Extract duplicated GetPrimaryApplicability method to ApplicabilitySelector utility class

- Created new ApplicabilitySelector class in Elastic.Documentation.AppliesTo namespace
- Removed duplicated GetPrimaryApplicability method from ApplicabilityRenderer and ApplicableToViewModel
- Updated both classes to use the new utility class
- Improves code reusability and reduces duplication

Author: reakaleek

src/Elastic.Documentation/AppliesTo/ApplicabilitySelector.cs

@@ -0,0 +1,60 @@
+// Licensed to Elasticsearch B.V under one or more agreements.
+// Elasticsearch B.V licenses this file to you under the Apache 2.0 License.
+// See the LICENSE file in the project root for more information
+
+using Elastic.Documentation.Configuration.Versions;
+
+namespace Elastic.Documentation.AppliesTo;
+
+/// <summary>
+/// Utility class for selecting the most relevant applicability from a collection of applicabilities.
+/// </summary>
+public static class ApplicabilitySelector
+{
+	/// <summary>
+	/// Selects the most relevant applicability for display: available versions first (highest version), then closest future version
+	/// </summary>
+	/// <param name="applicabilities">The collection of applicabilities to select from</param>
+	/// <param name="versioningSystem">The versioning system to use for comparison</param>
+	/// <returns>The most relevant applicability for display</returns>
+	public static Applicability GetPrimaryApplicability(IEnumerable<Applicability> applicabilities, VersioningSystem versioningSystem)
+	{
+		var applicabilityList = applicabilities.ToList();
+		var lifecycleOrder = new Dictionary<ProductLifecycle, int>
+		{
+			[ProductLifecycle.GenerallyAvailable] = 0,
+			[ProductLifecycle.Beta] = 1,
+			[ProductLifecycle.TechnicalPreview] = 2,
+			[ProductLifecycle.Planned] = 3,
+			[ProductLifecycle.Deprecated] = 4,
+			[ProductLifecycle.Removed] = 5,
+			[ProductLifecycle.Unavailable] = 6
+		};
+
+		var availableApplicabilities = applicabilityList
+			.Where(a => a.Version is null || a.Version is AllVersions || a.Version <= versioningSystem.Current)
+			.ToList();
+
+		if (availableApplicabilities.Count != 0)
+		{
+			return availableApplicabilities
+				.OrderByDescending(a => a.Version ?? new SemVersion(0, 0, 0))
+				.ThenBy(a => lifecycleOrder.GetValueOrDefault(a.Lifecycle, 999))
+				.First();
+		}
+
+		var futureApplicabilities = applicabilityList
+			.Where(a => a.Version is not null && a.Version is not AllVersions && a.Version > versioningSystem.Current)
+			.ToList();
+
+		if (futureApplicabilities.Count != 0)
+		{
+			return futureApplicabilities
+				.OrderBy(a => a.Version!.CompareTo(versioningSystem.Current))
+				.ThenBy(a => lifecycleOrder.GetValueOrDefault(a.Lifecycle, 999))
+				.First();
+		}
+
+		return applicabilityList.First();
+	}
+}

src/Elastic.Markdown/Myst/Components/ApplicabilityRenderer.cs

@@ -53,53 +53,14 @@ public ApplicabilityRenderData RenderCombinedApplicability(
 		AppliesCollection allApplications)
 	{
 		var applicabilityList = applicabilities.ToList();
-		var primaryApplicability = GetPrimaryApplicability(applicabilityList, versioningSystem);
+		var primaryApplicability = ApplicabilitySelector.GetPrimaryApplicability(applicabilityList, versioningSystem);
 
 		var primaryRenderData = RenderApplicability(primaryApplicability, applicabilityDefinition, versioningSystem, allApplications);
 		var combinedTooltip = BuildCombinedTooltipText(applicabilityList, applicabilityDefinition, versioningSystem);
 
