using Apimanager_backend.Exceptions;
using StackExchange.Redis;

namespace Apimanager_backend.Services
{
    public class RefreshTokenService : IRefreshTokenService
    {
        private readonly IConnectionMultiplexer redis;
        private readonly IConfiguration configuration;
        public RefreshTokenService(IConnectionMultiplexer redis, IConfiguration configuration)
        {
            this.redis = redis;
            this.configuration = configuration;
        }

        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();
            var res = await db.StringSetAsync(refreshToken, userId, TimeSpan.FromDays(expiryDays));
            if (!res)
            {
                throw new BaseException(1006, "Service unavailable");
            }
            return refreshToken;
        }

        public async Task DeleterRefreshTokenAsync(string refreshToken)
        {
            var db = redis.GetDatabase();
            bool res = await db.KeyDeleteAsync(refreshToken);
            if (!res)
            {
                throw new BaseException(1006, "Service unavailable");
            }
        }

        public async Task UpdateRefreshTokenAsync(string refreshToken)
        {
            var db = redis.GetDatabase();
            var expiryDays = Convert.ToDouble(configuration["JwtSettings:RefreshTokenExpiryDays"]);
            //获取refresh剩余有效时间
            var time =await db.KeyTimeToLiveAsync(refreshToken);
            //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(refreshToken,TimeSpan.FromDays(expiryDays));
        }

        public async Task<string?> ValidateRefreshTokenAsync(string refreshToken)
        {
            var db = redis.GetDatabase();
            var redisValue = await db.StringGetAsync(refreshToken);
            //验证refreshToken是否存在
            if (!redisValue.HasValue)
            {
                return null;
            }
            return redisValue.ToString();
        }
    }
}