/*
    * 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 org.openehealth.ipf.commons.ihe.xds.core.XdsRuntimeException;
  import org.openehealth.ipf.commons.ihe.xds.core.ebxml.EbXMLAdhocQueryRequest;
  import org.openehealth.ipf.commons.ihe.xds.core.responses.ErrorCode;
  import org.openehealth.ipf.commons.ihe.xds.core.responses.Severity;
  import org.openehealth.ipf.commons.ihe.xds.core.transform.requests.QueryParameter;
  import org.openehealth.ipf.commons.ihe.xds.core.validate.XDSMetaDataException;
  
  import java.util.Arrays;
  import java.util.List;
  import java.util.Objects;
  import java.util.stream.Collectors;
  
  import static org.apache.commons.lang3.Validate.notNull;
  import static org.openehealth.ipf.commons.ihe.xds.core.validate.ValidationMessage.MISSING_REQUIRED_QUERY_PARAMETER;
  import static org.openehealth.ipf.commons.ihe.xds.core.validate.ValidationMessage.QUERY_PARAMETERS_CANNOT_BE_SET_TOGETHER;
  
  /**
   * Query parameter validation to ensure that only one of the given parameters is specified.
   * Also has the "either ... or ... " check to avoid the case that all parameters haven't a
   * value set.
   * @author Jens Riemschneider
   */
  public class ChoiceValidation implements QueryParameterValidation {
      private final QueryParameter[] params;
  
      /**
       * Constructs a validation object.
       * @param params
       *          parameters to validate.
       */
      public ChoiceValidation(QueryParameter... params) {
          notNull(params, "params cannot be null");        
          this.params = params;
      }
  
      @Override
      public void validate(EbXMLAdhocQueryRequest request) throws XDSMetaDataException {
          List<String> paramSlotNames = Arrays.stream(params)
                  .map(QueryParameter::getSlotName)
                  .collect(Collectors.toList());
  
          long count = paramSlotNames.stream()
                  .map(request::getSingleSlotValue)
                  .filter(Objects::nonNull)
                  .count();
  
          if (count == 0L) {
              throw new XDSMetaDataException(MISSING_REQUIRED_QUERY_PARAMETER, "one of " + paramSlotNames);
          }
          if (count > 1L) {
              throw new XdsRuntimeException(
                      ErrorCode.STORED_QUERY_PARAM_NUMBER,
                      String.format(QUERY_PARAMETERS_CANNOT_BE_SET_TOGETHER.getText(), paramSlotNames),
                      Severity.ERROR,
                      null);
          }
      }
  }