channel mirror validation improvements (#2396)

* improve channel mirror validation

* fix playout offset

ErsatzTV.Application/Channels/Commands/CreateChannelHandler.cs

@@ -39,13 +39,15 @@ public class CreateChannelHandler(
         (ValidateName(request), await ValidateNumber(dbContext, request, cancellationToken),
             await FFmpegProfileMustExist(dbContext, request, cancellationToken),
             await WatermarkMustExist(dbContext, request, cancellationToken),
-            await FillerPresetMustExist(dbContext, request, cancellationToken))
+            await FillerPresetMustExist(dbContext, request, cancellationToken),
+            await MirrorSourceMustBeValid(dbContext, request, cancellationToken))
         .Apply((
             name,
             number,
             ffmpegProfileId,
             watermarkId,
-            fillerPresetId) =>
+            fillerPresetId,
+            _) =>
         {
             var artwork = new List<Artwork>();
             if (!string.IsNullOrWhiteSpace(request.Logo?.Path))
@@ -192,4 +194,46 @@ public class CreateChannelHandler(
             .Map(o => o.ToValidation<BaseError>(
                 $"Fallback filler {createChannel.FallbackFillerId} does not exist."));
     }
+
+    private static async Task<Validation<BaseError, Unit>> MirrorSourceMustBeValid(
+        TvContext dbContext,
+        CreateChannel createChannel,
+        CancellationToken cancellationToken)
+    {
+        if (createChannel.PlayoutSource is not ChannelPlayoutSource.Mirror)
+        {
+            return Unit.Default;
+        }
+
+        Option<Channel> maybeMirrorSource = await dbContext.Channels
+            .AsNoTracking()
+            .SelectOneAsync(
+                c => c.Id == createChannel.MirrorSourceChannelId,
+                c => c.Id == createChannel.MirrorSourceChannelId,
+                cancellationToken);
+
+        if (maybeMirrorSource.IsNone)
+        {
+            return BaseError.New("Mirror source channel does not exist.");
+        }
+
+        foreach (var mirrorSource in maybeMirrorSource)
+        {
+            if (mirrorSource.PlayoutSource is not ChannelPlayoutSource.Generated)
+            {
+                return BaseError.New(
+                    $"Mirror source channel {mirrorSource.Name} must use generated playout source");
+            }
+        }
+
+        foreach (TimeSpan playoutOffset in Optional(createChannel.PlayoutOffset))
+        {
+            if (playoutOffset < TimeSpan.FromHours(-12) || playoutOffset > TimeSpan.FromHours(12))
+            {
+                return BaseError.New("Playout offset must not be greater than 12 hours");
+            }
+        }
+
+        return Unit.Default;
+    }
 }

ErsatzTV.Application/Channels/Commands/UpdateChannelHandler.cs

@@ -33,6 +33,16 @@ public class UpdateChannelHandler(
         UpdateChannel update,
         CancellationToken cancellationToken)
     {
+        // don't save mirror when playout exists
+        if (c.Playouts.Count > 0)
+        {
+            update = update with
+            {
+                PlayoutSource = ChannelPlayoutSource.Generated,
+                MirrorSourceChannelId = null
+            };
+        }
+
         bool hasEpgChange = c.PlayoutSource != update.PlayoutSource || c.ShowInEpg != update.ShowInEpg;
 
         c.Name = update.Name;
@@ -150,9 +160,11 @@ public class UpdateChannelHandler(
         TvContext dbContext,
         UpdateChannel request,
         CancellationToken cancellationToken) =>
-        (await ChannelMustExist(dbContext, request, cancellationToken), ValidateName(request),
-            await ValidateNumber(dbContext, request, cancellationToken))
-        .Apply((channelToUpdate, _, _) => channelToUpdate);
+        (await ChannelMustExist(dbContext, request, cancellationToken),
+            ValidateName(request),
+            await ValidateNumber(dbContext, request, cancellationToken),
+            await MirrorSourceMustBeValid(dbContext, request, cancellationToken))
+        .Apply((channelToUpdate, _, _, _) => channelToUpdate);
 
     private static Task<Validation<BaseError, Channel>> ChannelMustExist(
         TvContext dbContext,
@@ -161,9 +173,52 @@ public class UpdateChannelHandler(
         dbContext.Channels
             .Include(c => c.Artwork)
             .Include(c => c.Watermark)
+            .Include(c => c.Playouts)
             .SelectOneAsync(c => c.Id, c => c.Id == updateChannel.ChannelId, cancellationToken)
             .Map(o => o.ToValidation<BaseError>("Channel does not exist."));
 
