Feature: Adjust/Hide Events/Courses (#197)

* feat: allow filtering courses from calendar

* feat: fix tests, add filtering test

* fix: adjust course tag regex

* fix: address style comments, fix switch statement

* feat: filter by course name, not tag

* replace redundant code

* fix variable rename during rebase

* app_test: fix course filtering

* add recurrences to course adjustment view

* change 'filter' to 'hide', add offet input

* output course adjustments as query params

* remove todo for prefilling course adjustments

In order to be able to prefill the course adjustment page with
previously selected values, we would need to have the user
provide his https://campus.tum... link instead of https://cal.tum.ap...

It's probably better to just store the settings in the browser and
load them when revisiting the site.

* parse offsets and apply to vevents

* fix parseOffsetQuery

* adjustEventTimes: actually do the adjustment (facepalm)

* adjustTimes: use endOffset (not startOffset)

* fix test: change of getCleanedCalendar parameters

* add test for time adjustment

* display recurringid on course adjustment section

* Fix startOffset generation and improve parsing robustness (#198)

- Fixed a bug in `internal/static/main.js` where negative start offsets were generated with an extra space (e.g., `123 -10` instead of `123-10`), causing parsing errors on the backend.
- Updated `internal/app.go` `parseOffsetsQuery` to trim spaces from input parts, making the backend robust against malformed or space-padded offset strings.
- Refactored boolean checks in `internal/app.go` to use idiomatic Go (e.g., `!exists` instead of `exists == false`).
- Added comprehensive unit tests for `parseOffsetsQuery` in `internal/app_test.go` covering valid, negative, malformed, and space-padded inputs.

Co-authored-by: google-labs-jules[bot] <161369871+google-labs-jules[bot]@users.noreply.github.com>

* Remove time adjustment query parameters and functionality (#199)

- Removed `startOffset` and `endOffset` query parameter handling in `internal/app.go`.
- Removed `adjustEventTimes` logic for shifting event times.
- Updated `getCleanedCalendar` signature to remove offset maps.
- Removed frontend UI and logic for setting time offsets in `internal/static/main.js`.
- Cleaned up tests in `internal/app_test.go` by removing `TestCourseTimeAdjustment` and updating calls.
- Removed unused imports in `internal/app.go`.

Co-authored-by: google-labs-jules[bot] <161369871+google-labs-jules[bot]@users.noreply.github.com>
Co-authored-by: Kordian Bruck <[email protected]>

* Fix imports

* Fix variable overload

* Use non versioned alpine image for go, instead of locking the alpine version.

* Remove test cases for time adjustments

* Remove time adjustment code

* Fixups to make this work properly.

* Cleanup the code a bit more.

* Properly cleanup the summary for hiding courses.

* Make sure to respect the boolean when populating the checkboxes in the frontend.

* Fix test cases

---------

Co-authored-by: Florian Pfisterer <[email protected]>
Co-authored-by: Sandro Pischinger <[email protected]>
Co-authored-by: Joscha Henningsen <[email protected]>
Co-authored-by: nycex <[email protected]>
Co-authored-by: google-labs-jules[bot] <161369871+google-labs-jules[bot]@users.noreply.github.com>

Author: 6 people

Dockerfile

@@ -1,4 +1,4 @@
-FROM golang:1.24-alpine3.20 as builder
+FROM golang:1.24-alpine as builder
 
 # Ca-certificates are required to call HTTPS endpoints.
 RUN apk update && apk add --no-cache ca-certificates tzdata alpine-sdk bash && update-ca-certificates

internal/app.go

@@ -3,8 +3,10 @@ package internal
 import (
 	"embed"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
+	"log"
 	"net/http"
 	"net/url"
 	"regexp"
@@ -41,6 +43,11 @@ type Replacement struct {
 	value string
 }
 
+type Course struct {
+	Summary string `json:"summary"`
+	Hide    bool   `json:"hide"`
+}
+
 // for sorting replacements by length, then alphabetically
 func (r1 *Replacement) isLessThan(r2 *Replacement) bool {
 	if len(r1.key) != len(r2.key) {
@@ -141,6 +148,7 @@ func (a *App) Run() error {
 }
 
 func (a *App) configRoutes() {
+	a.engine.GET("/api/courses", a.handleGetCourses)
 	a.engine.GET("/health", func(c *gin.Context) {
 		c.JSON(http.StatusOK, gin.H{
 			"status": "ok",
@@ -180,54 +188,119 @@ func getUrl(c *gin.Context) string {
 	return fmt.Sprintf("https://campus.tum.de/tumonlinej/ws/termin/ical?pStud=%s&pToken=%s", stud, token)
 }
 
