add first ical implementation

addRoute.go

@@ -6,6 +6,8 @@ import (
 	"github.com/pocketbase/pocketbase/apis"
 	"github.com/pocketbase/pocketbase/core"
 	"htwk-planner/service"
+	"htwk-planner/service/fetch"
+	"htwk-planner/service/ical"
 	"net/http"
 	"os"
 )
@@ -22,7 +24,7 @@ func addRoutes(app *pocketbase.PocketBase) {
 			Method: http.MethodGet,
 			Path:   "/api/fetchPlans",
 			Handler: func(c echo.Context) error {
-				return service.FetchHTWK(c, app)
+				return fetch.FetchHTWK(c, app)
 			},
 			Middlewares: []echo.MiddlewareFunc{
 				apis.ActivityLogger(app),
@@ -39,7 +41,7 @@ func addRoutes(app *pocketbase.PocketBase) {
 			Method: http.MethodGet,
 			Path:   "/api/fetchGroups",
 			Handler: func(c echo.Context) error {
-				return service.FetchSeminarGroups(c, app)
+				return fetch.SeminarGroups(c, app)
 			},
 			Middlewares: []echo.MiddlewareFunc{
 				apis.ActivityLogger(app),
@@ -68,4 +70,38 @@ func addRoutes(app *pocketbase.PocketBase) {
 		return nil
 	})
 
+	app.OnBeforeServe().Add(func(e *core.ServeEvent) error {
+		_, err := e.Router.AddRoute(echo.Route{
+			Method: http.MethodGet,
+			Path:   "/api/feedURL",
+			Handler: func(c echo.Context) error {
+				return ical.FeedURL(c, app)
+			},
+			Middlewares: []echo.MiddlewareFunc{
+				apis.ActivityLogger(app),
+			},
+		})
+		if err != nil {
+			return err
+		}
+		return nil
+	})
+
+	app.OnBeforeServe().Add(func(e *core.ServeEvent) error {
+		_, err := e.Router.AddRoute(echo.Route{
+			Method: http.MethodGet,
+			Path:   "/api/feed",
+			Handler: func(c echo.Context) error {
+				return ical.Feed(c, app)
+			},
+			Middlewares: []echo.MiddlewareFunc{
+				apis.ActivityLogger(app),
+			},
+		})
+		if err != nil {
+			return err
+		}
+		return nil
+	})
+
 }

go.mod

@@ -3,6 +3,7 @@ module htwk-planner
 go 1.20
 
 require (
+	github.com/jordic/goics v0.0.0-20210404174824-5a0337b716a0
 	github.com/labstack/echo/v5 v5.0.0-20230722203903-ec5b858dab61
 	github.com/pocketbase/pocketbase v0.17.5
 	golang.org/x/net v0.14.0

