/*
 * Licensed to STRATIO (C) under one or more contributor license agreements.
 * See the NOTICE file distributed with this work for additional information
 * regarding copyright ownership.  The STRATIO (C) 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 com.stratio.cassandra.lucene.util;

import org.codehaus.jackson.JsonGenerator;
import org.codehaus.jackson.JsonParser;
import org.codehaus.jackson.map.DeserializationConfig;
import org.codehaus.jackson.map.ObjectMapper;
import org.codehaus.jackson.map.SerializationConfig;
import org.codehaus.jackson.map.annotate.JsonSerialize;

import java.io.IOException;

/**
 * A JSON mapper based on Codehaus {@link ObjectMapper} annotations.
 *
 * @author Andres de la Pena {@literal <adelapena@stratio.com>}
 */
public final class JsonSerializer {

    private static final JsonSerializer INSTANCE = new JsonSerializer();

    /** The embedded JSON serializer. */
    private final ObjectMapper jsonMapper = new ObjectMapper();

    /** Private constructor to hide the implicit public one. */
    private JsonSerializer() {
        jsonMapper.configure(JsonGenerator.Feature.QUOTE_FIELD_NAMES, false);
        jsonMapper.configure(JsonParser.Feature.ALLOW_UNQUOTED_FIELD_NAMES, true);
        jsonMapper.configure(SerializationConfig.Feature.AUTO_DETECT_IS_GETTERS, false);
        jsonMapper.configure(DeserializationConfig.Feature.FAIL_ON_UNKNOWN_PROPERTIES, false);
        jsonMapper.setSerializationInclusion(JsonSerialize.Inclusion.NON_NULL);
    }

    /**
     * Returns the JSON {@code String} representation of the specified object.
     *
     * @param value the object to be serialized.
     * @return the JSON {@code String} representation of {@code value}
     * @throws IOException if there are serialization problems
     */
    public static String toString(Object value) throws IOException {
        return INSTANCE.jsonMapper.writeValueAsString(value);
    }

    /**
     * Returns the object of the specified class represented by the specified JSON {@code String}.
     *
     * @param value the JSON {@code String} to be parsed
     * @param valueType the class of the object to be parsed
     * @param <T> the type of the object to be parsed
     * @return an object of the specified class represented by {@code value}
     * @throws IOException if there are parsing problems
     */
    public static <T> T fromString(String value, Class<T> valueType) throws IOException {
        return INSTANCE.jsonMapper.readValue(value, valueType);
    }
}