/*
    * Copyright 2015 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.xml;
  
  import org.openehealth.ipf.commons.core.modules.api.ValidationException;
  import org.openehealth.ipf.commons.core.modules.api.Validator;
  import org.openehealth.ipf.commons.xml.svrl.DiagnosticReference;
  import org.openehealth.ipf.commons.xml.svrl.FailedAssert;
  import org.openehealth.ipf.commons.xml.svrl.SchematronOutput;
  
  import javax.xml.transform.Source;
  import java.util.ArrayList;
  import java.util.List;
  
  /**
   * Validation wrapper around the {@link SchematronTransmogrifier}. The
   * result is scanned for <code>svrl:failed-assert</code> elements, and
   * error text and details (if available) are put into the {@link ValidationException}'s message.
   * <p>
   * The Validator accepts a {@link Source} as input, and a {@link SchematronProfile}
   * as validation profile parameter.
   *
   * @author Christian Ohr
   */
  public class SchematronValidator implements Validator<Source, SchematronProfile> {
  
      private final SchematronTransmogrifier<SchematronOutput> schematronTransmogrifier =
              new SchematronTransmogrifier<>(SchematronOutput.class);
  
      public void validate(Source message, SchematronProfile profile) {
          SchematronOutput svrl = schematronTransmogrifier.zap(message, profile);
          List<ValidationException> exceptions = new ArrayList<>();
          svrl.getActivePatternAndFiredRuleAndFailedAssert().stream()
                  .filter(o -> o instanceof FailedAssert)
                  .forEach(o -> {
                      FailedAssert failedAssert = (FailedAssert) o;
                      exceptions.add(new ValidationException(message(failedAssert)));
                  });
          if (!exceptions.isEmpty()) {
              throw new SchematronValidationException(exceptions, svrl);
          }
      }
  
      private static String message(FailedAssert failedAssert) {
          StringBuilder sb = new StringBuilder()
                  .append("Validation error at ")
                  .append(failedAssert.getLocation())
                  .append(" : ")
                  .append(failedAssert.getText());
  
          if (!failedAssert.getDiagnosticReference().isEmpty()) {
              sb.append("\nDetail:");
              for (DiagnosticReference diagnosticReference : failedAssert.getDiagnosticReference()) {
                  sb.append('\n').append(diagnosticReference.getText());
              }
          }
  
          return sb.toString();
      }
  
  }