package com.poyee.aspectj;

import com.alibaba.fastjson.JSONObject;
import com.alibaba.fastjson.parser.Feature;
import com.poyee.annotation.RedisCache;
import com.poyee.base.dto.BaseReq;
import com.poyee.base.dto.Page;
import com.poyee.base.dto.Result;
import com.poyee.base.dto.UserInfo;
import com.poyee.enums.CacheExpirePolicy;
import com.poyee.util.DateUtils;
import com.poyee.util.ServletUtils;
import com.poyee.util.SpElUtils;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.StringUtils;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.reflect.MethodSignature;
import org.springframework.core.DefaultParameterNameDiscoverer;
import org.springframework.core.annotation.Order;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.stereotype.Component;

import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Objects;

/**
 *  Redis 缓存切面
 */
@Slf4j
@Aspect
@Component
@Order(1)
public class RedisCacheAspect {

    private final RedisTemplate<String, Object> redisTemplate;

    public RedisCacheAspect(RedisTemplate<String, Object> redisTemplate) {
        this.redisTemplate = redisTemplate;
    }

    @Around("@annotation(redisCache)")
    public Object doAround(ProceedingJoinPoint joinPoint, RedisCache redisCache) throws Throwable {
        String keyExpression = redisCache.key();
        String keySource = redisCache.keySource();
        CacheExpirePolicy expirePolicy = redisCache.expirePolicy();
        long customExpireTime = redisCache.expireTime();

        if (expirePolicy == CacheExpirePolicy.CUSTOM) {
            expirePolicy.setExpireTime(customExpireTime);
        }

        // 构建上下文变量
        Map<String, Object> contextVars = new HashMap<>();

        //如果获取不到用户信息， 判断方法参数中 doCache 是否为 true，如果是则解析方法参数中数据 进行缓存， 否则直接返回结果
        Object[] args = joinPoint.getArgs();
        MethodSignature methodSignature = (MethodSignature) joinPoint.getSignature();
        Method method = methodSignature.getMethod();
        DefaultParameterNameDiscoverer nameDiscoverer = new DefaultParameterNameDiscoverer();
        String[] paramNames = nameDiscoverer.getParameterNames(method);

        // 检查方法参数中是否有 doCache 参数且为 true
        boolean doCache = false;
        Object arg = null;
        for (int i = 0; i < args.length; i++) {
            if (paramNames != null && i < paramNames.length) {
                arg = args[i];
                if(arg instanceof BaseReq && ((BaseReq) arg).isDoRedis()){
                    doCache = true;
                }
            }
        }

        // 从指定 source 获取变量值（如 userContext）
        switch (keySource) {
            case "userContext":
                //根据
                List<String> strings = SpElUtils.extractLabels(keyExpression);
                String keyWord = strings.get(0);
                if(doCache && Objects.nonNull(arg)){
                    Field declaredField = arg.getClass().getDeclaredField(keyWord);
                    declaredField.setAccessible(true);
                    Object valueObj = declaredField.get(arg);
                    contextVars.put(keyWord, valueObj);
                } else {
                    //获取当前用户信息
                    UserInfo userInfo = ServletUtils.getUserInfo();
                    try {
                        Class<?> aClass = userInfo.getClass();
                        Field declaredField = aClass.getDeclaredField(keyWord);
                        declaredField.setAccessible(true);
                        Object valueObj = declaredField.get(userInfo);
                        contextVars.put(keyWord, valueObj);
                    } catch (Exception e) {

                    }
                }
                break;
            case "args":
//                Object[] args = joinPoint.getArgs();
//                MethodSignature methodSignature = (MethodSignature) joinPoint.getSignature();
//                Method method = methodSignature.getMethod();
//                DefaultParameterNameDiscoverer nameDiscoverer = new DefaultParameterNameDiscoverer();
//                String[] paramNames = nameDiscoverer.getParameterNames(method);
                for (int i = 0; i < args.length; i++) {
                    if (paramNames != null && i < paramNames.length) {
                        contextVars.put(paramNames[i], args[i]);
                    }
                }
                break;
            default:
                // 自定义 source，可扩展
                break;
        }

        // 解析 key
        String finalKey = SpElUtils.parseKey(keyExpression, contextVars);

        // 查询缓存
        Object cachedValue = redisTemplate.opsForValue().get(finalKey);
        if (cachedValue != null) {
            //判断是否为JSONObject 进行转换
            if(cachedValue instanceof String){
                //获取过期时间
                long expireTime = redisTemplate.getExpire(finalKey);
                log.debug("缓存命中[剩余时间：{} s]，返回结果：{}", expireTime,(cachedValue.toString().length() > 200 ? cachedValue.toString().substring(0, 200) +"..." : cachedValue.toString()));
                //解析为json 并 取得 type 区分是 page 还是result
                String type = "result";
                if(cachedValue.toString().startsWith("{")){
                    JSONObject jsonObject = JSONObject.parseObject((String) cachedValue);
                    type = jsonObject.getString("type");
                }
                if(type.equals("page")){
                    Page page = JSONObject.parseObject((String) cachedValue, Page.class, Feature.OrderedField);
                    //设置缓存过期时间
                    page.setRedisCacheTimes(expireTime);
                    //如果缓存key 为空 则设置  key
                    if(StringUtils.isBlank(page.getRedisCacheKey())){
                        page.setRedisCacheKey(finalKey);
                    }
                    //如果是分页 则判断 结果是否排序 排序字段和规则， 对结果重新排序
//                    doCheckSortByPageOrderBy(page);
                    return page;
                }else{
                    Result result = JSONObject.parseObject((String) cachedValue, Result.class, Feature.OrderedField);
                    //设置缓存过期时间
                    result.setRedisCacheTimes(expireTime);
                    //如果缓存key 为空 则设置  key
                    if(StringUtils.isBlank(result.getRedisCacheKey())){
                        result.setRedisCacheKey(finalKey);
                    }
                    return result;
                }
            }
            return cachedValue;
        }

