/*
    * $Id$
    *
    * 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.struts.validator.validwhen;
  
  import jakarta.servlet.http.HttpServletRequest;
  
  import org.antlr.v4.runtime.CharStreams;
  import org.antlr.v4.runtime.CommonTokenStream;
  import org.apache.commons.validator.Field;
  import org.apache.commons.validator.Validator;
  import org.apache.commons.validator.ValidatorAction;
  import org.apache.commons.validator.util.ValidatorUtils;
  import org.apache.struts.action.ActionMessage;
  import org.apache.struts.action.ActionMessages;
  import org.apache.struts.util.MessageResources;
  import org.apache.struts.validator.Resources;
  import org.apache.struts.validator.validwhen.ValidWhenParser.ExpressionContext;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * This class contains the validwhen validation that is used in the
   * validator-rules.xml file.
   *
   * @since Struts 1.2
   */
  public class ValidWhen {
  
      /**
       * The {@code Log} instance for this class.
       */
      private final static Logger LOG =
          LoggerFactory.getLogger(ValidWhen.class);
  
      /**
       * The message resources for this package.
       */
      private static MessageResources sysmsgs =
          MessageResources.getMessageResources(
              "org.apache.struts.validator.LocalStrings");
  
      /**
       * Returns true if <code>obj</code> is null or a String.
       */
      private static boolean isString(Object obj) {
          return (obj == null) ? true : String.class.isInstance(obj);
      }
  
      /**
       * Checks if the field matches the boolean expression specified in
       * <code>test</code> parameter.
       *
       * @param bean    The bean validation is being performed on.
       * @param va      The <code>ValidatorAction</code> that is currently being
       *                performed.
       * @param field   The <code>Field</code> object associated with the
       *                current field being validated.
       * @param errors  The <code>ActionMessages</code> object to add errors to
       *                if any validation errors occur.
       * @param request Current request object.
       * @return <code>true</code> if meets stated requirements,
       *         <code>false</code> otherwise.
       */
      public static boolean validateValidWhen(Object bean, ValidatorAction va,
          Field field, ActionMessages errors, Validator validator,
          HttpServletRequest request) {
          Object form = validator.getParameterValue(Validator.BEAN_PARAM);
          String value = null;
          boolean valid = false;
          int index = -1;
  
          if (field.isIndexed()) {
              String key = field.getKey();
  
              final int leftBracket = key.indexOf("[");
              final int rightBracket = key.indexOf("]");
  
              if ((leftBracket > -1) && (rightBracket > -1)) {
                  index =
                      Integer.parseInt(key.substring(leftBracket + 1,
                          rightBracket));
             }
         }
 
         if (isString(bean)) {
             value = (String) bean;
         } else {
             value = ValidatorUtils.getValueAsString(bean, field.getProperty());
         }
 
         String test = null;
 
         try {
             test =
                 Resources.getVarValue("test", field, validator, request, true);
         } catch (IllegalArgumentException ex) {
             LOG.atError().log(() -> sysmsgs.getMessage("validation.failed", "validwhen",
                 field.getProperty(), validator.getFormName(), ex.toString()));
 
             String userErrorMsg = sysmsgs.getMessage("system.error");
 
             errors.add(field.getKey(), new ActionMessage(userErrorMsg, false));
 
             return false;
         }
 
         // Create the Lexer
         ValidWhenLexer lexer = null;
 
         try {
             lexer = new ValidWhenLexer(CharStreams.fromString(test));
         } catch (Exception ex) {
             LOG.error("ValidWhenLexer Error for field '{}'",
                 field.getKey(), ex);
 
             String userErrorMsg = sysmsgs.getMessage("system.error");
 
             errors.add(field.getKey(), new ActionMessage(userErrorMsg, false));
 
             return false;
         }
 
         // Create the Parser
         ValidWhenParser parser = null;
 
         try {
             parser = new ValidWhenParser(new CommonTokenStream(lexer));
         } catch (Exception ex) {
             LOG.error("ValidWhenParser Error for field '{}'",
                 field.getKey(), ex);
 
             String userErrorMsg = sysmsgs.getMessage("system.error");
 
             errors.add(field.getKey(), new ActionMessage(userErrorMsg, false));
 
             return false;
         }
 
         ValidWhenEvaluator validWhenEvaluator = new ValidWhenEvaluator(form, value, index);
 
         try {
             ExpressionContext expressionContext = parser.expression();
             ValidWhenResult<?> result = validWhenEvaluator.visitExpression(expressionContext);
             valid = result == null ? false : result.toBoolean();
         } catch (Exception ex) {
             LOG.error("ValidWhen Error for field '{}'",
                 field.getKey(), ex);
 
             String userErrorMsg = sysmsgs.getMessage("system.error");
 
             errors.add(field.getKey(), new ActionMessage(userErrorMsg, false));
 
             return false;
         }
 
         if (!valid) {
             errors.add(field.getKey(),
                 Resources.getActionMessage(validator, request, va, field));
 
             return false;
         }
 
         return true;
     }
 }