/*
    * 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 java.io.ByteArrayInputStream;
  import java.io.ByteArrayOutputStream;
  import java.io.ObjectInputStream;
  import java.io.ObjectOutputStream;
  import java.util.List;
  import java.util.ArrayList;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  
  import junit.framework.TestCase;
  
  /**
   * Luhn Check Digit Test.
   *
   * @version $Revision$
   * @since Validator 1.4
   */
  public abstract class AbstractCheckDigitTest extends TestCase {
  
      /** 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 = new String[] {"12345678A"};
  
      /** code value which sums to zero */
      protected String zeroSum = "0000000000";
  
      /** Prefix for error messages */
      protected String missingMessage = "Code is missing";
  
      /**
       * Constructor
       * @param name test name
       */
      public AbstractCheckDigitTest(String name) {
          super(name);
      }
  
      /**
       * Tear Down - clears routine and valid codes.
       */
      @Override
      protected void tearDown() throws Exception {
          super.tearDown();
         valid = null;
         routine = null;
     }
 
     /**
      * Test isValid() for valid values.
      */
     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("valid[" + i +"]: " + valid[i], routine.isValid(valid[i]));
         }
     }
 
     /**
      * Test isValid() for invalid values.
      */
     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("invalid[" + i +"]: " + invalid[i], routine.isValid(invalid[i]));
         }
 
         // test invalid check digit values
         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("invalid check digit[" + i +"]: " + invalidCheckDigits[i], routine.isValid(invalidCheckDigits[i]));
         }
     }
 
     /**
      * Test calculate() for valid values.
      */
     public void testCalculateValid() {
         if (log.isDebugEnabled()) {
             log.debug("testCalculateValid() for " + routine.getClass().getName());
         }
 
         // test valid values
         for (int i = 0; i < valid.length; i++) {
             String code = removeCheckDigit(valid[i]);
             String expected = checkDigit(valid[i]);
             try {
                 if (log.isDebugEnabled()) {
                     log.debug("   " + i + " Testing Valid Check Digit, Code=[" + code + "] expected=[" + expected + "]");
                 }
                 assertEquals("valid[" + i +"]: " + valid[i], expected, routine.calculate(code));
             } catch (Exception e) {
                 fail("valid[" + i +"]=" + valid[i] + " threw " + e);
             }
         }
 
     }
 
     /**
      * Test calculate() for invalid values.
      */
     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 + "]");
                 }
                 String expected = checkDigit(code);
                 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 (CheckDigitException e) {
                 // possible failure messages:
                 // Invalid ISBN Length ...
                 // Invalid Character[ ...
                 // Are there any others?
                 assertTrue("Invalid Character[" +i +"]=" +  e.getMessage(), e.getMessage().startsWith("Invalid "));
 // WAS                assertTrue("Invalid Character[" +i +"]=" +  e.getMessage(), e.getMessage().startsWith("Invalid Character["));
             }
         }
     }
 
     /**
      * Test missing code
      */
     public void testMissingCode() {
 
         // isValid() null
         assertFalse("isValid() Null", routine.isValid(null));
 
         // isValid() zero length
         assertFalse("isValid() Zero Length", routine.isValid(""));
 
         // isValid() length 1
         // Don't use 0, because that passes for Verhoef (not sure why yet)
         assertFalse("isValid() Length 1", routine.isValid("9"));
 
         // calculate() null
         try {
             routine.calculate(null);
             fail("calculate() Null - expected exception");
         } catch (Exception e) {
             assertEquals("calculate() Null", missingMessage, e.getMessage());
         }
 
         // calculate() zero length
         try {
             routine.calculate("");
             fail("calculate() Zero Length - expected exception");
         } catch (Exception e) {
             assertEquals("calculate() Zero Length",  missingMessage, e.getMessage());
         }
     }
 
     /**
      * Test zero sum
      */
     public void testZeroSum() {
         
         assertFalse("isValid() Zero Sum", routine.isValid(zeroSum));
 
         try {
             routine.calculate(zeroSum);
             fail("Zero Sum - expected exception");
         } catch (Exception e) {
             assertEquals("isValid() Zero Sum",  "Invalid code, sum is zero", e.getMessage());
         }
 
     }
 
     /**
      * Test check digit serialization.
      */
     public void testSerialization() {
         // Serialize the check digit routine
         ByteArrayOutputStream baos = new ByteArrayOutputStream();
         try {
             ObjectOutputStream oos = new ObjectOutputStream(baos);
             oos.writeObject(routine);
             oos.flush();
             oos.close();
         } catch (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();
             bais.close();
         } catch (Exception e) {
             fail(routine.getClass().getName() + " error during deserialization: " + e);
         }
         assertNotNull(result);
     }
 
     private static final String POSSIBLE_CHECK_DIGITS = "0123456789 ABCDEFHIJKLMNOPQRSTUVWXYZ\tabcdefghijklmnopqrstuvwxyz!@£$%^&*()_+";
 //    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(String[] codes) {
         List<String> list = new ArrayList<String>();
 
         // create invalid check digit values
         for (String fullCode : codes) {
             String code = removeCheckDigit(fullCode);
             String check = checkDigit(fullCode);
             for (int j = 0; j < POSSIBLE_CHECK_DIGITS.length(); j++) {
                 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[list.size()]);
     }
 
     /**
      * 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(String code) {
         if (code == null || code.length() <= checkDigitLth) {
             return null;
         }
         return code.substring(0, code.length() - checkDigitLth);
     }
 
     /**
      * Returns the check digit (i.e. last character) for a code.
      *
      * @param code The code
      * @return The check digit
      */
     protected String checkDigit(String code) {
         if (code == null || code.length() <= checkDigitLth) {
             return "";
         }
         int start = code.length() - checkDigitLth;
         return code.substring(start);
     }
 
 }