<?php
/**
 * Pulls "recommend %", review count, and follower count from The Old
 * Fitz's Facebook Page via the Graph API, cached to a local JSON file so
 * we don't hit Facebook on every page load. Falls back to the numbers in
 * config.php whenever there's no access token yet, or the API call fails
 * for any reason — the homepage never breaks because of this.
 *
 * Known limitation: Facebook's newer thumbs-up/down "recommendation"
 * system (the "X% recommend (Y reviews)" wording used on the Page today)
 * doesn't have a confirmed, stable Graph API field the way star ratings
 * do. This code requests overall_star_rating/rating_count and converts
 * a star rating to a percentage if Facebook returns one; if the Page's
 * review data isn't exposed that way, recommend_pct/review_count will
 * silently stay at the config.php fallback while followers_count still
 * goes live. That's expected, not a bug — Meta's review-related API
 * access has gotten more restricted over time.
 */

function fritz_facebook_stats(): array {
    $fallback = [
        'recommend_pct' => FB_FALLBACK_RECOMMEND_PCT,
        'review_count'  => FB_FALLBACK_REVIEW_COUNT,
        'followers'     => FB_FALLBACK_FOLLOWERS,
        'source'        => 'fallback',
        'fetched_at'    => null,
    ];

    if (FB_PAGE_ACCESS_TOKEN === '') {
        return $fallback;
    }

    $cacheFile = __DIR__ . '/../cache/facebook-stats.json';

    if (is_file($cacheFile)) {
        $cached = json_decode((string) file_get_contents($cacheFile), true);
        if (is_array($cached) && (time() - ($cached['fetched_at'] ?? 0)) < FB_STATS_CACHE_TTL) {
            $cached['source'] = 'cache';
            return $cached;
        }
    }

    $fresh = fritz_fetch_facebook_stats($fallback);
    $fresh['fetched_at'] = time();

    $cacheDir = dirname($cacheFile);
    if (!is_dir($cacheDir)) {
        @mkdir($cacheDir, 0775, true);
    }
    @file_put_contents($cacheFile, json_encode($fresh));

    return $fresh;
}

function fritz_fetch_facebook_stats(array $fallback): array {
    if (!function_exists('curl_init')) {
        return $fallback;
    }

    $url = sprintf(
        'https://graph.facebook.com/v21.0/%s?fields=followers_count,overall_star_rating,rating_count&access_token=%s',
        FB_PAGE_ID,
        urlencode(FB_PAGE_ACCESS_TOKEN)
    );

    $ch = curl_init($url);
    curl_setopt_array($ch, [
        CURLOPT_RETURNTRANSFER => true,
        CURLOPT_TIMEOUT        => 5,
    ]);
    $body = curl_exec($ch);
    $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
    curl_close($ch);

    if ($body === false || $httpCode !== 200) {
        return $fallback;
    }

    $data = json_decode($body, true);
    if (!is_array($data) || isset($data['error'])) {
        return $fallback;
    }

    $recommendPct = isset($data['overall_star_rating'])
        ? (int) round(($data['overall_star_rating'] / 5) * 100)
        : $fallback['recommend_pct'];

    return [
        'recommend_pct' => $recommendPct,
        'review_count'  => $data['rating_count'] ?? $fallback['review_count'],
        'followers'     => $data['followers_count'] ?? $fallback['followers'],
        'source'        => 'live',
    ];
}