| 1 | import { env } from "cloudflare:workers"; |
| 2 | import { |
| 3 | type MiddlewareFunction, |
| 4 | type RouterContextProvider, |
| 5 | createContext, |
| 6 | data, |
| 7 | redirect, |
| 8 | } from "react-router"; |
| 9 | |
| 10 | import { type Result, type User, type Viewer, httpStatus } from "@g1t/contracts"; |
| 11 | |
| 12 | const SESSION_COOKIE = "g1t_session"; |
| 13 | const SESSION_TTL_SECONDS = 30 * 24 * 60 * 60; |
| 14 | |
| 15 | const viewerContext = createContext<Viewer>(null); |
| 16 | |
| 17 | function sessionToken(request: Request): string | null { |
| 18 | const cookies = request.headers.get("cookie") ?? ""; |
| 19 | const match = new RegExp(`(?:^|; )${SESSION_COOKIE}=([0-9a-f]{64})`).exec(cookies); |
| 20 | return match ? match[1] : null; |
| 21 | } |
| 22 | |
| 23 | function sessionCookie(value: string, maxAge: number): string { |
| 24 | return `${SESSION_COOKIE}=${value}; Path=/; HttpOnly; Secure; SameSite=Lax; Max-Age=${maxAge}`; |
| 25 | } |
| 26 | |
| 27 | /** Root middleware: resolves the signed-in user once per request. */ |
| 28 | export const viewerMiddleware: MiddlewareFunction<Response> = async ({ |
| 29 | request, |
| 30 | context, |
| 31 | }) => { |
| 32 | const token = sessionToken(request); |
| 33 | if (token) { |
| 34 | context.set(viewerContext, await env.IDENTITY.userForSession(token)); |
| 35 | } |
| 36 | }; |
| 37 | |
| 38 | type Context = Readonly<RouterContextProvider>; |
| 39 | |
| 40 | export function getViewer(context: Context): Viewer { |
| 41 | return context.get(viewerContext); |
| 42 | } |
| 43 | |
| 44 | export function requireUser(context: Context, request: Request): User { |
| 45 | const viewer = getViewer(context); |
| 46 | if (!viewer) { |
| 47 | const next = new URL(request.url).pathname; |
| 48 | throw redirect(`/login?next=${encodeURIComponent(next)}`); |
| 49 | } |
| 50 | return viewer; |
| 51 | } |
| 52 | |
| 53 | /** `Set-Cookie` value that starts a session. */ |
| 54 | export function startSession(token: string): string { |
| 55 | return sessionCookie(token, SESSION_TTL_SECONDS); |
| 56 | } |
| 57 | |
| 58 | /** Ends the session and returns the `Set-Cookie` value that clears it. */ |
| 59 | export async function endSession(request: Request): Promise<string> { |
| 60 | const token = sessionToken(request); |
| 61 | if (token) await env.IDENTITY.signOut(token); |
| 62 | return sessionCookie("", 0); |
| 63 | } |
| 64 | |
| 65 | /** Rejects cross-site form posts; call at the top of every action. */ |
| 66 | export function assertSameOrigin(request: Request): void { |
| 67 | const origin = request.headers.get("origin"); |
| 68 | if (origin && origin !== new URL(request.url).origin) { |
| 69 | throw new Response("Cross-origin request rejected", { status: 403 }); |
| 70 | } |
| 71 | } |
| 72 | |
| 73 | /** The value of a service result, or the matching HTTP error. */ |
| 74 | export function unwrap<T>(result: Result<T>): T { |
| 75 | if (result.ok) return result.value; |
| 76 | throw data(result.error.message, { status: httpStatus(result.error) }); |
| 77 | } |