enhance/ilm-forecast (#51)

pkg/es/duration.go

@@ -0,0 +1,126 @@
+/*
+Copyright © 2026 Thomas von Dein
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+package es
+
+import (
+	"fmt"
+	"math"
+	"regexp"
+	"strconv"
+	"time"
+)
+
+var (
+	matchDuration = regexp.MustCompile(`(\d+)([dhms])`)
+)
+
+type esDuration struct {
+	days, hours, minutes, seconds int
+}
+
+/*
+We could use time.ParseDuration(), but this doesn't support days.
+
+We  could also  use github.com/xhit/go-str2duration/v2,  which does
+the job,  but it's  just another dependency,  just for  this little
+gem. And  we don't need a  time.Time value. And int  is good enough
+for duration comparison.
+
+Convert a  duration into  an integer.  Valid  time units  are "s", "m", "h" and "d".
+
+	via https://codeberg.org/scip/tablizer/src/branch/main/lib/sort.go#L113
+*/
+func parseDuration(duration string) time.Duration {
+
+	seconds := 0
+
+	for _, match := range matchDuration.FindAllStringSubmatch(duration, -1) {
+		if len(match) == 3 {
+			durationvalue, _ := strconv.Atoi(match[1])
+
+			switch match[2][0] {
+			case 'd':
+				seconds += durationvalue * 86400
+			case 'h':
+				seconds += durationvalue * 3600
+			case 'm':
+				seconds += durationvalue * 60
+			case 's':
+				seconds += durationvalue
+			}
+		}
+	}
+
+	return time.Duration(seconds) * time.Second
+}
+
+// pretty much the same as above, but return a struct filled with int duration values
+func extractDuration(duration string) esDuration {
+	esd := esDuration{}
+
+	for _, match := range matchDuration.FindAllStringSubmatch(duration, -1) {
+		if len(match) == 3 {
+			durationvalue, _ := strconv.Atoi(match[1])
+
+			switch match[2][0] {
+			case 'd':
+				esd.days = durationvalue
+			case 'h':
+				esd.hours = durationvalue
+			case 'm':
+				esd.minutes = durationvalue
+			case 's':
+				esd.seconds = durationvalue
+			}
+		}
+	}
+
+	return esd
+}
+
+// convert a duration like 156h6m15.095s-6d/12h/6m => 6d:12h:6m
+func formatDuration(val time.Duration) string {
+	esd := extractDuration(val.String())
+
+	daysF := float64(esd.hours) / 24.0
+	days := math.Floor(daysF)
+	hoursLeft := (daysF - days) * 24
+
+	switch {
+	case val.Minutes() < 1:
+		return fmt.Sprintf("%ds", int64(esd.seconds))
+
+	case val.Hours() < 1:
+		return fmt.Sprintf("%dm", int64(esd.minutes))
+
+	case val.Hours() < 24:
+		if esd.minutes == 0 {
+			return fmt.Sprintf("%dh", esd.hours)
+		}
+		return fmt.Sprintf("%dh:%dm", esd.hours, int64(esd.minutes))
+
+	default:
+		if esd.minutes == 0 && hoursLeft == 0 {
+			return fmt.Sprintf("%dd", int64(days))
+		}
+		return fmt.Sprintf("%dd:%dh:%dm",
+			int64(days),
+			int64(hoursLeft),
+			esd.minutes,
+		)
+	}
+}