using IM.Commons;
using Microsoft.Extensions.Options;
using Microsoft.IdentityModel.Tokens;
using Newtonsoft.Json;
using StackExchange.Redis;
using System.IdentityModel.Tokens.Jwt;
using System.Security.Claims;
using System.Security.Cryptography;
using System.Text;
using System.Text.Json;

namespace IM.Jwt
{
    public class TokenService : ITokenService
    {
        private readonly IDatabase _redis;
        private readonly IOptions<JwtOptions> _options;
        public TokenService(IConnectionMultiplexer multiplexer, IOptions<JwtOptions> options)
        {
            _redis = multiplexer.GetDatabase();
            _options = options;
        }

        private static string GenerateTokenStr()
        {
            var bytes = RandomNumberGenerator.GetBytes(32);
            return Convert.ToBase64String(bytes);
        }
        public async Task<string> CreateRefreshTokenAsync(Guid userId, CancellationToken cancellationToken = default, string? stamp = null, int? days = null)
        {
            string token = GenerateTokenStr();
            var payload = new { UserId = userId, CreateAt = DateTime.UtcNow, Stamp = stamp };
            string json = JsonConvert.SerializeObject(payload);
            //token写入redis
            await _redis.StringSetAsync(RedisHelper.GetRefreshTokenKey(token), json, TimeSpan.FromDays(days is > 0 ? days.Value : _options.Value.RefreshTokenDays));
            return token;
        }

        public string GetToken(IEnumerable<Claim> claims, JwtOptions options)
        {
            TimeSpan ExpiryDuration = TimeSpan.FromMinutes(options.AccessTokenMinutes);
            var securityKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(options.Key));
            var credentials = new SigningCredentials(securityKey, SecurityAlgorithms.HmacSha256Signature);
            var tokenDescriptor = new JwtSecurityToken(options.Issuer, options.Audience, claims,
                expires: DateTime.Now.Add(ExpiryDuration), signingCredentials: credentials);
            return new JwtSecurityTokenHandler().WriteToken(tokenDescriptor);
        }

        public async Task RevokeRefreshTokenAsync(string refreshToken)
        {
            await _redis.KeyDeleteAsync(RedisHelper.GetRefreshTokenKey(refreshToken));
        }

        public async Task<(bool ok, Guid userId, string? stamp)> ValidateRefreshTokenAsync(string token, CancellationToken cancellation = default)
        {
            var json = await _redis.StringGetAsync(RedisHelper.GetRefreshTokenKey(token));
            if (json.IsNullOrEmpty) return (false, Guid.Empty, null);
            try
            {
                using var doc = JsonDocument.Parse(json.ToString());
                var userId = doc.RootElement.GetProperty("UserId").GetGuid();
                return (true, userId, doc.RootElement.TryGetProperty("Stamp", out var stamp) ? stamp.GetString() : null);
            }
            catch
            {
                return (false, Guid.Empty, null);
            }
        }
    }
}