/*
 * Copyright (c) 2011-2022, baomidou (jobob@qq.com).
 *
 * 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 com.baomidou.mybatisplus.extension.handlers;

import com.baomidou.mybatisplus.core.toolkit.Assert;
import com.google.gson.Gson;
import lombok.extern.slf4j.Slf4j;
import org.apache.ibatis.type.JdbcType;
import org.apache.ibatis.type.MappedJdbcTypes;
import org.apache.ibatis.type.MappedTypes;

/**
 * Gson 实现 JSON 字段类型处理器
 *
 * @author hubin
 * @since 2019-08-25
 */
@Slf4j
@MappedTypes({Object.class})
@MappedJdbcTypes(JdbcType.VARCHAR)
public class GsonTypeHandler extends AbstractJsonTypeHandler<Object> {
    private static Gson GSON;
    private final Class<?> type;

    public GsonTypeHandler(Class<?> type) {
        if (log.isTraceEnabled()) {
            log.trace("GsonTypeHandler(" + type + ")");
        }
        Assert.notNull(type, "Type argument cannot be null");
        this.type = type;
    }

    @Override
    protected Object parse(String json) {
        return getGson().fromJson(json, type);
    }

    @Override
    protected String toJson(Object obj) {
        return getGson().toJson(obj);
    }

    public static Gson getGson() {
        if (null == GSON) {
            GSON = new Gson();
        }
        return GSON;
    }

    public static void setGson(Gson gson) {
        Assert.notNull(gson, "Gson should not be null");
        GsonTypeHandler.GSON = gson;
    }
}
