<?php
declare(strict_types=1);

header('Content-Type: application/json; charset=utf-8');
header('Cache-Control: no-store, no-cache, must-revalidate, max-age=0');
header('Pragma: no-cache');

$service = 'seoul';
$root = __DIR__;
$scanRoots = [
    '.' => ['php', 'js', 'css', 'webmanifest', 'svg', 'png', 'ico'],
];
$excludePrefixes = ['car/'];

function collect_asset_files(string $root, array $scanRoots, array $excludePrefixes): array
{
    $files = [];
    $rootPath = realpath($root);
    if (!$rootPath) {
        return $files;
    }

    foreach ($scanRoots as $relativeRoot => $extensions) {
        $base = realpath($rootPath . DIRECTORY_SEPARATOR . $relativeRoot);
        if (!$base || strpos($base, $rootPath) !== 0) {
            continue;
        }

        $allowed = array_fill_keys(array_map('strtolower', $extensions), true);
        $iterator = new RecursiveIteratorIterator(
            new RecursiveDirectoryIterator($base, FilesystemIterator::SKIP_DOTS)
        );

        foreach ($iterator as $file) {
            if (!$file instanceof SplFileInfo || !$file->isFile()) {
                continue;
            }

            $path = $file->getRealPath();
            if (!$path || strpos($path, $rootPath . DIRECTORY_SEPARATOR) !== 0) {
                continue;
            }

            $relativePath = str_replace(DIRECTORY_SEPARATOR, '/', ltrim(str_replace($rootPath, '', $path), DIRECTORY_SEPARATOR));
            foreach ($excludePrefixes as $prefix) {
                if (strpos($relativePath, $prefix) === 0) {
                    continue 2;
                }
            }

            $extension = strtolower($file->getExtension());
            if (isset($allowed[$extension])) {
                $files[] = $path;
            }
        }
    }

    sort($files, SORT_STRING);
    return array_values(array_unique($files));
}

clearstatcache();
$rootPath = realpath($root);
$fingerprints = [];

foreach (collect_asset_files($root, $scanRoots, $excludePrefixes) as $fullPath) {
    $relativePath = ltrim(str_replace($rootPath ?: $root, '', $fullPath), DIRECTORY_SEPARATOR);
    $fileHash = is_readable($fullPath) ? (hash_file('sha256', $fullPath) ?: 'hash-failed') : 'unreadable';
    $fingerprints[] = implode('|', [
        str_replace(DIRECTORY_SEPARATOR, '/', $relativePath),
        (string)filesize($fullPath),
        (string)filemtime($fullPath),
        $fileHash,
    ]);
}

echo json_encode([
    'result' => 'ok',
    'service' => $service,
    'version' => hash('sha256', implode("\n", $fingerprints)),
    'count' => count($fingerprints),
    'generatedAt' => time(),
], JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);