internal async Task CreateCustomTokenAsync()

in FirebaseAdmin/FirebaseAdmin/Auth/Jwt/FirebaseTokenFactory.cs [122:174]
48 lines of code
8 McCabe index (conditional complexity)

        internal async Task<string> CreateCustomTokenAsync(
            string uid,
            IDictionary<string, object> developerClaims = null,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            if (string.IsNullOrEmpty(uid))
            {
                throw new ArgumentException("uid must not be null or empty");
            }
            else if (uid.Length > 128)
            {
                throw new ArgumentException("uid must not be longer than 128 characters");
            }

            if (developerClaims != null)
            {
                foreach (var entry in developerClaims)
                {
                    if (ReservedClaims.Contains(entry.Key))
                    {
                        throw new ArgumentException(
                            $"reserved claim {entry.Key} not allowed in developerClaims");
                    }
                }
            }

            var header = new JsonWebSignature.Header()
            {
                Algorithm = this.Signer.Algorithm,
                Type = "JWT",
            };

            var issued = (int)(this.Clock.UtcNow - UnixEpoch).TotalSeconds;
            var keyId = await this.Signer.GetKeyIdAsync(cancellationToken).ConfigureAwait(false);
            var payload = new CustomTokenPayload()
            {
                Uid = uid,
                Issuer = keyId,
                Subject = keyId,
                Audience = FirebaseAudience,
                IssuedAtTimeSeconds = issued,
                ExpirationTimeSeconds = issued + TokenDurationSeconds,
                TenantId = this.TenantId,
            };

            if (developerClaims != null && developerClaims.Count > 0)
            {
                payload.Claims = developerClaims;
            }

            return await JwtUtils.CreateSignedJwtAsync(
                header, payload, this.Signer, cancellationToken).ConfigureAwait(false);
        }