add iCalender export

Author: orltom

cmd/create_command.go

@@ -21,6 +21,7 @@ const (
 	CVS Format = iota
 	Table
 	JSON
+	ICS
 )
 
 func RunCreateShiftPlan(writer io.Writer, arguments []string) error {
@@ -35,6 +36,9 @@ func RunCreateShiftPlan(writer io.Writer, arguments []string) error {
 		JSON: func() apis.Exporter {
 			return export.NewJSONExporter()
 		},
+		ICS: func() apis.Exporter {
+			return export.NewICSExporter()
+		},
 	}
 
 	start := new(time.Time)
@@ -52,7 +56,7 @@ func RunCreateShiftPlan(writer io.Writer, arguments []string) error {
 	createCommand.Func("start", "(required) start time of the schedule plan", cli.TimeValueVar(start))
 	createCommand.Func("end", "(required) end time of the schedule plan", cli.TimeValueVar(end))
 	createCommand.Func("team-file", "(required) path to the file that contain all on-call duties", cli.FilePathVar(teamFilePath))
-	createCommand.Func("output", "output format. One of (cvs, table, json)", cli.EnumValueVar(enums, &outputFormat))
+	createCommand.Func("output", "output format. One of (cvs, table, json, ics)", cli.EnumValueVar(enums, &outputFormat))
 	createCommand.StringVar(primaryRules, "primary-rules", "vacation", "Rule to decide which employee should be on-call for the next shift")
 	createCommand.StringVar(secondaryRules, "secondary-rules", "vacation", "Rule to decide which employee should be on-call for the next shift")
 	createCommand.Usage = func() {

internal/export/ics.go

@@ -0,0 +1,76 @@
+package export
+
+import (
+	_ "embed"
+	"errors"
+	"fmt"
+	"io"
+	"text/template"
+
+	"github.com/orltom/on-call-schedule/pkg/apis"
+)
+
+//go:embed ics.tmpl
+var templateICSFile string
+
+var _ apis.Exporter = &TableExporter{}
+
+type event struct {
+	apis.Shift
+	UID         string
+	Category    string
+	XColor      string
+	Attendee    string
+	Summary     string
+	Description string
+}
+
+type ICSExporter struct {
+	template *template.Template
+}
+
+func NewICSExporter() *ICSExporter {
+	tmpl, _ := template.New("ical").Parse(templateICSFile)
+	return &ICSExporter{template: tmpl}
+}
+
+func (e *ICSExporter) Write(plan []apis.Shift, writer io.Writer) error {
+	if plan == nil {
+		return errors.New("shifts must not be nil")
+	}
+
+	events := make([]event, 0, len(plan))
+	for idx := range plan {
+		s := plan[idx]
+		events = append(events, mapPrimaryEvent(s), mapSecondaryEvent(s))
+	}
+
+	if err := e.template.ExecuteTemplate(writer, "icalCalendar", events); err != nil {
+		return fmt.Errorf("can not generate ICS: %w", err)
+	}
+	return nil
+}
+
+func mapPrimaryEvent(shift apis.Shift) event {
+	return event{
+		Shift:       shift,
+		UID:         "primary-" + shift.Start.Format("20060102"),
+		Category:    "Primary",
+		XColor:      "#FF5733",
+		Attendee:    string(shift.Primary),
+		Summary:     "Primary On-Call: " + string(shift.Primary),
+		Description: fmt.Sprintf("Primary: %s\\nSecondary: %s", shift.Primary, shift.Secondary),
+	}
+}
+
+func mapSecondaryEvent(shift apis.Shift) event {
+	return event{
+		Shift:       shift,
+		UID:         "secondary-" + shift.Start.Format("20060102"),
+		Category:    "Secondary",
+		XColor:      "#33FF57",
+		Attendee:    string(shift.Secondary),
+		Summary:     "Secondary On-Call: " + string(shift.Secondary),
+		Description: fmt.Sprintf("Primary: %s\\nSecondary: %s", shift.Primary, shift.Secondary),
+	}
+}

