package ca.uhn.hl7v2.conf.store;
   
   import java.util.StringTokenizer;
   
   import org.slf4j.Logger;
   import org.slf4j.LoggerFactory;
   
   /**
    * Abstract class for used retrieving and validating codes from user defined and HL7 specific tables
   * that correspond to a conformance profile.
   * 
   * @author Neal Acharya
   */
  public abstract class AbstractCodeStore implements CodeStore {
  
      private static final Logger log = LoggerFactory.getLogger(AbstractCodeStore.class);
      
      private static final RegisteredPattern[] WILDCARDS = { 
              new RegisteredPattern("ISOnnnn", "ISO\\d\\d\\d\\d"),
              new RegisteredPattern("HL7nnnn", "HL7\\d\\d\\d\\d"), 
              new RegisteredPattern("99zzz", "99[\\w]*"),
              new RegisteredPattern("NNxxx", "99[\\w]*") 
              };
  
      /**
       * @see ca.uhn.hl7v2.conf.store.CodeStore#isValidCode(java.lang.String, java.lang.String)
       */
      public boolean isValidCode(String codeSystem, String code) {
          try {
              for (String validCode : getValidCodes(codeSystem)) {
                  if (checkCode(code, validCode)) return true;
              }
              return false;
          }
          catch (Exception e) {
              log.error("Error checking code " + code + " in code system " + codeSystem, e);
              return false;
          } 
      }
  
      /**
       * Checks a code for an exact match, and using certain sequences where some characters are
       * wildcards (e.g. HL7nnnn). If the pattern contains one of " or ", " OR ", or "," each operand
       * is checked.
       */
      private boolean checkCode(String code, String pattern) {
          // mod by Neal acharya - Do full match on with the pattern. If code matches pattern then
          // return true
          // else parse pattern to look for wildcard characters
          if (code.equals(pattern)) return true;
          
          if (pattern.indexOf(' ') >= 0 || pattern.indexOf(',') >= 0) {
              StringTokenizer tok = new StringTokenizer(pattern, ", ", false);
              while (tok.hasMoreTokens()) {
                  String t = tok.nextToken();
                  if (!t.equalsIgnoreCase("or") && checkCode(code, t)) 
                      return true;
              }
          } else {
              for (RegisteredPattern wildcard : WILDCARDS) {
                  if (wildcard.matches(pattern, code)) 
                      return true;
              }
          }
          
          return false;
      }
  
  }