package org.apache.lucene.util;

import org.junit.BeforeClass;

/**
 * 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.
 */

import java.nio.CharBuffer;
import java.nio.ByteBuffer;

public class TestIndexableBinaryStringTools extends LuceneTestCase {
  private static int NUM_RANDOM_TESTS;
  private static int MAX_RANDOM_BINARY_LENGTH;

  @BeforeClass
  public static void beforeClass() throws Exception {
    NUM_RANDOM_TESTS = atLeast(200);
    MAX_RANDOM_BINARY_LENGTH = atLeast(300);
  }

  /** @deprecated remove this test for Lucene 4.0 */
  @Deprecated
  public void testSingleBinaryRoundTripNIO() {
    byte[] binary = new byte[] 
      { (byte)0x23, (byte)0x98, (byte)0x13, (byte)0xE4, (byte)0x76, (byte)0x41,
        (byte)0xB2, (byte)0xC9, (byte)0x7F, (byte)0x0A, (byte)0xA6, (byte)0xD8 };

    ByteBuffer binaryBuf = ByteBuffer.wrap(binary);
    CharBuffer encoded = IndexableBinaryStringTools.encode(binaryBuf);
    ByteBuffer decoded = IndexableBinaryStringTools.decode(encoded);
    assertEquals("Round trip decode/decode returned different results:"
                 + System.getProperty("line.separator")
                 + "original: " + binaryDumpNIO(binaryBuf)
                 + System.getProperty("line.separator")
                 + " encoded: " + charArrayDumpNIO(encoded)
                 + System.getProperty("line.separator")
                 + " decoded: " + binaryDumpNIO(decoded),
                 binaryBuf, decoded);
  }
  
  public void testSingleBinaryRoundTrip() {
    byte[] binary = new byte[] { (byte) 0x23, (byte) 0x98, (byte) 0x13,
        (byte) 0xE4, (byte) 0x76, (byte) 0x41, (byte) 0xB2, (byte) 0xC9,
        (byte) 0x7F, (byte) 0x0A, (byte) 0xA6, (byte) 0xD8 };

    int encodedLen = IndexableBinaryStringTools.getEncodedLength(binary, 0,
        binary.length);
    char encoded[] = new char[encodedLen];
    IndexableBinaryStringTools.encode(binary, 0, binary.length, encoded, 0,
        encoded.length);

    int decodedLen = IndexableBinaryStringTools.getDecodedLength(encoded, 0,
        encoded.length);
    byte decoded[] = new byte[decodedLen];
    IndexableBinaryStringTools.decode(encoded, 0, encoded.length, decoded, 0,
        decoded.length);

    assertEquals("Round trip decode/decode returned different results:"
        + System.getProperty("line.separator") + "original: "
        + binaryDump(binary, binary.length)
        + System.getProperty("line.separator") + " encoded: "
        + charArrayDump(encoded, encoded.length)
        + System.getProperty("line.separator") + " decoded: "
        + binaryDump(decoded, decoded.length),
        binaryDump(binary, binary.length), binaryDump(decoded, decoded.length));
  }
  
  /** @deprecated remove this test for Lucene 4.0 */
  @Deprecated
  public void testEncodedSortabilityNIO() {
    byte[] originalArray1 = new byte[MAX_RANDOM_BINARY_LENGTH];
    ByteBuffer originalBuf1 = ByteBuffer.wrap(originalArray1);
    char[] originalString1 = new char[MAX_RANDOM_BINARY_LENGTH];
    CharBuffer originalStringBuf1 = CharBuffer.wrap(originalString1);
    char[] encoded1 = new char[IndexableBinaryStringTools.getEncodedLength(originalBuf1)];
    CharBuffer encodedBuf1 = CharBuffer.wrap(encoded1);
    byte[] original2 = new byte[MAX_RANDOM_BINARY_LENGTH];
    ByteBuffer originalBuf2 = ByteBuffer.wrap(original2);
    char[] originalString2 = new char[MAX_RANDOM_BINARY_LENGTH];
    CharBuffer originalStringBuf2 = CharBuffer.wrap(originalString2);
    char[] encoded2 = new char[IndexableBinaryStringTools.getEncodedLength(originalBuf2)];
    CharBuffer encodedBuf2 = CharBuffer.wrap(encoded2);
    for (int testNum = 0 ; testNum < NUM_RANDOM_TESTS ; ++testNum) {
      int numBytes1 = random.nextInt(MAX_RANDOM_BINARY_LENGTH - 1) + 1; // Min == 1
      originalBuf1.limit(numBytes1);
      originalStringBuf1.limit(numBytes1);
      
