(core) move home server into core

Summary: This moves enough server material into core to run a home server.  The data engine is not yet incorporated (though in manual testing it works when ported).

Test Plan: existing tests pass

Reviewers: dsagal

Reviewed By: dsagal

Differential Revision: https://phab.getgrist.com/D2552

app/common/timeFormat.ts

@@ -0,0 +1,56 @@
+/**
+ * timeFormat(format, date) formats the passed-in Date object using the format string. The format
+ * string may contain the following:
+ *    'h': hour (00 - 23)
+ *    'm': minute (00 - 59)
+ *    's': second (00 - 59)
+ *    'd': day of the month (01 - 31)
+ *    'n': month (01 - 12)
+ *    'y': 4-digit year
+ *    'M': milliseconds (000 - 999)
+ *    'Y': date as 20140212
+ *    'D': date as 2014-02-12
+ *    'T': time as 00:51:06
+ *    'A': full time and date, as 2014-02-12 00:51:06.123
+ * @param {String} format The format string.
+ * @param {Date} date The date/time object to format.
+ * @returns {String} The formatted date and/or time.
+ */
+
+function pad(num: number, len: number): string {
+  const s = num.toString();
+  return s.length >= len ? s : "00000000".slice(0, len - s.length) + s;
+}
+
+type FormatHelper = (out: string[], date: Date) => void;
+const timeFormatKeys: {[spec: string]: FormatHelper} = {
+  h: (out, date) => out.push(pad(date.getHours(), 2)),
+  m: (out, date) => out.push(pad(date.getMinutes(), 2)),
+  s: (out, date) => out.push(pad(date.getSeconds(), 2)),
+  d: (out, date) => out.push(pad(date.getDate(), 2)),
+  n: (out, date) => out.push(pad(date.getMonth() + 1, 2)),
+  y: (out, date) => out.push("" + date.getFullYear()),
+  M: (out, date) => out.push(pad(date.getMilliseconds(), 3)),
+  Y: (out, date) => timeFormatHelper(out, 'ynd', date),
+  D: (out, date) => timeFormatHelper(out, 'y-n-d', date),
+  T: (out, date) => timeFormatHelper(out, 'h:m:s', date),
+  A: (out, date) => timeFormatHelper(out, 'D T.M', date),
+};
+
+function timeFormatHelper(out: string[], format: string, date: Date) {
+  for (let i = 0, len = format.length; i < len; i++) {
+    const c = format[i];
+    const helper = timeFormatKeys[c];
+    if (helper) {
+      helper(out, date);
+    } else {
+      out.push(c);
+    }
+  }
+}
+
+export function timeFormat(format: string, date: Date): string {
+  const out: string[] = [];
+  timeFormatHelper(out, format, date);
+  return out.join("");
+}