validate filler mode pad settings (#1516)

CHANGELOG.md

@@ -4,6 +4,9 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 ## [Unreleased]
+### Fixed
+- Fix playout builder crash with improperly configured pad filler preset
+- Properly validate filler preset mode pad to require `filler pad to nearest minute` value
 
 ## [0.8.3-beta] - 2023-11-22
 ### Added

ErsatzTV.Core/Scheduling/PlayoutModeSchedulerBase.cs

@@ -224,6 +224,17 @@ public abstract class PlayoutModeSchedulerBase<T> : IPlayoutModeScheduler<T> whe
             return new List<PlayoutItem> { playoutItem };
         }
         
+        // missing pad-to-nearest-minute value is invalid; use no filler
+        FillerPreset invalidPadFiller = allFiller
+            .FirstOrDefault(f => f.FillerMode == FillerMode.Pad && f.PadToNearestMinute.HasValue == false);
+        if (invalidPadFiller is not null)
+        {
+            Logger.LogError(
+                "Pad filler ({Filler}) without pad-to-nearest-minute value is invalid; no filler will be used",
+                invalidPadFiller.Name);
+            return new List<PlayoutItem> { playoutItem };
+        }
+
         List<MediaChapter> effectiveChapters = chapters;
         if (allFiller.All(fp => fp.FillerKind != FillerKind.MidRoll) || effectiveChapters.Count <= 1)
         {

ErsatzTV/Validators/FillerPresetEditViewModelValidator.cs

@@ -21,6 +21,9 @@ public class FillerPresetEditViewModelValidator : AbstractValidator<FillerPreset
         When(
             fp => fp.FillerMode == FillerMode.Duration,
             () => RuleFor(fp => fp.Duration).NotNull());
+        When(
+            fp => fp.FillerMode == FillerMode.Pad,
+            () => RuleFor(fp => fp.PadToNearestMinute).NotNull());
 
         When(
             fp => fp.CollectionType == ProgramScheduleItemCollectionType.Collection,