/*-
 * ============LICENSE_START=======================================================
 * org.openecomp.aai
 * ================================================================================
 * Copyright (C) 2017 AT&T Intellectual Property. All rights reserved.
 * ================================================================================
 * Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

     http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
 * ============LICENSE_END=========================================================
 */

package org.openecomp.aai.serialization.queryformats;

import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.List;

import org.apache.tinkerpop.gremlin.structure.Vertex;

import org.openecomp.aai.db.props.AAIProperties;
import org.openecomp.aai.exceptions.AAIException;
import org.openecomp.aai.introspection.Introspector;
import org.openecomp.aai.introspection.Loader;
import org.openecomp.aai.introspection.exceptions.AAIUnknownObjectException;
import org.openecomp.aai.serialization.db.DBSerializer;
import org.openecomp.aai.serialization.queryformats.exceptions.AAIFormatVertexException;
import org.openecomp.aai.serialization.queryformats.utils.UrlBuilder;
import com.google.gson.JsonObject;
import com.google.gson.JsonParser;

public class Resource implements FormatMapper {

	private final Loader loader;
	private final DBSerializer serializer;
	private final JsonParser parser;
	private final UrlBuilder urlBuilder;
	private final boolean includeUrl;
	
	private Resource (Builder builder) {
		this.parser = new JsonParser();
		this.loader = builder.getLoader();
		this.serializer = builder.getSerializer();
		this.urlBuilder = builder.getUrlBuilder();
		this.includeUrl = builder.isIncludeUrl();
	}

	@Override
	public JsonObject formatObject(Object input) throws AAIFormatVertexException {
		Vertex v = (Vertex)input;
		JsonObject json = new JsonObject();
		
		if (this.includeUrl) {
			json.addProperty("url", this.urlBuilder.pathed(v));
		}
		json.add(v.<String>property(AAIProperties.NODE_TYPE)
											.orElse(null), this.vertexToJsonObject(v));
		
		return json;
	}

	protected JsonObject vertexToJsonObject(Vertex v) throws AAIFormatVertexException {
		try {
			final Introspector obj = getLoader().introspectorFromName(
										v.<String>property(AAIProperties.NODE_TYPE)
											.orElse(null)
									 );

			final List<Vertex> wrapper = new ArrayList<>();

			wrapper.add(v);

			try {
				getSerializer().dbToObject(wrapper, obj, 1, false, "false");
			} catch (AAIException | UnsupportedEncodingException  e) {
				throw new AAIFormatVertexException("Failed to format vertex - error while serializing: " + e.getMessage(), e);
			}

			final String json = obj.marshal(false);

			return getParser().parse(json).getAsJsonObject();
		} catch (AAIUnknownObjectException e) {
			throw new AAIFormatVertexException("Failed to format vertex - unknown object", e);
		}
	}

	@Override
	public int parallelThreshold() {
		return 20;
	}

	private Loader getLoader() { return loader; }
	private DBSerializer getSerializer() { return serializer; }
	private JsonParser getParser() { return parser; }
	
	public static class Builder {
		
		private final Loader loader;
		private final DBSerializer serializer;
		private final UrlBuilder urlBuilder;
		private boolean includeUrl = false;
		
		public Builder(Loader loader, DBSerializer serializer, UrlBuilder urlBuilder) {
			this.loader = loader;
			this.serializer = serializer;
			this.urlBuilder = urlBuilder;
		}
		
		protected Loader getLoader() {
			return this.loader;
		}

		protected DBSerializer getSerializer() {
			return this.serializer;
		}

		protected UrlBuilder getUrlBuilder() {
			return this.urlBuilder;
		}
		
		public Builder includeUrl() {
			this.includeUrl = true;
			return this;
		}

		protected boolean isIncludeUrl() {
			return this.includeUrl;
		}
		
		public Resource build() {
			return new Resource(this);
		}
	}
}