/*
    * Portions of this software was developed by employees of the National Institute
    * of Standards and Technology (NIST), an agency of the Federal Government and is
    * being made available as a public service. Pursuant to title 17 United States
    * Code Section 105, works of NIST employees are not subject to copyright
    * protection in the United States. This software may be subject to foreign
    * copyright. Permission in the United States and in foreign countries, to the
    * extent that NIST may hold copyright, to use, copy, modify, create derivative
    * works, and distribute this software and its documentation without fee is hereby
   * granted on a non-exclusive basis, provided that this notice and disclaimer
   * of warranty appears in all copies.
   *
   * THE SOFTWARE IS PROVIDED 'AS IS' WITHOUT ANY WARRANTY OF ANY KIND, EITHER
   * EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, ANY WARRANTY
   * THAT THE SOFTWARE WILL CONFORM TO SPECIFICATIONS, ANY IMPLIED WARRANTIES OF
   * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND FREEDOM FROM
   * INFRINGEMENT, AND ANY WARRANTY THAT THE DOCUMENTATION WILL CONFORM TO THE
   * SOFTWARE, OR ANY WARRANTY THAT THE SOFTWARE WILL BE ERROR FREE.  IN NO EVENT
   * SHALL NIST BE LIABLE FOR ANY DAMAGES, INCLUDING, BUT NOT LIMITED TO, DIRECT,
   * INDIRECT, SPECIAL OR CONSEQUENTIAL DAMAGES, ARISING OUT OF, RESULTING FROM,
   * OR IN ANY WAY CONNECTED WITH THIS SOFTWARE, WHETHER OR NOT BASED UPON WARRANTY,
   * CONTRACT, TORT, OR OTHERWISE, WHETHER OR NOT INJURY WAS SUSTAINED BY PERSONS OR
   * PROPERTY OR OTHERWISE, AND WHETHER OR NOT LOSS WAS SUSTAINED FROM, OR AROSE OUT
   * OF THE RESULTS OF, OR USE OF, THE SOFTWARE OR SERVICES PROVIDED HEREUNDER.
   */
  
  package gov.nist.secauto.metaschema.core.model.xml;
  
  import gov.nist.secauto.metaschema.core.model.IAssemblyInstance;
  import gov.nist.secauto.metaschema.core.model.IFieldInstance;
  import gov.nist.secauto.metaschema.core.model.IModelContainer;
  import gov.nist.secauto.metaschema.core.model.IModelInstance;
  import gov.nist.secauto.metaschema.core.model.INamedModelInstance;
  import gov.nist.secauto.metaschema.core.model.JsonGroupAsBehavior;
  import gov.nist.secauto.metaschema.core.model.MetaschemaModelConstants;
  import gov.nist.secauto.metaschema.core.model.XmlGroupAsBehavior;
  import gov.nist.secauto.metaschema.core.model.xml.xmlbeans.AssemblyReferenceType;
  import gov.nist.secauto.metaschema.core.model.xml.xmlbeans.ChoiceType;
  import gov.nist.secauto.metaschema.core.model.xml.xmlbeans.FieldReferenceType;
  import gov.nist.secauto.metaschema.core.model.xml.xmlbeans.GroupAsType;
  import gov.nist.secauto.metaschema.core.model.xml.xmlbeans.InlineAssemblyDefinitionType;
  import gov.nist.secauto.metaschema.core.model.xml.xmlbeans.InlineFieldDefinitionType;
  import gov.nist.secauto.metaschema.core.util.CustomCollectors;
  import gov.nist.secauto.metaschema.core.util.ObjectUtils;
  
  import org.apache.xmlbeans.XmlCursor;
  import org.apache.xmlbeans.XmlObject;
  
  import java.math.BigInteger;
  import java.util.Collections;
  import java.util.LinkedHashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.function.Function;
  import java.util.stream.Collectors;
  import java.util.stream.Stream;
  
  import edu.umd.cs.findbugs.annotations.NonNull;
  import edu.umd.cs.findbugs.annotations.Nullable;
  
