| 1 | /** |
| 2 | * Whether a visitor has agreed to site analytics, where the law asks |
| 3 | * first: the EU and EEA, the UK and Switzerland. The server decides from |
| 4 | * the visitor's country and marks the page (`<meta name="g1t-analytics" |
| 5 | * content="consent">`); the choice is kept in this browser's local |
| 6 | * storage. Safe to import on the server, where nothing is chosen. |
| 7 | */ |
| 8 | |
| 9 | /** Countries whose visitors are asked before analytics runs. */ |
| 10 | const ASK_FIRST = new Set([ |
| 11 | // The EU. |
| 12 | "AT", "BE", "BG", "HR", "CY", "CZ", "DK", "EE", "FI", "FR", "DE", "GR", "HU", "IE", "IT", "LV", "LT", "LU", |
| 13 | "MT", "NL", "PL", "PT", "RO", "SK", "SI", "ES", "SE", |
| 14 | // The rest of the EEA, the UK and Switzerland. |
| 15 | "IS", "LI", "NO", "GB", "CH", |
| 16 | ]); |
| 17 | |
| 18 | /** Whether a visitor from `country` (ISO 3166 alpha-2, as Cloudflare gives it) is asked first. */ |
| 19 | export function asksFirst(country: string | null | undefined): boolean { |
| 20 | return !!country && ASK_FIRST.has(country.toUpperCase()); |
| 21 | } |
| 22 | |
| 23 | /** |
| 24 | * Whether the visitor making `request` is asked first. Cloudflare sets the |
| 25 | * country header (replacing any the visitor sent); `cf` is the same answer. |
| 26 | */ |
| 27 | export function visitorAsksFirst(request: Request): boolean { |
| 28 | return asksFirst(request.headers.get("cf-ipcountry") ?? (request as Request & { cf?: { country?: string } }).cf?.country); |
| 29 | } |
| 30 | |
| 31 | /** The installation analytics runs on; anywhere else nothing is sent or asked. */ |
| 32 | export const ANALYTICS_HOST = "g1t.sh"; |
| 33 | |
| 34 | export function analyticsHere(): boolean { |
| 35 | return typeof window !== "undefined" && window.location.hostname === ANALYTICS_HOST; |
| 36 | } |
| 37 | |
| 38 | /** Whether this page was marked as one whose visitor is asked first. */ |
| 39 | export function consentRequired(): boolean { |
| 40 | return typeof document !== "undefined" && document.querySelector('meta[name="g1t-analytics"][content="consent"]') !== null; |
| 41 | } |
| 42 | |
| 43 | export type Choice = "yes" | "no" | null; |
| 44 | |
| 45 | const KEY = "g1t_analytics"; |
| 46 | let current: Choice | undefined; |
| 47 | const listeners = new Set<() => void>(); |
| 48 | |
| 49 | /** What this browser chose; null until it has. */ |
| 50 | export function choice(): Choice { |
| 51 | if (typeof window === "undefined") return null; |
| 52 | if (current === undefined) { |
| 53 | try { |
| 54 | const stored = window.localStorage.getItem(KEY); |
| 55 | current = stored === "yes" || stored === "no" ? stored : null; |
| 56 | } catch { |
| 57 | current = null; |
| 58 | } |
| 59 | } |
| 60 | return current; |
| 61 | } |
| 62 | |
| 63 | /** Record a choice, or null to ask again. */ |
| 64 | export function choose(next: Choice) { |
| 65 | current = next; |
| 66 | try { |
| 67 | if (next) window.localStorage.setItem(KEY, next); |
| 68 | else window.localStorage.removeItem(KEY); |
| 69 | } catch { |
| 70 | // No storage: the choice holds for this page only. |
| 71 | } |
| 72 | for (const listener of listeners) listener(); |
| 73 | } |
| 74 | |
| 75 | export function onChoice(listener: () => void): () => void { |
| 76 | listeners.add(listener); |
| 77 | return () => listeners.delete(listener); |
| 78 | } |
| 79 | |
| 80 | /** Whether analytics may run in this browser now. */ |
| 81 | export function allowed(): boolean { |
| 82 | return analyticsHere() && (!consentRequired() || choice() === "yes"); |
| 83 | } |