/*
    * 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.
   */
  package org.apache.commons.validator.routines.checkdigit;
  
  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.assertTrue;
  import static org.junit.jupiter.api.Assertions.fail;
  
  import java.io.ByteArrayInputStream;
  import java.io.ByteArrayOutputStream;
  import java.io.ObjectInputStream;
  import java.io.ObjectOutputStream;
  import java.util.ArrayList;
  import java.util.List;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.junit.jupiter.api.AfterEach;
  import org.junit.jupiter.api.Test;
  
  /**
   * Luhn Check Digit Test.
   *
   * @since 1.4
   */
  public abstract class AbstractCheckDigitTest {
  
      private static final String POSSIBLE_CHECK_DIGITS = "0123456789 ABCDEFHIJKLMNOPQRSTUVWXYZ\tabcdefghijklmnopqrstuvwxyz!@£$%^&*()_+";
  
      /** logging instance */
      protected Log log = LogFactory.getLog(getClass());
  
      /** Check digit routine being tested */
      protected int checkDigitLth = 1;
  
      /** Check digit routine being tested */
      protected CheckDigit routine;
  
      /**
       * Array of valid code values These must contain valid strings *including* the check digit.
       *
       * They are passed to: CheckDigit.isValid(expects string including checkdigit) which is expected to return true and
       * AbstractCheckDigitTest.createInvalidCodes() which mangles the last character to check that the result is now invalid. and the truncated string is passed
       * to CheckDigit.calculate(expects string without checkdigit) the result is compared with the last character
       */
      protected String[] valid;
  
      /**
       * Array of invalid code values
       *
       * These are currently passed to both CheckDigit.calculate(expects a string without checkdigit) which is expected to throw an exception However that only
       * applies if the string is syntactically incorrect; and CheckDigit.isValid(expects a string including checkdigit) which is expected to return false
       *
       * See https://issues.apache.org/jira/browse/VALIDATOR-344 for some dicussion on this
       */
      protected String[] invalid = { "12345678A" };
  
      /** code value which sums to zero */
      protected String zeroSum = "0000000000";
  
      /** Prefix for error messages */
      protected String missingMessage = "Code is missing";
  
      /**
       * Returns the check digit (i.e. last character) for a code.
       *
       * @param code The code
       * @return The check digit
       */
      protected String checkDigit(final String code) {
          if (code == null || code.length() <= checkDigitLth) {
              return "";
          }
          final int start = code.length() - checkDigitLth;
          return code.substring(start);
      }
  
      // private static final String POSSIBLE_CHECK_DIGITS = "0123456789";
      /**
       * Returns an array of codes with invalid check digits.
       *
       * @param codes Codes with valid check digits
       * @return Codes with invalid check digits
      */
     protected String[] createInvalidCodes(final String[] codes) {
         final List<String> list = new ArrayList<>();
 
         // create invalid check digit values
         for (final String fullCode : codes) {
             final String code = removeCheckDigit(fullCode);
             final String check = checkDigit(fullCode);
             for (int j = 0; j < POSSIBLE_CHECK_DIGITS.length(); j++) {
                 final String curr = POSSIBLE_CHECK_DIGITS.substring(j, j + 1);// "" + Character.forDigit(j, 10);
                 if (!curr.equals(check)) {
                     list.add(code + curr);
                 }
             }
         }
 
         return list.toArray(new String[0]);
     }
 
     /**
      * Returns a code with the Check Digit (i.e. last character) removed.
      *
      * @param code The code
      * @return The code without the check digit
      */
     protected String removeCheckDigit(final String code) {
         if (code == null || code.length() <= checkDigitLth) {
             return null;
         }
         return code.substring(0, code.length() - checkDigitLth);
     }
 
     /**
      * Tear Down - clears routine and valid codes.
      */
     @AfterEach
     protected void tearDown() {
         valid = null;
         routine = null;
     }
 
     /**
      * Test calculate() for invalid values.
      */
     @Test
     public void testCalculateInvalid() {
 
         if (log.isDebugEnabled()) {
             log.debug("testCalculateInvalid() for " + routine.getClass().getName());
         }
 
         // test invalid code values
         for (int i = 0; i < invalid.length; i++) {
             try {
                 final String code = invalid[i];
                 if (log.isDebugEnabled()) {
                     log.debug("   " + i + " Testing Invalid Check Digit, Code=[" + code + "]");
                 }
                 final String expected = checkDigit(code);
                 final String actual = routine.calculate(removeCheckDigit(code));
                 // If exception not thrown, check that the digit is incorrect instead
                 if (expected.equals(actual)) {
                     fail("Expected mismatch for " + code + " expected " + expected + " actual " + actual);
                 }
             } catch (final CheckDigitException e) {
                 // possible failure messages:
                 // Invalid ISBN Length ...
                 // Invalid Character[ ...
                 // Are there any others?
                 assertTrue(e.getMessage().startsWith("Invalid "), "Invalid Character[" + i + "]=" + e.getMessage());
 // WAS                assertTrue("Invalid Character[" +i +"]=" +  e.getMessage(), e.getMessage().startsWith("Invalid Character["));
             }
         }
     }
 
