'use strict';

exports = module.exports = {
    initialize,
    uninitialize,
    getConfig,
    getLogs,

    reboot,
    isRebootRequired,

    onActivated,

    setupDnsAndCert,

    prepareDashboardDomain,
    setDashboardDomain,
    updateDashboardDomain,
    renewCerts,
    syncDnsRecords,

    runSystemChecks
};

const apps = require('./apps.js'),
    appstore = require('./appstore.js'),
    assert = require('assert'),
    async = require('async'),
    auditSource = require('./auditsource.js'),
    backups = require('./backups.js'),
    BoxError = require('./boxerror.js'),
    branding = require('./branding.js'),
    constants = require('./constants.js'),
    cron = require('./cron.js'),
    debug = require('debug')('box:cloudron'),
    delay = require('delay'),
    dns = require('./dns.js'),
    domains = require('./domains.js'),
    eventlog = require('./eventlog.js'),
    fs = require('fs'),
    mail = require('./mail.js'),
    notifications = require('./notifications.js'),
    path = require('path'),
    paths = require('./paths.js'),
    platform = require('./platform.js'),
    reverseProxy = require('./reverseproxy.js'),
    safe = require('safetydance'),
    services = require('./services.js'),
    settings = require('./settings.js'),
    shell = require('./shell.js'),
    spawn = require('child_process').spawn,
    split = require('split'),
    sysinfo = require('./sysinfo.js'),
    tasks = require('./tasks.js'),
    users = require('./users.js'),
    util = require('util');

const REBOOT_CMD = path.join(__dirname, 'scripts/reboot.sh');

const NOOP_CALLBACK = function (error) { if (error) debug(error); };

async function initialize() {
    runStartupTasks();

    await notifyUpdate();
}

async function uninitialize() {
    await cron.stopJobs();
    await platform.stopAllTasks();
}

function onActivated(options, callback) {
    assert.strictEqual(typeof options, 'object');
    assert.strictEqual(typeof callback, 'function');

    debug('onActivated: running post activation tasks');

    // Starting the platform after a user is available means:
    // 1. mail bounces can now be sent to the cloudron owner
    // 2. the restore code path can run without sudo (since mail/ is non-root)
    async.series([
        platform.start.bind(null, options),
        cron.startJobs,
        // disable responding to api calls via IP to not leak domain info. this is carefully placed as the last item, so it buys
        // the UI some time to query the dashboard domain in the restore code path
        async () => {
            await delay(30000);
            await reverseProxy.writeDefaultConfig({ activated :true });
        }
    ], callback);
}

async function notifyUpdate() {
    const version = safe.fs.readFileSync(paths.VERSION_FILE, 'utf8');
    if (version === constants.VERSION) return;

    await eventlog.add(eventlog.ACTION_UPDATE_FINISH, auditSource.CRON, { errorMessage: '', oldVersion: version || 'dev', newVersion: constants.VERSION });

    const [error] = await safe(tasks.setCompletedByType(tasks.TASK_UPDATE, { error: null }));
    if (error && error.reason !== BoxError.NOT_FOUND) throw error; // when hotfixing, task may not exist

    safe.fs.writeFileSync(paths.VERSION_FILE, constants.VERSION, 'utf8');
}

// each of these tasks can fail. we will add some routes to fix/re-run them
function runStartupTasks() {
    const tasks = [
        // stop all the systemd tasks
        platform.stopAllTasks,

        // this configures collectd to collect backup storage metrics if filesystem is used. This is also triggerd when the settings change with the rest api
        async function () {
            const backupConfig = await settings.getBackupConfig();
            await backups.configureCollectd(backupConfig);
        },

        // always generate webadmin config since we have no versioning mechanism for the ejs
        async function () {
            if (!settings.dashboardDomain()) return;

            await reverseProxy.writeDashboardConfig(settings.dashboardDomain());
        },

        // check activation state and start the platform
        async function () {
            const activated = await users.isActivated();

            // configure nginx to be reachable by IP when not activated. for the moment, the IP based redirect exists even after domain is setup
            // just in case user forgot or some network error happenned in the middle (then browser refresh takes you to activation page)
            // we remove the config as a simple security measure to not expose IP <-> domain
            if (!activated) {
                debug('runStartupTasks: not activated. generating IP based redirection config');
                return await reverseProxy.writeDefaultConfig({ activated: false });
            }

            await util.promisify(onActivated)({});
        }
    ];

