Add OIDC authentification in project

src/app/api/auth/oidc/authorize/route.ts

@@ -0,0 +1,40 @@
+import { NextRequest } from 'next/server';
+import {
+  getEffectiveOIDCConfig,
+  generateState,
+  generateCodeVerifier,
+  generateCodeChallenge,
+  getAuthorizationUrl,
+} from '@/lib/oidc';
+import { json, badRequest } from '@/lib/response';
+
+export const runtime = 'nodejs';
+
+export async function GET(request: NextRequest) {
+  const cfg = await getEffectiveOIDCConfig();
+
+  if (!cfg.enabled) {
+    return badRequest('OIDC is not enabled');
+  }
+
+  const url = new URL(request.url);
+  const returnUrl = url.searchParams.get('returnUrl') || '/dashboard';
+
+  const state = await generateState();
+  const codeVerifier = await generateCodeVerifier();
+  const codeChallenge = await generateCodeChallenge(codeVerifier);
+
+  const authUrl = await getAuthorizationUrl(cfg, state, codeChallenge);
+
+  const stateData = Buffer.from(
+    JSON.stringify({
+      state,
+      codeVerifier,
+      returnUrl,
+    }),
+  ).toString('base64url');
+
+  const finalAuthUrl = authUrl.replace(`state=${state}`, `state=${stateData}`);
+
+  return json({ url: finalAuthUrl });
+}