using Apimanager_backend.Exceptions;
using StackExchange.Redis;

namespace Apimanager_backend.Services
{
    public class RefreshTokenService : IRefreshTokenService
    {
        private readonly IConnectionMultiplexer redis;
        private readonly IConfiguration configuration;
        private readonly int DbIndex = 0;
        public RefreshTokenService(IConnectionMultiplexer redis, IConfiguration configuration)
        {
            this.redis = redis;
            this.configuration = configuration;
        }
        #region 创建刷新令牌
        public async Task<string> CreateRefereshTokenAsync(string userId)
        {
            var refreshToken = Guid.NewGuid().ToString();
            var expiryDays = Convert.ToDouble(configuration["JwtSettings:RefreshTokenExpiryDays"]);

            // 保存到Redis，设置过期时间
            var db = redis.GetDatabase(DbIndex);
            var res = await db.StringSetAsync( userId , refreshToken, TimeSpan.FromDays(expiryDays));
            if (!res)
            {
                throw new BaseException(1006, "Service unavailable");
            }
            return refreshToken;
        }
        #endregion
        #region 删除刷新令牌
        public async Task DeleterRefreshTokenAsync(string userId)
        {
            var db = redis.GetDatabase(DbIndex);
            bool res = await db.KeyDeleteAsync(userId);
            if (!res)
            {
                throw new BaseException(1006, "Service unavailable");
            }
        }
        #endregion
        #region 刷新令牌有效期
        public async Task UpdateRefreshTokenAsync(string userId)
        {
            var db = redis.GetDatabase(DbIndex);
            var expiryDays = Convert.ToDouble(configuration["JwtSettings:RefreshTokenExpiryDays"]);
            //获取refresh剩余有效时间
            var time =await db.KeyTimeToLiveAsync(userId);
            //判断有效时间是否大于零天小于三天，否则不刷新有效期
            if(time <= TimeSpan.Zero || time >= TimeSpan.FromDays(3))
            {
                return;
            }
            //刷新过期时间
            await db.KeyExpireAsync(userId,TimeSpan.FromDays(expiryDays));
        }
        #endregion
        #region 验证令牌
        public async Task<bool> ValidateRefreshTokenAsync(string userId,string refreshToken)
        {
            var db = redis.GetDatabase(DbIndex);
            var redisValue = await db.StringGetAsync(userId);
            //验证refreshToken是否存在
            if (!redisValue.HasValue)
            {
                return false;
            }
            string refreshTokenTrue = redisValue.ToString();
            if (!refreshToken.Equals(refreshTokenTrue))
            {
                return false;
            }
            return true;
        }
        #endregion
    }
}