  @SuppressWarnings("PMD.CouplingBetweenObjects")
  class XmlModelParser {
    private Map<String, INamedModelInstance> namedModelInstances;
    private Map<String, IFieldInstance> fieldInstances;
    private Map<String, IAssemblyInstance> assemblyInstances;
    private List<IModelInstance> modelInstances;
  
    // TODO: move back to calling location
    void parseChoice(XmlObject xmlObject, @NonNull IModelContainer container) {
      try (XmlCursor cursor = xmlObject.newCursor()) {
        cursor.selectPath("declare namespace m='http://csrc.nist.gov/ns/oscal/metaschema/1.0';"
            + "$this/m:assembly|$this/m:define-assembly|$this/m:field"
            + "|$this/m:define-field");
        parseInternal(cursor, container);
      }
    }
  
    // TODO: move back to calling location
    void parseModel(XmlObject xmlObject, @NonNull IModelContainer container) {
      // handle the model
      try (XmlCursor cursor = xmlObject.newCursor()) {
        cursor.selectPath("declare namespace m='http://csrc.nist.gov/ns/oscal/metaschema/1.0';"
            + "$this/m:model/m:assembly|$this/m:model/m:define-assembly|$this/m:model/m:field"
            + "|$this/m:model/m:define-field|$this/m:model/m:choice");
  
        parseInternal(cursor, container);
      }
    }
  
    @SuppressWarnings("null")
    @NonNull
    protected <S> Stream<S> append(@NonNull Stream<S> original, @NonNull S item) {
      Stream<S> newStream = Stream.of(item).sequential();
      return Stream.concat(original, newStream);
    }
  
    @SuppressWarnings("null")
    private void parseInternal(XmlCursor cursor, @NonNull IModelContainer container) {
  
     // ensure the streams are treated as sequential, since concatenated streams will
     // only be sequential
     // if both streams are sequential
     Stream<IFieldInstance> fieldInstances = Stream.empty();
     fieldInstances = fieldInstances.sequential();
     Stream<IAssemblyInstance> assemblyInstances = Stream.empty();
     assemblyInstances = assemblyInstances.sequential();
     Stream<INamedModelInstance> namedModelInstances = Stream.empty();
     namedModelInstances = namedModelInstances.sequential();
     Stream<IModelInstance> modelInstances = Stream.empty();
     modelInstances = modelInstances.sequential();
 
     while (cursor.toNextSelection()) {
       XmlObject obj = cursor.getObject();
       if (obj instanceof FieldReferenceType) {
         XmlFieldInstance field
             = new XmlFieldInstance((FieldReferenceType) obj, container); // NOPMD - intentional
         fieldInstances = append(fieldInstances, field);
         namedModelInstances = append(namedModelInstances, field);
         modelInstances = append(modelInstances, field);
       } else if (obj instanceof InlineFieldDefinitionType) {
         XmlInlineFieldDefinition field
             = new XmlInlineFieldDefinition((InlineFieldDefinitionType) obj, container); // NOPMD - intentional
         fieldInstances = append(fieldInstances, field);
         namedModelInstances = append(namedModelInstances, field);
         modelInstances = append(modelInstances, field);
       } else if (obj instanceof AssemblyReferenceType) {
         XmlAssemblyInstance assembly
             = new XmlAssemblyInstance((AssemblyReferenceType) obj, container); // NOPMD - intentional
         assemblyInstances = append(assemblyInstances, assembly);
         namedModelInstances = append(namedModelInstances, assembly);
         modelInstances = append(modelInstances, assembly);
       } else if (obj instanceof InlineAssemblyDefinitionType) {
         XmlInlineAssemblyDefinition assembly
             = new XmlInlineAssemblyDefinition((InlineAssemblyDefinitionType) obj, container); // NOPMD - intentional
         assemblyInstances = append(assemblyInstances, assembly);
         namedModelInstances = append(namedModelInstances, assembly);
         modelInstances = append(modelInstances, assembly);
       } else if (obj instanceof ChoiceType) {
         XmlChoiceInstance choice
             = new XmlChoiceInstance((ChoiceType) obj, container); // NOPMD - intentional
         // assemblyInstances.putAll(choice.getAssemblyInstanceMap());
         // fieldInstances..putAll(choice.getFieldInstanceMap());
         modelInstances = append(modelInstances, choice);
       }
     }
 
