/*
    * 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.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertFalse;
  import static org.junit.jupiter.api.Assertions.assertNotNull;
  import static org.junit.jupiter.api.Assertions.assertThrows;
  
  import java.io.ByteArrayInputStream;
  import java.io.IOException;
  import java.io.InputStream;
  
  import org.junit.jupiter.api.Test;
  
  /**
   * Tests {@link Base16InputStream}.
   */
  class Base16InputStreamTest {
  
      /**
       * Decodes to {202, 254, 186, 190, 255, 255}
       */
      private static final String ENCODED_B16 = "CAFEBABEFFFF";
  
      private static final String STRING_FIXTURE = "Hello World";
  
      /**
       * Tests skipping past the end of a stream.
       *
       * @throws IOException for some failure scenarios.
       */
      @Test
      void testAvailable() throws IOException {
          final InputStream ins = new ByteArrayInputStream(StringUtils.getBytesIso8859_1(ENCODED_B16));
          try (Base16InputStream b16Stream = new Base16InputStream(ins)) {
              assertEquals(1, b16Stream.available());
              assertEquals(6, b16Stream.skip(10));
              // End of stream reached
              assertEquals(0, b16Stream.available());
              assertEquals(-1, b16Stream.read());
              assertEquals(-1, b16Stream.read());
              assertEquals(0, b16Stream.available());
          }
      }
  
      /**
       * Tests the Base16InputStream implementation against empty input.
       *
       * @throws IOException for some failure scenarios.
       */
      @Test
      void testBase16EmptyInputStream() throws IOException {
          final byte[] emptyEncoded = {};
          final byte[] emptyDecoded = {};
          testByteByByte(emptyEncoded, emptyDecoded);
          testByChunk(emptyEncoded, emptyDecoded);
      }
  
      /**
       * Tests the Base16InputStream implementation.
       *
       * @throws IOException for some failure scenarios.
       */
      @Test
      void testBase16InputStreamByChunk() 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);
          // OpenSSL interop test.
          encoded = StringUtils.getBytesUtf8(Base16TestData.ENCODED_UTF8_UPPERCASE);
          decoded = BaseNTestData.DECODED;
          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);
         }
     }
 
     /**
      * Tests the Base16InputStream implementation.
      *
      * @throws IOException for some failure scenarios.
      */
     @Test
     void testBase16InputStreamByteByByte() 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);
         // OpenSSL interop test.
         encoded = StringUtils.getBytesUtf8(Base16TestData.ENCODED_UTF8_UPPERCASE);
         decoded = BaseNTestData.DECODED;
         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(Base16InputStream.builder().getBaseNCodec());
     }
 
     /**
      * Tests 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 Base16InputStream 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);
     }
 
     /**
      * Tests 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 Base16InputStream 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 (InputStream in = new Base16InputStream(new ByteArrayInputStream(decoded), true, lowerCase)) {
             final byte[] output = BaseNTestData.streamToBytes(in);
             assertEquals(-1, in.read(), "EOF");
             assertEquals(-1, in.read(), "Still EOF");
             assertArrayEquals(encoded, output, "Streaming Base16 encode");
         }
         // Now let's try to decode.
         try (InputStream in = new Base16InputStream(new ByteArrayInputStream(encoded), false, lowerCase)) {
             final byte[] output = BaseNTestData.streamToBytes(in);
             assertEquals(-1, in.read(), "EOF");
             assertEquals(-1, in.read(), "Still EOF");
             assertArrayEquals(decoded, output, "Streaming Base16 decode");
         }
         // wrap encoder with decoder
         try (InputStream in = new ByteArrayInputStream(decoded);
                 InputStream inEncode = new Base16InputStream(in, true, lowerCase);
                 InputStream inDecode = new Base16InputStream(inEncode, false, lowerCase)) {
             final byte[] output = BaseNTestData.streamToBytes(inDecode);
             assertEquals(-1, inDecode.read(), "EOF");
             assertEquals(-1, inDecode.read(), "Still EOF");
             assertArrayEquals(decoded, output, "Streaming Base16 wrap-wrap!");
         }
     }
 
     /**
      * Tests 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 Base16InputStream 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);
     }
 
