/*
 * Seldon -- open source prediction engine
 * =======================================
 * Copyright 2011-2015 Seldon Technologies Ltd and Rummble Ltd (http://www.seldon.io/)
 *
 **********************************************************************************************
 *
 * 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.
 *
 ********************************************************************************************** 
*/
package io.seldon.stream.serializer;

import java.util.Map;

import org.apache.kafka.common.serialization.Deserializer;

import com.google.gson.Gson;

/**
 * Copied from https://github.com/bbejeck/kafka-streams/blob/master/src/main/java/bbejeck/serializer/JsonDeserializer.java
 */

public class JsonDeserializer<T> implements Deserializer<T> {

    private Gson gson = new Gson();
    private Class<T> deserializedClass;

    public JsonDeserializer(Class<T> deserializedClass) {
        this.deserializedClass = deserializedClass;
    }

    public JsonDeserializer() {
    }

    @Override
    @SuppressWarnings("unchecked")
    public void configure(Map<String, ?> map, boolean b) {
        if(deserializedClass == null) {
            deserializedClass = (Class<T>) map.get("serializedClass");
        }
    }

    @Override
    public T deserialize(String s, byte[] bytes) {
         if(bytes == null){
             return null;
         }

         return gson.fromJson(new String(bytes),deserializedClass);

    }

    @Override
    public void close() {

    }
}