import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.JavaType;
import com.fasterxml.jackson.databind.ObjectMapper;

import java.util.ArrayList;
import
 
 java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Jackson 工具類
 * <p>Title: MapperUtils</p>
 * <p>Description: </p>
 *
 * 
 */
public class JacksonUtils {
    private static final Logger logger = LoggerFactory.getLogger(JacksonUtils.class
 
);
    private final static ObjectMapper objectMapper = new ObjectMapper();

    public static ObjectMapper getInstance() {
        return objectMapper;
    }

    /**
     * 轉換為 JSON 字串
     *
     * @param obj
     * @return
     * @throws Exception
     */
    public static String obj2json(Object obj) throws
 
 Exception {
        return objectMapper.writeValueAsString(obj);
    }
    
    /**
     * 將物件轉換為json字串
     * @param obj
     * @return
     */
    public static String obj2jsonStr(Object obj) {
        try {
            return JacksonUtils.obj2json(obj);
        } catch (Exception e) {
            logger.error("對像轉換成json字串報錯：", e);
        }
        return "";
    }

    /**
     * 轉換為 JSON 字串，忽略空值
     *
     * @param obj
     * @return
     * @throws Exception
     */
    public static String obj2jsonIgnoreNull(Object obj) throws Exception {
        ObjectMapper mapper = new ObjectMapper();
        mapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
        return mapper.writeValueAsString(obj);
    }

    /**
     * 轉換為 JavaBean
     *
     * @param jsonString
     * @param clazz
     * @return
     * @throws Exception
     */
    public static <T> T json2pojo(String jsonString, Class<? extends T> clazz) throws Exception {
        objectMapper.configure(DeserializationFeature.ACCEPT_SINGLE_VALUE_AS_ARRAY, true);
        return objectMapper.readValue(jsonString, clazz);
    }

    /**
     * 字串轉換為 Map<String, Object>
     *
     * @param jsonString
     * @return
     * @throws Exception
     */
    public static <T> Map<String, Object> json2map(String jsonString) throws Exception {
        ObjectMapper mapper = new ObjectMapper();
        mapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
        return mapper.readValue(jsonString, Map.class);
    }

    /**
     * 字串轉換為 Map<String, T>
     */
    public static <T> Map<String, T> json2map(String jsonString, Class<T> clazz) throws Exception {
        Map<String, Map<String, Object>> map = objectMapper.readValue(jsonString, new TypeReference<Map<String, T>>() {
        });
        Map<String, T> result = new HashMap<String, T>();
        for (Map.Entry<String, Map<String, Object>> entry : map.entrySet()) {
            result.put(entry.getKey(), map2pojo(entry.getValue(), clazz));
        }
        return result;
    }

    /**
     * 深度轉換 JSON 成 Map
     *
     * @param json
     * @return
     */
    public static Map<String, Object> json2mapDeeply(String json) throws Exception {
        return json2MapRecursion(json, objectMapper);
    }

    /**
     * 把 JSON 解析成 List，如果 List 內部的元素存在 jsonString，繼續解析
     *
     * @param json
     * @param mapper 解析工具
     * @return
     * @throws Exception
     */
    private static List<Object> json2ListRecursion(String json, ObjectMapper mapper) throws Exception {
        if (json == null) {
            return null;
        }

        List<Object> list = mapper.readValue(json, List.class);

        for (Object obj : list) {
            if (obj != null && obj instanceof String) {
                String str = (String) obj;
                if (str.startsWith("[")) {
                    obj = json2ListRecursion(str, mapper);
                } else if (obj.toString().startsWith("{")) {
                    obj = json2MapRecursion(str, mapper);
                }
            }
        }

        return list;
    }

    /**
     * 把 JSON 解析成 Map，如果 Map 內部的 Value 存在 jsonString，繼續解析
     *
     * @param json
     * @param mapper
     * @return
     * @throws Exception
     */
    private static Map<String, Object> json2MapRecursion(String json, ObjectMapper mapper) throws Exception {
        if (json == null) {
            return null;
        }

        Map<String, Object> map = mapper.readValue(json, Map.class);

        for (Map.Entry<String, Object> entry : map.entrySet()) {
            Object obj = entry.getValue();
            if (obj != null && obj instanceof String) {
                String str = ((String) obj);

                if (str.startsWith("[")) {
                    List<?> list = json2ListRecursion(str, mapper);
                    map.put(entry.getKey(), list);
                } else if (str.startsWith("{")) {
                    Map<String, Object> mapRecursion = json2MapRecursion(str, mapper);
                    map.put(entry.getKey(), mapRecursion);
                }
            }
        }

        return map;
    }

    /**
     * 將 JSON 陣列轉換為集合
     *
     * @param jsonArrayStr
     * @param clazz
     * @return
     * @throws Exception
     */
    public static <T> List<T> json2list(String jsonArrayStr, Class<T> clazz) throws Exception {
        JavaType javaType = getCollectionType(ArrayList.class, clazz);
        List<T> list = (List<T>) objectMapper.readValue(jsonArrayStr, javaType);
        return list;
    }


    /**
     * 獲取泛型的 Collection Type
     *
     * @param collectionClass 泛型的Collection
     * @param elementClasses  元素類
     * @return JavaType Java型別
     * @since 1.0
     */
    public static JavaType getCollectionType(Class<?> collectionClass, Class<?>... elementClasses) {
        return objectMapper.getTypeFactory().constructParametricType(collectionClass, elementClasses);
    }

    /**
     * 將 Map 轉換為 JavaBean
     *
     * @param map
     * @param clazz
     * @return
     */
    public static <T> T map2pojo(Map map, Class<T> clazz) {
        return objectMapper.convertValue(map, clazz);
    }

    /**
     * 將 Map 轉換為 JSON
     *
     * @param map
     * @return
     */
    public static String mapToJson(Map map) {
        try {
            return objectMapper.writeValueAsString(map);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return "";
    }

    /**
     * 將 JSON 物件轉換為 JavaBean
     *
     * @param obj
     * @param clazz
     * @return
     */
    public static <T> T obj2pojo(Object obj, Class<T> clazz) {
        return objectMapper.convertValue(obj, clazz);
    }
}