     /**
      * Tests 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 Base16InputStream 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 testByteByByte(final byte[] encoded, final byte[] decoded, final boolean lowerCase) throws IOException {
         // Start with encode.
         try (InputStream in = new Base16InputStream(new ByteArrayInputStream(decoded), true, lowerCase)) {
             final byte[] output = new byte[encoded.length];
             for (int i = 0; i < output.length; i++) {
                 output[i] = (byte) in.read();
             }
             assertEquals(-1, in.read(), "EOF");
             assertEquals(-1, in.read(), "Still EOF");
             assertArrayEquals(encoded, output, "Streaming Base16 encode");
         }
         try (InputStream in = Base16InputStream.builder()
                 .setInputStream(new ByteArrayInputStream(decoded))
                 .setEncode(true).setBaseNCodec(Base16.builder().setLowerCase(lowerCase).get())
                 .get()) {
             final byte[] output = new byte[encoded.length];
             for (int i = 0; i < output.length; i++) {
                 output[i] = (byte) in.read();
             }
             assertEquals(-1, in.read(), "EOF");
             assertEquals(-1, in.read(), "Still EOF");
             assertArrayEquals(encoded, output, "Streaming Base16 encode");
         }
         // Now let's try to decode.
         try (InputStream in = new Base16InputStream(new ByteArrayInputStream(encoded), false, lowerCase)) {
             final byte[] output = new byte[decoded.length];
             for (int i = 0; i < output.length; i++) {
                 output[i] = (byte) in.read();
             }
             assertEquals(-1, in.read(), "EOF");
             assertEquals(-1, in.read(), "Still EOF");
             assertArrayEquals(decoded, output, "Streaming Base16 decode");
         }
         // wrap encoder with decoder
         try (InputStream in = new ByteArrayInputStream(decoded);
                 InputStream inEncode = new Base16InputStream(in, true, lowerCase);
                 InputStream inDecode = new Base16InputStream(inEncode, false, lowerCase)) {
             final byte[] output = new byte[decoded.length];
             for (int i = 0; i < output.length; i++) {
                 output[i] = (byte) inDecode.read();
             }
             assertEquals(-1, inDecode.read(), "EOF");
             assertEquals(-1, inDecode.read(), "Still EOF");
             assertArrayEquals(decoded, output, "Streaming Base16 wrap-wrap!");
         }
     }
 
     /**
      * Tests markSupported.
      *
      * @throws IOException for some failure scenarios.
      */
     @Test
     void testMarkSupported() throws IOException {
         final byte[] decoded = StringUtils.getBytesUtf8(STRING_FIXTURE);
         final ByteArrayInputStream bin = new ByteArrayInputStream(decoded);
         try (Base16InputStream in = new Base16InputStream(bin, true)) {
             // Always returns false for now.
             assertFalse(in.markSupported(), "Base16InputStream.markSupported() is false");
         }
     }
 
     /**
      * Tests read returning 0
      *
      * @throws IOException for some failure scenarios.
      */
     @Test
     void testRead0() throws IOException {
         final byte[] decoded = StringUtils.getBytesUtf8(STRING_FIXTURE);
         final byte[] buf = new byte[1024];
         int bytesRead = 0;
         final ByteArrayInputStream bin = new ByteArrayInputStream(decoded);
         try (Base16InputStream in = new Base16InputStream(bin, true)) {
             bytesRead = in.read(buf, 0, 0);
             assertEquals(0, bytesRead, "Base16InputStream.read(buf, 0, 0) returns 0");
         }
     }
 
     /**
      * Tests read with null.
      *
      * @throws IOException for some failure scenarios.
      */
     @Test
     void testReadNull() throws IOException {
         final byte[] decoded = StringUtils.getBytesUtf8(STRING_FIXTURE);
         final ByteArrayInputStream bin = new ByteArrayInputStream(decoded);
         try (Base16InputStream in = new Base16InputStream(bin, true)) {
             assertThrows(NullPointerException.class, () -> in.read(null, 0, 0), "Base16InputStream.read(null, 0, 0)");
         }
     }
 