      for (int byteNum = 0 ; byteNum < numBytes1 ; ++byteNum) {
        int randomInt = random.nextInt(0x100);
        originalArray1[byteNum] = (byte) randomInt;
        originalString1[byteNum] = (char)randomInt;
      }
      
      int numBytes2 = random.nextInt(MAX_RANDOM_BINARY_LENGTH - 1) + 1; // Min == 1
      originalBuf2.limit(numBytes2);
      originalStringBuf2.limit(numBytes2);
      for (int byteNum = 0 ; byteNum < numBytes2 ; ++byteNum) {
        int randomInt = random.nextInt(0x100);
        original2[byteNum] = (byte)randomInt;
        originalString2[byteNum] = (char)randomInt;
      }
      int originalComparison = originalStringBuf1.compareTo(originalStringBuf2);
      originalComparison = originalComparison < 0 ? -1 : originalComparison > 0 ? 1 : 0;
      
      IndexableBinaryStringTools.encode(originalBuf1, encodedBuf1);
      IndexableBinaryStringTools.encode(originalBuf2, encodedBuf2);
      
      int encodedComparison = encodedBuf1.compareTo(encodedBuf2);
      encodedComparison = encodedComparison < 0 ? -1 : encodedComparison > 0 ? 1 : 0;
      
      assertEquals("Test #" + (testNum + 1) 
                   + ": Original bytes and encoded chars compare differently:"
                   + System.getProperty("line.separator")
                   + " binary 1: " + binaryDumpNIO(originalBuf1)
                   + System.getProperty("line.separator")
                   + " binary 2: " + binaryDumpNIO(originalBuf2)
                   + System.getProperty("line.separator")
                   + "encoded 1: " + charArrayDumpNIO(encodedBuf1)
                   + System.getProperty("line.separator")
                   + "encoded 2: " + charArrayDumpNIO(encodedBuf2)
                   + System.getProperty("line.separator"),
                   originalComparison, encodedComparison);
    }
  }

  public void testEncodedSortability() {
    byte[] originalArray1 = new byte[MAX_RANDOM_BINARY_LENGTH];
    char[] originalString1 = new char[MAX_RANDOM_BINARY_LENGTH];
    char[] encoded1 = new char[MAX_RANDOM_BINARY_LENGTH * 10];
    byte[] original2 = new byte[MAX_RANDOM_BINARY_LENGTH];
    char[] originalString2 = new char[MAX_RANDOM_BINARY_LENGTH];
    char[] encoded2 = new char[MAX_RANDOM_BINARY_LENGTH * 10];

    for (int testNum = 0; testNum < NUM_RANDOM_TESTS; ++testNum) {
      int numBytes1 = random.nextInt(MAX_RANDOM_BINARY_LENGTH - 1) + 1; // Min == 1

      for (int byteNum = 0; byteNum < numBytes1; ++byteNum) {
        int randomInt = random.nextInt(0x100);
        originalArray1[byteNum] = (byte) randomInt;
        originalString1[byteNum] = (char) randomInt;
      }

      int numBytes2 = random.nextInt(MAX_RANDOM_BINARY_LENGTH - 1) + 1; // Min == 1

      for (int byteNum = 0; byteNum < numBytes2; ++byteNum) {
        int randomInt = random.nextInt(0x100);
        original2[byteNum] = (byte) randomInt;
        originalString2[byteNum] = (char) randomInt;
      }
      int originalComparison = new String(originalString1, 0, numBytes1)
          .compareTo(new String(originalString2, 0, numBytes2));
      originalComparison = originalComparison < 0 ? -1
          : originalComparison > 0 ? 1 : 0;

      int encodedLen1 = IndexableBinaryStringTools.getEncodedLength(
          originalArray1, 0, numBytes1);
      if (encodedLen1 > encoded1.length)
        encoded1 = new char[ArrayUtil.oversize(encodedLen1, RamUsageEstimator.NUM_BYTES_CHAR)];
      IndexableBinaryStringTools.encode(originalArray1, 0, numBytes1, encoded1,
          0, encodedLen1);

      int encodedLen2 = IndexableBinaryStringTools.getEncodedLength(original2,
          0, numBytes2);
      if (encodedLen2 > encoded2.length)
        encoded2 = new char[ArrayUtil.oversize(encodedLen2, RamUsageEstimator.NUM_BYTES_CHAR)];
      IndexableBinaryStringTools.encode(original2, 0, numBytes2, encoded2, 0,
          encodedLen2);

