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package org.macrocloud.kernel.toolkit.jackson;

import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.databind.*;
import com.fasterxml.jackson.databind.ser.BeanPropertyWriter;
import com.fasterxml.jackson.databind.ser.BeanSerializerModifier;
import org.macrocloud.kernel.toolkit.utils.StringPool;
import org.macrocloud.kernel.toolkit.utils.StringUtil;

import java.io.IOException;
import java.time.OffsetDateTime;
import java.time.temporal.TemporalAccessor;
import java.util.Collection;
import java.util.Date;
import java.util.List;



/**
 * jackson 默认值为 null 时的处理
 * 
 * 主要是为了避免 app 端出现null导致闪退
 * 

 * 规则：
 * number -1
 * string ""
 * date ""
 * boolean false
 * array []
 * Object {}.
 *
 * @author macro
 */
public class BaseBeanSerializerModifier extends BeanSerializerModifier {
	
	/**
	 * 
Title: changeProperties
	 * Description: .
	 *
	 * @param config the config
	 * @param beanDesc the bean desc
	 * @param beanProperties the bean properties
	 * @return the list
	 * @see com.fasterxml.jackson.databind.ser.BeanSerializerModifier#changeProperties(com.fasterxml.jackson.databind.SerializationConfig, com.fasterxml.jackson.databind.BeanDescription, java.util.List)
	 */
	@Override
	public List changeProperties(
		SerializationConfig config, BeanDescription beanDesc,
		List beanProperties) {
		// 循环所有的beanPropertyWriter
		beanProperties.forEach(writer -> {
			// 如果已经有 null 序列化处理如注解：@JsonSerialize(nullsUsing = xxx) 跳过
			if (writer.hasNullSerializer()) {
				return;
			}
			JavaType type = writer.getType();
			Class clazz = type.getRawClass();
			if (type.isTypeOrSubTypeOf(Number.class)) {
				writer.assignNullSerializer(NullJsonSerializers.NUMBER_JSON_SERIALIZER);
			} else if (type.isTypeOrSubTypeOf(Boolean.class)) {
				writer.assignNullSerializer(NullJsonSerializers.BOOLEAN_JSON_SERIALIZER);
			} else if (type.isTypeOrSubTypeOf(Character.class)) {
				writer.assignNullSerializer(NullJsonSerializers.STRING_JSON_SERIALIZER);
			} else if (type.isTypeOrSubTypeOf(String.class)) {
				writer.assignNullSerializer(NullJsonSerializers.STRING_JSON_SERIALIZER);
			} else if (type.isArrayType() || clazz.isArray() || type.isTypeOrSubTypeOf(Collection.class)) {
				writer.assignNullSerializer(NullJsonSerializers.ARRAY_JSON_SERIALIZER);
			} else if (type.isTypeOrSubTypeOf(OffsetDateTime.class)) {
				writer.assignNullSerializer(NullJsonSerializers.STRING_JSON_SERIALIZER);
			} else if (type.isTypeOrSubTypeOf(Date.class) || type.isTypeOrSubTypeOf(TemporalAccessor.class)) {
				writer.assignNullSerializer(NullJsonSerializers.STRING_JSON_SERIALIZER);
			} else {
				writer.assignNullSerializer(NullJsonSerializers.OBJECT_JSON_SERIALIZER);
			}
		});
		return super.changeProperties(config, beanDesc, beanProperties);
	}


	/**
	 * The Interface NullJsonSerializers.
	 */
	public interface NullJsonSerializers {

		/** The string json serializer. */
		JsonSerializer