Implement generation of ics file from CLI args

go.mod

@@ -1,3 +1,8 @@
 module github.com/kevinmorio/holidays2ical
 
 go 1.19
+
+require (
+	github.com/arran4/golang-ical v0.0.0-20221122102835-109346913e54 // indirect
+	github.com/google/uuid v1.3.0 // indirect
+)

main.go

@@ -3,8 +3,13 @@ package main
 import (
 	"flag"
 	"fmt"
+	"os"
 	"sort"
+	"strings"
 	"time"
+
+	ics "github.com/arran4/golang-ical"
+	"github.com/google/uuid"
 )
 
 /// Calculation of the easter date
@@ -37,6 +42,24 @@ type Holiday struct {
 	Date time.Time
 }
 
+func (h *Holiday) holidayToEvent(lang string) *ics.VEvent {
+	event := ics.NewEvent(strings.ToUpper(uuid.NewString()))
+	// event.SetAllDayStartAt(h.Date)
+	// event.SetAllDayEndAt(h.Date.AddDate(0, 0, 1))
+
+	event.SetProperty(ics.ComponentPropertyDtStart, h.Date.UTC().Format("20060102"), ics.WithValue(string(ics.ValueDataTypeDate)))
+	event.SetProperty(ics.ComponentPropertyDtEnd, h.Date.AddDate(0, 0, 1).UTC().Format("20060102"), ics.WithValue(string(ics.ValueDataTypeDate)))
+
+	// event.SetProperty(ics.ComponentPropertyDtStart, h.Date.UTC().Format("20060102"))
+	// event.SetProperty(ics.ComponentPropertyDtEnd, h.Date.AddDate(0, 0, 1).UTC().Format("20060102"))
+
+	event.SetTimeTransparency(ics.TransparencyTransparent)
+	event.SetSummary(h.Name[lang])
+	event.SetDtStampTime(time.Now())
+
+	return event
+}
+
 func NewYear(year int) Holiday {
 	return Holiday{
 		Name: map[string]string{
@@ -287,19 +310,39 @@ func HolidaysForYear(year int) []Holiday {
 	return holidays
 }
 
+var calendarName = map[string]string{
+	"de-DE": "Feiertage",
+	"en-US": "Holidays",
+}
+
 func main() {
 	fromYear := flag.Int("from", time.Now().Year(), "year to start from")
 	tillYear := flag.Int("till", time.Now().Year(), "year to end")
 	lang := flag.String("lang", "de-DE", "the language used for the holidays")
 
+	defaultOutfilePath := fmt.Sprintf("./%s.ics", calendarName[*lang])
+	outfilePath := flag.String("outfile", defaultOutfilePath, "the outfile of the calendar")
+
 	flag.Parse()
 
-	for year := *fromYear; year <= *tillYear; year++ {
-		fmt.Printf("---------------- YEAR %d ----------------\n", year)
+	cal := ics.NewCalendarFor("-//Kevin Morio//holidays2ics")
+	cal.SetCalscale("GREGORIAN")
+	cal.SetXWRCalName(calendarName[*lang])
 
+	for year := *fromYear; year <= *tillYear; year++ {
 		for _, holiday := range HolidaysForYear(year) {
-			fmt.Printf("  %s: %v\n", holiday.Name[*lang], holiday.Date)
+			cal.AddVEvent(holiday.holidayToEvent(*lang))
 		}
-		fmt.Printf("-------------------------------------------\n")
 	}
+
+	outfile, err := os.Create(*outfilePath)
+	if err != nil {
+		panic(err)
+	}
+	defer outfile.Close()
+
+	if err := cal.SerializeTo(outfile); err != nil {
+		panic(err)
+	}
+	fmt.Printf("Saved calendar to %s\n", *outfilePath)
 }