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// *  http://www.apache.org/licenses/LICENSE-2.0                                                                             *
// *                                                                                                                         *
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// * specific language governing permissions and limitations under the License.                                              *
// ***************************************************************************************************************************
package org.apache.juneau.json;

import java.util.*;
import java.util.concurrent.*;

import org.apache.juneau.*;
import org.apache.juneau.annotation.*;
import org.apache.juneau.jsonschema.*;
import org.apache.juneau.serializer.*;

/**
 * Serializes POJO metadata to HTTP responses as JSON-Schema.
 *
 * <h5 class='topic'>Media types</h5>
 *
 * Handles <c>Accept</c> types:  <bc>application/json+schema, text/json+schema</bc>
 * <p>
 * Produces <c>Content-Type</c> types:  <bc>application/json</bc>
 *
 * <h5 class='topic'>Description</h5>
 *
 * Produces the JSON-schema for the JSON produced by the {@link JsonSerializer} class with the same properties.
 */
@ConfigurableContext
public class JsonSchemaSerializer extends JsonSerializer implements JsonSchemaMetaProvider {

	//-------------------------------------------------------------------------------------------------------------------
	// Configurable properties
	//-------------------------------------------------------------------------------------------------------------------

	static final String PREFIX = "JsonSchemaSerializer";

	//-------------------------------------------------------------------------------------------------------------------
	// Predefined instances
	//-------------------------------------------------------------------------------------------------------------------

	/** Default serializer, all default settings.*/
	public static final JsonSchemaSerializer DEFAULT = new JsonSchemaSerializer(PropertyStore.DEFAULT);

	/** Default serializer, all default settings.*/
	public static final JsonSchemaSerializer DEFAULT_READABLE = new Readable(PropertyStore.DEFAULT);

	/** Default serializer, single quotes, simple mode. */
	public static final JsonSchemaSerializer DEFAULT_SIMPLE = new Simple(PropertyStore.DEFAULT);

	/** Default serializer, single quotes, simple mode, with whitespace. */
	public static final JsonSchemaSerializer DEFAULT_SIMPLE_READABLE = new SimpleReadable(PropertyStore.DEFAULT);


	//-------------------------------------------------------------------------------------------------------------------
	// Predefined subclasses
	//-------------------------------------------------------------------------------------------------------------------

	/** Default serializer, with whitespace. */
	public static class Readable extends JsonSchemaSerializer {

		/**
		 * Constructor.
		 *
		 * @param ps The property store containing all the settings for this object.
		 */
		public Readable(PropertyStore ps) {
			super(
				ps.builder().set(WSERIALIZER_useWhitespace, true).build()
			);
		}
	}

	/** Default serializer, single quotes, simple mode. */
	public static class Simple extends JsonSchemaSerializer {

		/**
		 * Constructor.
		 *
		 * @param ps The property store containing all the settings for this object.
		 */
		public Simple(PropertyStore ps) {
			super(
				ps.builder()
					.set(JSON_simpleMode, true)
					.set(WSERIALIZER_quoteChar, '\'')
					.build()
				);
		}
	}

	/** Default serializer, single quotes, simple mode, with whitespace. */
	public static class SimpleReadable extends JsonSchemaSerializer {

		/**
		 * Constructor.
		 *
		 * @param ps The property store containing all the settings for this object.
		 */
		public SimpleReadable(PropertyStore ps) {
			super(
				ps.builder()
					.set(JSON_simpleMode, true)
					.set(WSERIALIZER_quoteChar, '\'')
					.set(WSERIALIZER_useWhitespace, true)
					.build()
			);
		}
	}


	//-------------------------------------------------------------------------------------------------------------------
	// Instance
	//-------------------------------------------------------------------------------------------------------------------

	private final JsonSchemaGenerator generator;
	private final Map<ClassMeta<?>,JsonSchemaClassMeta> jsonSchemaClassMetas = new ConcurrentHashMap<>();
	private final Map<BeanPropertyMeta,JsonSchemaBeanPropertyMeta> jsonSchemaBeanPropertyMetas = new ConcurrentHashMap<>();

	/**
	 * Constructor.
	 *
	 * @param ps Initialize with the specified config property store.
	 */
	public JsonSchemaSerializer(PropertyStore ps) {
		super(
			ps.builder()
				.set(BEANTRAVERSE_detectRecursions, true)
				.set(BEANTRAVERSE_ignoreRecursions, true)
				.build(),
			"application/json", "application/json+schema,text/json+schema"
		);

		generator = JsonSchemaGenerator.create().apply(getPropertyStore()).build();
	}

	@Override /* Context */
	public JsonSchemaSerializerBuilder builder() {
		return new JsonSchemaSerializerBuilder(getPropertyStore());
	}

	/**
	 * Instantiates a new clean-slate {@link JsonSerializerBuilder} object.
	 *
	 * <p>
	 * This is equivalent to simply calling <code><jk>new</jk> JsonSerializerBuilder()</code>.
	 *
	 * @return A new {@link JsonSerializerBuilder} object.
	 */
	public static JsonSchemaSerializerBuilder create() {
		return new JsonSchemaSerializerBuilder();
	}

	@Override /* Context */
	public JsonSchemaSerializerSession createSession() {
		return createSession(createDefaultSessionArgs());
	}

	@Override /* Serializer */
	public JsonSchemaSerializerSession createSession(SerializerSessionArgs args) {
		return new JsonSchemaSerializerSession(this, args);
	}

	JsonSchemaGenerator getGenerator() {
		return generator;
	}

	//-----------------------------------------------------------------------------------------------------------------
	// Extended metadata
	//-----------------------------------------------------------------------------------------------------------------

	@Override /* JsonSchemaMetaProvider */
	public JsonSchemaClassMeta getJsonSchemaClassMeta(ClassMeta<?> cm) {
		JsonSchemaClassMeta m = jsonSchemaClassMetas.get(cm);
		if (m == null) {
			m = new JsonSchemaClassMeta(cm, this);
			jsonSchemaClassMetas.put(cm, m);
		}
		return m;
	}

	@Override /* JsonSchemaMetaProvider */
	public JsonSchemaBeanPropertyMeta getJsonSchemaBeanPropertyMeta(BeanPropertyMeta bpm) {
		JsonSchemaBeanPropertyMeta m = jsonSchemaBeanPropertyMetas.get(bpm);
		if (m == null) {
			m = new JsonSchemaBeanPropertyMeta(bpm.getDelegateFor(), this);
			jsonSchemaBeanPropertyMetas.put(bpm, m);
		}
		return m;
	}

	//-----------------------------------------------------------------------------------------------------------------
	// Other methods
	//-----------------------------------------------------------------------------------------------------------------

	@Override /* Context */
	public ObjectMap toMap() {
		return super.toMap()
			.append("JsonSchemaSerializer", new DefaultFilteringObjectMap()
				.append("generator", generator)
			);
	}
}