go.sum

@@ -81,6 +81,7 @@ github.com/ganigeorgiev/fexpr v0.3.0/go.mod h1:RyGiGqmeXhEQ6+mlGdnUleLHgtzzu/VGO
 github.com/go-ozzo/ozzo-validation/v4 v4.3.0 h1:byhDUpfEwjsVQb1vBunvIjh2BHQ9ead57VkAEY4V+Es=
 github.com/go-ozzo/ozzo-validation/v4 v4.3.0/go.mod h1:2NKgrcHl3z6cJs+3Oo940FPRiTzuqKbvfrL2RxCj6Ew=
 github.com/go-sql-driver/mysql v1.4.1/go.mod h1:zAC/RDZ24gD3HViQzih4MyKcchzm+sOG5ZlKdlhCg5w=
+github.com/go-sql-driver/mysql v1.5.0/go.mod h1:DCzpHaOWr8IXmIStZouvnhqoel9Qv2LBy8hT2VhHyBg=
 github.com/go-sql-driver/mysql v1.7.1 h1:lUIinVbN1DY0xBg0eMOzmmtGoHwWBbvnWubQUrtU8EI=
 github.com/golang-jwt/jwt/v4 v4.5.0 h1:7cYmW1XlMY7h7ii7UhUyChSgS5wUJEnm9uZVTGqOWzg=
 github.com/golang-jwt/jwt/v4 v4.5.0/go.mod h1:m21LjoU+eqJr34lmDMbreY2eSTRJ1cv77w39/MY0Ch0=
@@ -125,6 +126,7 @@ github.com/google/wire v0.5.0/go.mod h1:ngWDr9Qvq3yZA10YrxfyGELY/AFWGVpy9c1LTRi1
 github.com/googleapis/enterprise-certificate-proxy v0.2.5 h1:UR4rDjcgpgEnqpIEvkiqTYKBCKLNmlge2eVjoZfySzM=
 github.com/googleapis/gax-go/v2 v2.12.0 h1:A+gCJKdRfqXkr+BIRGtZLibNXf0m1f9E4HG56etFpas=
 github.com/googleapis/gax-go/v2 v2.12.0/go.mod h1:y+aIqrI5eb1YGMVJfuV3185Ts/D7qKpsEkdD5+I6QGU=
+github.com/gorilla/mux v1.8.0/go.mod h1:DVbg23sWSpFRCP0SfiEN6jmj59UnW/n46BH5rLB71So=
 github.com/hinshun/vt10x v0.0.0-20220119200601-820417d04eec h1:qv2VnGeEQHchGaZ/u7lxST/RaJw+cv273q79D81Xbog=
 github.com/hinshun/vt10x v0.0.0-20220119200601-820417d04eec/go.mod h1:Q48J4R4DvxnHolD5P8pOtXigYlRuPLGl6moFx3ulM68=
 github.com/inconshreveable/mousetrap v1.1.0 h1:wN+x4NVGpMsO7ErUn/mUI3vEoE6Jt13X2s0bqwp9tc8=
@@ -133,12 +135,16 @@ github.com/jmespath/go-jmespath v0.4.0 h1:BEgLn5cpjn8UN1mAw4NjwDrS35OdebyEtFe+9Y
 github.com/jmespath/go-jmespath v0.4.0/go.mod h1:T8mJZnbsbmF+m6zOOFylbeCJqk5+pHWvzYPziyZiYoo=
 github.com/jmespath/go-jmespath/internal/testify v1.5.1 h1:shLQSRRSCCPj3f2gpwzGwWFoC7ycTf1rcQZHOlsJ6N8=
 github.com/jmespath/go-jmespath/internal/testify v1.5.1/go.mod h1:L3OGu8Wl2/fWfCI6z80xFu9LTZmf1ZRjMHUOPmWr69U=
+github.com/jmoiron/sqlx v1.3.1/go.mod h1:2BljVx/86SuTyjE+aPYlHCTNvZrnJXghYGpNiXLBMCQ=
+github.com/jordic/goics v0.0.0-20210404174824-5a0337b716a0 h1:p+k2RozdR141dIkAbOuZafkZjrcjT/YvwYYH7qCSG+c=
+github.com/jordic/goics v0.0.0-20210404174824-5a0337b716a0/go.mod h1:YHaw6sOIeFRob8Y9q/blEAMfVcLpeE9+vdhrwyEMxoI=
 github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51 h1:Z9n2FFNUXsshfwJMBgNA0RU6/i7WVaAegv3PtuIHPMs=
 github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51/go.mod h1:CzGEWj7cYgsdH8dAjBGEr58BoE7ScuLd+fwFZ44+/x8=
 github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/labstack/echo/v5 v5.0.0-20230722203903-ec5b858dab61 h1:FwuzbVh87iLiUQj1+uQUsuw9x5t9m5n5g7rG7o4svW4=
 github.com/labstack/echo/v5 v5.0.0-20230722203903-ec5b858dab61/go.mod h1:paQfF1YtHe+GrGg5fOgjsjoCX/UKDr9bc1DoWpZfns8=
+github.com/lib/pq v1.2.0/go.mod h1:5WUZQaWbwv1U+lTReE5YruASi9Al49XbQIvNi/34Woo=
 github.com/mattn/go-colorable v0.1.2/go.mod h1:U0ppj6V5qS13XJ6of8GYAs25YV2eR4EVcfRqFIhoBtE=
 github.com/mattn/go-colorable v0.1.13 h1:fFA4WZxdEF4tXPZVKMLwD8oUnCTTo08duU7wxecdEvA=
 github.com/mattn/go-colorable v0.1.13/go.mod h1:7S9/ev0klgBDR4GtXTXX8a3vIGJpMovkB8vQcUbaXHg=
@@ -146,6 +152,7 @@ github.com/mattn/go-isatty v0.0.8/go.mod h1:Iq45c/XA43vh69/j3iqttzPXn0bhXyGjM0Hd
 github.com/mattn/go-isatty v0.0.16/go.mod h1:kYGgaQfpe5nmfYZH+SKPsOc2e4SrIfOl2e/yFXSvRLM=
 github.com/mattn/go-isatty v0.0.19 h1:JITubQf0MOLdlGRuRq+jtsDlekdYPia9ZFsB8h/APPA=
 github.com/mattn/go-isatty v0.0.19/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
+github.com/mattn/go-sqlite3 v1.14.6/go.mod h1:NyWgC/yNuGj7Q9rpYnZvas74GogHl5/Z4A/KQRfk6bU=
 github.com/mattn/go-sqlite3 v1.14.17 h1:mCRHCLDUBXgpKAqIKsaAaAsrAlbkeomtRFKXh2L6YIM=
 github.com/mattn/go-sqlite3 v1.14.17/go.mod h1:2eHXhiwb8IkHr+BDWZGa96P6+rkvnG63S2DGjv9HUNg=
 github.com/mgutz/ansi v0.0.0-20170206155736-9520e82c474b/go.mod h1:01TrycV0kFyexm33Z7vhZRXopbI8J3TDReVlkTgMUxE=

