package com.github.mygreen.supercsv.cellprocessor.constraint;
   
   import org.supercsv.cellprocessor.ift.StringCellProcessor;
   import org.supercsv.util.CsvContext;
   
   import com.github.mygreen.supercsv.cellprocessor.ValidationCellProcessor;
   
   
   /**
   * 文字列に対して、正規表現に一致するか検証するCellProcessor.
   *
   * @since 2.0
   * @author T.TSUCHIE
   *
   */
  public class Pattern extends ValidationCellProcessor implements StringCellProcessor {
      
      private final java.util.regex.Pattern pattern;
      
      private final String description;
      
      public Pattern(final java.util.regex.Pattern regexPattern, final String regexDescriptoin) {
          super();
          checkPreconditions(regexPattern);
          this.pattern = regexPattern;
          this.description = regexDescriptoin;
      }
      
      public Pattern(final java.util.regex.Pattern regexPattern, final String regexDescriptoin, final StringCellProcessor next) {
          super(next);
          checkPreconditions(regexPattern);
          this.pattern = regexPattern;
          this.description = regexDescriptoin;
      }
      
      private static void checkPreconditions(final java.util.regex.Pattern regexPattern) {
          if(regexPattern == null) {
              throw new NullPointerException("regexPattern should not be null");
          }
      }
      
      @SuppressWarnings("unchecked")
      @Override
      public Object execute(final Object value, final CsvContext context) {
          
          if(value == null) {
              return next.execute(value, context);
          }
          
          final boolean matches = pattern.matcher((String) value).matches();
          if(!matches) {
              throw createValidationException(context)
                  .messageFormat("'%s' does not match the regular expression '%s'", value, getRegex())
                  .rejectedValue(value)
                  .messageVariables("regex", getRegex())
                  .messageVariables("flags", getFlags())
                  .messageVariables("description", getDescription())
                  .build();
          }
          
          return next.execute(value, context);
      }
      
      /**
       * 
       * @return 設定せれた正規表現
       */
      public String getRegex() {
          return pattern.pattern();
      }
      
      /**
       * 
       * @return 正規表現のフラグ
       */
      public int getFlags() {
          return pattern.flags();
      }
      
      /**
       * 
       * @return 正規表現の説明
       */
      public String getDescription() {
          return description;
      }
      
  }