/*
    * 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.text;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertFalse;
  import static org.junit.jupiter.api.Assertions.assertNotEquals;
  import static org.junit.jupiter.api.Assertions.assertNull;
  import static org.junit.jupiter.api.Assertions.assertThrows;
  import static org.junit.jupiter.api.Assertions.assertTrue;
  
  import java.io.UnsupportedEncodingException;
  import java.util.Arrays;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  import org.apache.commons.lang3.ArrayUtils;
  import org.junit.jupiter.api.Test;
  
  /**
   * Tests {@link AlphabetConverter}.
   */
  class AlphabetConverterTest {
  
      private static final Character[] LOWER_CASE_ENGLISH = { ' ', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's',
              't', 'u', 'v', 'w', 'x', 'y', 'z' };
  
      private static final Character[] ENGLISH_AND_NUMBERS = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j',
              'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
              'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', ' ' };
  
      private static final Character[] LOWER_CASE_ENGLISH_AND_NUMBERS = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f', 'g',
              'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', ' ' };
  
      private static final Character[] NUMBERS = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9' };
  
      private static final Character[] BINARY = { '0', '1' };
  
      private static final Character[] HEBREW = { '_', ' ', '\u05e7', '\u05e8', '\u05d0', '\u05d8', '\u05d5', '\u05df', '\u05dd', '\u05e4', '\u05e9', '\u05d3',
              '\u05d2', '\u05db', '\u05e2', '\u05d9', '\u05d7', '\u05dc', '\u05da', '\u05e3', '\u05d6', '\u05e1', '\u05d1', '\u05d4', '\u05e0', '\u05de',
              '\u05e6', '\u05ea', '\u05e5' };
  
      private static final Integer[] UNICODE = { 32, 35395, 35397, 36302, 36291, 35203, 35201, 35215, 35219, 35268, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106,
              107, 108, 109, 110, 1001, 1002, 1003, 1004, 1005 };
  
      private static final Integer[] LOWER_CASE_ENGLISH_CODEPOINTS = { 32, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114,
              115, 116, 117, 118, 119, 120, 121, 122 };
  
      private static final Integer[] DO_NOT_ENCODE_CODEPOINTS = { 32, 97, 98, 99 }; // space, a, b, c
  
      private AlphabetConverter createJavadocExample() {
          final Character[] original = { 'a', 'b', 'c', 'd' };
          final Character[] encoding = { '0', '1', 'd' };
          final Character[] doNotEncode = { 'd' };
  
          return AlphabetConverter.createConverterFromChars(original, encoding, doNotEncode);
      }
  
      private void test(final Character[] originalChars, final Character[] encodingChars, final Character[] doNotEncodeChars, final String... strings)
              throws UnsupportedEncodingException {
  
          final AlphabetConverter ac = AlphabetConverter.createConverterFromChars(originalChars, encodingChars, doNotEncodeChars);
  
          final AlphabetConverter reconstructedAlphabetConverter = AlphabetConverter.createConverterFromMap(ac.getOriginalToEncoded());
  
          assertEquals(ac, reconstructedAlphabetConverter);
          assertEquals(ac.hashCode(), reconstructedAlphabetConverter.hashCode());
          assertEquals(ac.toString(), reconstructedAlphabetConverter.toString());
          assertNull(ac.encode(null)); // test null conversions
          assertEquals("", ac.encode("")); // test empty conversion
  
          // test all the trial strings
          for (final String s : strings) {
              final String encoded = ac.encode(s);
  
              // test that only encoding chars are used
              final List<Character> originalEncodingChars = Arrays.asList(encodingChars);
              for (int i = 0; i < encoded.length(); i++) {
                  assertTrue(originalEncodingChars.contains(encoded.charAt(i)));
              }
  
              final String decoded = ac.decode(encoded);
  
              // test that only the original alphabet is used after decoding
             final List<Character> originalCharsList = Arrays.asList(originalChars);
             for (int i = 0; i < decoded.length(); i++) {
                 assertTrue(originalCharsList.contains(decoded.charAt(i)));
             }
 
             assertEquals(s, decoded, () -> "Encoded '" + s + "' into '" + encoded + "', but decoded into '" + decoded + "'");
         }
     }
 
     @Test
     void testBinaryTest() throws UnsupportedEncodingException {
         test(BINARY, NUMBERS, ArrayUtils.EMPTY_CHARACTER_OBJECT_ARRAY, "0", "1", "10", "11");
         test(NUMBERS, BINARY, ArrayUtils.EMPTY_CHARACTER_OBJECT_ARRAY, "12345", "0");
         test(LOWER_CASE_ENGLISH, BINARY, ArrayUtils.EMPTY_CHARACTER_OBJECT_ARRAY, "abc", "a");
     }
 