      int encodedComparison = new String(encoded1, 0, encodedLen1)
          .compareTo(new String(encoded2, 0, encodedLen2));
      encodedComparison = encodedComparison < 0 ? -1
          : encodedComparison > 0 ? 1 : 0;

      assertEquals("Test #" + (testNum + 1)
          + ": Original bytes and encoded chars compare differently:"
          + System.getProperty("line.separator") + " binary 1: "
          + binaryDump(originalArray1, numBytes1)
          + System.getProperty("line.separator") + " binary 2: "
          + binaryDump(original2, numBytes2)
          + System.getProperty("line.separator") + "encoded 1: "
          + charArrayDump(encoded1, encodedLen1)
          + System.getProperty("line.separator") + "encoded 2: "
          + charArrayDump(encoded2, encodedLen2)
          + System.getProperty("line.separator"), originalComparison,
          encodedComparison);
    }
  }

  /** @deprecated remove this test for Lucene 4.0 */
  @Deprecated
  public void testEmptyInputNIO() {
    byte[] binary = new byte[0];
    CharBuffer encoded = IndexableBinaryStringTools.encode(ByteBuffer.wrap(binary));
    ByteBuffer decoded = IndexableBinaryStringTools.decode(encoded);
    assertNotNull("decode() returned null", decoded);
    assertEquals("decoded empty input was not empty", decoded.limit(), 0);
  }
  
  public void testEmptyInput() {
    byte[] binary = new byte[0];

    int encodedLen = IndexableBinaryStringTools.getEncodedLength(binary, 0,
        binary.length);
    char[] encoded = new char[encodedLen];
    IndexableBinaryStringTools.encode(binary, 0, binary.length, encoded, 0,
        encoded.length);

    int decodedLen = IndexableBinaryStringTools.getDecodedLength(encoded, 0,
        encoded.length);
    byte[] decoded = new byte[decodedLen];
    IndexableBinaryStringTools.decode(encoded, 0, encoded.length, decoded, 0,
        decoded.length);

    assertEquals("decoded empty input was not empty", decoded.length, 0);
  }
  
  /** @deprecated remove this test for Lucene 4.0 */
  @Deprecated
  public void testAllNullInputNIO() {
    byte[] binary = new byte[] { 0, 0, 0, 0, 0, 0, 0, 0, 0 };
    ByteBuffer binaryBuf = ByteBuffer.wrap(binary);
    CharBuffer encoded = IndexableBinaryStringTools.encode(binaryBuf);
    assertNotNull("encode() returned null", encoded);
    ByteBuffer decodedBuf = IndexableBinaryStringTools.decode(encoded);
    assertNotNull("decode() returned null", decodedBuf);
    assertEquals("Round trip decode/decode returned different results:"
                 + System.getProperty("line.separator")
                 + "  original: " + binaryDumpNIO(binaryBuf)
                 + System.getProperty("line.separator")
                 + "decodedBuf: " + binaryDumpNIO(decodedBuf),
                 binaryBuf, decodedBuf);
  }
  
  public void testAllNullInput() {
    byte[] binary = new byte[] { 0, 0, 0, 0, 0, 0, 0, 0, 0 };

    int encodedLen = IndexableBinaryStringTools.getEncodedLength(binary, 0,
        binary.length);
    char encoded[] = new char[encodedLen];
    IndexableBinaryStringTools.encode(binary, 0, binary.length, encoded, 0,
        encoded.length);

    int decodedLen = IndexableBinaryStringTools.getDecodedLength(encoded, 0,
        encoded.length);
    byte[] decoded = new byte[decodedLen];
    IndexableBinaryStringTools.decode(encoded, 0, encoded.length, decoded, 0,
        decoded.length);

    assertEquals("Round trip decode/decode returned different results:"
        + System.getProperty("line.separator") + "  original: "
        + binaryDump(binary, binary.length)
        + System.getProperty("line.separator") + "decodedBuf: "
        + binaryDump(decoded, decoded.length),
        binaryDump(binary, binary.length), binaryDump(decoded, decoded.length));
  }
  