model/seminarGroup.go

@@ -7,10 +7,10 @@ type SeminarGroup struct {
 	Course        string
 	Faculty       string
 	FacultyId     string
-	Events        []Events
+	Events        []Event
 }
 
-type Events struct {
+type Event struct {
 	Day       string
 	Week      string
 	Start     string
@@ -21,4 +21,5 @@ type Events struct {
 	Rooms     string
 	Notes     string
 	BookedAt  string
+	Semester  string
 }

pb_schema.json

@@ -281,6 +281,18 @@
           "max": null,
           "pattern": ""
         }
+      },
+      {
+        "id": "vlbpm9fz",
+        "name": "semester",
+        "type": "text",
+        "system": false,
+        "required": false,
+        "options": {
+          "min": null,
+          "max": null,
+          "pattern": ""
+        }
       }
     ],
     "indexes": [

service/date/dateFormat.go

@@ -0,0 +1,47 @@
+package date
+
+import "time"
+
+func GetDateFromWeekNumber(year int, weekNumber int, dayName string) (time.Time, error) {
+	// Create a time.Date for the first day of the year
+	firstDayOfYear := time.Date(year, time.January, 1, 0, 0, 0, 0, time.UTC)
+
+	// Calculate the number of days to add to reach the desired week
+	daysToAdd := time.Duration((weekNumber-1)*7) * 24 * time.Hour
+
+	// Find the starting day of the week (e.g., Monday)
+	startingDayOfWeek := firstDayOfYear
+
+	// check if the first day of the year is friday or saturday or sunday
+
+	if startingDayOfWeek.Weekday() == time.Friday || startingDayOfWeek.Weekday() == time.Saturday || startingDayOfWeek.Weekday() == time.Sunday {
+		for startingDayOfWeek.Weekday() != time.Monday {
+			startingDayOfWeek = startingDayOfWeek.Add(24 * time.Hour)
+		}
+	} else {
+		for startingDayOfWeek.Weekday() != time.Monday {
+			startingDayOfWeek = startingDayOfWeek.Add(-24 * time.Hour)
+		}
+	}
+
+	// Calculate the desired date by adding daysToAdd and adjusting for the day name
+	desiredDate := startingDayOfWeek.Add(daysToAdd)
+
+	// Find the day of the week
+	dayOfWeek := map[string]time.Weekday{
+		"Montag":     time.Monday,
+		"Dienstag":   time.Tuesday,
+		"Mittwoch":   time.Wednesday,
+		"Donnerstag": time.Thursday,
+		"Freitag":    time.Friday,
+		"Samstag":    time.Saturday,
+		"Sonntag":    time.Sunday,
+	}[dayName]
+
+	// Adjust to the desired day of the week
+	for desiredDate.Weekday() != dayOfWeek {
+		desiredDate = desiredDate.Add(24 * time.Hour)
+	}
+
+	return desiredDate, nil
+}