     @Test
     void testCreateConverterFromCharsAndEquals() {
         final Character[] characterArray = new Character[2];
         final char charOne = '+';
         final char character = '+';
         characterArray[0] = character;
         characterArray[1] = characterArray[0];
         final AlphabetConverter alphabetConverter = AlphabetConverter.createConverterFromChars(characterArray, characterArray, characterArray);
 
         assertNotEquals(alphabetConverter, charOne);
     }
 
     @Test
     void testCreateConverterFromCharsOne() {
         final Character[] characterArray = new Character[2];
         characterArray[0] = '5';
         characterArray[1] = characterArray[0];
         final AlphabetConverter alphabetConverter = AlphabetConverter.createConverterFromChars(characterArray, characterArray, characterArray);
 
         assertEquals(1, alphabetConverter.getEncodedCharLength());
     }
 
     @Test
     void testCreateConverterFromCharsWithNullAndNull() {
         assertThrows(IllegalArgumentException.class, () -> {
             final Character[] characterArray = new Character[2];
             characterArray[0] = '$';
             characterArray[1] = characterArray[0];
             AlphabetConverter.createConverterFromChars(characterArray, null, null);
         });
     }
 
     @Test
     void testCreateConverterFromMapAndEquals() {
         final Map<Integer, String> hashMap = new HashMap<>();
         final AlphabetConverter alphabetConverter = AlphabetConverter.createConverterFromMap(hashMap);
         hashMap.put(0, "CtDs");
         final AlphabetConverter alphabetConverterTwo = AlphabetConverter.createConverterFromMap(hashMap);
         assertNotEquals(alphabetConverter, alphabetConverterTwo);
         assertEquals(1, alphabetConverter.getEncodedCharLength());
     }
 
     @Test
     void testDecodeReturningNull() throws UnsupportedEncodingException {
         final Map<Integer, String> map = new HashMap<>();
         final AlphabetConverter alphabetConverter = AlphabetConverter.createConverterFromMap(map);
         alphabetConverter.decode(null);
         assertEquals(1, alphabetConverter.getEncodedCharLength());
     }
 
     @Test
     void testDoNotEncodeTest() throws UnsupportedEncodingException {
         test(ENGLISH_AND_NUMBERS, LOWER_CASE_ENGLISH_AND_NUMBERS, LOWER_CASE_ENGLISH, "1", "456", "abc", "ABC", "this will not be converted but THIS WILL");
         test(ENGLISH_AND_NUMBERS, LOWER_CASE_ENGLISH_AND_NUMBERS, NUMBERS, "1", "456", "abc", "ABC", "this will be converted but 12345 and this will be");
     }
 
     @Test
     void testEncodeFailureTest() {
         assertEquals("Couldn't find encoding for '3' in 3",
                 assertThrows(UnsupportedEncodingException.class, () -> test(BINARY, NUMBERS, ArrayUtils.EMPTY_CHARACTER_OBJECT_ARRAY, "3")).getMessage());
     }
 
     @Test
     void testEquals() {
         final Character[] characterArray = new Character[2];
         final char character = 'R';
         characterArray[0] = character;
         characterArray[1] = character;
         final AlphabetConverter alphabetConverter = AlphabetConverter.createConverterFromChars(characterArray, characterArray, characterArray);
         final Map<Integer, String> map = new HashMap<>();
         final AlphabetConverter alphabetConverterTwo = AlphabetConverter.createConverterFromMap(map);
 
         assertEquals(1, alphabetConverterTwo.getEncodedCharLength());
         assertNotEquals(alphabetConverter, alphabetConverterTwo);
     }
 
     @Test
     void testEqualsWithNull() {
         final Character[] characterArray = ArrayUtils.EMPTY_CHARACTER_OBJECT_ARRAY;
         final AlphabetConverter alphabetConverter = AlphabetConverter.createConverterFromChars(characterArray, null, null);
 
         assertFalse(alphabetConverter.equals(null));
     }
 
     @Test
     void testEqualsWithSameObject() {
         final Character[] characterArray = new Character[2];
         final char character = 'R';
         characterArray[0] = character;
         characterArray[1] = character;
         final AlphabetConverter alphabetConverter = AlphabetConverter.createConverterFromChars(characterArray, characterArray, characterArray);
 