  /** @deprecated remove this test for Lucene 4.0 */
  @Deprecated
  public void testRandomBinaryRoundTripNIO() {
    byte[] binary = new byte[MAX_RANDOM_BINARY_LENGTH];
    ByteBuffer binaryBuf = ByteBuffer.wrap(binary);
    char[] encoded = new char[IndexableBinaryStringTools.getEncodedLength(binaryBuf)];
    CharBuffer encodedBuf = CharBuffer.wrap(encoded);
    byte[] decoded = new byte[MAX_RANDOM_BINARY_LENGTH];
    ByteBuffer decodedBuf = ByteBuffer.wrap(decoded);
    for (int testNum = 0 ; testNum < NUM_RANDOM_TESTS ; ++testNum) {
      int numBytes = random.nextInt(MAX_RANDOM_BINARY_LENGTH - 1) + 1 ; // Min == 1
      binaryBuf.limit(numBytes);
      for (int byteNum = 0 ; byteNum < numBytes ; ++byteNum) {
        binary[byteNum] = (byte)random.nextInt(0x100);
      }
      IndexableBinaryStringTools.encode(binaryBuf, encodedBuf);
      IndexableBinaryStringTools.decode(encodedBuf, decodedBuf);
      assertEquals("Test #" + (testNum + 1) 
                   + ": Round trip decode/decode returned different results:"
                   + System.getProperty("line.separator")
                   + "  original: " + binaryDumpNIO(binaryBuf)
                   + System.getProperty("line.separator")
                   + "encodedBuf: " + charArrayDumpNIO(encodedBuf)
                   + System.getProperty("line.separator")
                   + "decodedBuf: " + binaryDumpNIO(decodedBuf),
                   binaryBuf, decodedBuf);
    }
  }

  public void testRandomBinaryRoundTrip() {
    byte[] binary = new byte[MAX_RANDOM_BINARY_LENGTH];
    char[] encoded = new char[MAX_RANDOM_BINARY_LENGTH * 10];
    byte[] decoded = new byte[MAX_RANDOM_BINARY_LENGTH];
    for (int testNum = 0; testNum < NUM_RANDOM_TESTS; ++testNum) {
      int numBytes = random.nextInt(MAX_RANDOM_BINARY_LENGTH - 1) + 1; // Min == 1                                                                   

      for (int byteNum = 0; byteNum < numBytes; ++byteNum) {
        binary[byteNum] = (byte) random.nextInt(0x100);
      }

      int encodedLen = IndexableBinaryStringTools.getEncodedLength(binary, 0,
          numBytes);
      if (encoded.length < encodedLen)
        encoded = new char[ArrayUtil.oversize(encodedLen, RamUsageEstimator.NUM_BYTES_CHAR)];
      IndexableBinaryStringTools.encode(binary, 0, numBytes, encoded, 0,
          encodedLen);

      int decodedLen = IndexableBinaryStringTools.getDecodedLength(encoded, 0,
          encodedLen);
      IndexableBinaryStringTools.decode(encoded, 0, encodedLen, decoded, 0,
          decodedLen);

      assertEquals("Test #" + (testNum + 1)
          + ": Round trip decode/decode returned different results:"
          + System.getProperty("line.separator") + "  original: "
          + binaryDump(binary, numBytes) + System.getProperty("line.separator")
          + "encodedBuf: " + charArrayDump(encoded, encodedLen)
          + System.getProperty("line.separator") + "decodedBuf: "
          + binaryDump(decoded, decodedLen), binaryDump(binary, numBytes),
          binaryDump(decoded, decodedLen));
    }
  }
  
  /** @deprecated remove this method for Lucene 4.0 */
  @Deprecated
  public String binaryDumpNIO(ByteBuffer binaryBuf) {
    return binaryDump(binaryBuf.array(), 
        binaryBuf.limit() - binaryBuf.arrayOffset());
  }

  public String binaryDump(byte[] binary, int numBytes) {
    StringBuilder buf = new StringBuilder();
    for (int byteNum = 0 ; byteNum < numBytes ; ++byteNum) {
      String hex = Integer.toHexString(binary[byteNum] & 0xFF);
      if (hex.length() == 1) {
        buf.append('0');
      }
      buf.append(hex.toUpperCase());
      if (byteNum < numBytes - 1) {
        buf.append(' ');
      }
    }
    return buf.toString();
  }
  /** @deprecated remove this method for Lucene 4.0 */
  @Deprecated
  public String charArrayDumpNIO(CharBuffer charBuf) {
    return charArrayDump(charBuf.array(), 
        charBuf.limit() - charBuf.arrayOffset());
  }
  
  public String charArrayDump(char[] charArray, int numBytes) {
    StringBuilder buf = new StringBuilder();
    for (int charNum = 0 ; charNum < numBytes ; ++charNum) {
      String hex = Integer.toHexString(charArray[charNum]);
      for (int digit = 0 ; digit < 4 - hex.length() ; ++digit) {
        buf.append('0');
      }
      buf.append(hex.toUpperCase());
      if (charNum < numBytes - 1) {
        buf.append(' ');
      }
    }
    return buf.toString();
  }
}