functions: split off time formatting functions

inc/functions/format.php

@@ -0,0 +1,28 @@
+<?php
+namespace Vichan\Functions\Format;
+
+
+function format_timestamp(int $delta): string {
+	switch (true) {
+		case $delta < 60:
+			return $delta . ' ' . ngettext('second', 'seconds', $delta);
+		case $delta < 3600: //60*60 = 3600
+			return ($num = round($delta/ 60)) . ' ' . ngettext('minute', 'minutes', $num);
+		case $delta < 86400: //60*60*24 = 86400
+			return ($num = round($delta / 3600)) . ' ' . ngettext('hour', 'hours', $num);
+		case $delta < 604800: //60*60*24*7 = 604800
+			return ($num = round($delta / 86400)) . ' ' . ngettext('day', 'days', $num);
+		case $delta < 31536000: //60*60*24*365 = 31536000
+			return ($num = round($delta / 604800)) . ' ' . ngettext('week', 'weeks', $num);
+		default:
+			return ($num = round($delta / 31536000)) . ' ' . ngettext('year', 'years', $num);
+	}
+}
+
+function until(int $timestamp): string {
+	return format_timestamp($timestamp - time());
+}
+
+function ago(int $timestamp): string {
+	return format_timestamp(time() - $timestamp);
+}