-func (a *App) handleIcal(c *gin.Context) {
-	url := getUrl(c)
-	if url == "" {
-		return
+func getCalendar(ctx *gin.Context) ([]byte, map[string]bool, error) {
+	fetchURL := getUrl(ctx)
+	if fetchURL == "" {
+		return nil, nil, errors.New("no fetchable URL passed")
 	}
-	resp, err := http.Get(url)
+	resp, err := http.Get(fetchURL)
 	if err != nil {
-		c.AbortWithStatusJSON(http.StatusInternalServerError, err)
-		return
+		return nil, nil, fmt.Errorf("can't fetch calendar: %w", err)
 	}
 	all, err := io.ReadAll(resp.Body)
 	if err != nil {
-		c.AbortWithStatusJSON(http.StatusInternalServerError, err)
+		return nil, nil, fmt.Errorf("can't read calendar: %w", err)
+	}
+
+	// Create map of all hidden courses
+	hide := ctx.QueryArray("hide")
+	hiddenCourses := make(map[string]bool)
+	for _, course := range hide {
+		hiddenCourses[course] = true
+	}
+
+	return all, hiddenCourses, nil
+}
+
+// handleIcal returns a filtered calendar with all courses that are currently offered on campus.
+func (a *App) handleIcal(ctx *gin.Context) {
+	allEvents, hiddenCourses, err := getCalendar(ctx)
+	if err != nil {
+		ctx.AbortWithStatusJSON(http.StatusInternalServerError, err)
 		return
 	}
-	cleaned, err := a.getCleanedCalendar(all)
+
+	cleaned, err := a.getCleanedCalendar(allEvents, hiddenCourses)
 	if err != nil {
-		c.AbortWithStatus(http.StatusInternalServerError)
+		ctx.AbortWithStatus(http.StatusInternalServerError)
 		return
 	}
+
 	response := []byte(cleaned.Serialize())
-	c.Header("Content-Type", "text/calendar")
-	c.Header("Content-Length", fmt.Sprintf("%d", len(response)))
+	ctx.Header("Content-Type", "text/calendar")
+	ctx.Header("Content-Length", fmt.Sprintf("%d", len(response)))
 
-	if _, err := c.Writer.Write(response); err != nil {
+	if _, err := ctx.Writer.Write(response); err != nil {
 		sentry.CaptureException(err)
 	}
 }
 
-func (a *App) getCleanedCalendar(all []byte) (*ics.Calendar, error) {
+// handleGetCourses returns a list of all courses that are currently offered on campus.
+// This is used to populate the dropdown in the landing page for hiding courses.
+func (a *App) handleGetCourses(ctx *gin.Context) {
+	allEvents, hidden, err := getCalendar(ctx)
+	if err != nil {
+		ctx.AbortWithStatusJSON(http.StatusInternalServerError, err)
+		return
+	}
+
+	cal, err := a.getCleanedCalendar(allEvents, map[string]bool{})
+	if err != nil {
+		ctx.AbortWithStatus(http.StatusInternalServerError)
+		return
+	}
+
+	// detect all courses, de-duplicate them by their summary (lecture name)
+	courses := make(map[string]Course)
+	for _, component := range cal.Components {
+		switch component.(type) {
+		case *ics.VEvent:
+			eventSummary := cleanEventSummary(component.(*ics.VEvent).GetProperty(ics.ComponentPropertySummary).Value)
+			if _, exists := courses[eventSummary]; !exists {
+				courses[eventSummary] = Course{
+					Summary: eventSummary,
+					// Check for existing hidden course, that might want to be updated
+					Hide: hidden[eventSummary],
+				}
+			}
+			log.Printf("summaries: %s", eventSummary)
+		default:
+			continue
+		}
+	}
+
+	ctx.JSON(http.StatusOK, courses)
+}
+
+func (a *App) getCleanedCalendar(all []byte, hiddenCourses map[string]bool) (*ics.Calendar, error) {
 	cal, err := ics.ParseCalendar(strings.NewReader(string(all)))
 	if err != nil {
 		return nil, err
 	}
 