service/date/dateFormat_test.go

@@ -0,0 +1,64 @@
+package date
+
+import (
+	"reflect"
+	"testing"
+	"time"
+)
+
+func Test_getDateFromWeekNumber(t *testing.T) {
+	type args struct {
+		year       int
+		weekNumber int
+		dayName    string
+	}
+	tests := []struct {
+		name    string
+		args    args
+		want    time.Time
+		wantErr bool
+	}{
+		{
+			name: "Test 1",
+			args: args{
+				year:       2021,
+				weekNumber: 1,
+				dayName:    "Montag",
+			},
+			want:    time.Date(2021, 1, 4, 0, 0, 0, 0, time.UTC),
+			wantErr: false,
+		},
+		{
+			name: "Test 2",
+			args: args{
+				year:       2023,
+				weekNumber: 57,
+				dayName:    "Montag",
+			},
+			want:    time.Date(2024, 1, 29, 0, 0, 0, 0, time.UTC),
+			wantErr: false,
+		},
+		{
+			name: "Test 3",
+			args: args{
+				year:       2023,
+				weekNumber: 1,
+				dayName:    "Montag",
+			},
+			want:    time.Date(2023, 1, 2, 0, 0, 0, 0, time.UTC),
+			wantErr: false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := GetDateFromWeekNumber(tt.args.year, tt.args.weekNumber, tt.args.dayName)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("getDateFromWeekNumber() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("getDateFromWeekNumber() got = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}

service/db/dbEvents.go

@@ -1,10 +1,13 @@
 package db
 
 import (
+	"github.com/jordic/goics"
+	"github.com/pocketbase/dbx"
 	"github.com/pocketbase/pocketbase"
 	"github.com/pocketbase/pocketbase/models"
 	"htwk-planner/model"
 	"strings"
+	"time"
 )
 
 func SaveEvents(seminarGroup []model.SeminarGroup, collection *models.Collection, app *pocketbase.PocketBase) error {
@@ -24,6 +27,7 @@ func SaveEvents(seminarGroup []model.SeminarGroup, collection *models.Collection
 			record.Set("Notes", event.Notes)
 			record.Set("BookedAt", event.BookedAt)
 			record.Set("course", seminarGroup.Course)
+			record.Set("semester", event.Semester)
 			err = app.Dao().SaveRecord(record)
 			if err != nil {
 				println("Error while saving record: ", err.Error())
@@ -42,7 +46,7 @@ func contains(s []string, e string) bool {
 	return false
 }
 
-// GetRooms function to get all rooms from database that are stored as a string in the Events struct
+// GetRooms function to get all rooms from database that are stored as a string in the Event struct
 func GetRooms(app *pocketbase.PocketBase) []string {
 
 	var events []struct {
@@ -70,3 +74,39 @@ func GetRooms(app *pocketbase.PocketBase) []string {
 	}
 	return roomArray
 }
+
+type Events []*model.Event
+
+// EmitICal implements the interface for goics
+func (e Events) EmitICal() goics.Componenter {
+	c := goics.NewComponent()
+	c.SetType("VCALENDAR")
+	c.AddProperty("CALSCAL", "GREGORIAN")
+	for _, event := range e {
+		s := goics.NewComponent()
+		s.SetType("VEVENT")
+		timeEnd, _ := time.Parse("2024-01-07 07:00:00 +0000 UTC", event.End)
+		timeStart, _ := time.Parse("2024-01-07 07:00:00 +0000 UTC", event.Start)
+		k, v := goics.FormatDateTimeField("DTEND", timeEnd)
+		s.AddProperty(k, v)
+		k, v = goics.FormatDateTimeField("DTSTART", timeStart)
+		s.AddProperty(k, v)
+		s.AddProperty("SUMMARY", event.Name)
+		s.AddProperty("DESCRIPTION", event.Notes)
+		s.AddProperty("LOCATION", event.Rooms)
+		c.AddComponent(s)
+	}
+	return c
+}
+
+// GetPlanForCourseAndSemester gets all events for specific course and semester
+func GetPlanForCourseAndSemester(app *pocketbase.PocketBase, course string, semester string) Events {
+	var events Events
+	// get all events from event records in the events collection
+	err := app.Dao().DB().Select("*").From("events").Where(dbx.NewExp("course = {:course} AND semester = {:semester}", dbx.Params{"course": course, "semester": semester})).All(&events)
+	if err != nil {
+		print("Error while getting events from database: ", err)
+		return nil
+	}
+	return events
+}

