Automatically detect token kind (#764)

DiscordChatExporter.Core/Discord/AuthToken.cs

@@ -1,12 +0,0 @@
-using System.Net.Http.Headers;
-
-namespace DiscordChatExporter.Core.Discord;
-
-public record AuthToken(AuthTokenKind Kind, string Value)
-{
-    public AuthenticationHeaderValue GetAuthenticationHeader() => Kind switch
-    {
-        AuthTokenKind.Bot => new AuthenticationHeaderValue("Bot", Value),
-        _ => new AuthenticationHeaderValue(Value)
-    };
-}

DiscordChatExporter.Core/Discord/DiscordClient.cs

@@ -3,6 +3,7 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Net;
 using System.Net.Http;
+using System.Net.Http.Headers;
 using System.Runtime.CompilerServices;
 using System.Text.Json;
 using System.Threading;
@@ -18,10 +19,30 @@ namespace DiscordChatExporter.Core.Discord;
 
 public class DiscordClient
 {
-    private readonly AuthToken _token;
+    private readonly string _token;
     private readonly Uri _baseUri = new("https://discord.com/api/v8/", UriKind.Absolute);
 
-    public DiscordClient(AuthToken token) => _token = token;
+    private TokenKind _tokenKind = TokenKind.Unknown;
+
+    public DiscordClient(string token) => _token = token;
+
+    private async ValueTask<HttpResponseMessage> GetResponseAsync(
+        string url,
+        bool isBot,
+        CancellationToken cancellationToken = default)
+    {
+        using var request = new HttpRequestMessage(HttpMethod.Get, new Uri(_baseUri, url));
+
+        request.Headers.Authorization = isBot
+            ? new AuthenticationHeaderValue("Bot", _token)
+            : new AuthenticationHeaderValue(_token);
+
+        return await Http.Client.SendAsync(
+            request,
+            HttpCompletionOption.ResponseHeadersRead,
+            cancellationToken
+        );
+    }
 
     private async ValueTask<HttpResponseMessage> GetResponseAsync(
         string url,
@@ -29,14 +50,33 @@ public class DiscordClient
     {
         return await Http.ResponsePolicy.ExecuteAsync(async innerCancellationToken =>
         {
-            using var request = new HttpRequestMessage(HttpMethod.Get, new Uri(_baseUri, url));
-            request.Headers.Authorization = _token.GetAuthenticationHeader();
+            if (_tokenKind == TokenKind.User)
+                return await GetResponseAsync(url, false, innerCancellationToken);
 
-            return await Http.Client.SendAsync(
-                request,
-                HttpCompletionOption.ResponseHeadersRead,
-                innerCancellationToken
-            );
+            if (_tokenKind == TokenKind.Bot)
+                return await GetResponseAsync(url, true, innerCancellationToken);
+
+            // Try to authenticate as user
+            var userResponse = await GetResponseAsync(url, false, innerCancellationToken);
+            if (userResponse.StatusCode != HttpStatusCode.Unauthorized)
+            {
+                _tokenKind = TokenKind.User;
+                return userResponse;
+            }
+
+            userResponse.Dispose();
+
+            // Otherwise, try to authenticate as bot
+            var botResponse = await GetResponseAsync(url, true, innerCancellationToken);
+            if (botResponse.StatusCode != HttpStatusCode.Unauthorized)
+            {
+                _tokenKind = TokenKind.Bot;
+                return botResponse;
+            }
+
+            // The token is probably invalid altogether.
+            // Return the last response anyway, upstream should handle the error.
+            return botResponse;
         }, cancellationToken);
     }
 

DiscordChatExporter.Core/Discord/TokenKind.cs

@@ -1,7 +1,8 @@
 namespace DiscordChatExporter.Core.Discord;
 
-public enum AuthTokenKind
+public enum TokenKind
 {
+    Unknown,
     User,
     Bot
 }

DiscordChatExporter.Core/Exporting/ChannelExporter.cs

@@ -17,8 +17,6 @@ public class ChannelExporter
 
     public ChannelExporter(DiscordClient discord) => _discord = discord;
 
-    public ChannelExporter(AuthToken token) : this(new DiscordClient(token)) {}
-
     public async ValueTask ExportChannelAsync(
         ExportRequest request,
         IProgress<double>? progress = null,