-	// Create map that tracks if we have allready seen a lecture name & datetime (e.g. "lecturexyz-1.2.2024 10:00" -> true)
+	// Create map that tracks if we have already seen a lecture name & datetime (e.g. "lecturexyz-1.2.2024 10:00" -> true)
 	hasLecture := make(map[string]bool)
 	var newComponents []ics.Component // saves the components we keep because they are not duplicated
 
 	for _, component := range cal.Components {
 		switch component.(type) {
 		case *ics.VEvent:
 			event := component.(*ics.VEvent)
+
+			// check if the summary contains any of the hidden keys, and if yes, skip it
+			eventSummary := event.GetProperty(ics.ComponentPropertySummary).Value
+			if hiddenCourses[eventSummary] {
+				continue
+			}
+
+			// deduplicate lectures by their summary and datetime
 			dedupKey := fmt.Sprintf("%s-%s", event.GetProperty(ics.ComponentPropertySummary).Value, event.GetProperty(ics.ComponentPropertyDtStart))
 			if _, ok := hasLecture[dedupKey]; ok {
 				continue
 			}
 			hasLecture[dedupKey] = true // mark event as seen
+
+			// clean up the event
 			a.cleanEvent(event)
 			newComponents = append(newComponents, event)
 		default: // keep everything that is not an event (metadata etc.)
@@ -248,7 +321,7 @@ var reLoc = regexp.MustCompile(" ?(München|Garching|Weihenstephan).+")
 // Matches repeated whitespaces
 var reSpace = regexp.MustCompile(`\s\s+`)
 
-// Matches weird starting numbers like "0000002467 " in "0000002467 Semantik"
+// Matches unique starting numbers like "0000002467 " in "0000002467 Semantik"
 var reWeirdStartingNumbers = regexp.MustCompile(`^0\d+ `)
 
 var unneeded = []string{
@@ -272,7 +345,7 @@ var reNavigaTUM = regexp.MustCompile("\\(\\d{4}\\.[a-zA-Z0-9]{2}\\.\\d{3}[A-Z]?\
 func (a *App) cleanEvent(event *ics.VEvent) {
 	summary := ""
 	if s := event.GetProperty(ics.ComponentPropertySummary); s != nil {
-		summary = strings.ReplaceAll(s.Value, "\\", "")
+		summary = cleanEventSummary(s.Value)
 	}
 
 	description := ""
@@ -285,9 +358,9 @@ func (a *App) cleanEvent(event *ics.VEvent) {
 		location = strings.ReplaceAll(event.GetProperty(ics.ComponentPropertyLocation).Value, "\\", "")
 	}
 
-	//Remove the TAG and anything after e.g.: (IN0001) or [MA0001]
+	// Remove the TAG and anything after e.g.: (IN0001) or [MA0001]
 	summary = reTag.ReplaceAllString(summary, "")
-	//remove location and teacher from language course title
+	// remove location and teacher from the language course title
 	summary = reLoc.ReplaceAllString(summary, "")
 	summary = reSpace.ReplaceAllString(summary, "")
 	for _, replace := range unneeded {
@@ -299,7 +372,7 @@ func (a *App) cleanEvent(event *ics.VEvent) {
 
 	event.SetSummary(summary)
 
-	//Remember the old title in the description
+	// Remember the old title in the description
 	description = summary + "\n" + description
 
 	results := reRoom.FindStringSubmatch(location)
@@ -329,3 +402,10 @@ func (a *App) cleanEvent(event *ics.VEvent) {
 		event.SetStatus(ics.ObjectStatusTentative)
 	}
 }
+
+func cleanEventSummary(eventSummary string) string {
+	eventSummary = strings.ReplaceAll(eventSummary, "\\", "")
+	eventSummary = strings.TrimSpace(eventSummary)
+	eventSummary = strings.TrimSuffix(eventSummary, " ,")
+	return eventSummary
+}

internal/app_test.go

@@ -1,10 +1,12 @@
 package internal
 
 import (
-	ics "github.com/arran4/golang-ical"
 	"io"
 	"os"
+	"strings"
 	"testing"
+
+	ics "github.com/arran4/golang-ical"
 )
 
 func getTestData(t *testing.T, name string) (string, *App) {
@@ -58,7 +60,7 @@ func TestReplacement(t *testing.T) {
 
