/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.
 *
 */


package org.apache.skywalking.apm.collector.agent.jetty.provider.handler.reader;

import com.google.gson.stream.JsonReader;
import java.io.IOException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * @author peng-yongsheng
 */
public class TraceSegmentJsonReader implements StreamJsonReader<TraceSegment> {

    private final Logger logger = LoggerFactory.getLogger(TraceSegmentJsonReader.class);

    private UniqueIdJsonReader uniqueIdJsonReader = new UniqueIdJsonReader();
    private SegmentJsonReader segmentJsonReader = new SegmentJsonReader();

    private static final String GLOBAL_TRACE_IDS = "gt";
    private static final String SEGMENT = "sg";

    @Override public TraceSegment read(JsonReader reader) throws IOException {
        TraceSegment traceSegment = new TraceSegment();

        reader.beginObject();
        while (reader.hasNext()) {
            switch (reader.nextName()) {
                case GLOBAL_TRACE_IDS:
                    reader.beginArray();
                    while (reader.hasNext()) {
                        traceSegment.addGlobalTraceId(uniqueIdJsonReader.read(reader));
                    }
                    reader.endArray();

                    break;
                case SEGMENT:
                    traceSegment.setTraceSegmentBuilder(segmentJsonReader.read(reader));
                    break;
                default:
                    reader.skipValue();
                    break;
            }
        }
        reader.endObject();

        return traceSegment;
    }
}