service/fetch/fetchSeminarGroupService.go

@@ -1,4 +1,4 @@
-package service
+package fetch
 
 import (
 	"encoding/xml"
@@ -40,7 +40,7 @@ func getSeminarHTML() (string, error) {
 
 }
 
-func FetchSeminarGroups(c echo.Context, app *pocketbase.PocketBase) error {
+func SeminarGroups(c echo.Context, app *pocketbase.PocketBase) error {
 
 	result, _ := getSeminarHTML()
 
@@ -55,7 +55,7 @@ func FetchSeminarGroups(c echo.Context, app *pocketbase.PocketBase) error {
 
 	dbError = db.SaveGroups(groups, collection, app)
 	if dbError != nil {
-		return apis.NewApiError(400, "Could not save Events into database", dbError)
+		return apis.NewApiError(400, "Could not save Event into database", dbError)
 	}
 
 	return c.JSON(http.StatusOK, groups)
@@ -64,7 +64,6 @@ func FetchSeminarGroups(c echo.Context, app *pocketbase.PocketBase) error {
 func parseSeminarGroups(result string) []model.SeminarGroup {
 
 	var studium model.Studium
-
 	err := xml.Unmarshal([]byte(result), &studium)
 	if err != nil {
 		return nil

service/fetch/fetchService.go

@@ -1,4 +1,4 @@
-package service
+package fetch
 
 import (
 	"fmt"
@@ -8,11 +8,14 @@ import (
 	"github.com/pocketbase/pocketbase/models"
 	"golang.org/x/net/html"
 	"htwk-planner/model"
+	"htwk-planner/service/date"
 	"htwk-planner/service/db"
 	"io"
 	"net/http"
+	"regexp"
 	"strconv"
 	"strings"
+	"time"
 )
 
 func FetchHTWK(c echo.Context, app *pocketbase.PocketBase) error {
@@ -44,7 +47,7 @@ func FetchHTWK(c echo.Context, app *pocketbase.PocketBase) error {
 
 	dbError = db.SaveEvents(seminarGroups, collection, app)
 	if dbError != nil {
-		return apis.NewApiError(400, "Could not save Events into database", dbError)
+		return apis.NewApiError(400, "Could not save Event into database", dbError)
 	}
 
 	return c.JSON(http.StatusOK, seminarGroups)
@@ -73,24 +76,87 @@ func parseSeminarGroup(result string) model.SeminarGroup {
 	eventsWithCombinedWeeks := toEvents(eventTables, allDayLabels)
 	splitEventsByWeekVal := splitEventsByWeek(eventsWithCombinedWeeks)
 	events := splitEventsBySingleWeek(splitEventsByWeekVal)
+	semesterString := findFirstSpanWithClass(table, "header-0-2-0").FirstChild.Data
+	semester, year := extractSemesterAndYear(semesterString)
+	events = convertWeeksToDates(events, semester, year)
 	var seminarGroup = model.SeminarGroup{
 		University: findFirstSpanWithClass(table, "header-1-0-0").FirstChild.Data,
 		Course:     findFirstSpanWithClass(table, "header-2-0-1").FirstChild.Data,
 		Events:     events,
 	}
-
 	return seminarGroup
 }
 
