// Pure, React-free helpers for the identity-proofing return flow (Phase 2, full-proxy hard-gate).
// Kept dependency-free so it unit-tests without dragging the services/hooks barrel - mirrors
// utils/paymentFlow.ts for the payment-checkout return flow, and lives here (rather than inside
// services/ProofingService.tsx or hooks/useProofingReturn.tsx) specifically so BOTH of those can
// import it without creating a services<->hooks circular import.
const RETURN_MARKER_PARAM = 'proofing_return';

// Build the return URL handed to POST /proofing/session as `returnUrl`. Mirrors paymentFlow.ts
// buildCheckoutUrls (origin + pathname + hash - the app is a HashRouter SPA, so the fragment must be
// preserved for the browser to land back on the right in-app route after Stripe) with the
// `proofing_return=1` marker appended so useProofingReturn can detect the return. If the current hash
// already carries its own query (`#/profile?foo=bar`) the marker is appended with `&` instead of `?`.
export const buildProofingReturnUrl = (origin: string, pathname: string, hash: string): string => {
    const separator = hash.includes('?') ? '&' : '?';
    return `${origin}${pathname}${hash}${separator}${RETURN_MARKER_PARAM}=1`;
};

// Detect the marker on return from Stripe Identity.
export const hasProofingReturnMarker = (href: string): boolean => {
    return new RegExp(`[?&]${RETURN_MARKER_PARAM}=1(?:&|#|$)`).test(href ?? '');
};

// Strip the marker (and tidy any dangling separators it leaves behind) so a manual refresh mid-poll
// doesn't restart the whole thing.
export const stripProofingReturnMarker = (href: string): string => {
    let out = href ?? '';
    out = out.replace(new RegExp(`([?&])${RETURN_MARKER_PARAM}=[^&#]*`, 'g'), '$1');
    out = out.replace(/([?&])&+/g, '$1'); // collapse "?&""?" and "&&""&"
    out = out.replace(/[?&]$/g, ''); // drop a now-empty trailing "?" or "&"
    return out;
};