     this.fieldInstances = fieldInstances
         .collect(Collectors.toMap(IFieldInstance::getEffectiveName, Function.identity(),
             CustomCollectors.useFirstMapper(), LinkedHashMap::new));
     this.assemblyInstances = assemblyInstances
         .collect(Collectors.toMap(IAssemblyInstance::getEffectiveName, Function.identity(),
             CustomCollectors.useFirstMapper(), LinkedHashMap::new));
     this.modelInstances = modelInstances
         .collect(Collectors.toUnmodifiableList());
     this.namedModelInstances = namedModelInstances
         .collect(Collectors.toMap(INamedModelInstance::getEffectiveName, Function.identity(),
             CustomCollectors.useFirstMapper(), LinkedHashMap::new));
   }
 
   @SuppressWarnings("null")
   @NonNull
   public Map<String, IFieldInstance> getFieldInstances() {
     return fieldInstances == null ? Collections.emptyMap() : fieldInstances;
   }
 
   @SuppressWarnings("null")
   @NonNull
   public Map<String, IAssemblyInstance> getAssemblyInstances() {
     return assemblyInstances == null ? Collections.emptyMap() : assemblyInstances;
   }
 
   @SuppressWarnings("null")
   @NonNull
   public Map<String, INamedModelInstance> getNamedModelInstances() {
     return namedModelInstances == null ? Collections.emptyMap() : namedModelInstances;
   }
 
   @SuppressWarnings("null")
   @NonNull
   protected List<IModelInstance> getModelInstances() {
     return modelInstances == null ? Collections.emptyList() : modelInstances;
   }
 
   @NonNull
   public static JsonGroupAsBehavior getJsonGroupAsBehavior(@Nullable GroupAsType groupAs) {
     JsonGroupAsBehavior retval = MetaschemaModelConstants.DEFAULT_JSON_GROUP_AS_BEHAVIOR;
     if (groupAs != null && groupAs.isSetInJson()) {
       retval = ObjectUtils.notNull(groupAs.getInJson());
     }
     return retval;
   }
 
   @NonNull
   public static XmlGroupAsBehavior getXmlGroupAsBehavior(@Nullable GroupAsType groupAs) {
     XmlGroupAsBehavior retval = MetaschemaModelConstants.DEFAULT_XML_GROUP_AS_BEHAVIOR;
     if (groupAs != null && groupAs.isSetInXml()) {
       retval = ObjectUtils.notNull(groupAs.getInXml());
     }
     return retval;
   }
 
   public static int getMinOccurs(@Nullable BigInteger value) {
     int retval = MetaschemaModelConstants.DEFAULT_GROUP_AS_MIN_OCCURS;
     if (value != null) {
       retval = value.intValueExact();
     }
     return retval;
   }
 
   public static int getMaxOccurs(@Nullable Object value) {
     int retval = MetaschemaModelConstants.DEFAULT_GROUP_AS_MAX_OCCURS;
     if (value != null) {
       if (value instanceof String) {
         // unbounded
         retval = -1;
       } else if (value instanceof BigInteger) {
         retval = ((BigInteger) value).intValueExact();
       } else {
         throw new IllegalStateException("Invalid type: " + value.getClass().getName());
       }
     }
     return retval;
   }
 }