+    private static async Task<Validation<BaseError, Unit>> MirrorSourceMustBeValid(
+        TvContext dbContext,
+        UpdateChannel request,
+        CancellationToken cancellationToken)
+    {
+        if (request.PlayoutSource is not ChannelPlayoutSource.Mirror)
+        {
+            return Unit.Default;
+        }
+
+        Option<Channel> maybeMirrorSource = await dbContext.Channels
+            .AsNoTracking()
+            .SelectOneAsync(
+                c => c.Id == request.MirrorSourceChannelId,
+                c => c.Id == request.MirrorSourceChannelId,
+                cancellationToken);
+
+        if (maybeMirrorSource.IsNone)
+        {
+            return BaseError.New("Mirror source channel does not exist.");
+        }
+
+        foreach (var mirrorSource in maybeMirrorSource)
+        {
+            if (mirrorSource.PlayoutSource is not ChannelPlayoutSource.Generated)
+            {
+                return BaseError.New(
+                    $"Mirror source channel {mirrorSource.Name} must use generated playout source");
+            }
+        }
+
+        foreach (TimeSpan playoutOffset in Optional(request.PlayoutOffset))
+        {
+            if (playoutOffset < TimeSpan.FromHours(-12) || playoutOffset > TimeSpan.FromHours(12))
+            {
+                return BaseError.New("Playout offset must not be greater than 12 hours");
+            }
+        }
+
+        return Unit.Default;
+    }
+
     private static Validation<BaseError, string> ValidateName(UpdateChannel updateChannel) =>
         updateChannel.NotEmpty(c => c.Name)
             .Bind(_ => updateChannel.NotLongerThan(50)(c => c.Name));

ErsatzTV.Application/Playouts/Commands/BuildPlayoutHandler.cs

@@ -171,7 +171,7 @@ public class BuildPlayoutHandler : IRequestHandler<BuildPlayout, Either<BaseErro
             {
                 changeCount += await dbContext.PlayoutItems
                     .Where(pi => pi.PlayoutId == playout.Id)
-                    .Where(pi => pi.Finish < removeBefore.UtcDateTime + referenceData.MinPlayoutOffset)
+                    .Where(pi => pi.Finish < removeBefore.UtcDateTime - referenceData.MaxPlayoutOffset)
                     .ExecuteDeleteAsync(cancellationToken);
             }
 
@@ -349,7 +349,7 @@ public class BuildPlayoutHandler : IRequestHandler<BuildPlayout, Either<BaseErro
             .Where(c => c.Playouts.Any(p => p.Id == playoutId))
             .FirstOrDefaultAsync();
 
-        TimeSpan minPlayoutOffset = TimeSpan.Zero;
+        TimeSpan maxPlayoutOffset = TimeSpan.Zero;
         List<Channel> mirrorChannels = await dbContext.Channels
             .AsNoTracking()
             .Where(c => c.MirrorSourceChannelId == channel.Id)
@@ -357,9 +357,9 @@ public class BuildPlayoutHandler : IRequestHandler<BuildPlayout, Either<BaseErro
         foreach (var mirrorChannel in mirrorChannels)
         {
             var offset = mirrorChannel.PlayoutOffset ?? TimeSpan.Zero;
-            if (offset < minPlayoutOffset)
+            if (offset > maxPlayoutOffset)
             {
-                minPlayoutOffset = offset;
+                maxPlayoutOffset = offset;
             }
         }
 
@@ -465,6 +465,6 @@ public class BuildPlayoutHandler : IRequestHandler<BuildPlayout, Either<BaseErro
             programSchedule,
             programScheduleAlternates,
             playoutHistory,
-            minPlayoutOffset);
+            maxPlayoutOffset);
     }
 }

ErsatzTV.Core/Scheduling/PlayoutReferenceData.cs

@@ -11,4 +11,4 @@ public record PlayoutReferenceData(
     ProgramSchedule ProgramSchedule,
     List<ProgramScheduleAlternate> ProgramScheduleAlternates,
     List<PlayoutHistory> PlayoutHistory,
-    TimeSpan MinPlayoutOffset);
+    TimeSpan MaxPlayoutOffset);

ErsatzTV/Pages/ChannelEditor.razor

@@ -72,7 +72,10 @@
     <div class="d-flex">
         <MudText>Playout Source</MudText>
     </div>
-    <MudSelect @bind-Value="_model.PlayoutSource" For="@(() => _model.PlayoutSource)" HelperText="Controls the source of the channel's content">
+    <MudSelect @bind-Value="_model.PlayoutSource"
+               For="@(() => _model.PlayoutSource)"
+               HelperText="Controls the source of the channel's content. This cannot be changed when the channel already has a playout."
+               Disabled="@(_channels.Any(c => c.Id == Id && c.PlayoutCount > 0))">
         <MudSelectItem Value="@(ChannelPlayoutSource.Generated)">Generated</MudSelectItem>
         <MudSelectItem Value="@(ChannelPlayoutSource.Mirror)">Mirror</MudSelectItem>
     </MudSelect>
@@ -86,7 +89,9 @@
         <MudSelect @bind-Value="_model.MirrorSourceChannelId" For="@(() => _model.MirrorSourceChannelId)"
                    Clearable="true">
             <MudSelectItem T="int?" Value="@((int?)null)">(none)</MudSelectItem>
-            @foreach (ChannelViewModel channel in _channels.OrderBy(c => decimal.Parse(c.Number, CultureInfo.InvariantCulture)))
+            @foreach (ChannelViewModel channel in _channels
+                .Where(c => c.Id != Id && c.PlayoutSource is ChannelPlayoutSource.Generated)
+                .OrderBy(c => decimal.Parse(c.Number, CultureInfo.InvariantCulture)))
             {
                 <MudSelectItem T="int?" Value="@channel.Id">(@channel.Number) - @channel.Name</MudSelectItem>
             }