/*
    * SPDX-FileCopyrightText: none
    * SPDX-License-Identifier: CC0-1.0
    */
   
   package dev.metaschema.schemagen.json;
   
   import com.fasterxml.jackson.core.JsonFactory;
   import com.fasterxml.jackson.core.JsonGenerator;
  import com.fasterxml.jackson.core.JsonGenerator.Feature;
  import com.fasterxml.jackson.databind.ObjectMapper;
  import com.fasterxml.jackson.databind.node.ObjectNode;
  
  import java.io.IOException;
  import java.io.Writer;
  
  import dev.metaschema.core.configuration.IConfiguration;
  import dev.metaschema.core.model.IModule;
  import dev.metaschema.core.util.ObjectUtils;
  import dev.metaschema.schemagen.AbstractSchemaGenerator;
  import dev.metaschema.schemagen.SchemaGenerationException;
  import dev.metaschema.schemagen.SchemaGenerationFeature;
  import dev.metaschema.schemagen.json.impl.IJsonSchema;
  import dev.metaschema.schemagen.json.impl.JsonDatatypeManager;
  import dev.metaschema.schemagen.json.impl.JsonGenerationState;
  import dev.metaschema.schemagen.json.impl.JsonSchemaModule;
  import edu.umd.cs.findbugs.annotations.NonNull;
  
  /**
   * Generates JSON Schema documents from Metaschema modules.
   * <p>
   * This generator produces JSON Schema draft-07 compatible schemas that can be
   * used to validate JSON and YAML content conforming to the Metaschema model.
   */
  public class JsonSchemaGenerator
      extends AbstractSchemaGenerator<JsonGenerator, JsonDatatypeManager, JsonGenerationState> {
    @NonNull
    private final JsonFactory jsonFactory;
  
    /**
     * Constructs a new JSON schema generator using a default JSON factory.
     */
    public JsonSchemaGenerator() {
      this(new JsonFactory());
    }
  
    /**
     * Constructs a new JSON schema generator using the specified JSON factory.
     *
     * @param jsonFactory
     *          the Jackson JSON factory to use for creating JSON generators
     */
    public JsonSchemaGenerator(@NonNull JsonFactory jsonFactory) {
      this.jsonFactory = jsonFactory;
    }
  
    /**
     * Retrieves the JSON factory used by this generator.
     *
     * @return the JSON factory instance
     */
    @NonNull
    public JsonFactory getJsonFactory() {
      return jsonFactory;
    }
  
    @SuppressWarnings("resource")
    @Override
    protected JsonGenerator newWriter(Writer out) {
      try {
        return ObjectUtils.notNull(getJsonFactory().createGenerator(out)
            .setCodec(new ObjectMapper())
            .useDefaultPrettyPrinter()
            .disable(Feature.AUTO_CLOSE_TARGET));
      } catch (IOException ex) {
        throw new SchemaGenerationException(ex);
      }
    }
  
    @Override
    protected JsonGenerationState newGenerationState(
        IModule module,
        JsonGenerator schemaWriter,
        IConfiguration<SchemaGenerationFeature<?>> configuration) {
      return new JsonGenerationState(module, schemaWriter, configuration);
    }
  
    @Override
    protected void generateSchema(JsonGenerationState state) {
      IModule module = state.getModule();
  
      IJsonSchema moduleSchema = new JsonSchemaModule(module, state);
      ObjectNode schemaNode = ObjectUtils.notNull(state.getJsonNodeFactory().objectNode());
      moduleSchema.generateInlineJsonSchema(schemaNode, state);
  
      try {
        state.writeObject(schemaNode);
      } catch (IOException ex) {
        throw new SchemaGenerationException(ex);
     }
   }
 }