chore: improve error messages

messages/uniworx/misc/de-de-formal.msg

@@ -2800,14 +2800,15 @@ BtnExamAutoOccurrenceNudgeUp: +
 BtnExamAutoOccurrenceNudgeDown: -
 ExamRoomMappingSurname: Nachnamen beginnend mit
 ExamRoomMappingMatriculation: Matrikelnummern endend in
-ExamRoomMappingRandom: Zufällige Zuordnung
+ExamRoomMappingRandom: Verteilung
+ExamRoomMappingRandomHere: Zufällig
 ExamRoomLoad: Auslastung
 ExamRegisteredCount: Anmeldungen
 ExamRegisteredCountOf num@Int64 count@Int64: #{num}/#{count}
 ExamAutoOccurrenceExceptionRuleNoOp: Keine Automatische Verteilung gewählt
-ExamAutoOccurrenceExceptionNotEnoughSpace: Nicht ausreichend Platz
-ExamAutoOccurrenceExceptionNoUsers: Keine Nutzer
-ExamAutoOccurrenceExceptionRoomTooSmall: Automatische Verteilung gescheitert. Es kann helfen kleine Räume zu entfernen.
+ExamAutoOccurrenceExceptionNotEnoughSpace: Mehr Teilnehmer als verfügbare Plätze
+ExamAutoOccurrenceExceptionNoUsers: Keine Teilnehmer
+ExamAutoOccurrenceExceptionRoomTooSmall: Automatische Verteilung gescheitert. Ein anderes Verteil-Verfahren kann erfolgreich sein. Alternativ kann es helfen Räume zu minimieren oder kleine Räume zu entfernen.
 
 NoFilter: Keine Einschränkung
 

messages/uniworx/misc/en-eu.msg

@@ -2792,7 +2792,7 @@ ExamAutoOccurrenceHeading: Automatic occurrence/room distribution
 ExamAutoOccurrenceMinimizeRooms: Minimize number of occurrences used
 ExamAutoOccurrenceMinimizeRoomsTip: Should the list of occurrences/rooms be reduced prior to distribution? Only as many occurrence/rooms as necessary would be used (starting with the biggest).
 ExamAutoOccurrenceOccurrencesChangedInFlight: Occurrences/rooms changed
-ExamAutoOccurrenceParticipantsAssigned num: Occurrence/room assignment rule saved successfully. Also assigned occurence/room to #{num} #{pluralEN num "participant" "participants"}
+ExamAutoOccurrenceParticipantsAssigned num: Occurrence/room assignment rule saved successfully. Also assigned occurrence/room to #{num} #{pluralEN num "participant" "participants"}
 TitleExamAutoOccurrence tid ssh csh examn: #{tid} - #{ssh} - #{csh} #{examn}: Automatic occurrence/room distribution
 BtnExamAutoOccurrenceCalculate: Calculate assignment rules
 BtnExamAutoOccurrenceAccept: Accept assignments
@@ -2800,14 +2800,15 @@ BtnExamAutoOccurrenceNudgeUp: +
 BtnExamAutoOccurrenceNudgeDown: -
 ExamRoomMappingSurname: Surnames starting with
 ExamRoomMappingMatriculation: Matriculation numbers ending in
-ExamRoomMappingRandom: Random assignment
+ExamRoomMappingRandom: Distribution
+ExamRoomMappingRandomHere: Random
 ExamRoomLoad: Utilisation
 ExamRegisteredCount: Registrations
 ExamRegisteredCountOf num count: #{num}/#{count}
 ExamAutoOccurrenceExceptionRuleNoOp: Didn't chose an automatic distribution
-ExamAutoOccurrenceExceptionNotEnoughSpace: Not enough space
+ExamAutoOccurrenceExceptionNotEnoughSpace: More participants than available space
 ExamAutoOccurrenceExceptionNoUsers: No participants
-ExamAutoOccurrenceExceptionRoomTooSmall: Automatic distribution failed. Removing small rooms might help.
+ExamAutoOccurrenceExceptionRoomTooSmall: Automatic distribution failed. A different distribution procedure might succeed. Alternatively, minimizing rooms or removing small rooms might help.
 
 NoFilter: No restriction
 

src/Handler/Utils/Exam.hs

@@ -613,7 +613,7 @@ examAutoOccurrence (hash -> seed) rule ExamAutoOccurrenceConfig{..} occurrences
                   | borderLength < maxTagLength
                   = go restartStart restartBorderLength [] result
                   | otherwise
-                  = []
+                  = []  -- shouldn't happen, but ensures termination on invalid input (e.g. non-monotonic)
                   where
                     restartBorderLength :: Int
                     restartBorderLength = succ borderLength

templates/widgets/exam-occurrence-mapping-description.hamlet

@@ -14,4 +14,4 @@ $newline never
           $else
             …#{titleCase special}
         $of ExamOccurrenceMappingRandom
-          Random
+          _{MsgExamRoomMappingRandomHere}