-func toEvents(tables [][]*html.Node, days []string) []model.Events {
+func convertWeeksToDates(events []model.Event, semester string, year string) []model.Event {
-	var events []model.Events
+	var newEvents []model.Event
+	eventYear, _ := strconv.Atoi(year)
+
+	// for each event we need to calculate the start and end date based on the week and the year
+	for _, event := range events {
+		eventWeek, _ := strconv.Atoi(event.Week)
+		eventDay, _ := date.GetDateFromWeekNumber(eventYear, eventWeek, event.Day)
+		start := addTimeToDate(eventDay, event.Start)
+		end := addTimeToDate(eventDay, event.End)
+		newEvent := event
+		newEvent.Start = start.String()
+		newEvent.End = end.String()
+		newEvent.Semester = semester
+		newEvents = append(newEvents, newEvent)
+	}
+	return newEvents
+}
+
+func addTimeToDate(date time.Time, timeString string) time.Time {
+	//convert time string to time
+	timeParts := strings.Split(timeString, ":")
+	hour, _ := strconv.Atoi(timeParts[0])
+	minute, _ := strconv.Atoi(timeParts[1])
+
+	return time.Date(date.Year(), date.Month(), date.Day(), hour, minute, 0, 0, time.UTC)
+}
+
+func extractSemesterAndYear(semesterString string) (string, string) {
+	winterPattern := "Wintersemester"
+	summerPattern := "Sommersemester"
+
+	winterMatch := strings.Contains(semesterString, winterPattern)
+	summerMatch := strings.Contains(semesterString, summerPattern)
+
+	semester := ""
+	semesterShortcut := ""
+
+	if winterMatch {
+		semester = "Wintersemester"
+		semesterShortcut = "ws"
+	} else if summerMatch {
+		semester = "Sommersemester"
+		semesterShortcut = "ss"
+	} else {
+		return "", ""
+	}
+
+	yearPattern := `\d{4}`
+	combinedPattern := semester + `\s` + yearPattern
+	re := regexp.MustCompile(combinedPattern)
+	match := re.FindString(semesterString)
+	year := ""
+
+	if match != "" {
+		reYear := regexp.MustCompile(yearPattern)
+		year = reYear.FindString(match)
+	}
+	return semesterShortcut, year
+}
+
+func toEvents(tables [][]*html.Node, days []string) []model.Event {
+	var events []model.Event
 
 	for table := range tables {
 		for row := range tables[table] {
 
 			tableData := findTableData(tables[table][row])
 			if len(tableData) > 0 {
-				events = append(events, model.Events{
+				events = append(events, model.Event{
 					Day:       days[table],
 					Week:      getTextContent(tableData[0]),
 					Start:     getTextContent(tableData[1]),
@@ -110,8 +176,8 @@ func toEvents(tables [][]*html.Node, days []string) []model.Events {
 	return events
 }
 
-func splitEventsByWeek(events []model.Events) []model.Events {
+func splitEventsByWeek(events []model.Event) []model.Event {
-	var newEvents []model.Events
+	var newEvents []model.Event
 
 	for _, event := range events {
 		weeks := strings.Split(event.Week, ",")
@@ -124,8 +190,8 @@ func splitEventsByWeek(events []model.Events) []model.Events {
 	return newEvents
 }
 
-func splitEventsBySingleWeek(events []model.Events) []model.Events {
+func splitEventsBySingleWeek(events []model.Event) []model.Event {
-	var newEvents []model.Events
+	var newEvents []model.Event
 
