package com.openisle.config;

import com.fasterxml.jackson.annotation.JsonAutoDetect;
import com.fasterxml.jackson.annotation.JsonTypeInfo;
import com.fasterxml.jackson.annotation.PropertyAccessor;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.jsontype.impl.LaissezFaireSubTypeValidator;
import com.fasterxml.jackson.datatype.hibernate6.Hibernate6Module;
import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
import java.time.Duration;
import java.util.HashMap;
import java.util.Map;
import org.springframework.cache.CacheManager;
import org.springframework.cache.annotation.EnableCaching;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.data.redis.cache.RedisCacheConfiguration;
import org.springframework.data.redis.cache.RedisCacheManager;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.serializer.GenericJackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.RedisSerializationContext;
import org.springframework.data.redis.serializer.RedisSerializer;
import org.springframework.data.redis.serializer.StringRedisSerializer;

/**
 * Redis 缓存配置类
 * @author smallclover
 * @since 2025-09-04
 */
@Configuration
@EnableCaching
public class CachingConfig {

  // 标签缓存名
  public static final String TAG_CACHE_NAME = "openisle_tags";
  // 分类缓存名
  public static final String CATEGORY_CACHE_NAME = "openisle_categories";
  // 在线人数缓存名
  public static final String ONLINE_CACHE_NAME = "openisle_online";
  // 注册验证码
  public static final String VERIFY_CACHE_NAME = "openisle_verify";
  // 发帖频率限制
  public static final String LIMIT_CACHE_NAME = "openisle_limit";
  // 用户访问统计
  public static final String VISIT_CACHE_NAME = "openisle_visit";
  // 文章缓存
  public static final String POST_CACHE_NAME = "openisle_posts";

  /**
   * 自定义Redis的序列化器
   * @return
   */
  @Bean
  @Primary
  public RedisSerializer<Object> redisSerializer() {
    // 注册 JavaTimeModule 來支持 Java 8 的日期和时间 API,否则回报一下错误，同时还要引入jsr310

    // org.springframework.data.redis.serializer.SerializationException: Could not write JSON: Java 8 date/time type `java.time.LocalDateTime` not supported by default:
    // add Module "com.fasterxml.jackson.datatype:jackson-datatype-jsr310" to enable handling
    // (through reference chain: java.util.ArrayList[0]->com.openisle.dto.TagDto["createdAt"])
    // 设置可见性，允许序列化所有元素
    ObjectMapper objectMapper = new ObjectMapper();
    objectMapper.registerModule(new JavaTimeModule());
    // Hibernate6Module 可以自动处理懒加载代理对象。
    // Tag对象的creator是FetchType.LAZY
    objectMapper.registerModule(
      new Hibernate6Module()
        .disable(Hibernate6Module.Feature.USE_TRANSIENT_ANNOTATION)
        // 将 Hibernate 特有的集合类型转换为标准 Java 集合类型
        // 避免序列化时出现 org.hibernate.collection.spi.PersistentSet 这样的类型信息
        .configure(Hibernate6Module.Feature.REPLACE_PERSISTENT_COLLECTIONS, true)
    );
    // service的时候带上类型信息
    // 启用类型信息，避免 LinkedHashMap 问题
    objectMapper.activateDefaultTyping(
      LaissezFaireSubTypeValidator.instance,
      ObjectMapper.DefaultTyping.NON_FINAL,
      JsonTypeInfo.As.PROPERTY
    );
    objectMapper.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
    return new GenericJackson2JsonRedisSerializer(objectMapper);
  }

  /**
   * 配置 Spring Cache 使用 RedisCacheManager
   */
  @Bean
  public CacheManager cacheManager(
    RedisConnectionFactory connectionFactory,
    RedisSerializer<Object> redisSerializer
  ) {
    RedisCacheConfiguration config = RedisCacheConfiguration.defaultCacheConfig()
      .entryTtl(Duration.ZERO) // 默认缓存不过期
      .serializeKeysWith(
        RedisSerializationContext.SerializationPair.fromSerializer(new StringRedisSerializer())
      )
      .serializeValuesWith(
        RedisSerializationContext.SerializationPair.fromSerializer(redisSerializer)
      )
      .disableCachingNullValues(); // 禁止缓存 null 值

    // 个别缓存单独设置 TTL 时间
    Map<String, RedisCacheConfiguration> cacheConfigs = new HashMap<>();
    RedisCacheConfiguration oneHourConfig = config.entryTtl(Duration.ofHours(1));
    RedisCacheConfiguration tenMinutesConfig = config.entryTtl(Duration.ofMinutes(10));
    cacheConfigs.put(TAG_CACHE_NAME, oneHourConfig);
    cacheConfigs.put(CATEGORY_CACHE_NAME, oneHourConfig);
    cacheConfigs.put(POST_CACHE_NAME, tenMinutesConfig);

    return RedisCacheManager.builder(connectionFactory)
      .cacheDefaults(config)
      .withInitialCacheConfigurations(cacheConfigs)
      .build();
  }

  /**
   * 配置 RedisTemplate，支持直接操作 Redis
   */
  @Bean
  public RedisTemplate<String, Object> redisTemplate(
    RedisConnectionFactory connectionFactory,
    RedisSerializer<Object> redisSerializer
  ) {
    RedisTemplate<String, Object> template = new RedisTemplate<>();
    template.setConnectionFactory(connectionFactory);

    // key 和 hashKey 使用 String 序列化
    template.setKeySerializer(new StringRedisSerializer());
    template.setHashKeySerializer(new StringRedisSerializer());

    // value 和 hashValue 使用 JSON 序列化
    template.setValueSerializer(redisSerializer);
    template.setHashValueSerializer(redisSerializer);

    return template;
  }
}