'use strict';

exports = module.exports = {
    sync
};

const apps = require('./apps.js'),
    assert = require('assert'),
    constants = require('./constants.js'),
    debug = require('debug')('box:dyndns'),
    dns = require('./dns.js'),
    eventlog = require('./eventlog.js'),
    paths = require('./paths.js'),
    safe = require('safetydance'),
    settings = require('./settings.js'),
    sysinfo = require('./sysinfo.js');

// called for dynamic dns setups where we have to update the IP
async function sync(auditSource) {
    assert.strictEqual(typeof auditSource, 'object');

    const ipv4 = await sysinfo.getServerIPv4();
    const ipv6 = await sysinfo.getServerIPv6();

    const info = safe.JSON.parse(safe.fs.readFileSync(paths.DYNDNS_INFO_FILE, 'utf8')) || { ipv4: null, ipv6: null };
    if (info.ip) { // legacy cache file
        info.ipv4 = info.ip;
        delete info.ip;
    }
    const ipv4Changed = info.ipv4 !== ipv4;
    const ipv6Changed = ipv6 && info.ipv6 !== ipv6; // both should be RFC 5952 format

    if (!ipv4Changed && !ipv6Changed) {
        debug(`refreshDNS: no change in IP ipv4: ${ipv4} ipv6: ${ipv6}`);
        return;
    }

    debug(`refreshDNS: updating IP from ${info.ipv4} to ipv4: ${ipv4} (changed: ${ipv4Changed}) ipv6: ${ipv6} (changed: ${ipv6Changed})`);
    if (ipv4Changed) await dns.upsertDnsRecords(constants.DASHBOARD_LOCATION, settings.dashboardDomain(), 'A', [ ipv4 ]);
    if (ipv6Changed) await dns.upsertDnsRecords(constants.DASHBOARD_LOCATION, settings.dashboardDomain(), 'AAAA', [ ipv6 ]);

    const result = await apps.list();
    for (const app of result) {
        // do not change state of installing apps since apptask will error if dns record already exists
        if (app.installationState !== apps.ISTATE_INSTALLED) continue;

        if (ipv4Changed) await dns.upsertDnsRecords(app.subdomain, app.domain, 'A', [ ipv4 ]);
        if (ipv6Changed) await dns.upsertDnsRecords(app.subdomain, app.domain, 'AAAA', [ ipv6 ]);
    }

    debug('refreshDNS: updated apps');

    await eventlog.add(eventlog.ACTION_DYNDNS_UPDATE, auditSource, { fromIpv4: info.ipv4, fromIpv6: info.ipv6, toIpv4: ipv4, toIpv6: ipv6 });
    info.ipv4 = ipv4;
    info.ipv6 = ipv6;
    safe.fs.writeFileSync(paths.DYNDNS_INFO_FILE, JSON.stringify(info), 'utf8');
}