refactor: Simplify Discourse OAuth callback with CallbackHandler component

src/app/(oauth)/q58/callback/page.tsx

@@ -1,12 +1,10 @@
 import { Suspense } from "react";
-import { redirect } from "next/navigation";
-import { signIn } from "@/auth";
 
 import { discourseCallbackVerify } from "@/lib/discourse/verify";
 import { findAuthorization } from "@/lib/dto/authorization";
 import { getClientByClientId } from "@/lib/dto/client";
 import { getAuthorizeUrl } from "@/lib/oauth/authorize-url";
-import { AuthorizationCard } from "@/components/auth/authorization-card";
+import { CallbackHandler } from "@/components/auth/callback-handler";
 
 export interface DiscourseCallbackParams extends Record<string, string> {
   sig: string;
@@ -34,32 +32,25 @@ export default async function DiscourseCallbackPage({
     searchParams.sig,
   );
 
-  // 设置用户会话
-  await signIn("credentials", {
-    id: user.id,
-    username: user.username,
-    email: user.email,
-    name: user.name,
-    avatarUrl: user.avatarUrl,
-    role: user.role,
-    moderator: user.moderator,
-    groups: JSON.stringify(user.groups),
-    redirect: false,
-  });
-
   // check authorization
   const authorization = await findAuthorization(user.id, client.id);
+  let redirectUrl: string | undefined;
 
   if (authorization) {
-    const redirectUrl = await getAuthorizeUrl(oauthParams);
+    redirectUrl = await getAuthorizeUrl(oauthParams);
-    return redirect(redirectUrl);
   }
 
   return (
     <main className="flex min-h-screen flex-col items-center justify-center">
       <div className="flex items-center justify-center">
         <Suspense>
-          <AuthorizationCard client={client} oauthParams={searchParams.oauth} />
+          <CallbackHandler
+            client={client}
+            user={user}
+            oauthParams={searchParams.oauth}
+            hasAuthorization={!!authorization}
+            redirectUrl={redirectUrl}
+          />
         </Suspense>
       </div>
     </main>

src/components/auth/callback-handler.tsx

@@ -0,0 +1,76 @@
+"use client";
+
+import { useEffect, useState } from "react";
+import { useRouter } from "next/navigation";
+import { signIn } from "@/auth";
+import { Client } from "@prisma/client";
+
+import { AuthorizationCard } from "./authorization-card";
+
+interface CallbackHandlerProps {
+  client: Client;
+  user: any;
+  oauthParams: string;
+  hasAuthorization: boolean;
+  redirectUrl?: string;
+}
+
+export function CallbackHandler({
+  client,
+  user,
+  oauthParams,
+  hasAuthorization,
+  redirectUrl,
+}: CallbackHandlerProps) {
+  const router = useRouter();
+  const [error, setError] = useState<string | null>(null);
+  const [isProcessing, setIsProcessing] = useState(true);
+
+  useEffect(() => {
+    async function handleAuth() {
+      try {
+        // 设置用户会话
+        await signIn("credentials", {
+          id: user.id,
+          username: user.username,
+          email: user.email,
+          name: user.name,
+          avatarUrl: user.avatarUrl,
+          role: user.role,
+          moderator: user.moderator,
+          groups: JSON.stringify(user.groups),
+          redirect: false,
+        });
+
+        // 如果已经授权过，直接重定向
+        if (hasAuthorization && redirectUrl) {
+          router.push(redirectUrl);
+          return;
+        }
+
+        setIsProcessing(false);
+      } catch (error) {
+        console.error("Auth error:", error);
+        setError("认证过程中发生错误");
+        setIsProcessing(false);
+      }
+    }
+
+    handleAuth();
+  }, []);
+
+  if (error) {
+    return <div className="text-red-500">{error}</div>;
+  }
+
+  if (isProcessing) {
+    return (
+      <div className="flex items-center justify-center">
+        <div className="h-8 w-8 animate-spin rounded-full border-4 border-primary border-t-transparent"></div>
+        <span className="ml-2">处理中...</span>
+      </div>
+    );
+  }
+
+  return <AuthorizationCard client={client} oauthParams={oauthParams} />;
+}