feat(options): eager startup validation for site-pipeline options (SiteRuntime, S&F, SiteEventLog) (arch-review 08 §1.5)

Claude-Session: https://claude.ai/code/session_01MtdgwpEeCUn6cUA5f1LMPj

src/ZB.MOM.WW.ScadaBridge.SiteEventLogging/SiteEventLogOptionsValidator.cs

@@ -0,0 +1,56 @@
+using ZB.MOM.WW.Configuration;
+
+namespace ZB.MOM.WW.ScadaBridge.SiteEventLogging;
+
+/// <summary>
+/// Validates <see cref="SiteEventLogOptions"/> at startup. Retention/purge values
+/// drive the daily purge PeriodicTimer (a zero/negative period trips
+/// <see cref="ArgumentOutOfRangeException"/>), the paging bounds gate query result
+/// sizes, and the write-queue capacity sizes a bounded channel; a
+/// <c>MaxQueryPageSize</c> below <c>QueryPageSize</c> would silently clamp the
+/// default page below itself. Registered with <c>ValidateOnStart()</c> so a bad
+/// <c>ScadaBridge:SiteEventLog</c> section fails fast at boot with a clear,
+/// key-naming message.
+/// </summary>
+public sealed class SiteEventLogOptionsValidator : OptionsValidatorBase<SiteEventLogOptions>
+{
+    /// <inheritdoc />
+    protected override void Validate(ValidationBuilder builder, SiteEventLogOptions options)
+    {
+        builder.RequireThat(options.RetentionDays > 0,
+            $"ScadaBridge:SiteEventLog:RetentionDays must be greater than 0 " +
+            $"(was {options.RetentionDays}).");
+
+        builder.RequireThat(options.MaxStorageMb > 0,
+            $"ScadaBridge:SiteEventLog:MaxStorageMb must be greater than 0 " +
+            $"(was {options.MaxStorageMb}).");
+
+        builder.RequireThat(!string.IsNullOrWhiteSpace(options.DatabasePath),
+            "ScadaBridge:SiteEventLog:DatabasePath must be a non-empty path; " +
+            "it is the SQLite file backing the site event log.");
+
+        builder.RequireThat(options.QueryPageSize > 0,
+            $"ScadaBridge:SiteEventLog:QueryPageSize must be greater than 0 " +
+            $"(was {options.QueryPageSize}).");
+
+        builder.RequireThat(options.WriteQueueCapacity > 0,
+            $"ScadaBridge:SiteEventLog:WriteQueueCapacity must be greater than 0 " +
+            $"(was {options.WriteQueueCapacity}); it bounds the background write channel.");
+
+        builder.RequireThat(options.PurgeInterval > TimeSpan.Zero,
+            $"ScadaBridge:SiteEventLog:PurgeInterval must be a positive duration " +
+            $"(was {options.PurgeInterval}); it is the purge PeriodicTimer period.");
+
+        // The hard page-size ceiling clamps a caller-supplied PageSize; a ceiling
+        // below the default QueryPageSize would silently clamp the default below
+        // itself. Only meaningful when both are positive (owned above), so stay
+        // silent when either is non-positive rather than double-firing.
+        builder.RequireThat(
+            !(options.QueryPageSize > 0
+              && options.MaxQueryPageSize > 0
+              && options.MaxQueryPageSize < options.QueryPageSize),
+            $"ScadaBridge:SiteEventLog:MaxQueryPageSize ({options.MaxQueryPageSize}) " +
+            $"must be >= QueryPageSize ({options.QueryPageSize}): the ceiling clamps a caller's " +
+            "requested page size, so it cannot be smaller than the default page size.");
+    }
+}

src/ZB.MOM.WW.ScadaBridge.SiteEventLogging/ZB.MOM.WW.ScadaBridge.SiteEventLogging.csproj

@@ -14,6 +14,7 @@
     <PackageReference Include="Microsoft.Extensions.Hosting.Abstractions" />
     <PackageReference Include="Microsoft.Extensions.Logging.Abstractions" />
     <PackageReference Include="Microsoft.Extensions.Options" />
+    <PackageReference Include="ZB.MOM.WW.Configuration" />
   </ItemGroup>
 
   <ItemGroup>