/*
    * Copyright (C) 2020-2023 Dipl.-Inform. Kai Hofmann. All rights reserved!
    */
   package de.powerstat.validation.values.impl;
   
   
   import java.util.Map;
   import java.util.Objects;
   import java.util.concurrent.ConcurrentHashMap;
  
  import de.powerstat.validation.containers.NTuple2;
  
  
  /**
   * IBAN verifier.
   */
  public final class IBANVerifier
   {
    /**
     * Cache for singletons.
     */
    private static final Map<NTuple2<Integer, String>, IBANVerifier> CACHE = new ConcurrentHashMap<>();
  
    /**
     * IBAN length.
     */
    private final int length;
  
    /**
     * IBAN regexp.
     */
    private final String regexp;
  
  
    /**
     * Constructor.
     *
     * @param length Country specific maximum IBAN length.
     * @param regexp Country specific regular expression
     */
    private IBANVerifier(final int length, final String regexp)
     {
      super();
      if ((length < 15) || (length > 34))
       {
        throw new IllegalArgumentException("Wrong length, must be between 15 and 34"); //$NON-NLS-1$
       }
      Objects.requireNonNull(regexp, "regexp"); //$NON-NLS-1$
      // TODO test regexp length and allowed characters
      if ((regexp.charAt(0) != '^') || (regexp.charAt(regexp.length() - 1) != '$'))
       {
        throw new IllegalArgumentException("Regexp does not start with ^ or ends with $"); //$NON-NLS-1$
       }
      this.length = length;
      this.regexp = regexp;
     }
  
  
    /**
     * IBAN verifier factory.
     *
     * @param length Country specific maximum IBAN length.
     * @param regexp Country specific regular expression
     * @return IBAN verifier object
     */
    public static IBANVerifier of(final int length, final String regexp)
     {
      final NTuple2<Integer, String> tuple = NTuple2.of(length, regexp);
      synchronized (IBANVerifier.class)
       {
        IBANVerifier obj = IBANVerifier.CACHE.get(tuple);
        if (obj != null)
         {
          return obj;
         }
        obj = new IBANVerifier(length, regexp);
        IBANVerifier.CACHE.put(tuple, obj);
        return obj;
       }
     }
  
  
    /**
     * Verify country specific iban.
     *
     * @param iban IBAN
     * @return true when IBAN is ok, false otherwise
     */
    public boolean verify(final String iban)
     {
      Objects.requireNonNull(iban, "iban"); //$NON-NLS-1$
      return ((iban.length() == this.length) && iban.matches(this.regexp));
     }
  
   }