package com.imyeyu.spring.util;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.data.redis.serializer.RedisSerializer;
import org.springframework.data.redis.serializer.SerializationException;
import org.springframework.data.redis.serializer.StringRedisSerializer;

import java.io.IOException;
import java.nio.charset.StandardCharsets;

/**
 * Redis 序列化工具
 *
 * @author 夜雨
 * @version 2023-07-17 16:20
 */
public class RedisSerializers {

	/** 工具类禁止实例化 */
	private RedisSerializers() {
	}

	/** 字符串序列化 */
	public static final StringRedisSerializer STRING = new StringRedisSerializer();

	/** 长整型序列化 */
	public static final RedisSerializer<Integer> INTEGER = new RedisSerializer<>() {

		@Override
		public byte[] serialize(Integer value) throws SerializationException {
			if (value == null) {
				return null;
			}
			byte[] result = new byte[Integer.BYTES];
			for (int i = Integer.BYTES - 1; 0 <= i; i--) {
				result[i] = (byte) (value & 0xFF);
				value >>= Byte.SIZE;
			}
			return result;
		}

		@Override
		public Integer deserialize(byte[] bytes) throws SerializationException {
			if (bytes == null) {
				return null;
			}
			int result = 0;
			for (int i = 0; i < Integer.BYTES; i++) {
				result <<= Byte.SIZE;
				result |= (bytes[i] & 0xFF);
			}
			return result;
		}
	};

	/** 长整型序列化 */
	public static final RedisSerializer<Long> LONG = new RedisSerializer<>() {

		@Override
		public byte[] serialize(Long value) throws SerializationException {
			if (value == null) {
				return null;
			}
			byte[] result = new byte[Long.BYTES];
			for (int i = Long.BYTES - 1; 0 <= i; i--) {
				result[i] = (byte) (value & 0xFF);
				value >>= Byte.SIZE;
			}
			return result;
		}

		@Override
		public Long deserialize(byte[] bytes) throws SerializationException {
			if (bytes == null) {
				return null;
			}
			long result = 0;
			for (int i = 0; i < Long.BYTES; i++) {
				result <<= Byte.SIZE;
				result |= (bytes[i] & 0xFF);
			}
			return result;
		}
	};

	/**
	 * Json 序列化
	 *
	 * @param <T>   数据类型
	 * @param clazz 数据类型
	 * @return Redis 序列化器
	 */
	public static <T> RedisSerializer<T> jacksonSerializer(Class<T> clazz) {
		return new RedisSerializer<>() {

			private static final ObjectMapper JACKSON = new ObjectMapper();

			@Override
			public byte[] serialize(T object) throws SerializationException {
				try {
					return JACKSON.writeValueAsString(object).getBytes(StandardCharsets.UTF_8);
				} catch (JsonProcessingException e) {
					throw new RuntimeException(e);
				}
			}

			@Override
			public T deserialize(byte[] bytes) throws SerializationException {
				if (bytes == null) {
					return null;
				}
				try {
					return JACKSON.readValue(new String(bytes, StandardCharsets.UTF_8), clazz);
				} catch (IOException e) {
					throw new RuntimeException(e);
				}
			}
		};
	}
}