/**

  * Copyright 2005-2011 The Kuali Foundation

  *

  * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php

  *

  * 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.kuali.rice.krad.datadictionary.validation.constraint;

 import java.util.ArrayList;

 import java.util.Arrays;

 import java.util.Collections;

 import java.util.List;

 import org.apache.commons.lang.StringUtils;

 import org.kuali.rice.core.api.CoreConstants;

 import org.kuali.rice.core.api.config.property.ConfigContext;

 import org.kuali.rice.core.api.config.property.ConfigurationService;

 import org.kuali.rice.krad.service.KRADServiceLocator;

 import org.kuali.rice.krad.uif.UifConstants;

 /**

  * DatePatternConstraint constrains a field to only allow dates which are part of the formats

  * defined in the system. Constraining a field all these formats is often not appropriate for

  * fields, and you may want to constrain the input to a subset of the allowed formats in the system.

  * This can be done by setting the allowed formats to this subset (see BasicDatePatternConstraint

  * bean for example)

  * 

  * @author Kuali Rice Team (rice.collab@kuali.org)

  */

 public class DatePatternConstraint extends ValidDataPatternConstraint {

     private List<String> allowedFormats;

     /**

      * Returns a regex representing all the allowed formats in the system. If allowedFormats is

      * supplied, returns a regex representing only those formats.

      * 

      * @see org.kuali.rice.krad.datadictionary.validation.constraint.ValidDataPatternConstraint#getRegexString()

      */

     @Override

     protected String getRegexString() {

         List<String> dateFormatParams =

                 parseConfigValues(ConfigContext.getCurrentContextConfig().getProperty(

                         CoreConstants.STRING_TO_DATE_FORMATS));

         if (allowedFormats != null && !allowedFormats.isEmpty()) {

             if (dateFormatParams.containsAll(allowedFormats)) {

                 dateFormatParams = allowedFormats;

             } else {

                 //throw new Exception("Some of these formats do not exist in configured allowed date formats: " + allowedFormats.toString());

             }

         }

         if (dateFormatParams.isEmpty()) {

             //exception

         }

         String regex = "";

         int i = 0;

         for (String format : dateFormatParams) {

             if (i == 0) {

                 regex = "(^" + convertDateFormatToRegex(format.trim()) + "$)";

             } else {

                 regex = regex + "|(^" + convertDateFormatToRegex(format.trim()) + "$)";

             }

             i++;

         }

         return regex;

     }

     /**

      * Converts a date format supplied to the appropriate date format regex equivalent

      * 

      * @param format

      * @return

      */

     private String convertDateFormatToRegex(String format) {

         format = format.replace("\\", "\\\\")

                 .replace(".", "\\.")

                 .replace("-", "\\-")

                 .replace("+", "\\+")

                 .replace("(", "\\(")

                 .replace(")", "\\)")

                 .replace("[", "\\[")

                 .replace("]", "\\]")

                 .replace("|", "\\|")

                 .replace("yyyy", "((19|2[0-9])[0-9]{2})")

                 .replace("yy", "([0-9]{2})")

                 .replaceAll("M{4,}", "([@]+)") //"(January|February|March|April|May|June|July|August|September|October|November|December)")

                 .replace("MMM", "([@]{3})") //"(Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)")

                 .replace("MM", "(0[1-9]|1[012])")

                 .replace("M", "(0?[1-9]|1[012])")

                 .replace("dd", "(0[1-9]|[12][0-9]|3[01])")

                 .replace("d", "(0?[1-9]|[12][0-9]|3[01])")

                 .replace("hh", "(1[0-2]|0[1-9])")

                 .replace("h", "(1[0-2]|0?[1-9])")

                 .replace("HH", "(2[0-3]|1[0-9]|0[0-9])")

                 .replace("H", "(2[0-3]|1[0-9]|0?[0-9])")

                 .replace("kk", "(2[0-4]|1[0-9]|0[1-9])")

                 .replace("k", "(2[0-4]|1[0-9]|0?[1-9])")

                 .replace("KK", "(1[01]|0[0-9])")

                 .replace("K", "(1[01]|0?[0-9])")

                 .replace("mm", "([0-5][0-9])")

                 .replace("m", "([1-5][0-9]|0?[0-9])")

                 .replace("ss", "([0-5][0-9])")

                 .replace("s", "([1-5][0-9]|0?[0-9])")

                 .replace("SSS", "([0-9][0-9][0-9])")

                 .replace("SS", "([0-9][0-9][0-9]?)")

                 .replace("S", "([0-9][0-9]?[0-9]?)")

                 .replaceAll("E{4,}", "([@]+)")//"(Monday|Tuesday|Wednesday|Thursday|Friday|Saturday|Sunday)")

                 .replaceAll("E{1,3}", "([@]{3})")//"(Mon|Tue|Wed|Thu|Fri|Sat|Sun)")

                 .replace("DDD", "(3[0-6][0-5]|[1-2][0-9][0-9]|0[0-9][1-9])")

                 .replace("DD", "(3[0-6][0-5]|[1-2][0-9][0-9]|0?[0-9][1-9])")

                 .replace("D", "(3[0-6][0-5]|[1-2][0-9][0-9]|0?[0-9]?[1-9])")

                 .replace("F", "([1-5])")

                 .replace("ww", "(5[0-3]|[1-4][0-9]|0[1-9])")

                 .replace("w", "(5[0-3]|[1-4][0-9]|[1-9])")

                 .replace("W", "([1-5])")

                 .replaceAll("z{4,}", "([@]+)")

                 .replaceAll("z{1,3}", "([@]{1,4})")

                 .replaceAll("a{1,}", "([aApP][mM])")

                 .replaceAll("G{1,}", "([aA][dD]|[bB][cC])")

                 .replace(" ", "\\s")

                 .replace("@", "a-zA-Z");

         return format;

     }

     /**

      * 

      * The dateTime config vars are ';' seperated.

      * 

      * @param configValue

      * @return

      */

     private List<String> parseConfigValues(String configValue) {

         if (configValue == null || "".equals(configValue)) {

             return Collections.emptyList();

         }

         return Arrays.asList(configValue.split(";"));

     }

     /**

      * @return the allowedFormats

      */

     public List<String> getAllowedFormats() {

         return this.allowedFormats;

     }

     /**

      * Sets the alloweFormats for this constraint, this must be a subset of the system configured

      * formats for a date - this list should be used for most fields where you are expecting a user

      * to enter a date in a specific format

      * @param allowedFormats the allowedFormats to set

      */

     public void setAllowedFormats(List<String> allowedFormats) {

         this.allowedFormats = allowedFormats;

     }

     /**

      * This overridden method ...

      * 

      * @see org.kuali.rice.krad.datadictionary.validation.constraint.ValidDataPatternConstraint#getValidationMessageParams()

      */

     @Override

     public List<String> getValidationMessageParams() {

         if (validationMessageParams == null) {

             validationMessageParams = new ArrayList<String>();

             if (allowedFormats != null && !allowedFormats.isEmpty()) {

                 validationMessageParams.add(StringUtils.join(allowedFormats, ", "));

             } else {

                 List<String> dateFormatParams =

                         parseConfigValues(ConfigContext.getCurrentContextConfig().getProperty(

                                 CoreConstants.STRING_TO_DATE_FORMATS));

                 validationMessageParams.add(StringUtils.join(dateFormatParams, ", "));

             }

         }

         return validationMessageParams;

     }

 }