Create Analytics Session

curl -X POST https://api.bio.re/api/v1/analytics/session \
  -H 'Content-Type: application/json' \
  -d '{
    "visitorId": "anon-localStorage-uuid",
    "landingPage": "https://bio.re/alice",
    "consentAnalytics": "granted",
    "referrer": "https://www.instagram.com/alice",
    "utmSource": "instagram",
    "utmMedium": "story",
    "utmCampaign": "spring-launch",
    "screenWidth": 390,
    "screenHeight": 844,
    "language": "en-US",
    "bioPageId": "11111111-2222-3333-4444-555555555555",
    "trackingToken": "<32-hex-from-SSR-html>"
  }'

type CreateSessionInput = {
  visitorId: string;
  landingPage: string;
  consentAnalytics: 'granted' | 'denied' | string;  // must be 'granted'
  bioPageId?: string;
  creatorId?: string;
  referrer?: string;
  utmSource?: string;
  utmMedium?: string;
  utmCampaign?: string;
  utmTerm?: string;
  utmContent?: string;
  trackingToken?: string;
  device?: string;
  browser?: string;
  os?: string;
  osVersion?: string;
  screenWidth?: number;
  screenHeight?: number;
  connectionType?: string;
  timezone?: string;
  language?: string;
};

type CreateSessionResult = { id: string | null; createdAt?: string };

async function createSession(input: CreateSessionInput): Promise<CreateSessionResult> {
  const res = await fetch('https://api.bio.re/api/v1/analytics/session', {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify(input),
  });
  const json = await res.json();
  return json.data; // { id: string | null, createdAt? }
}

// 1. Read consent state from your cookie banner / preference store.
const consent = readAnalyticsConsent(); // 'granted' | 'denied'

// 2. Stable anonymous id from localStorage.
const visitorId = (() => {
  let v = localStorage.getItem('bre.vid');
  if (!v) {
    v = crypto.randomUUID();
    localStorage.setItem('bre.vid', v);
  }
  return v;
})();

// 3. Open the session — `id: null` is a soft no-op, don't surface as an error.
const { id: sessionId } = await createSession({
  visitorId,
  landingPage: location.href,
  consentAnalytics: consent,
  referrer: document.referrer || undefined,
  utmSource: new URL(location.href).searchParams.get('utm_source') || undefined,
  bioPageId: window.__BIO_PAGE_ID__,                  // injected by SSR
  trackingToken: window.__TRACKING_TOKEN__,           // injected by SSR
  screenWidth: screen.width,
  screenHeight: screen.height,
  language: navigator.language,
  timezone: Intl.DateTimeFormat().resolvedOptions().timeZone,
});

// 4. If we got an id, instrument the rest of the page lifecycle.
if (sessionId) {
  recordPageView({ sessionId, url: location.href, path: location.pathname });
  setInterval(() => sessionHeartbeat(sessionId), 30_000);
}