using IM_API.Interface.Services;
using Microsoft.AspNetCore.Connections;
using Newtonsoft.Json;
using StackExchange.Redis;
using System.Numerics;
using System.Security.Cryptography;
using System.Text.Json;

namespace IM_API.Services
{
    public class RedisRefreshTokenService : IRefreshTokenService
    {
        private readonly ILogger<RedisRefreshTokenService> _logger;
        //redis数据库
        private readonly IDatabase _db;
        private IConfiguration configuration;
        //过期时长
        private readonly TimeSpan _refreshTTL;
        public RedisRefreshTokenService(ILogger<RedisRefreshTokenService> logger, IConnectionMultiplexer multiplexer, IConfiguration configuration)
        {
            _logger = logger;
            _db = multiplexer.GetDatabase();
            this.configuration = configuration;
            //设置refresh过期时间
            var days = int.Parse(this.configuration["Jwt:RefreshTokenDays"] ?? "30");
            _refreshTTL = TimeSpan.FromDays(days);
        }

        private static string GenerateTokenStr()
        {
            var bytes = RandomNumberGenerator.GetBytes(32);
            return Convert.ToBase64String(bytes);
        }

        public async Task<string> CreateRefreshTokenAsync(int userId, CancellationToken ct = default)
        {
            string token = GenerateTokenStr();
            var payload = new { UserId = userId,CreateAt = DateTime.Now};
            string json = JsonConvert.SerializeObject(payload);
            //token写入redis
            await _db.StringSetAsync(token,json,_refreshTTL);
            return token;
        }

        public async Task RevokeRefreshTokenAsync(string token, CancellationToken ct = default)
        {
            await _db.KeyDeleteAsync(token);
        }

        public async Task<(bool ok, int userId)> ValidateRefreshTokenAsync(string token, CancellationToken ct = default)
        {
            var json = await _db.StringGetAsync(token);
            if (json.IsNullOrEmpty) return (false,-1);
            try
            {
                var doc = JsonConvert.DeserializeObject<JsonElement>(json);
                var userId = doc.GetProperty("UserId").GetInt32();
                return (true,userId);
            }
            catch
            {
                return (false,-1);
            }
        }
    }
}