using FreeRedis;
using Masuit.Tools;
using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Meeting.Infrastructure
{
    public abstract class RedisHelper
    {

        private static RedisClient _instance;

        /// <summary>
        /// redis实例
        /// </summary>
        public static RedisClient Instance
        {
            get
            {
                if (_instance == null)
                {
                    throw new Exception("使用前初始化redis静态访问类 RedisHelper.Initialization(new FreeRedis.RedisClient(\"127.0.0.1:6379,password=123,defaultDatabase=13,maxpoolsize=50,prefix=key前辍\"));");
                }

                return _instance;
            }
        }
        public static void SetLoginToken(long userId, string token)
        {
            var key = "Login_Token";
            Instance.HSet(key, userId.ToString(), token);
        }
        public static void DeleteLoginToken(long userId)
        {
            var key = "Login_Token";
            Instance.HDel(key, userId.ToString());
        }


        /// <summary>
        /// 初始化redis静态访问类 RedisHelper.Initialization(new FreeRedis.RedisClient(\"127.0.0.1:6379,password=123,defaultDatabase=13,maxpoolsize=50,prefix=key前辍\"))
        /// </summary>
        /// <param name="redisClient"></param>
        public static void Initialization(string connectionString)
        {
            _instance = new FreeRedis.RedisClient(connectionString)
            {
                Serialize = (x) => x.ToJsonString(),
                Deserialize = (x, t) => JsonConvert.DeserializeObject(x, t),
            };
        }

        internal static ThreadLocal<Random> rnd = new ThreadLocal<Random>(() => new Random());
        /// <summary>
        /// 随机秒（防止所有key同一时间过期，雪崩）
        /// </summary>
        /// <param name="minTimeoutSeconds">最小秒数</param>
        /// <param name="maxTimeoutSeconds">最大秒数</param>
        /// <returns></returns>
        public static int RandomExpired(int minTimeoutSeconds, int maxTimeoutSeconds) => rnd.Value.Next(minTimeoutSeconds, maxTimeoutSeconds);

        /// <summary>
        /// 获取Redis分布式锁
        /// </summary>
        /// <param name="lockKey">锁键</param>
        /// <param name="lockValue">锁值（建议使用GUID）</param>
        /// <param name="expireSeconds">过期时间（秒）</param>
        /// <returns>是否获取成功</returns>
        public static bool TryLock(string lockKey, string lockValue, int expireSeconds = 30)
        {
            return Instance.SetNx(lockKey, lockValue, expireSeconds);
        }

        /// <summary>
        /// 释放Redis分布式锁
        /// </summary>
        /// <param name="lockKey">锁键</param>
        /// <param name="lockValue">锁值（必须与加锁时一致）</param>
        /// <returns>是否释放成功</returns>
        public static bool ReleaseLock(string lockKey, string lockValue)
        {
            // 使用Lua脚本确保原子性：只有当锁的值匹配时才删除
            const string luaScript = @"
                if redis.call('GET', KEYS[1]) == ARGV[1] then
                    return redis.call('DEL', KEYS[1])
                else
                    return 0
                end";

            var result = Instance.Eval(luaScript, new[] { lockKey }, new[] { lockValue });
            return (long)result == 1;
        }

        /// <summary>
        /// 延长Redis锁的过期时间
        /// </summary>
        /// <param name="lockKey">锁键</param>
        /// <param name="lockValue">锁值</param>
        /// <param name="expireSeconds">新的过期时间（秒）</param>
        /// <returns>是否续期成功</returns>
        public static bool RenewLock(string lockKey, string lockValue, int expireSeconds)
        {
            // 使用Lua脚本确保原子性：只有当锁的值匹配时才更新过期时间
            const string luaScript = @"
                if redis.call('GET', KEYS[1]) == ARGV[1] then
                    return redis.call('EXPIRE', KEYS[1], ARGV[2])
                else
                    return 0
                end";

            var result = Instance.Eval(luaScript, new[] { lockKey }, new[] { lockValue, expireSeconds.ToString() });
            return (long)result == 1;
        }
    }
}