         assertEquals(alphabetConverter, alphabetConverter);
     }
 
     @Test
     void testHebrewTest() throws UnsupportedEncodingException {
         test(HEBREW, BINARY, ArrayUtils.EMPTY_CHARACTER_OBJECT_ARRAY, "\u05d0", "\u05e2",
                 "\u05d0\u05dc\u05e3_\u05d0\u05d5\u05d4\u05d1\u05dc_\u05d1\u05d9\u05ea_\u05d6\u05d4_\u05d1\u05d9\u05ea_"
               + "\u05d2\u05d9\u05de\u05dc_\u05d6\u05d4_\u05db\u05de\u05dc_\u05d2\u05d3\u05d5\u05dc");
         test(HEBREW, NUMBERS, ArrayUtils.EMPTY_CHARACTER_OBJECT_ARRAY, "\u05d0", "\u05e2",
                 "\u05d0\u05dc\u05e3_\u05d0\u05d5\u05d4\u05d1\u05dc_\u05d1\u05d9\u05ea_\u05d6\u05d4_\u05d1\u05d9\u05ea_"
               + "\u05d2\u05d9\u05de\u05dc_\u05d6\u05d4_\u05db\u05de\u05dc_\u05d2\u05d3\u05d5\u05dc");
         test(NUMBERS, HEBREW, ArrayUtils.EMPTY_CHARACTER_OBJECT_ARRAY, "123456789", "1", "5");
         test(LOWER_CASE_ENGLISH, HEBREW, ArrayUtils.EMPTY_CHARACTER_OBJECT_ARRAY, "this is a test");
     }
 
     /*
      * Test example in javadocs for consistency
      */
     @Test
     void testJavadocExampleTest() throws UnsupportedEncodingException {
         final AlphabetConverter ac = createJavadocExample();
 
         assertEquals("00", ac.encode("a"));
         assertEquals("01", ac.encode("b"));
         assertEquals("0d", ac.encode("c"));
         assertEquals("d", ac.encode("d"));
         assertEquals("00010dd", ac.encode("abcd"));
     }
 
     @Test
     void testMissingDoNotEncodeLettersFromEncodingTest() {
         assertEquals("Can not use 'do not encode' list because encoding alphabet does not contain '0'",
                 assertThrows(IllegalArgumentException.class, () -> AlphabetConverter.createConverterFromChars(ENGLISH_AND_NUMBERS, LOWER_CASE_ENGLISH, NUMBERS))
                         .getMessage());
     }
 
     @Test
     void testMissingDoNotEncodeLettersFromOriginalTest() {
         assertEquals("Can not use 'do not encode' list because original alphabet does not contain '0'",
                 assertThrows(IllegalArgumentException.class, () -> AlphabetConverter.createConverterFromChars(LOWER_CASE_ENGLISH, ENGLISH_AND_NUMBERS, NUMBERS))
                         .getMessage());
     }
 
     @Test
     void testNoEncodingLettersTest() {
         assertEquals("Must have at least two encoding characters (excluding those in the 'do not encode' list), but has 0",
                 assertThrows(IllegalArgumentException.class, () -> AlphabetConverter.createConverterFromChars(ENGLISH_AND_NUMBERS, NUMBERS, NUMBERS))
                         .getMessage());
     }
 
     @Test
     void testOnlyOneEncodingLettersTest() {
         assertEquals("Must have at least two encoding characters (excluding those in the 'do not encode' list), but has 1",
                 assertThrows(IllegalArgumentException.class, () -> {
                     final Character[] numbersPlusUnderscore = Arrays.copyOf(NUMBERS, NUMBERS.length + 1);
                     numbersPlusUnderscore[numbersPlusUnderscore.length - 1] = '_';
 
                     AlphabetConverter.createConverterFromChars(ENGLISH_AND_NUMBERS, numbersPlusUnderscore, NUMBERS);
                 }).getMessage());
     }
 
     @Test
     void testUnexpectedEndWhileDecodingTest() {
         final String toDecode = "00d01d0";
         assertEquals("Unexpected end of string while decoding " + toDecode,
                 assertThrows(UnsupportedEncodingException.class, () -> createJavadocExample().decode(toDecode)).getMessage());
     }
 
     @Test
     void testUnexpectedStringWhileDecodingTest() {
         final String toDecode = "00XX";
         assertEquals("Unexpected string without decoding (XX) in " + toDecode,
                 assertThrows(UnsupportedEncodingException.class, () -> createJavadocExample().decode(toDecode)).getMessage());
     }
 
     /**
      * Test constructor from code points
      */
     @Test
     void testUnicodeTest() throws UnsupportedEncodingException {
         final AlphabetConverter ac = AlphabetConverter.createConverter(UNICODE, LOWER_CASE_ENGLISH_CODEPOINTS, DO_NOT_ENCODE_CODEPOINTS);
         assertEquals(2, ac.getEncodedCharLength());
         final String original = "\u8a43\u8a45 \u8dce ab \u8dc3 c \u8983";
         final String encoded = ac.encode(original);
         final String decoded = ac.decode(encoded);
         assertEquals(original, decoded, () -> "Encoded '" + original + "' into '" + encoded + "', but decoded into '" + decoded + "'");
     }
 
 }