Amazon.SellingPartnerApi.API/Amazon.SellingPartnerApiSDK/Services/TokenGeneration.cs

using System;
using System.Collections.Generic;
using System.Threading;
using System.Threading.Tasks;
using Amazon.SellingPartnerApiSDK.AmazonSpApiSDK.Models.Token;
using Amazon.SellingPartnerApiSDK.AmazonSpApiSDK.Runtime;
using Amazon.SellingPartnerApiSDK.Misc;

namespace Amazon.SellingPartnerApiSDK.Services
{
    public static class TokenGeneration
    {
        public static async Task<TokenResponse> RefreshAccessTokenAsync(AmazonCredential credentials,
            CacheTokenData.TokenDataType tokenDataType = CacheTokenData.TokenDataType.Normal, CancellationToken cancellationToken = default)
        {
            var lwaCredentials = new LWAAuthorizationCredentials()
            {
                ClientId = credentials.ClientId,
                ClientSecret = credentials.ClientSecret,
                Endpoint = new Uri(Constants.AmazonTokenEndPoint),
                RefreshToken = credentials.RefreshToken,
                Scopes = null
            };
            if (tokenDataType == CacheTokenData.TokenDataType.Grantless)
                lwaCredentials.Scopes = new List<string>()
                    { ScopeConstants.ScopeMigrationAPI, ScopeConstants.ScopeNotificationsAPI };

            var client = new LWAClient(lwaCredentials, credentials.ProxyAddress);
            var accessToken = await client.GetAccessTokenAsync(cancellationToken);

            return accessToken;
        }
    }
}