    // we used to run tasks in parallel but simultaneous nginx reloads was causing issues
    async.series(async.reflectAll(tasks), function (error, results) {
        results.forEach((result, idx) => {
            if (result.error) debug(`Startup task at index ${idx} failed: ${result.error.message}`);
        });
    });
}

async function getConfig() {
    const release = safe.fs.readFileSync('/etc/lsb-release', 'utf-8');
    if (release === null) throw new BoxError(BoxError.FS_ERROR, safe.error.message);
    const ubuntuVersion = release.match(/DISTRIB_DESCRIPTION="(.*)"/)[1];

    const allSettings = await settings.list();

    // be picky about what we send out here since this is sent for 'normal' users as well
    return {
        apiServerOrigin: settings.apiServerOrigin(),
        webServerOrigin: settings.webServerOrigin(),
        adminDomain: settings.dashboardDomain(),
        adminFqdn: settings.dashboardFqdn(),
        mailFqdn: settings.mailFqdn(),
        version: constants.VERSION,
        ubuntuVersion,
        isDemo: settings.isDemo(),
        cloudronName: allSettings[settings.CLOUDRON_NAME_KEY],
        footer: branding.renderFooter(allSettings[settings.FOOTER_KEY] || constants.FOOTER),
        features: appstore.getFeatures(),
        profileLocked: allSettings[settings.DIRECTORY_CONFIG_KEY].lockUserProfiles,
        mandatory2FA: allSettings[settings.DIRECTORY_CONFIG_KEY].mandatory2FA
    };
}

async function reboot() {
    await notifications.alert(notifications.ALERT_REBOOT, 'Reboot Required', '');

    const [error] = await safe(shell.promises.sudo('reboot', [ REBOOT_CMD ], {}));
    if (error) debug('reboot: could not reboot', error);
}

async function isRebootRequired() {
    // https://serverfault.com/questions/92932/how-does-ubuntu-keep-track-of-the-system-restart-required-flag-in-motd
    return fs.existsSync('/var/run/reboot-required');
}

// called from cron.js
function runSystemChecks(callback) {
    assert.strictEqual(typeof callback, 'function');

    debug('runSystemChecks: checking status');

    async.parallel([
        checkMailStatus,
        checkRebootRequired,
        checkUbuntuVersion
    ], callback);
}

async function checkMailStatus() {
    const message = await mail.checkConfiguration();
    await notifications.alert(notifications.ALERT_MAIL_STATUS, 'Email is not configured properly', message);
}

async function checkRebootRequired() {
    const rebootRequired = await isRebootRequired();
    await notifications.alert(notifications.ALERT_REBOOT, 'Reboot Required', rebootRequired ? 'To finish ubuntu security updates, a reboot is necessary.' : '');
}

async function checkUbuntuVersion() {
    const isXenial = fs.readFileSync('/etc/lsb-release', 'utf-8').includes('16.04');
    if (!isXenial) return;

    await notifications.alert(notifications.ALERT_UPDATE_UBUNTU, 'Ubuntu upgrade required', 'Ubuntu 16.04 has reached end of life and will not receive security and maintenance updates. Please follow https://docs.cloudron.io/guides/upgrade-ubuntu-18/ to upgrade to Ubuntu 18 at the earliest.');
}

async function getLogs(unit, options) {
    assert.strictEqual(typeof unit, 'string');
    assert(options && typeof options === 'object');

    assert.strictEqual(typeof options.lines, 'number');
    assert.strictEqual(typeof options.format, 'string');
    assert.strictEqual(typeof options.follow, 'boolean');

    var lines = options.lines === -1 ? '+1' : options.lines,
        format = options.format || 'json',
        follow = options.follow;

    debug('Getting logs for %s as %s', unit, format);

    let args = [ '--lines=' + lines ];
    if (follow) args.push('--follow');