 	for _, event := range events {
 		if strings.Contains(event.Week, "-") {

service/fetch/fetchService_test.go

@@ -0,0 +1,52 @@
+package fetch
+
+import "testing"
+
+func Test_extractSemesterAndYear(t *testing.T) {
+	type args struct {
+		semesterString string
+	}
+	tests := []struct {
+		name  string
+		args  args
+		want  string
+		want1 string
+	}{
+		// TODO: Add test cases.
+		{
+			name: "Test 1",
+			args: args{
+				semesterString: "Wintersemester 2023/24 (Planungszeitraum 01.09.2023 bis 03.03.2024)",
+			},
+			want:  "ws",
+			want1: "2023",
+		},
+		{
+			name: "Test 2",
+			args: args{
+				semesterString: "Sommersemester 2023 (Planungszeitraum 06.03. bis 31.08.2023)",
+			},
+			want:  "ss",
+			want1: "2023",
+		},
+		{
+			name: "Test 3",
+			args: args{
+				semesterString: "Sommersemester 2010 (Planungszeitraum 06.03. bis 31.08.2023)",
+			},
+			want:  "ss",
+			want1: "2010",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, got1 := extractSemesterAndYear(tt.args.semesterString)
+			if got != tt.want {
+				t.Errorf("extractSemesterAndYear() got = %v, want %v", got, tt.want)
+			}
+			if got1 != tt.want1 {
+				t.Errorf("extractSemesterAndYear() got1 = %v, want %v", got1, tt.want1)
+			}
+		})
+	}
+}

service/ical/ical.go

@@ -0,0 +1,79 @@
+package ical
+
+import (
+	"bytes"
+	"crypto/rand"
+	"fmt"
+	"github.com/jordic/goics"
+	"github.com/labstack/echo/v5"
+	"github.com/pocketbase/pocketbase"
+	"htwk-planner/service/db"
+	"log"
+	"net/http"
+	"time"
+)
+
+const expirationTime = 5 * time.Minute
+
+var cache = make(map[string]*FeedModel)
+
+func FeedURL(c echo.Context, app *pocketbase.PocketBase) error {
+	token := randomToken(20)
+	_, err := createFeedForToken(app, token)
+	if err != nil {
+		return err
+	}
+	return c.JSON(http.StatusOK, fmt.Sprintf("FeedToken: %s", token))
+}
+
+func Feed(c echo.Context, app *pocketbase.PocketBase) error {
+
+	var result string
+	var responseWriter http.ResponseWriter
+	token := c.Request().Header.Get("token")
+	log.Print("iCal feed Token: " + token)
+	feed, ok := cache[token]
+	if !ok || feed == nil {
+		return c.JSON(http.StatusNotFound, "No FeedModel for this Token")
+	}
+
+	result = feed.Content
+	if feed.ExpiresAt.Before(time.Now()) {
+		newFeed, err := createFeedForToken(app, token)
+		if err != nil {
+			return c.JSON(http.StatusInternalServerError, err)
+		}
+		result = newFeed.Content
+	}
+
+	responseWriter.Header().Set("Content-type", "text/calendar")
+	responseWriter.Header().Set("charset", "utf-8")
+	responseWriter.Header().Set("Content-Disposition", "inline")
+	responseWriter.Header().Set("filename", "calendar.ics")
+	writeSuccess(result, responseWriter)
+	c.Response().Writer = responseWriter
+	return nil
+}
+
+func createFeedForToken(app *pocketbase.PocketBase, token string) (*FeedModel, error) {
+	res := db.GetPlanForCourseAndSemester(app, "22INM", "ws")
+	b := bytes.Buffer{}
+	goics.NewICalEncode(&b).Encode(res)
+	feed := &FeedModel{Content: b.String(), ExpiresAt: time.Now().Add(expirationTime)}
+	cache[token] = feed
+	return feed, nil
+}
+
+func randomToken(len int) string {
+	b := make([]byte, len)
+	read, err := rand.Read(b)
+	if err != nil {
+		return ""
+	}
+	return fmt.Sprintf("%x", read)
+}
+
+func writeSuccess(message string, w http.ResponseWriter) {
+	w.WriteHeader(http.StatusOK)
+	w.Write([]byte(message))
+}

service/ical/icalModel.go

@@ -0,0 +1,24 @@
+package ical
+
+import (
+	"htwk-planner/model"
+	"time"
+)
+
+// FeedModel is an iCal feed
+type FeedModel struct {
+	Content   string
+	ExpiresAt time.Time
+}
+
+// Entry is a time entry
+type Entry struct {
+	DateStart   time.Time `json:"dateStart"`
+	DateEnd     time.Time `json:"dateEnd"`
+	Description string    `json:"description"`
+}
+
+// Entries is a collection of entries
+type Entries []*Entry
+
+type Events []*model.Event