/*
    * SPDX-FileCopyrightText: none
    * SPDX-License-Identifier: CC0-1.0
    */
   
   package gov.nist.secauto.metaschema.databind.model.impl;
   
   import gov.nist.secauto.metaschema.core.model.DefaultAssemblyModelBuilder;
   import gov.nist.secauto.metaschema.core.model.IChoiceInstance;
  import gov.nist.secauto.metaschema.core.model.IContainerModelAssemblySupport;
  import gov.nist.secauto.metaschema.core.util.CollectionUtil;
  import gov.nist.secauto.metaschema.core.util.ObjectUtils;
  import gov.nist.secauto.metaschema.databind.model.IBoundDefinitionModelAssembly;
  import gov.nist.secauto.metaschema.databind.model.IBoundInstanceModel;
  import gov.nist.secauto.metaschema.databind.model.IBoundInstanceModelAssembly;
  import gov.nist.secauto.metaschema.databind.model.IBoundInstanceModelChoiceGroup;
  import gov.nist.secauto.metaschema.databind.model.IBoundInstanceModelField;
  import gov.nist.secauto.metaschema.databind.model.IBoundInstanceModelNamed;
  import gov.nist.secauto.metaschema.databind.model.annotations.BoundAssembly;
  import gov.nist.secauto.metaschema.databind.model.annotations.BoundChoiceGroup;
  import gov.nist.secauto.metaschema.databind.model.annotations.BoundField;
  import gov.nist.secauto.metaschema.databind.model.annotations.Ignore;
  
  import java.lang.reflect.Field;
  import java.util.Arrays;
  import java.util.List;
  import java.util.Objects;
  import java.util.stream.Collectors;
  import java.util.stream.Stream;
  
  import edu.umd.cs.findbugs.annotations.NonNull;
  
  final class AssemblyModelGenerator {
  
    @SuppressWarnings("PMD.ShortMethodName")
    @NonNull
    public static IContainerModelAssemblySupport<
        IBoundInstanceModel<?>,
        IBoundInstanceModelNamed<?>,
        IBoundInstanceModelField<?>,
        IBoundInstanceModelAssembly,
        IChoiceInstance,
        IBoundInstanceModelChoiceGroup> of(@NonNull DefinitionAssembly containingDefinition) {
      DefaultAssemblyModelBuilder<IBoundInstanceModel<?>,
          IBoundInstanceModelNamed<?>,
          IBoundInstanceModelField<?>,
          IBoundInstanceModelAssembly,
          IChoiceInstance,
          IBoundInstanceModelChoiceGroup> builder = new DefaultAssemblyModelBuilder<>();
  
      List<IBoundInstanceModel<?>> modelInstances = CollectionUtil.unmodifiableList(ObjectUtils.notNull(
          getModelInstanceStream(containingDefinition, containingDefinition.getBoundClass())
              .collect(Collectors.toUnmodifiableList())));
  
      for (IBoundInstanceModel<?> instance : modelInstances) {
        if (instance instanceof IBoundInstanceModelNamed) {
          IBoundInstanceModelNamed<?> named = (IBoundInstanceModelNamed<?>) instance;
          if (instance instanceof IBoundInstanceModelField) {
            builder.append((IBoundInstanceModelField<?>) named);
          } else if (instance instanceof IBoundInstanceModelAssembly) {
            builder.append((IBoundInstanceModelAssembly) named);
          }
        } else if (instance instanceof IBoundInstanceModelChoiceGroup) {
          IBoundInstanceModelChoiceGroup choiceGroup = (IBoundInstanceModelChoiceGroup) instance;
          builder.append(choiceGroup);
        }
      }
      return builder.buildAssembly();
    }
  
    private static IBoundInstanceModel<?> newBoundModelInstance(
        @NonNull Field field,
        @NonNull IBoundDefinitionModelAssembly definition) {
      IBoundInstanceModel<?> retval = null;
      if (field.isAnnotationPresent(BoundAssembly.class)) {
        retval = IBoundInstanceModelAssembly.newInstance(field, definition);
      } else if (field.isAnnotationPresent(BoundField.class)) {
        retval = IBoundInstanceModelField.newInstance(field, definition);
      } else if (field.isAnnotationPresent(BoundChoiceGroup.class)) {
        retval = IBoundInstanceModelChoiceGroup.newInstance(field, definition);
      }
      return retval;
    }
  
    @NonNull
    private static Stream<IBoundInstanceModel<?>> getModelInstanceStream(
        @NonNull IBoundDefinitionModelAssembly definition,
        @NonNull Class<?> clazz) {
  
      Stream<IBoundInstanceModel<?>> superInstances;
      Class<?> superClass = clazz.getSuperclass();
      if (superClass == null) {
        superInstances = Stream.empty();
      } else {
        // get instances from superclass
        superInstances = getModelInstanceStream(definition, superClass);
      }
  
      return ObjectUtils.notNull(Stream.concat(superInstances, Arrays.stream(clazz.getDeclaredFields())
         // skip this field, since it is ignored
         .filter(field -> !field.isAnnotationPresent(Ignore.class))
         // skip fields that aren't a Module field or assembly instance
         .filter(field -> field.isAnnotationPresent(BoundField.class)
             || field.isAnnotationPresent(BoundAssembly.class)
             || field.isAnnotationPresent(BoundChoiceGroup.class))
         .map(field -> {
           assert field != null;
 
           IBoundInstanceModel<?> retval = newBoundModelInstance(field, definition);
           if (retval == null) {
             throw new IllegalStateException(
                 String.format("The field '%s' on class '%s' is not bound", field.getName(), clazz.getName()));
           }
           return retval;
         })
         .filter(Objects::nonNull)));
   }
 
   private AssemblyModelGenerator() {
     // disable construction
   }
 }