using System.Linq;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Threading;
using System.Threading.Tasks;

namespace Sony.Filtr.AppleMusic
{
    public class AppleMusicAuthClientCredentialsHttpMessageHandler : DelegatingHandler
    {
        private readonly AppleMusicTokenGenerator _tokenGenerator;

        public AppleMusicAuthClientCredentialsHttpMessageHandler(AppleMusicTokenGenerator tokenGenerator, HttpMessageHandler httpMessageHandler): base(httpMessageHandler)
        {
            _tokenGenerator = tokenGenerator;
        }

        protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
        {
            if (request.Headers.Authorization == null)
            {
                request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", GetJwtToken());
            }
            
            var response = await base.SendAsync(request, cancellationToken);

            return response;
        }


        private string _jwtTokenString;

        private string GetJwtToken()
        {
            if (_jwtTokenString != null)
                return _jwtTokenString;

            _jwtTokenString = _tokenGenerator.GetJwtToken();

            return _jwtTokenString;
        }
    }
}