<?php
header('Content-Type: application/json; charset=utf-8');

$avisosDir = __DIR__ . '/avisos';
$avisosUrl = 'app/avisos/';
$timezone = new DateTimeZone('America/La_Paz');
$today = new DateTimeImmutable('today', $timezone);
$activeAvisos = [];

if (is_dir($avisosDir)) {
    $files = scandir($avisosDir);

    foreach ($files as $file) {
        if (!preg_match('/^aviso-(\d{2})-(\d{2})-(\d{2})\.(jpg|jpeg|png|webp)$/i', $file, $matches)) {
            continue;
        }

        $day = (int) $matches[1];
        $month = (int) $matches[2];
        $year = 2000 + (int) $matches[3];

        if (!checkdate($month, $day, $year)) {
            continue;
        }

        $expiresAt = DateTimeImmutable::createFromFormat(
            '!Y-m-d',
            sprintf('%04d-%02d-%02d', $year, $month, $day),
            $timezone
        );

        if ($expiresAt && $expiresAt >= $today) {
            $activeAvisos[] = [
                'file' => $file,
                'url' => $avisosUrl . rawurlencode($file),
                'expires' => $expiresAt->format('Y-m-d'),
            ];
        }
    }
}

usort($activeAvisos, function ($a, $b) {
    return strcmp($b['expires'], $a['expires']);
});

echo json_encode([
    'active' => !empty($activeAvisos),
    'aviso' => $activeAvisos[0] ?? null,
]);