<?php

declare(strict_types=1);

namespace Box\Mod\Mailgateway;

class RuntimeConfig
{
    public static function get(string $key): mixed
    {
        static $settings = null;
        $settings ??= self::load(__DIR__ . '/config.php');
        return $settings[$key] ?? throw new \RuntimeException('Unknown Mail Gateway operational setting: ' . $key);
    }

    public static function load(string $path): array
    {
        $settings = require $path;
        if (!is_array($settings)) {
            throw new \RuntimeException('Mail Gateway config.php must return an array');
        }
        foreach (['poll_interval_seconds', 'messages_per_mailbox', 'poll_budget_seconds',
            'imap_timeout_seconds', 'max_message_bytes', 'max_ticket_body_bytes',
            'notification_cooldown_seconds', 'composer_timeout_seconds'] as $key) {
            if (!isset($settings[$key]) || !is_int($settings[$key]) || $settings[$key] < 1) {
                throw new \RuntimeException('Mail Gateway config.php requires a positive integer for ' . $key);
            }
        }
        if ($settings['max_ticket_body_bytes'] > 65535) {
            throw new \RuntimeException('Mail Gateway ticket body limit cannot exceed 65535 bytes');
        }
        foreach (['php_cli_paths', 'composer_paths'] as $key) {
            if (!isset($settings[$key]) || !is_array($settings[$key]) || $settings[$key] === []) {
                throw new \RuntimeException('Mail Gateway config.php requires executable paths for ' . $key);
            }
            foreach ($settings[$key] as $value) {
                if (!is_string($value) || !str_starts_with($value, '/') || str_contains($value, "\0")) {
                    throw new \RuntimeException('Mail Gateway executable paths must be absolute paths');
                }
            }
        }
        return $settings;
    }
}