    // need to handle box.log without subdir
    if (unit === 'box') args.push(path.join(paths.LOG_DIR, 'box.log'));
    else if (unit.startsWith('crash-')) args.push(path.join(paths.CRASH_LOG_DIR, unit.slice(6) + '.log'));
    else throw new BoxError(BoxError.BAD_FIELD, 'No such unit', { field: 'unit' });

    const cp = spawn('/usr/bin/tail', args);

    const transformStream = split(function mapper(line) {
        if (format !== 'json') return line + '\n';

        const data = line.split(' '); // logs are <ISOtimestamp> <msg>
        let timestamp = (new Date(data[0])).getTime();
        if (isNaN(timestamp)) timestamp = 0;

        return JSON.stringify({
            realtimeTimestamp: timestamp * 1000,
            message: line.slice(data[0].length+1),
            source: unit
        }) + '\n';
    });

    transformStream.close = cp.kill.bind(cp, 'SIGKILL'); // closing stream kills the child process

    cp.stdout.pipe(transformStream);

    return transformStream;
}

async function prepareDashboardDomain(domain, auditSource) {
    assert.strictEqual(typeof domain, 'string');
    assert.strictEqual(typeof auditSource, 'object');

    debug(`prepareDashboardDomain: ${domain}`);

    if (settings.isDemo()) throw new BoxError(BoxError.CONFLICT, 'Not allowed in demo mode');

    const domainObject = await domains.get(domain);
    if (!domain) throw new BoxError(BoxError.NOT_FOUND, 'No such domain');

    const fqdn = dns.fqdn(constants.DASHBOARD_LOCATION, domainObject);

    const result = await apps.list();
    if (result.some(app => app.fqdn === fqdn)) throw new BoxError(BoxError.BAD_STATE, 'Dashboard location conflicts with an existing app');

    const taskId = await tasks.add(tasks.TASK_SETUP_DNS_AND_CERT, [ constants.DASHBOARD_LOCATION, domain, auditSource ]);

    tasks.startTask(taskId, {}, NOOP_CALLBACK);

    return taskId;
}

// call this only pre activation since it won't start mail server
async function setDashboardDomain(domain, auditSource) {
    assert.strictEqual(typeof domain, 'string');
    assert.strictEqual(typeof auditSource, 'object');

    debug(`setDashboardDomain: ${domain}`);

    const domainObject = await domains.get(domain);
    if (!domain) throw new BoxError(BoxError.NOT_FOUND, 'No such domain');

    await reverseProxy.writeDashboardConfig(domain);
    const fqdn = dns.fqdn(constants.DASHBOARD_LOCATION, domainObject);

    await settings.setDashboardLocation(domain, fqdn);

    await safe(appstore.updateCloudron({ domain }));

    await eventlog.add(eventlog.ACTION_DASHBOARD_DOMAIN_UPDATE, auditSource, { domain, fqdn });
}

// call this only post activation because it will restart mail server
async function updateDashboardDomain(domain, auditSource) {
    assert.strictEqual(typeof domain, 'string');
    assert.strictEqual(typeof auditSource, 'object');

    debug(`updateDashboardDomain: ${domain}`);

    if (settings.isDemo()) throw new BoxError(BoxError.CONFLICT, 'Not allowed in demo mode');

    await setDashboardDomain(domain, auditSource);

    services.rebuildService('turn', NOOP_CALLBACK); // to update the realm variable
}

async function renewCerts(options, auditSource) {
    assert.strictEqual(typeof options, 'object');
    assert.strictEqual(typeof auditSource, 'object');

    const taskId = await tasks.add(tasks.TASK_CHECK_CERTS, [ options, auditSource ]);
    tasks.startTask(taskId, {}, NOOP_CALLBACK);
    return taskId;
}

async function setupDnsAndCert(subdomain, domain, auditSource, progressCallback) {
    assert.strictEqual(typeof subdomain, 'string');
    assert.strictEqual(typeof domain, 'string');
    assert.strictEqual(typeof auditSource, 'object');
    assert.strictEqual(typeof progressCallback, 'function');

    const domainObject = await domains.get(domain);
    const dashboardFqdn = dns.fqdn(subdomain, domainObject);

    const ip = await sysinfo.getServerIp();

    progressCallback({ message: `Updating DNS of ${dashboardFqdn}` });
    await dns.upsertDnsRecords(subdomain, domain, 'A', [ ip ]);
    progressCallback({ message: `Waiting for DNS of ${dashboardFqdn}` });
    await dns.waitForDnsRecord(subdomain, domain, 'A', ip, { interval: 30000, times: 50000 });
    progressCallback({ message: `Getting certificate of ${dashboardFqdn}` });
    await reverseProxy.ensureCertificate(dns.fqdn(subdomain, domainObject), domain, auditSource);
}

async function syncDnsRecords(options) {
    assert.strictEqual(typeof options, 'object');

    const taskId = await tasks.add(tasks.TASK_SYNC_DNS_RECORDS, [ options ]);
    tasks.startTask(taskId, {}, NOOP_CALLBACK);
    return taskId;
}