using Microsoft.AspNetCore.Authentication;
using Microsoft.AspNetCore.Authentication.OAuth;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;
using Newtonsoft.Json.Linq;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Security.Claims;
using System.Text.Encodings.Web;
using System.Threading.Tasks;

namespace Discord.OAuth2
{
    internal class DiscordHandler : OAuthHandler<DiscordOptions>
    {
        public DiscordHandler(IOptionsMonitor<DiscordOptions> options, ILoggerFactory logger, UrlEncoder encoder, ISystemClock clock)
            : base(options, logger, encoder, clock)
        {
        }

        protected override async Task<AuthenticationTicket> CreateTicketAsync(ClaimsIdentity identity, AuthenticationProperties properties, OAuthTokenResponse tokens)
        {
            var request = new HttpRequestMessage(HttpMethod.Get, Options.UserInformationEndpoint);
            request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", tokens.AccessToken);
            request.Headers.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));

            var response = await Backchannel.SendAsync(request, Context.RequestAborted);
            if (!response.IsSuccessStatusCode)
                throw new HttpRequestException($"Failed to retrieve Discord user information ({response.StatusCode}).");

            var payload = JObject.Parse(await response.Content.ReadAsStringAsync());

            var context = new OAuthCreatingTicketContext(new ClaimsPrincipal(identity), properties, Context, Scheme, Options, Backchannel, tokens, payload);
            context.RunClaimActions();

            await Events.CreatingTicket(context);
            return new AuthenticationTicket(context.Principal, context.Properties, Scheme.Name);
        }
    }
}