namespace ZhiYi.Core.Application.Middleware
{
    public class TokenService
    {
        private readonly IConfiguration _configuration;
        private readonly IDatabase _redis;

        public TokenService(IConfiguration configuration, IConnectionMultiplexer redis)
        {
            _configuration = configuration;
            _redis = redis.GetDatabase();
        }

        public string GenerateTokenAsync(long userid, string username)
        {

            var key = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(_configuration["Jwt:Key"]));
            var expiryInMinutes = int.Parse(_configuration["Jwt:ExpiryInMinutes"]);
            var credentials = new SigningCredentials(key, SecurityAlgorithms.HmacSha256);

            var token = new JwtSecurityToken(
                issuer: _configuration["Jwt:Issuer"],
                audience: _configuration["Jwt:Audience"],
                expires: DateTime.Now.AddMinutes(expiryInMinutes),
                claims: new[]
                {
                    new Claim(ClaimTypes.Name, username), // 设置用户名
                    new Claim(ClaimTypes.Sid, userid.ToString()) //用户ID
                },
                signingCredentials: credentials
            );

            var tokenString = new JwtSecurityTokenHandler().WriteToken(token);
            // 将 Token 存储到 Redis 有效时间30分钟
            _redis.StringSet($"token:{userid}", tokenString, TimeSpan.FromMinutes(30));

            return tokenString;
        }

        /// <summary>
        /// 获取签名
        /// </summary>
        /// <param name="appSecret"></param>
        /// <param name="path"></param>
        /// <param name="timestamp"></param>
        /// <param name="token"></param>
        /// <returns></returns>
        public string GenerateSignature(string appSecret, string path, string timestamp, string token)
        {
            using var hmac = new HMACSHA256(Encoding.UTF8.GetBytes(appSecret));
            var data = $"{path.ToLower()}|{timestamp}|{token}";
            var hash = hmac.ComputeHash(Encoding.UTF8.GetBytes(data));
            return Convert.ToBase64String(hash);
        }

        public bool ValidateToken(string userid, string token)
        {
            var storedToken = _redis.StringGet($"token:{userid}");
            return storedToken == token;
        }

    }
}