 		return primaryRenderData with { TooltipText = combinedTooltip };
 	}
 
-	private static Applicability GetPrimaryApplicability(List<Applicability> applicabilities, VersioningSystem versioningSystem)
-	{
-		var lifecycleOrder = new Dictionary<ProductLifecycle, int>
-		{
-			[ProductLifecycle.GenerallyAvailable] = 0,
-			[ProductLifecycle.Beta] = 1,
-			[ProductLifecycle.TechnicalPreview] = 2,
-			[ProductLifecycle.Planned] = 3,
-			[ProductLifecycle.Deprecated] = 4,
-			[ProductLifecycle.Removed] = 5,
-			[ProductLifecycle.Unavailable] = 6
-		};
-
-		var availableApplicabilities = applicabilities
-			.Where(a => a.Version is null || a.Version is AllVersions || a.Version <= versioningSystem.Current)
-			.ToList();
-
-		if (availableApplicabilities.Count != 0)
-		{
-			return availableApplicabilities
-				.OrderByDescending(a => a.Version ?? new SemVersion(0, 0, 0))
-				.ThenBy(a => lifecycleOrder.GetValueOrDefault(a.Lifecycle, 999))
-				.First();
-		}
-
-		var futureApplicabilities = applicabilities
-			.Where(a => a.Version is not null && a.Version is not AllVersions && a.Version > versioningSystem.Current)
-			.ToList();
-
-		if (futureApplicabilities.Count != 0)
-		{
-			return futureApplicabilities
-				.OrderBy(a => a.Version!.CompareTo(versioningSystem.Current))
-				.ThenBy(a => lifecycleOrder.GetValueOrDefault(a.Lifecycle, 999))
-				.First();
-		}
-
-		return applicabilities.First();
-	}
 
 	private static string BuildCombinedTooltipText(
 		List<Applicability> applicabilities,

src/Elastic.Markdown/Myst/Components/ApplicableToViewModel.cs

@@ -148,7 +148,7 @@ private IEnumerable<ApplicabilityItem> CombineItemsByKey(List<ApplicabilityItem>
 					new AppliesCollection(allApplicabilities.ToArray()));
 
 				// Select the closest version to current as the primary display
-				var primaryApplicability = GetPrimaryApplicability(allApplicabilities, versioningSystem);
+				var primaryApplicability = ApplicabilitySelector.GetPrimaryApplicability(allApplicabilities, versioningSystem);
 
 				return new ApplicabilityItem(
 					Key: firstItem.Key,
@@ -159,47 +159,5 @@ private IEnumerable<ApplicabilityItem> CombineItemsByKey(List<ApplicabilityItem>
 			});
 
 
-	/// <summary>
-	/// Selects the most relevant applicability for display: available versions first (highest version), then closest future version
-	/// </summary>
-	private static Applicability GetPrimaryApplicability(List<Applicability> applicabilities, VersioningSystem versioningSystem)
-	{
-		var lifecycleOrder = new Dictionary<ProductLifecycle, int>
-		{
-			[ProductLifecycle.GenerallyAvailable] = 0,
-			[ProductLifecycle.Beta] = 1,
-			[ProductLifecycle.TechnicalPreview] = 2,
-			[ProductLifecycle.Planned] = 3,
-			[ProductLifecycle.Deprecated] = 4,
-			[ProductLifecycle.Removed] = 5,
-			[ProductLifecycle.Unavailable] = 6
-		};
-
-		var availableApplicabilities = applicabilities
-			.Where(a => a.Version is null || a.Version is AllVersions || a.Version <= versioningSystem.Current)
-			.ToList();
-
-		if (availableApplicabilities.Count != 0)
-		{
-			return availableApplicabilities
-				.OrderByDescending(a => a.Version ?? new SemVersion(0, 0, 0))
-				.ThenBy(a => lifecycleOrder.GetValueOrDefault(a.Lifecycle, 999))
-				.First();
-		}
-
-		var futureApplicabilities = applicabilities
-			.Where(a => a.Version is not null && a.Version is not AllVersions && a.Version > versioningSystem.Current)
-			.ToList();
-
-		if (futureApplicabilities.Count != 0)
-		{
-			return futureApplicabilities
-				.OrderBy(a => a.Version!.CompareTo(versioningSystem.Current))
-				.ThenBy(a => lifecycleOrder.GetValueOrDefault(a.Lifecycle, 999))
-				.First();
-		}
-
-		return applicabilities.First();
-	}
 
 }