/*
    * SPDX-FileCopyrightText: none
    * SPDX-License-Identifier: CC0-1.0
    */
   
   package gov.nist.secauto.metaschema.schemagen.json.impl;
   
   import com.fasterxml.jackson.core.JsonGenerator;
   import com.fasterxml.jackson.databind.node.JsonNodeFactory;
  import com.fasterxml.jackson.databind.node.ObjectNode;
  
  import gov.nist.secauto.metaschema.core.configuration.IConfiguration;
  import gov.nist.secauto.metaschema.core.datatype.IDataTypeAdapter;
  import gov.nist.secauto.metaschema.core.model.IAssemblyDefinition;
  import gov.nist.secauto.metaschema.core.model.IDefinition;
  import gov.nist.secauto.metaschema.core.model.IFieldDefinition;
  import gov.nist.secauto.metaschema.core.model.IFlagDefinition;
  import gov.nist.secauto.metaschema.core.model.IModule;
  import gov.nist.secauto.metaschema.core.model.IValuedDefinition;
  import gov.nist.secauto.metaschema.core.model.constraint.IAllowedValue;
  import gov.nist.secauto.metaschema.core.util.ObjectUtils;
  import gov.nist.secauto.metaschema.schemagen.AbstractGenerationState;
  import gov.nist.secauto.metaschema.schemagen.SchemaGenerationFeature;
  import gov.nist.secauto.metaschema.schemagen.json.IDataTypeJsonSchema;
  import gov.nist.secauto.metaschema.schemagen.json.IDefineableJsonSchema.IKey;
  import gov.nist.secauto.metaschema.schemagen.json.IDefinitionJsonSchema;
  import gov.nist.secauto.metaschema.schemagen.json.IJsonGenerationState;
  
  import java.io.IOException;
  import java.util.Comparator;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.concurrent.ConcurrentHashMap;
  
  import edu.umd.cs.findbugs.annotations.NonNull;
  import edu.umd.cs.findbugs.annotations.Nullable;
  
  public class JsonGenerationState
      extends AbstractGenerationState<JsonGenerator, JsonDatatypeManager>
      implements IJsonGenerationState {
  
    @NonNull
    private final JsonNodeFactory jsonNodeFactory = new JsonNodeFactory(true);
    @NonNull
    private final Map<IKey, IDefinitionJsonSchema<?>> schemaDefinitions = new HashMap<>();
    @NonNull
    private final Map<IValuedDefinition, IDataTypeJsonSchema> definitionValueToDataTypeSchemaMap
        = new ConcurrentHashMap<>();
    @NonNull
    private final Map<IDataTypeAdapter<?>, IDataTypeJsonSchema> dataTypeToSchemaMap = new ConcurrentHashMap<>();
  
    public JsonGenerationState(
        @NonNull IModule module,
        @NonNull JsonGenerator writer,
        @NonNull IConfiguration<SchemaGenerationFeature<?>> configuration) {
      super(module, writer, configuration, new JsonDatatypeManager());
  
      // // seed definition schema mapping
      // this.schemaDefinitions =
      // ObjectUtils.notNull(getMetaschemaIndex().getDefinitions().stream()
      // .filter(entry -> !isInline(entry.getDefinition()) &&
      // entry.isUsedWithoutJsonKey()
      // && !entry.isChoiceGroupMember())
      // .map(entry -> newJsonSchema(entry.getDefinition(), null, null, null, this))
      // .collect(Collectors.toMap(
      // schema -> schema.getKey(),
      // Function.identity(),
      // (v1, v2) -> v2,
      // ConcurrentHashMap::new)));
    }
  
    @Override
    @NonNull
    public <DEF extends IDefinition> IDefinitionJsonSchema<DEF> getSchema(@NonNull IKey key) {
      IDefinitionJsonSchema<?> retval = getDefinitionSchema(key, this);
      return ObjectUtils.asType(ObjectUtils.requireNonNull(retval));
    }
  
    @Override
    @NonNull
    public IDataTypeJsonSchema getSchema(@NonNull IDataTypeAdapter<?> datatype) {
      IDataTypeJsonSchema retval = dataTypeToSchemaMap.get(datatype);
      if (retval == null) {
        retval = new DataTypeJsonSchema(
            getDatatypeManager().getTypeNameForDatatype(datatype),
            datatype);
        dataTypeToSchemaMap.put(datatype, retval);
      }
      return retval;
    }
  
    /**
     * Get the JSON schema info for the provided definition.
     *
     * @param key
     *          the key to use to lookup the definition schema info
     * @return the definition's schema info
     */
   private IDefinitionJsonSchema<?> getDefinitionSchema(
       @NonNull IKey key,
       @NonNull IJsonGenerationState state) {
     synchronized (schemaDefinitions) {
       return schemaDefinitions.computeIfAbsent(key, (k) -> {
         IDefinitionJsonSchema<?> retval = newJsonSchema(
             k.getDefinition(),
             k.getJsonKeyFlagName(),
             k.getDiscriminatorProperty(),
             k.getDiscriminatorValue(),
             state);
         assert key.equals(retval.getKey());
         return retval;
       });
     }
   }
 
