<?php

namespace App\Support\Qr;

class QrWifiPayload
{
    /**
     * Build a WiFi QR payload (ZXing MECARD format) for one-tap network join on scan.
     *
     * @param  array<string, mixed>  $content
     */
    public static function encode(array $content): string
    {
        $encryption = strtoupper(trim((string) ($content['encryption'] ?? 'WPA')));
        $auth = $encryption === 'NOPASS' ? 'nopass' : $encryption;
        if (! in_array($auth, ['WPA', 'WEP', 'nopass'], true)) {
            $auth = 'WPA';
        }

        $ssid = self::escape(trim((string) ($content['ssid'] ?? '')));
        $payload = 'WIFI:T:' . $auth . ';S:' . $ssid;

        if ($auth !== 'nopass') {
            $password = trim((string) ($content['password'] ?? ''));
            if ($password !== '') {
                $payload .= ';P:' . self::escape($password);
            }
        }

        if (filter_var($content['hidden'] ?? false, FILTER_VALIDATE_BOOL)) {
            $payload .= ';H:true';
        }

        return $payload . ';;';
    }

    private static function escape(string $value): string
    {
        return str_replace(
            ['\\', ';', ',', '"', ':'],
            ['\\\\', '\\;', '\\,', '\\"', '\\:'],
            $value
        );
    }
}