feat:#34 refactored function to intended service, fixed docker files

services/data-manager/service/ical/icalFileGeneration.go

@@ -0,0 +1,173 @@
+//Calendar implementation for the HTWK Leipzig timetable. Evaluation and display of the individual dates in iCal format.
+//Copyright (C) 2024 HTWKalender support@htwkalender.de
+
+//This program is free software: you can redistribute it and/or modify
+//it under the terms of the GNU Affero 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 Affero General Public License for more details.
+
+//You should have received a copy of the GNU Affero General Public License
+//along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package ical
+
+import (
+	"htwkalender/model"
+	"htwkalender/service/functions"
+	clock "htwkalender/service/functions/time"
+	"htwkalender/service/names"
+	"time"
+
+	"github.com/jordic/goics"
+	_ "time/tzdata"
+)
+
+// IcalModel local type for EmitICal function
+type IcalModel struct {
+	Events  model.Events
+	Mapping map[string]model.FeedCollection
+}
+
+// EmitICal implements the interface for goics
+func (icalModel IcalModel) EmitICal() goics.Componenter {
+	internalClock := clock.RealClock{}
+	c := generateIcalEmit(icalModel, internalClock)
+	return c
+}
+
+func generateIcalEmit(icalModel IcalModel, internalClock clock.Clock) *goics.Component {
+	europeTime, _ := time.LoadLocation("Europe/Berlin")
+	c := goics.NewComponent()
+	c.SetType("VCALENDAR")
+	// PRODID is required by the standard
+	c.AddProperty("PRODID", "-//HTWK Kalender//htwkalender.de//DE")
+
+	c.AddProperty("VERSION", "2.0")
+	c.AddProperty("CALSCALE", "GREGORIAN")
+	c.AddProperty("TZID", "EUROPE/BERLIN")
+	c.AddProperty("X-WR-CALNAME", "HTWK Kalender")
+	c.AddProperty("X-WR-TIMEZONE", "EUROPE/BERLIN")
+	//add v time zone
+	icalModel.vtimezone(c)
+
+	for _, event := range icalModel.Events {
+		mapEntry, mappingFound := icalModel.Mapping[event.UUID]
+
+		s := goics.NewComponent()
+		s.SetType("VEVENT")
+
+		s.AddProperty(goics.FormatDateTime("DTSTAMP", internalClock.Now().Local().In(europeTime)))
+
+		// create a unique id for the event by hashing the event start, end, course and name
+		var eventHash = functions.HashString(event.Start.String() + event.End.String() + event.Course + event.Name + event.Rooms)
+
+		s.AddProperty("UID", eventHash+"@htwkalender.de")
+		s.AddProperty(goics.FormatDateTime("DTEND", event.End.Time().Local().In(europeTime)))
+		s.AddProperty(goics.FormatDateTime("DTSTART", event.Start.Time().Local().In(europeTime)))
+
+		if mappingFound {
+			addPropertyIfNotEmpty(s, "SUMMARY", replaceNameIfUserDefined(&event, mapEntry))
+			addAlarmIfSpecified(s, event, mapEntry, internalClock)
+		} else {
+			addPropertyIfNotEmpty(s, "SUMMARY", event.Name)
+		}
+
+		addPropertyIfNotEmpty(s, "DESCRIPTION", generateDescription(event))
+		addPropertyIfNotEmpty(s, "LOCATION", event.Rooms)
+		c.AddComponent(s)
+	}
+	return c
+}
+
+func (icalModel IcalModel) vtimezone(c *goics.Component) {
+	tz := goics.NewComponent()
+	tz.SetType("VTIMEZONE")
+	tz.AddProperty("TZID", "EUROPE/BERLIN")
+	//add standard time
+	icalModel.standard(tz)
+	//add daylight time
+	icalModel.daylight(tz)
+
+	c.AddComponent(tz)
+}
+
+func (icalModel IcalModel) standard(tz *goics.Component) {
+	st := NewHtwkalenderComponent()
+	st.SetType("STANDARD")
+	st.AddProperty("DTSTART", "19701025T030000")
+	st.AddProperty("RRULE", "FREQ=YEARLY;BYMONTH=10;BYDAY=-1SU")
+	st.AddProperty("TZOFFSETFROM", "+0200")
+	st.AddProperty("TZOFFSETTO", "+0100")
+	st.AddProperty("TZNAME", "CET")
+	tz.AddComponent(st)
+}
+
+// create an override for goics component function Write
+// to add the RRULE property
+
+func (icalModel IcalModel) daylight(tz *goics.Component) {
+	dt := NewHtwkalenderComponent()
+	dt.SetType("DAYLIGHT")
+	dt.AddProperty("DTSTART", "19700329T020000")
+	dt.AddProperty("TZOFFSETFROM", "+0100")
+	dt.AddProperty("TZOFFSETTO", "+0200")
+	dt.AddProperty("TZNAME", "CEST")
+	dt.AddProperty("RRULE", "FREQ=YEARLY;BYMONTH=3;BYDAY=-1SU")
+	tz.AddComponent(dt)
+}
+
+// if reminder is specified in the configuration for this event, an alarm will be added to the event
+func addAlarmIfSpecified(s *goics.Component, event model.Event, mapping model.FeedCollection, clock clock.Clock) {
+	// if event.Start > now
+	// then add alarm
+	if event.Start.Time().Local().After(clock.Now().Local()) && mapping.Reminder {
+		a := goics.NewComponent()
+		a.SetType("VALARM")
+		a.AddProperty("TRIGGER", "-P0DT0H15M0S")
+		a.AddProperty("ACTION", "DISPLAY")
+		a.AddProperty("DESCRIPTION", "Next course: "+replaceNameIfUserDefined(&event, mapping)+" in "+event.Rooms)
+		s.AddComponent(a)
+	}
+}
+
+// replaceNameIfUserDefined replaces the name of the event with the user defined name if it is not empty
+// all contained template strings will be replaced with the corresponding values from the event
+func replaceNameIfUserDefined(event *model.Event, mapping model.FeedCollection) string {
+	if !functions.OnlyWhitespace(mapping.UserDefinedName) {
+		return names.ReplaceTemplateSubStrings(mapping.UserDefinedName, *event)
+	}
+
+	return event.Name
+}
+
+// AddPropertyIfNotEmpty adds a property to the component if the value is not empty
+// or contains only whitespaces
+func addPropertyIfNotEmpty(component *goics.Component, key string, value string) {
+	if !functions.OnlyWhitespace(value) {
+		component.AddProperty(key, value)
+	}
+}
+
+func generateDescription(event model.Event) string {
+	var description string
+
+	if !functions.OnlyWhitespace(event.Prof) {
+		description += "Profs: " + event.Prof + "\n"
+	}
+	if !functions.OnlyWhitespace(event.Course) {
+		description += "Gruppen: " + event.Course + "\n"
+	}
+	if !functions.OnlyWhitespace(event.EventType) {
+		description += "Typ: " + event.EventType + event.Compulsory + "\n"
+	}
+	if !functions.OnlyWhitespace(event.Notes) {
+		description += "Notizen: " + event.Notes + "\n"
+	}
+
+	return description
+}