fix: correctly passthrough and handle a new OIDC redirect_uri system

app/utils/oidc-state.ts

@@ -0,0 +1,46 @@
+import { createCookie } from 'react-router';
+import type { HeadplaneConfig } from '~/server/config/config-schema';
+
+export interface OidcStateCookie {
+	nonce: string;
+	state: string;
+	redirect_uri: string;
+}
+
+export function createOidcStateCookie(config: HeadplaneConfig) {
+	const cookie = createCookie('__oidc_state', {
+		httpOnly: true,
+		maxAge: 1800,
+		secure: config.server.cookie_secure,
+		domain: config.server.cookie_domain,
+		path: `${__PREFIX__}/oidc/callback`,
+	});
+
+	return {
+		...cookie,
+		serialize: async (value: OidcStateCookie): Promise<string> => {
+			return cookie.serialize(value);
+		},
+
+		parse: async (
+			cookieHeader: string | null,
+		): Promise<OidcStateCookie | null> => {
+			const parsed = await cookie.parse(cookieHeader);
+			if (
+				parsed == null ||
+				typeof parsed !== 'object' ||
+				typeof parsed.nonce !== 'string' ||
+				typeof parsed.state !== 'string' ||
+				typeof parsed.redirect_uri !== 'string'
+			) {
+				return null;
+			}
+
+			return {
+				nonce: parsed.nonce,
+				state: parsed.state,
+				redirect_uri: parsed.redirect_uri,
+			};
+		},
+	};
+}