New project structure

Beta of extract.js for extracting english locale

server/services/tzupdate.js

@@ -0,0 +1,54 @@
+'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
+
+const moment = require('moment-timezone');
+const knex = require('../lib/knex');
+const log = require('../lib/log');
+let lastCheck = false;
+
+const timezone_timeout = 60 * 60 * 1000;
+
+async function updateTimezoneOffsets() {
+    log.verbose('UTC', 'Updating timezone offsets');
+    const values = [];
+    for (const tz of moment.tz.names()) {
+        values.push({
+            tz: tz.toLowerCase().trim(),
+            offset: moment.tz(tz).utcOffset()
+        });
+    }
+
+    await knex.transaction(async tx => {
+        await tx('tzoffset').del();
+        await tx('tzoffset').insert(values);
+    });
+}
+
+function start() {
+    let curUtcDate = new Date().toISOString().split('T').shift();
+    if (curUtcDate !== lastCheck) {
+        updateTimezoneOffsets()
+            .then(() => {
+                setTimeout(start, timezone_timeout)
+            })
+            .catch(err => {
+                log.error('UTC', err);
+                setTimeout(start, timezone_timeout);
+            });
+    } else {
+        setTimeout(start, timezone_timeout);
+    }
+    lastCheck = curUtcDate;
+}
+
+module.exports = {
+    start
+};
+