mailtrain/services/tzupdate.js
2017-02-02 16:47:50 +02:00

65 lines
2.2 KiB
JavaScript

'use strict';
// This script re-calculates timezone offsets once a day.
// We need this to be able to send messages using subscriber's local time
// The best option would be to use built-in timezone data of MySQL but
// the availability of timezone data is not guaranteed as it's an optional add on.
// So instead we keep a list of timezone offsets in a table that we can use to
// JOIN with subscription table. Subscription table includes timezone name for
// a subscriber and tzoffset table includes offset from UTC in minutes
let moment = require('moment-timezone');
let db = require('../lib/db');
let log = require('npmlog');
let lastCheck = false;
const timezone_timeout = 60 * 60 * 1000;
function updateTimezoneOffsets(callback) {
log.verbose('UTC', 'Updating timezone offsets');
db.getConnection((err, connection) => {
if (err) {
return callback(err);
}
let values = [];
moment.tz.names().forEach(tz => {
let time = moment();
values.push('(' + connection.escape(tz.toLowerCase().trim()) + ',' + connection.escape(time.tz(tz).utcOffset()) + ')');
});
let query = 'INSERT INTO tzoffset (`tz`, `offset`) VALUES ' + values.join(', ') + ' ON DUPLICATE KEY UPDATE `offset` = VALUES(`offset`)';
connection.query(query, values, (err, result) => {
connection.release();
if (err) {
return callback(err);
}
return callback(null, result);
});
});
}
module.exports = callback => {
updateTimezoneOffsets(err => {
if (err) {
return callback(err);
}
let checkLoop = () => {
let curUtcDate = new Date().toISOString().split('T').shift();
if (curUtcDate !== lastCheck) {
updateTimezoneOffsets(err => {
if (err) {
log.error('UTC', err);
}
setTimeout(checkLoop, timezone_timeout);
});
} else {
setTimeout(checkLoop, timezone_timeout);
}
lastCheck = curUtcDate;
};
setTimeout(checkLoop, timezone_timeout);
callback(null, true);
});
};