<?php

namespace App\Support;

use Illuminate\Http\Request;

/**
 * Cloudflare CF-IPCountry: ISO 3166-1 alpha-2, plus T1 (Tor) and XX (unknown).
 */
final class CfIpCountry
{
    public static function fromRequest(Request $request): ?string
    {
        return self::normalize($request->headers->get('CF-IPCountry'));
    }

    public static function normalize(?string $raw): ?string
    {
        $code = strtoupper(trim((string) $raw));
        if ($code === 'T1') {
            return 'T1';
        }
        if (preg_match('/^[A-Z]{2}$/', $code) !== 1) {
            return null;
        }

        return $code;
    }

    public static function label(?string $code): string
    {
        $code = self::normalize($code);
        if ($code === null) {
            return '';
        }

        return self::names()[$code] ?? $code;
    }

    /** @return array<string, string> */
    public static function names(): array
    {
        return [
            'AE' => '阿联酋',
            'AU' => '澳大利亚',
            'BR' => '巴西',
            'CA' => '加拿大',
            'CN' => '中国',
            'DE' => '德国',
            'ES' => '西班牙',
            'FR' => '法国',
            'GB' => '英国',
            'HK' => '香港',
            'ID' => '印尼',
            'IN' => '印度',
            'IT' => '意大利',
            'JP' => '日本',
            'KR' => '韩国',
            'MO' => '澳门',
            'MY' => '马来西亚',
            'NL' => '荷兰',
            'PH' => '菲律宾',
            'RU' => '俄罗斯',
            'SA' => '沙特',
            'SG' => '新加坡',
            'TH' => '泰国',
            'TR' => '土耳其',
            'TW' => '台湾',
            'US' => '美国',
            'VN' => '越南',
            'T1' => 'Tor',
            'XX' => '未知',
        ];
    }
}