     /**
      * Test calculate() for valid values.
      */
     @Test
     public void testCalculateValid() {
         if (log.isDebugEnabled()) {
             log.debug("testCalculateValid() for " + routine.getClass().getName());
         }
 
         // test valid values
         for (int i = 0; i < valid.length; i++) {
             final String code = removeCheckDigit(valid[i]);
             final String expected = checkDigit(valid[i]);
             try {
                 if (log.isDebugEnabled()) {
                     log.debug("   " + i + " Testing Valid Check Digit, Code=[" + code + "] expected=[" + expected + "]");
                 }
                 assertEquals(expected, routine.calculate(code), "valid[" + i + "]: " + valid[i]);
             } catch (final Exception e) {
                 fail("valid[" + i + "]=" + valid[i] + " threw " + e);
             }
         }
 
     }
 
     /**
      * Test isValid() for invalid values.
      */
     @Test
     public void testIsValidFalse() {
         if (log.isDebugEnabled()) {
             log.debug("testIsValidFalse() for " + routine.getClass().getName());
         }
 
         // test invalid code values
         for (int i = 0; i < invalid.length; i++) {
             if (log.isDebugEnabled()) {
                 log.debug("   " + i + " Testing Invalid Code=[" + invalid[i] + "]");
             }
             assertFalse(routine.isValid(invalid[i]), "invalid[" + i + "]: " + invalid[i]);
         }
 
         // test invalid check digit values
         final String[] invalidCheckDigits = createInvalidCodes(valid);
         for (int i = 0; i < invalidCheckDigits.length; i++) {
             if (log.isDebugEnabled()) {
                 log.debug("   " + i + " Testing Invalid Check Digit, Code=[" + invalidCheckDigits[i] + "]");
             }
             assertFalse(routine.isValid(invalidCheckDigits[i]), "invalid check digit[" + i + "]: " + invalidCheckDigits[i]);
         }
     }
 
     /**
      * Test isValid() for valid values.
      */
     @Test
     public void testIsValidTrue() {
         if (log.isDebugEnabled()) {
             log.debug("testIsValidTrue() for " + routine.getClass().getName());
         }
 
         // test valid values
         for (int i = 0; i < valid.length; i++) {
             if (log.isDebugEnabled()) {
                 log.debug("   " + i + " Testing Valid Code=[" + valid[i] + "]");
             }
             assertTrue(routine.isValid(valid[i]), "valid[" + i + "]: " + valid[i]);
         }
     }
 
     /**
      * Test missing code
      */
     @Test
     public void testMissingCode() {
 
         // isValid() null
         assertFalse(routine.isValid(null), "isValid() Null");
 
         // isValid() zero length
         assertFalse(routine.isValid(""), "isValid() Zero Length");
 
         // isValid() length 1
         // Don't use 0, because that passes for Verhoef (not sure why yet)
         assertFalse(routine.isValid("9"), "isValid() Length 1");
 
         // calculate() null
         try {
             routine.calculate(null);
             fail("calculate() Null - expected exception");
         } catch (final Exception e) {
             assertEquals(missingMessage, e.getMessage(), "calculate() Null");
         }
 
         // calculate() zero length
         try {
             routine.calculate("");
             fail("calculate() Zero Length - expected exception");
         } catch (final Exception e) {
             assertEquals(missingMessage, e.getMessage(), "calculate() Zero Length");
         }
     }
 
     /**
      * Test check digit serialization.
      */
     @Test
     public void testSerialization() {
         // Serialize the check digit routine
         final ByteArrayOutputStream baos = new ByteArrayOutputStream();
         try (ObjectOutputStream oos = new ObjectOutputStream(baos)) {
             oos.writeObject(routine);
             oos.flush();
         } catch (final Exception e) {
             fail(routine.getClass().getName() + " error during serialization: " + e);
         }
 
         // Deserialize the test object
         Object result = null;
         try (ByteArrayInputStream bais = new ByteArrayInputStream(baos.toByteArray())) {
             ObjectInputStream ois = new ObjectInputStream(bais);
             result = ois.readObject();
         } catch (final Exception e) {
             fail(routine.getClass().getName() + " error during deserialization: " + e);
         }
         assertNotNull(result);
     }
 
     /**
      * Test zero sum
      */
     @Test
     public void testZeroSum() {
         assertFalse(routine.isValid(zeroSum), "isValid() Zero Sum");
         try {
             routine.calculate(zeroSum);
             fail("Zero Sum - expected exception");
         } catch (final Exception e) {
             assertEquals("Invalid code, sum is zero", e.getMessage(), "isValid() Zero Sum");
         }
     }
 
 }