feat:#53 added merge events for ical feed

backend/service/feed/feedFunctions.go

@@ -20,9 +20,12 @@ import (
 	"database/sql"
 	"github.com/pocketbase/dbx"
 	"github.com/pocketbase/pocketbase/daos"
+	"htwkalender/model"
 	database "htwkalender/service/db"
+	"htwkalender/service/functions"
 	localTime "htwkalender/service/functions/time"
 	"log/slog"
+	"strings"
 )
 
 func ClearFeeds(db *daos.Dao, months int, clock localTime.Clock) {
@@ -50,3 +53,89 @@ func ClearFeeds(db *daos.Dao, months int, clock localTime.Clock) {
 		}
 	}
 }
+
+func CombineEventsInFeed(events model.Events) model.Events {
+	// Combine events with the same Prof, Name, Start and End time into one event
+	// if the note is empty then there is no room displayed in the new note
+	// room listing isn't displayed if there is only one event.
+
+	combinedEvents := make(model.Events, 0)
+	combinedEvents = append(combinedEvents, events[0])
+
+	for index1 := 1; index1 < len(events); index1++ {
+		for index2 := 0; index2 < len(combinedEvents); index2++ {
+
+			if events[index1].Name == combinedEvents[index2].Name &&
+				events[index1].Start == combinedEvents[index2].Start &&
+				events[index1].End == combinedEvents[index2].End &&
+				events[index1].Course == combinedEvents[index2].Course {
+
+				// if no notes are present skip
+				if !functions.OnlyWhitespace(events[index1].Notes) {
+					// if combinedEvents notes are empty, add the new notes
+					if functions.OnlyWhitespace(combinedEvents[index2].Notes) {
+						combinedEvents[index2].Notes = descriptionString(events[index1])
+					} else {
+						addNotesIfAlreadyRoomsAdded(events, combinedEvents, index2, index1)
+					}
+				}
+
+				combineRooms(events, index1, combinedEvents, index2)
+				combineProfs(events, index1, combinedEvents, index2)
+
+				// remove the event from the events list
+				events = append(events[:index1], events[index1+1:]...)
+
+				break
+
+			} else {
+				// if the event is not in the combinedEvents list, add it
+				if index2 == len(combinedEvents)-1 {
+					combinedEvents = append(combinedEvents, events[index1])
+					events = append(events[:index1], events[index1+1:]...)
+					break
+				}
+			}
+		}
+	}
+	return combinedEvents
+}
+
+func addNotesIfAlreadyRoomsAdded(events model.Events, combinedEvents model.Events, index2 int, index1 int) {
+	// check if combinedEvents[index2].Rooms string contains comma "," &#44
+	if !strings.Contains(combinedEvents[index2].Rooms, ",") {
+		combinedEvents[index2].Notes = descriptionString(combinedEvents[index2]) + "\n" + descriptionString(events[index1])
+	} else {
+		combinedEvents[index2].Notes += "\n" + descriptionString(events[index1])
+	}
+}
+
+func combineProfs(events model.Events, index1 int, combinedEvents model.Events, index2 int) {
+	// combine the profs
+	if events[index1].Prof != "" {
+		if combinedEvents[index2].Prof == "" {
+			combinedEvents[index2].Prof = events[index1].Prof
+		} else {
+			if !strings.Contains(combinedEvents[index2].Prof, events[index1].Prof) {
+				combinedEvents[index2].Prof += ", " + events[index1].Prof
+			}
+		}
+	}
+}
+
+func descriptionString(event model.Event) string {
+	return event.Rooms + " - " + event.Notes + " (" + event.Prof + ")"
+}
+
+func combineRooms(events model.Events, index1 int, combinedEvents model.Events, index2 int) {
+	// combine the rooms
+	if events[index1].Rooms != "" {
+		if combinedEvents[index2].Rooms == "" {
+			combinedEvents[index2].Rooms = events[index1].Rooms
+		} else {
+			if !strings.Contains(combinedEvents[index2].Rooms, events[index1].Rooms) {
+				combinedEvents[index2].Rooms += ", " + events[index1].Rooms
+			}
+		}
+	}
+}