        // 执行目标方法
        Object result = joinPoint.proceed();

        // 判断返回值是否有效（非空、非异常）
        if (result == null || result instanceof Boolean && !(Boolean) result) {
            return result;
        }
        //处理 返回 code
        if((result.getClass().getName().equals("com.poyee.base.dto.Result") || result.getClass().getName().equals("com.poyee.base.dto.Page") )
                && result.getClass().getDeclaredField("code") != null){
            try{
                Field codeField = result.getClass().getDeclaredField("code");
                codeField.setAccessible(true);
                Object codeObj = codeField.get(result);
                if(codeObj != null && Integer.parseInt(codeObj.toString()) != 200 && Integer.parseInt(codeObj.toString()) != 0 ){
                    return result;
                }
            }catch (Exception e){
                //忽略异常
            }
        }
        // 设置缓存
        long expireSeconds = expirePolicy.getExpireSeconds();
        //设置 查询数据库操作时间
        try{
            Field codeField = result.getClass().getDeclaredField("lastOptTime");
            codeField.setAccessible(true);
            Object codeObj = codeField.get(result);
            //设置当前时间为最后一次操作时间
            if(codeObj == null){
                codeField.set(result, DateUtils.dateTimeNow(DateUtils.YYYY_MM_DD_HH_MM_SS));
            }
            //设置缓存key
            codeField = result.getClass().getDeclaredField("redisCacheKey");
            codeField.setAccessible(true);
            codeField.set(result, finalKey);
            //设置缓存时间
            codeField = result.getClass().getDeclaredField("redisCacheTimes");
            codeField.setAccessible(true);
            codeField.set(result, expirePolicy.getExpireSeconds());

        }catch (Exception e){
            log.error("设置 查询数据库操作时间 异常",e);
        }
        String jsonString = JSONObject.toJSONString(result);
        if (expireSeconds > 0) {

        } else {
            // 默认设置缓存时间为1小时 (3600秒)
            expireSeconds = 3600;
        }
        redisTemplate.opsForValue().set(finalKey, jsonString, expireSeconds, java.util.concurrent.TimeUnit.SECONDS);
        //判断是否需要缓存key集合
        if(redisCache.logKey()
                && StringUtils.isNotBlank(redisCache.logKeyRule())
                && !Objects.equals(redisCache.logKeyRule(),"key")){
            String logKeyExpression = redisCache.logKeyRule();
            // 解析 key
            String finalLogKey = SpElUtils.parseKey(logKeyExpression, contextVars);
            // redis 缓存 设置 list add 值
            redisTemplate.opsForList()
                         .leftPush(finalLogKey, finalKey);
            // 设置列表过期时间，与缓存过期时间一致
            redisTemplate.expire(finalLogKey, expireSeconds, java.util.concurrent.TimeUnit.SECONDS);
        }
        log.debug("缓存结果：{}", jsonString.length() > 200 ? jsonString.substring(0, 200) + "..." : jsonString);
        return result;
    }

    private void doCheckSortByPageOrderBy(Page page) {
        String orderByField = page.getOrderBy();
        if(StringUtils.isNotBlank(orderByField)) {
            List<?> rows = page.getRows();
            boolean isDesc = page.isDesc(); // 是否降序

            try {
                rows.sort((o1, o2) -> {
                    if (o1 == null || o2 == null) return 0;

                    // 使用反射获取 orderByField 的值
                    Object v1 = getFieldValue(o1, orderByField);
                    Object v2 = getFieldValue(o2, orderByField);

                    if (v1 == null && v2 == null) return 0;
                    if (v1 == null) return isDesc ? 1 : -1;
                    if (v2 == null) return isDesc ? -1 : 1;

                    // 按类型安全比较
                    int result;
                    if (v1 instanceof Comparable && v2.getClass()
                                                      .isAssignableFrom(v1.getClass())) {
                        result = ((Comparable) v1).compareTo(v2);
                    } else {
                        // 转为字符串比较（兜底）
                        result = v1.toString()
                                   .compareTo(v2.toString());
                    }

                    return isDesc ? -result : result; // 反转符号实现降序
                });
            } catch (Exception e) {
                log.warn("缓存分页数据排序失败，orderByField={}", orderByField, e);
            }
        }
    }

    // 使用反射获取字段值
    private Object getFieldValue(Object obj, String fieldName) {
        if (obj == null || StringUtils.isBlank(fieldName)) return null;

        Class<?> clazz = obj.getClass();
        String[] fields = fieldName.split("\\."); // 支持嵌套属性 a.b.c

        try {
            for (String field : fields) {
                Field declaredField = findField(clazz, field);
                if (declaredField == null) return null;
                declaredField.setAccessible(true);
                obj = declaredField.get(obj);
                if (obj == null) break;
                clazz = obj.getClass();
            }
            return obj;
        } catch (Exception e) {
            log.debug("获取对象 {} 字段 {} 值失败", obj.getClass().getSimpleName(), fieldName, e);
            return null;
        }
    }

    // 支持父类字段查找
    private Field findField(Class<?> clazz, String name) {
        while (clazz != null) {
            try {
                return clazz.getDeclaredField(name);
            } catch (NoSuchFieldException e) {
                clazz = clazz.getSuperclass();
            }
        }
        return null;
    }

}