     /**
      * Tests read throwing IndexOutOfBoundsException
      *
      * @throws IOException for some failure scenarios.
      */
     @Test
     void testReadOutOfBounds() throws IOException {
         final byte[] decoded = StringUtils.getBytesUtf8(STRING_FIXTURE);
         final byte[] buf = new byte[1024];
         final ByteArrayInputStream bin = new ByteArrayInputStream(decoded);
         try (Base16InputStream in = new Base16InputStream(bin, true)) {
             assertThrows(IndexOutOfBoundsException.class, () -> in.read(buf, -1, 0), "Base16InputStream.read(buf, -1, 0)");
             assertThrows(IndexOutOfBoundsException.class, () -> in.read(buf, 0, -1), "Base16InputStream.read(buf, 0, -1)");
             assertThrows(IndexOutOfBoundsException.class, () -> in.read(buf, buf.length + 1, 0), "Base16InputStream.read(buf, buf.length + 1, 0)");
             assertThrows(IndexOutOfBoundsException.class, () -> in.read(buf, buf.length - 1, 2), "Base16InputStream.read(buf, buf.length - 1, 2)");
         }
     }
 
     /**
      * Tests skipping number of characters larger than the internal buffer.
      *
      * @throws IOException for some failure scenarios.
      */
     @Test
     void testSkipBig() throws IOException {
         final InputStream ins = new ByteArrayInputStream(StringUtils.getBytesIso8859_1(ENCODED_B16));
         try (Base16InputStream b16Stream = new Base16InputStream(ins)) {
             assertEquals(6, b16Stream.skip(Integer.MAX_VALUE));
             // End of stream reached
             assertEquals(-1, b16Stream.read());
             assertEquals(-1, b16Stream.read());
         }
     }
 
     /**
      * Tests skipping as a noop
      *
      * @throws IOException for some failure scenarios.
      */
     @Test
     void testSkipNone() throws IOException {
         final InputStream ins = new ByteArrayInputStream(StringUtils.getBytesIso8859_1(ENCODED_B16));
         try (Base16InputStream b16Stream = new Base16InputStream(ins)) {
             final byte[] actualBytes = new byte[6];
             assertEquals(0, b16Stream.skip(0));
             b16Stream.read(actualBytes, 0, actualBytes.length);
             assertArrayEquals(actualBytes, new byte[] { (byte) 202, (byte) 254, (byte) 186, (byte) 190, (byte) 255, (byte) 255 });
             // End of stream reached
             assertEquals(-1, b16Stream.read());
         }
     }
 
     /**
      * Tests skipping past the end of a stream.
      *
      * @throws IOException for some failure scenarios.
      */
     @Test
     void testSkipPastEnd() throws IOException {
         final InputStream ins = new ByteArrayInputStream(StringUtils.getBytesIso8859_1(ENCODED_B16));
         try (Base16InputStream b16Stream = new Base16InputStream(ins)) {
             // due to CODEC-130, skip now skips correctly decoded characters rather than encoded
             assertEquals(6, b16Stream.skip(10));
             // End of stream reached
             assertEquals(-1, b16Stream.read());
             assertEquals(-1, b16Stream.read());
         }
     }
 
     /**
      * Tests skipping to the end of a stream.
      *
      * @throws IOException for some failure scenarios.
      */
     @Test
     void testSkipToEnd() throws IOException {
         final InputStream ins = new ByteArrayInputStream(StringUtils.getBytesIso8859_1(ENCODED_B16));
         try (Base16InputStream b16Stream = new Base16InputStream(ins)) {
             // due to CODEC-130, skip now skips correctly decoded characters rather than encoded
             assertEquals(6, b16Stream.skip(6));
             // End of stream reached
             assertEquals(-1, b16Stream.read());
             assertEquals(-1, b16Stream.read());
         }
     }
 
     /**
      * Tests if negative arguments to skip are handled correctly.
      *
      * @throws IOException for some failure scenarios.
      */
     @Test
     void testSkipWrongArgument() throws IOException {
         final InputStream ins = new ByteArrayInputStream(StringUtils.getBytesIso8859_1(ENCODED_B16));
         try (Base16InputStream b16Stream = new Base16InputStream(ins)) {
             assertThrows(IllegalArgumentException.class, () -> b16Stream.skip(-10));
         }
         // Same with a builder
         try (Base16InputStream b16Stream = Base16InputStream.builder().setInputStream(ins).get()) {
             assertThrows(IllegalArgumentException.class, () -> b16Stream.skip(-10));
         }
     }
 }