feat: add authentication

routes/api/auth/login.ts

@@ -0,0 +1,29 @@
+import { Handlers } from "$fresh/server.ts";
+import { oauth2Client } from "@lib/auth.ts";
+import { sha256 } from "@lib/string.ts";
+import { setCookie } from "https://deno.land/std@0.197.0/http/cookie.ts";
+
+export const codeChallengeMap = new Map();
+
+export const handler: Handlers = {
+  async GET() {
+    const { codeVerifier, uri } = await oauth2Client.code.getAuthorizationUri();
+
+    const codeChallenge = uri.searchParams.get("code_challenge");
+    if (!codeChallenge) return new Response();
+
+    codeChallengeMap.set(codeChallenge, codeVerifier);
+
+    const headers = new Headers();
+    setCookie(headers, {
+      name: "code_challenge",
+      value: codeChallenge,
+    });
+    headers.append("location", uri.href);
+
+    return new Response(null, {
+      headers,
+      status: 302,
+    });
+  },
+};