   @Override
   public boolean isDefinitionRegistered(IDefinitionJsonSchema<?> schema) {
     return schemaDefinitions.containsKey(schema.getKey());
   }
 
   @Override
   public void registerDefinitionSchema(IDefinitionJsonSchema<?> schema) {
     IDefinitionJsonSchema<?> old = schemaDefinitions.put(schema.getKey(), schema);
     assert old == null;
   }
 
   /**
    * Get the JSON schema info for the provided definition.
    *
    * @param definition
    *          the definition to get the schema info for
    * @param jsonKeyFlagName
    *          the name of the flag to use as the JSON key, or @{code null} if no
    *          flag is used as the JSON key
    * @param discriminatorProperty
    *          the property name to use as the choice group discriminator,
    *          or @{code null} if no choice group discriminator is used
    * @param discriminatorValue
    *          the property value to use as the choice group discriminator,
    *          or @{code null} if no choice group discriminator is used
    * @return the definition's schema info
    */
   @NonNull
   private static IDefinitionJsonSchema<?> newJsonSchema(
       @NonNull IDefinition definition,
       @Nullable String jsonKeyFlagName,
       @Nullable String discriminatorProperty,
       @Nullable String discriminatorValue,
       @NonNull IJsonGenerationState state) {
     IDefinitionJsonSchema<?> retval;
     if (definition instanceof IFlagDefinition) {
       retval = new FlagDefinitionJsonSchema((IFlagDefinition) definition, state);
     } else if (definition instanceof IAssemblyDefinition) {
       retval = new AssemblyDefinitionJsonSchema(
           (IAssemblyDefinition) definition,
           jsonKeyFlagName,
           discriminatorProperty,
           discriminatorValue,
           state);
     } else if (definition instanceof IFieldDefinition) {
       retval = new FieldDefinitionJsonSchema(
           (IFieldDefinition) definition,
           jsonKeyFlagName,
           discriminatorProperty,
           discriminatorValue,
           state);
     } else {
       throw new IllegalArgumentException("Unsupported definition type" + definition.getClass().getName());
     }
     return retval;
   }
 
   public ObjectNode generateDefinitions() {
     @NonNull Map<IKey, IDefinitionJsonSchema<?>> gatheredDefinitions = new HashMap<>();
 
     getMetaschemaIndex().getDefinitions().stream()
         .filter(entry -> entry.isRoot())
         .map(entry -> entry.getDefinition())
         .forEachOrdered(def -> {
           IDefinitionJsonSchema<?> definitionSchema = getSchema(IKey.of(def));
           assert definitionSchema != null;
           definitionSchema.gatherDefinitions(gatheredDefinitions, this);
         });
 
     ObjectNode definitionsObject = ObjectUtils.notNull(JsonNodeFactory.instance.objectNode());
 
     gatheredDefinitions.values().stream()
         .filter(schema -> !isInline(schema.getDefinition()))
         .sorted(Comparator.comparing(schema -> schema.getDefinitionName(this)))
         .forEachOrdered(schema -> {
           schema.generateDefinition(this, definitionsObject);
         });
 
     getDatatypeManager().generateDatatypes(definitionsObject);
 
     return definitionsObject;
   }
 
   @Override
   public JsonNodeFactory getJsonNodeFactory() {
     return jsonNodeFactory;
   }
 
   @Override
   @NonNull
   public IDataTypeJsonSchema getDataTypeSchemaForDefinition(@NonNull IValuedDefinition definition) {
     IDataTypeJsonSchema retval = definitionValueToDataTypeSchemaMap.get(definition);
     if (retval == null) {
       AllowedValueCollection allowedValuesCollection = getContextIndependentEnumeratedValues(definition);
       List<IAllowedValue> allowedValues = allowedValuesCollection.getValues();
 
       IDataTypeAdapter<?> dataTypeAdapter = definition.getJavaTypeAdapter();
 
       // register data type use
       retval = getSchema(dataTypeAdapter);
       if (!allowedValues.isEmpty()) {
         // create restriction
         retval = new DataTypeRestrictionDefinitionJsonSchema(definition, allowedValuesCollection);
       }
       definitionValueToDataTypeSchemaMap.put(definition, retval);
     }
     return retval;
   }
 
   @SuppressWarnings("resource")
   public void writeStartObject() throws IOException {
     getWriter().writeStartObject();
   }
 
   @SuppressWarnings("resource")
   public void writeEndObject() throws IOException {
     getWriter().writeEndObject();
   }
 
   @SuppressWarnings("resource")
   public void writeField(String fieldName, String value) throws IOException {
     getWriter().writeStringField(fieldName, value);
 
   }
 
   @SuppressWarnings("resource")
   public void writeField(String fieldName, ObjectNode obj) throws IOException {
     JsonGenerator writer = getWriter(); // NOPMD not closable here
 
     writer.writeFieldName(fieldName);
     writer.writeTree(obj);
   }
 
   @Override
   public void flushWriter() throws IOException {
     getWriter().flush();
   }
 
 }