internal/export/ics.tmpl

@@ -0,0 +1,29 @@
+{{- define "icalEvent" }}
+BEGIN:VEVENT
+UID:{{ .UID }}
+DTSTART:{{ .Start.Format "20060102T150405Z" }}
+DTEND:{{ .End.Format "20060102T150405Z" }}
+SUMMARY:{{ .Summary }}
+DESCRIPTION:Primary: {{ .Primary }}\nSecondary: {{ .Secondary }}
+CATEGORIES:{{ .Category }}
+ATTENDEE:mailto:{{ .Attendee }}
+X-COLOR:{{ .XColor }}
+BEGIN:VALARM
+TRIGGER:-PT8H
+ACTION:DISPLAY
+DESCRIPTION:Reminder: {{ .Summary }} starts in 8 hours.
+END:VALARM
+END:VEVENT
+{{ end -}}
+
+{{- define "icalCalendar" -}}
+BEGIN:VCALENDAR
+VERSION:2.0
+PRODID:-//ocsctl//on-call-shift//EN
+CALSCALE:GREGORIAN
+{{ range . }}
+{{- template "icalEvent" . }}
+{{- end }}
+END:VCALENDAR
+
+{{- end -}}

internal/export/ics_test.go

@@ -0,0 +1,95 @@
+package export
+
+import (
+	"bytes"
+	"testing"
+
+	"github.com/orltom/on-call-schedule/pkg/apis"
+)
+
+func TestICSExporter_Write(t *testing.T) {
+	type args struct {
+		plan []apis.Shift
+	}
+	tests := []struct {
+		name       string
+		args       args
+		wantWriter string
+		wantErr    bool
+	}{
+		{
+			name: "When plan is nil, throw an error",
+			args: args{
+				plan: nil,
+			},
+			wantWriter: "",
+			wantErr:    true,
+		},
+		{
+			name: "Print ICS result according shift plan",
+			args: args{
+				plan: []apis.Shift{
+					{
+						Start:     date("2024-12-25"),
+						End:       date("2024-12-26"),
+						Primary:   "a",
+						Secondary: "b",
+					},
+				},
+			},
+			wantWriter: `BEGIN:VCALENDAR
+VERSION:2.0
+PRODID:-//ocsctl//on-call-shift//EN
+CALSCALE:GREGORIAN
+
+BEGIN:VEVENT
+UID:primary-20241225
+DTSTART:20241225T000000Z
+DTEND:20241226T000000Z
+SUMMARY:Primary On-Call: a
+DESCRIPTION:Primary: a\nSecondary: b
+CATEGORIES:Primary
+ATTENDEE:mailto:a
+X-COLOR:#FF5733
+BEGIN:VALARM
+TRIGGER:-PT8H
+ACTION:DISPLAY
+DESCRIPTION:Reminder: Primary On-Call: a starts in 8 hours.
+END:VALARM
+END:VEVENT
+
+BEGIN:VEVENT
+UID:secondary-20241225
+DTSTART:20241225T000000Z
+DTEND:20241226T000000Z
+SUMMARY:Secondary On-Call: b
+DESCRIPTION:Primary: a\nSecondary: b
+CATEGORIES:Secondary
+ATTENDEE:mailto:b
+X-COLOR:#33FF57
+BEGIN:VALARM
+TRIGGER:-PT8H
+ACTION:DISPLAY
+DESCRIPTION:Reminder: Secondary On-Call: b starts in 8 hours.
+END:VALARM
+END:VEVENT
+
+END:VCALENDAR`,
+			wantErr: false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			e := NewICSExporter()
+			writer := &bytes.Buffer{}
+			err := e.Write(tt.args.plan, writer)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("Write() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if gotWriter := writer.String(); gotWriter != tt.wantWriter {
+				t.Errorf("Write() gotWriter = %v, want %v", gotWriter, tt.wantWriter)
+			}
+		})
+	}
+}