<?php
declare(strict_types=1);

/**
 * The editor plugins in `data/plugins/`: one ES module per `.js` file, and every file there is
 * active. Read-only for now – putting a file there is done by hand, by the build and by the e2e
 * seeder. The folder is not served statically: a module is only ever handed out by its bare file
 * name, so no request can reach past it.
 */
final class PluginStore
{
    public function __construct(private readonly string $dir)
    {
    }

    /** A file name as it may be asked for: no path, no leading dot, `.js` at the end. */
    public static function isValidName(string $name): bool
    {
        return (bool) preg_match('/^[A-Za-z0-9][A-Za-z0-9._-]*\.js$/', $name);
    }

    /**
     * Sorted by file name, which is also the order the editor activates them in.
     *
     * @return list<array{file: string, bytes: int, updatedAt: int}>
     */
    public function list(): array
    {
        $files = is_dir($this->dir) ? scandir($this->dir) : [];
        $out = [];
        foreach ($files === false ? [] : $files as $file) {
            $path = "{$this->dir}/{$file}";
            if (!self::isValidName($file) || !is_file($path)) {
                continue;
            }
            $out[] = ['file' => $file, 'bytes' => (int) filesize($path), 'updatedAt' => (int) filemtime($path)];
        }
        usort($out, static fn (array $a, array $b): int => strcmp($a['file'], $b['file']));
        return $out;
    }

    /** The module's source, or null when there is no such plugin. */
    public function read(string $file): ?string
    {
        $path = "{$this->dir}/{$file}";
        if (!self::isValidName($file) || !is_file($path)) {
            return null;
        }
        $source = file_get_contents($path);
        return $source === false ? null : $source;
    }
}