initial commit

protonvpn-wg-confgen/pkg/timeutil/duration.go

@@ -0,0 +1,148 @@
+// Package timeutil provides time-related utility functions.
+package timeutil
+
+import (
+	"fmt"
+	"strings"
+	"time"
+)
+
+// pluralize returns singular or plural form based on count
+func pluralize(count int, singular, plural string) string {
+	if count == 1 {
+		return fmt.Sprintf("1 %s", singular)
+	}
+	return fmt.Sprintf("%d %s", count, plural)
+}
+
+// formatTimeComponents formats non-zero time components into a string
+func formatTimeComponents(parts []string) string {
+	return strings.Join(parts, " ")
+}
+
+// formatWeeksAndDays formats weeks and remaining days
+func formatWeeksAndDays(days int) []string {
+	var parts []string
+	weeks := days / 7
+	remainingDays := days % 7
+
+	if weeks > 0 {
+		parts = append(parts, pluralize(weeks, "week", "weeks"))
+	}
+	if remainingDays > 0 {
+		parts = append(parts, pluralize(remainingDays, "day", "days"))
+	}
+	return parts
+}
+
+// formatHoursMinutes formats hours and minutes
+func formatHoursMinutes(hours, minutes int) string {
+	switch {
+	case hours > 0 && minutes > 0:
+		return fmt.Sprintf("%d hours %d minutes", hours, minutes)
+	case hours > 0:
+		return fmt.Sprintf("%d hours", hours)
+	default:
+		return fmt.Sprintf("%d minutes", minutes)
+	}
+}
+
+// formatDaysHoursMinutes formats days, hours, and minutes into a string
+func formatDaysHoursMinutes(days, hours, minutes int) string {
+	// Simple days format (less than a week)
+	if days < 7 {
+		return formatSimpleDays(days, hours, minutes)
+	}
+
+	// Weeks format
+	parts := formatWeeksAndDays(days)
+	if hours > 0 || minutes > 0 {
+		parts = append(parts, formatHoursMinutes(hours, minutes))
+	}
+	return formatTimeComponents(parts)
+}
+
+// formatSimpleDays formats days less than a week with hours and minutes
+func formatSimpleDays(days, hours, minutes int) string {
+	if hours == 0 && minutes == 0 {
+		return pluralize(days, "day", "days")
+	}
+	if minutes == 0 {
+		return fmt.Sprintf("%d days %d hours", days, hours)
+	}
+	return fmt.Sprintf("%d days %d hours %d minutes", days, hours, minutes)
+}
+
+// HumanizeDuration converts a duration to a human-readable format with high precision.
+// It shows progressively less detail for longer durations:
+// - Less than a minute: "less than a minute"
+// - Less than an hour: "X minutes"
+// - Less than a day: "X hours Y minutes"
+// - Less than a week: "X days Y hours Z minutes"
+// - Less than a month: "X weeks Y days Z hours W minutes"
+// - Longer periods: months and years with appropriate detail
+func HumanizeDuration(d time.Duration) string {
+	if d < 0 {
+		return "expired"
+	}
+
+	if d < time.Minute {
+		return "less than a minute"
+	}
+
+	if d < time.Hour {
+		return pluralize(int(d.Minutes()), "minute", "minutes")
+	}
+
+	if d < 24*time.Hour {
+		return formatHoursDuration(d)
+	}
+
+	days := int(d.Hours() / 24)
+	hours := int(d.Hours()) % 24
+	minutes := int(d.Minutes()) % 60
+
+	if days < 30 {
+		return formatDaysHoursMinutes(days, hours, minutes)
+	}
+
+	if days < 365 {
+		return formatMonthsDuration(days)
+	}
+
+	return formatYearsDuration(days)
+}
+
+// formatHoursDuration formats durations less than a day
+func formatHoursDuration(d time.Duration) string {
+	hours := int(d.Hours())
+	minutes := int(d.Minutes()) % 60
+	if minutes == 0 {
+		return pluralize(hours, "hour", "hours")
+	}
+	return fmt.Sprintf("%d hours %d minutes", hours, minutes)
+}
+
+// formatMonthsDuration formats durations between 30 and 365 days
+func formatMonthsDuration(days int) string {
+	months := days / 30
+	remainingDays := days % 30
+	if remainingDays == 0 {
+		return pluralize(months, "month", "months")
+	}
+	return fmt.Sprintf("%d months %d days", months, remainingDays)
+}
+
+// formatYearsDuration formats durations of 365 days or more
+func formatYearsDuration(days int) string {
+	years := days / 365
+	remainingDays := days % 365
+	if remainingDays == 0 {
+		return pluralize(years, "year", "years")
+	}
+	if remainingDays < 30 {
+		return fmt.Sprintf("%d years %d days", years, remainingDays)
+	}
+	months := remainingDays / 30
+	return fmt.Sprintf("%d years %d months", years, months)
+}