.write(buf, buf.length + 1, 0)");
             assertThrows(IndexOutOfBoundsException.class, () -> out.write(buf, buf.length - 1, 2), "Base16InputStream.write(buf, buf.length - 1, 2)");
         }
     }
 
     /**
      * Tests Base16OutputStream.write(null).
      *
      * @throws IOException for some failure scenarios.
      */
     @Test
     void testWriteToNullCoverage() throws IOException {
         final ByteArrayOutputStream bout = new ByteArrayOutputStream();
         try (Base16OutputStream out = new Base16OutputStream(bout)) {
             assertThrows(NullPointerException.class, () -> out.write(null, 0, 0));
         }
     }
 }