Verify Reddit identity before Matrix capture

src/services/account-auth-context.ts

@@ -33,6 +33,26 @@ export interface AccountAuthContextOptions {
   now?: () => number;
 }
 
+export interface CurrentAccountAuthentication {
+  getRedditUsername(): Promise<string | null>;
+  refreshMatrixCredentials(): Promise<{ userId: string } | null>;
+}
+
+export async function authenticateCurrentAccount(
+  authentication: CurrentAccountAuthentication,
+): Promise<AuthenticatedAccount | null> {
+  const redditUsername = await authentication.getRedditUsername();
+  if (!redditUsername) return null;
+
+  const credentials = await authentication.refreshMatrixCredentials();
+  if (!credentials?.userId) return null;
+  return {
+    accountId: credentials.userId,
+    redditUsername,
+    matrixUserId: credentials.userId,
+  };
+}
+
 export const denyAccountAuth: AccountAuthGate = {
   isFullyAuthenticated: () => false,
   invalidate: () => undefined,