ic-ctbu-backend/lib/Lepao/ipRegionLookup.js

/**
 * 与 requestLog 相同：本地 ip2region.xdb，仅支持 IPv4。
 */
const path = require('path')
const ipSearcher = require('../../plugin/ip2region')

let _searcher = null

function getSearcher() {
    if (!_searcher) {
        _searcher = ipSearcher.newWithFileOnly(path.join(__dirname, '../../plugin/ip2region/ip2region.xdb'))
    }
    return _searcher
}

/**
 * @param {string|null|undefined} ip
 * @returns {Promise<string>} 可读属地，失败或非法为「未知」
 */
async function lookupIpv4Region(ip) {
    const s = String(ip || '').trim()
    if (!s || !ipSearcher.isValidIp(s)) return '未知'
    try {
        const r = await getSearcher().search(s)
        const raw = r?.region
        if (!raw || typeof raw !== 'string') return '未知'
        return raw.split('|').filter(Boolean).join(' · ')
    } catch {
        return '未知'
    }
}

/**
 * 从 server 字段形如 host:port 取 IP
 */
function extractIpFromServer(server) {
    if (!server || typeof server !== 'string') return null
    const host = server.split(':')[0].trim()
    return ipSearcher.isValidIp(host) ? host : null
}

module.exports = {
    lookupIpv4Region,
    extractIpFromServer
}