feat: show additional rooms in notes when deduplicating calendar events (#210)

* Initial plan

* feat: add additional rooms to notes when events are deduplicated

When the same lecture has multiple duplicate calendar entries with
different room locations (same summary and start time), the deduplication
now preserves the additional room information by including them in the
event's description/notes field.

The format is:
Additional rooms:
<room1>
<room2>

<original description>

Co-authored-by: kordianbruck <[email protected]>

* refactor: prevent duplicate room names in additional rooms list

Use a map to track seen locations and prevent duplicates from appearing
in the additional rooms section of the description.

Co-authored-by: kordianbruck <[email protected]>

* Add missing argument.

---------

Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: kordianbruck <[email protected]>
Co-authored-by: Kordian Bruck <[email protected]>
Co-authored-by: Kordian Bruck <[email protected]>

Author: Copilot

internal/app.go

@@ -278,7 +278,25 @@ func (a *App) getCleanedCalendar(all []byte, hiddenCourses map[string]bool) (*ic
 		return nil, err
 	}
 
-	// Create map that tracks if we have already seen a lecture name & datetime (e.g. "lecturexyz-1.2.2024 10:00" -> true)
+	// First pass: collect all locations for each dedup key (lecture name + datetime)
+	// This allows us to show additional rooms in the description when events are deduplicated
+	eventLocations := make(map[string][]string)
+	for _, component := range cal.Components {
+		switch component.(type) {
+		case *ics.VEvent:
+			event := component.(*ics.VEvent)
+			eventSummary := event.GetProperty(ics.ComponentPropertySummary).Value
+			if hiddenCourses[eventSummary] {
+				continue
+			}
+			dedupKey := fmt.Sprintf("%s-%s", eventSummary, event.GetProperty(ics.ComponentPropertyDtStart))
+			if l := event.GetProperty(ics.ComponentPropertyLocation); l != nil && l.Value != "" {
+				eventLocations[dedupKey] = append(eventLocations[dedupKey], l.Value)
+			}
+		}
+	}
+
+	// Second pass: deduplicate and clean events, adding additional rooms to description
 	hasLecture := make(map[string]bool)
 	var newComponents []ics.Component // saves the components we keep because they are not duplicated
 
@@ -300,8 +318,25 @@ func (a *App) getCleanedCalendar(all []byte, hiddenCourses map[string]bool) (*ic
 			}
 			hasLecture[dedupKey] = true // mark event as seen
 
-			// clean up the event
-			a.cleanEvent(event)
+			// Get additional locations from duplicated events (skip the current event's location and duplicates)
+			var additionalLocations []string
+			if locations := eventLocations[dedupKey]; len(locations) > 1 {
+				currentLocation := ""
+				if l := event.GetProperty(ics.ComponentPropertyLocation); l != nil {
+					currentLocation = l.Value
+				}
+				seen := make(map[string]bool)
+				seen[currentLocation] = true
+				for _, loc := range locations {
+					if !seen[loc] {
+						seen[loc] = true
+						additionalLocations = append(additionalLocations, loc)
+					}
+				}
+			}
+
+			// clean up the event (with additional locations for the description)
+			a.cleanEvent(event, additionalLocations)
 			newComponents = append(newComponents, event)
 		default: // keep everything that is not an event (metadata etc.)
 			newComponents = append(newComponents, component)
@@ -342,7 +377,7 @@ var reRoom = regexp.MustCompile("^(.*?),.*?(\\d{4})\\.(?:\\d\\d|EG|UG|DG|Z\\d|U\
 // matches strings like: (5612.03.017), (5612.EG.017), (5612.EG.010B)
 var reNavigaTUM = regexp.MustCompile("\\(\\d{4}\\.[a-zA-Z0-9]{2}\\.\\d{3}[A-Z]?\\)")
 
-func (a *App) cleanEvent(event *ics.VEvent) {
+func (a *App) cleanEvent(event *ics.VEvent, additionalLocations []string) {
 	summary := ""
 	if s := event.GetProperty(ics.ComponentPropertySummary); s != nil {
 		summary = cleanEventSummary(s.Value)
@@ -388,6 +423,12 @@ func (a *App) cleanEvent(event *ics.VEvent) {
 			}
 		}
 	}
+
+	// Add additional locations from deduplicated events to the description
+	if len(additionalLocations) > 0 {
+		description = "Additional rooms:\n" + strings.Join(additionalLocations, "\n") + "\n\n" + description
+	}
+
 	event.SetDescription(description)
 
 	// set title on summary:

internal/app_test.go

@@ -69,6 +69,17 @@ func TestDeduplication(t *testing.T) {
 		t.Errorf("Calendar should have only 1 entry after deduplication but has %d", len(calendar.Components))
 		return
 	}
+
+	// Verify that the additional room from the deduplicated event is in the description
+	desc := calendar.Components[0].(*ics.VEvent).GetProperty(ics.ComponentPropertyDescription).Value
+	if !strings.Contains(desc, "Additional rooms:") {
+		t.Error("Description should contain 'Additional rooms:' when events are deduplicated with different locations")
+		return
+	}
+	if !strings.Contains(desc, "MI HS 1") {
+		t.Error("Description should contain the additional room 'MI HS 1' from the deduplicated event")
+		return
+	}
 }
 
 func TestMultipleRooms(t *testing.T) {
@@ -94,7 +105,7 @@ func TestMultipleRooms(t *testing.T) {
 	event.SetProperty(ics.ComponentPropertyDescription, "Original Description")
 	event.SetProperty(ics.ComponentPropertyStatus, "CONFIRMED")
 
-	app.cleanEvent(event)
+	app.cleanEvent(event, []string{})
 
 	desc := event.GetProperty(ics.ComponentPropertyDescription).Value
 	loc := event.GetProperty(ics.ComponentPropertyLocation).Value
@@ -153,7 +164,7 @@ func TestLocationReplacement(t *testing.T) {
 		return
 	}
 	desc := calendar.Components[0].(*ics.VEvent).GetProperty(ics.ComponentPropertyDescription).Value
-	expectedDescription := "https://nav.tum.de/room/5508.02.801\nMW 1801, Ernst-Schmidt-Hörsaal (5508.02.801)\nEinführung in die Rechnerarchitektur\nfix; Abhaltung;"
+	expectedDescription := "Additional rooms:\nMI HS 1\n\nhttps://nav.tum.de/room/5508.02.801\nMW 1801, Ernst-Schmidt-Hörsaal (5508.02.801)\nEinführung in die Rechnerarchitektur\nfix; Abhaltung;"
 	if desc != expectedDescription {
 		t.Errorf("Description should be %s but is %s", expectedDescription, desc)
 		return