<?php
/**
 * Demo helper
 * ───────────
 * Resolves which *connected* school the demo checkout pages should run as.
 *
 * The PayPal widget (paypal-checkout-widget.php) only renders buttons for a
 * school that has a saved merchant_id and is PayPal-ready. The demo pages used
 * to hardcode "Demo School", which is never connected — so the buttons silently
 * never appeared. These helpers let the demos auto-pick a school that can
 * actually accept PayPal, so the page is testable out of the box.
 */

/** All onboarded schools keyed by school name. */
function pp_demo_schools(): array
{
    $file = __DIR__ . '/data/school_merchants.json';
    if (!file_exists($file)) {
        return [];
    }
    return json_decode(file_get_contents($file), true) ?: [];
}

/**
 * Decide which school the demo should check out as.
 *
 * Priority:
 *   1. An explicit ?school= value, if that school is actually connected.
 *   2. Otherwise the first connected school that is PayPal-ready.
 *   3. null when no school can accept PayPal yet.
 */
function pp_demo_resolve_school(?string $requested = null): ?string
{
    $merchants = pp_demo_schools();

    // Honour an explicit request only if that school is connected.
    if ($requested !== null && $requested !== '' && isset($merchants[$requested])) {
        return $requested;
    }

    // Auto-pick the first school that can actually receive payments.
    foreach ($merchants as $name => $rec) {
        if (empty($rec['merchant_id'])) {
            continue;
        }
        // paypal_ready may be absent (status never checked) — treat absence as ready.
        if (array_key_exists('paypal_ready', $rec) && !$rec['paypal_ready']) {
            continue;
        }
        if (!empty($rec['consent_revoked'])) {
            continue;
        }
        return $name;
    }

    return null;
}