 func TestDeduplication(t *testing.T) {
 	testData, app := getTestData(t, "duplication.ics")
-	calendar, err := app.getCleanedCalendar([]byte(testData))
+	calendar, err := app.getCleanedCalendar([]byte(testData), map[string]bool{})
 	if err != nil {
 		t.Error(err)
 		return
@@ -71,7 +73,7 @@ func TestDeduplication(t *testing.T) {
 
 func TestNameShortening(t *testing.T) {
 	testData, app := getTestData(t, "nameshortening.ics")
-	calendar, err := app.getCleanedCalendar([]byte(testData))
+	calendar, err := app.getCleanedCalendar([]byte(testData), map[string]bool{})
 	if err != nil {
 		t.Error(err)
 		return
@@ -85,7 +87,7 @@ func TestNameShortening(t *testing.T) {
 
 func TestLocationReplacement(t *testing.T) {
 	testData, app := getTestData(t, "location.ics")
-	calendar, err := app.getCleanedCalendar([]byte(testData))
+	calendar, err := app.getCleanedCalendar([]byte(testData), map[string]bool{})
 	if err != nil {
 		t.Error(err)
 		return
@@ -103,3 +105,37 @@ func TestLocationReplacement(t *testing.T) {
 		return
 	}
 }
+
+func TestCourseFiltering(t *testing.T) {
+	testData, app := getTestData(t, "coursefiltering.ics")
+
+	// make sure the unfiltered calendar has 2 entries
+	fullCalendar, err := app.getCleanedCalendar([]byte(testData), map[string]bool{})
+	if err != nil {
+		t.Error(err)
+		return
+	}
+	if len(fullCalendar.Components) != 2 {
+		t.Errorf("Calendar should have 2 entries before course filtering but has %d", len(fullCalendar.Components))
+		return
+	}
+
+	// now filter out one course
+	filter := "Einführung in die Rechnerarchitektur (IN0004) VO\\, Standardgruppe"
+	filteredCalendar, err := app.getCleanedCalendar([]byte(testData), map[string]bool{filter: true})
+	if err != nil {
+		t.Error(err)
+		return
+	}
+	if len(filteredCalendar.Components) != 1 {
+		t.Errorf("Calendar should have only 1 entry after course filtering but has %d", len(filteredCalendar.Components))
+		return
+	}
+
+	// make sure the summary does not contain the filtered course's name
+	summary := filteredCalendar.Components[0].(*ics.VEvent).GetProperty(ics.ComponentPropertySummary).Value
+	if strings.Contains(summary, filter) {
+		t.Errorf("Summary should not contain %s but is %s", filter, summary)
+		return
+	}
+}

internal/static/index.html

@@ -47,6 +47,7 @@ <h2>About</h2>
           </li>
           <li>Replaces 'Tutorübung' with 'TÜ'</li>
           <li>Remove event duplicates due to multiple rooms</li>
+          <li>Allows you to hide courses in your calendar without de-registering in TUMOnline</li>
         </ul>
 
         <h2>HowTo</h2>
@@ -62,6 +63,7 @@ <h2>HowTo</h2>
                 type="url"
                 id="tumCalLink"
                 placeholder="https://campus.tum.de/tumonlinej/ws/termin/ical?pStud=abc&pToken=xyz"
+                oninput="reloadCourses()"
               />
               <button id="generateLinkBtn" onclick="generateLink()">
                 Generate & Copy
@@ -74,15 +76,14 @@ <h2>HowTo</h2>
             Go to Google Calendar (or similar) and import the resulting url
           </li>
         </ol>
-        <i>
-          If step 2 does not work, try to copy 'n' Paste the query string
-          (everything after the ? sign, e.g. "?pStud=ABCDEF&pToken=XYZ") and
-          append it to this url:
-          <a href="#dontclickme">https://cal.tum.app/</a> so it looks like this:
-          <a href="#dontclickme"
-            >https://cal.tum.app/?pStud=ABCDEF&amp;pToken=XYZ</a
-          >
-        </i>
+
+        <div id="courseAdjustDiv" hidden>
+          <h2>Adjust Courses</h2>
+          <p>
+            You can hide courses from your calendar by un-ticking the checkmarks next to them. This allows you to clean up your calendar without deregistering from the course in TUMOnline. Make sure to click the "Generate & Copy" button again after you have made your changes.
+          </p>
+          <ul id="courseAdjustList"></ul>
+        </div>
 
         <h3>Contribute / Suggest</h3>
         If you want to suggest something create an issue at