/*
    * Copyright 2009 the original author or authors.
    * 
    * Licensed 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.openehealth.ipf.commons.ihe.xds.core.validate.query;
  
  import static org.apache.commons.lang3.Validate.notNull;
  import org.openehealth.ipf.commons.ihe.xds.core.ebxml.EbXMLAdhocQueryRequest;
  import org.openehealth.ipf.commons.ihe.xds.core.transform.requests.QueryParameter;
  import org.openehealth.ipf.commons.ihe.xds.core.transform.requests.query.QuerySlotHelper;
  import static org.openehealth.ipf.commons.ihe.xds.core.validate.ValidationMessage.*;
  import static org.openehealth.ipf.commons.ihe.xds.core.validate.ValidatorAssertions.metaDataAssert;
  import org.openehealth.ipf.commons.ihe.xds.core.validate.ValueValidator;
  import org.openehealth.ipf.commons.ihe.xds.core.validate.XDSMetaDataException;
  
  import java.util.List;
  import java.util.regex.Pattern;
  
  /**
   * Query parameter validation for parameters that are String-based.
   * @author Jens Riemschneider
   */
  public class StringValidation implements QueryParameterValidation {
      private static final Pattern PATTERN = Pattern.compile("'.*'");
  
      private final QueryParameter param;
      private final ValueValidator validator;
      private final boolean optional;
  
      /**
       * Constructs a validation object.
       * @param param
       *          parameter to validate.
       * @param validator
       *          validator to use on the parameter value.
       * @param optional
       *          <code>true</code> if this parameter is optional.
       */
      public StringValidation(QueryParameter param, ValueValidator validator, boolean optional) {
          notNull(param, "param cannot be null");
          notNull(validator, "validator cannot be null");
          
          this.param = param;
          this.validator = validator;
          this.optional = optional;
      }
  
      @Override
      public void validate(EbXMLAdhocQueryRequest request) throws XDSMetaDataException {
          List<String> slotValues = request.getSlotValues(param.getSlotName());
          metaDataAssert(optional || slotValues.size() >= 1, MISSING_REQUIRED_QUERY_PARAMETER, param);
          metaDataAssert(optional || slotValues.size() == 1, TOO_MANY_VALUES_FOR_QUERY_PARAMETER, param);
          
          if (slotValues.size() > 0) {
              String slotValue = slotValues.get(0);
              metaDataAssert(slotValue != null || optional, MISSING_REQUIRED_QUERY_PARAMETER, param);
              metaDataAssert(PATTERN.matcher(slotValue).matches(), PARAMETER_VALUE_NOT_STRING, param);
          }
          
          QuerySlotHelper slots = new QuerySlotHelper(request);        
          String value = slots.toString(param);
          metaDataAssert(value != null || optional, MISSING_REQUIRED_QUERY_PARAMETER, param);
          if (value != null) {
              validator.validate(value);
          }
      }
  }