Add SearchUsecase result logs (#2197)

* Add SearchUsecase result logs

* Update src/api/Elastic.Documentation.Api.Core/Search/SearchUsecase.cs

Co-authored-by: Martijn Laarman <[email protected]>

* Use LogProperties

---------

Co-authored-by: Martijn Laarman <[email protected]>

Author: reakaleek

Directory.Packages.props

@@ -26,6 +26,7 @@
     <PackageVersion Include="AWSSDK.SQS" Version="4.0.2.2" />
     <PackageVersion Include="AWSSDK.S3" Version="4.0.7.14" />
     <PackageVersion Include="Elastic.OpenTelemetry" Version="1.1.0" />
+    <PackageVersion Include="Microsoft.Extensions.Telemetry.Abstractions" Version="9.7.0" />
     <PackageVersion Include="OpenTelemetry.Instrumentation.AspNetCore" Version="1.13.0" />
     <PackageVersion Include="Generator.Equals" Version="3.2.1" PrivateAssets="all" IncludeAssets="runtime; build; native; contentfiles; analyzers; buildtransitive" />
     <PackageVersion Include="KubernetesClient" Version="17.0.14" />

src/api/Elastic.Documentation.Api.Core/Elastic.Documentation.Api.Core.csproj

@@ -10,6 +10,7 @@
 
     <ItemGroup>
       <PackageReference Include="Microsoft.Extensions.Logging" />
+      <PackageReference Include="Microsoft.Extensions.Telemetry.Abstractions" />
     </ItemGroup>
 
 </Project>

src/api/Elastic.Documentation.Api.Core/Search/SearchUsecase.cs

@@ -2,33 +2,44 @@
 // 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 Microsoft.Extensions.Logging;
+
 namespace Elastic.Documentation.Api.Core.Search;
 
-public class SearchUsecase(ISearchGateway searchGateway)
+public partial class SearchUsecase(ISearchGateway searchGateway, ILogger<SearchUsecase> logger)
 {
 	public async Task<SearchResponse> Search(SearchRequest request, Cancel ctx = default)
 	{
-
-		// var validationResult = validator.Validate(request);
-		// if (!validationResult.IsValid)
-		// 	throw new ArgumentException(validationResult.Message);
-
 		var (totalHits, results) = await searchGateway.SearchAsync(
 			request.Query,
 			request.PageNumber,
 			request.PageSize,
 			ctx
 		);
 
-
-		return new SearchResponse
+		var response = new SearchResponse
 		{
 			Results = results,
 			TotalResults = totalHits,
 			PageNumber = request.PageNumber,
 			PageSize = request.PageSize,
 		};
+
+		LogSearchResults(
+			logger,
+			response.PageSize,
+			response.PageNumber,
+			request.Query,
+			new SearchResultsLogProperties(results.Select(i => i.Url).ToArray())
+		);
+
+		return response;
 	}
+
+	[LoggerMessage(Level = LogLevel.Information, Message = "Search completed with {PageSize} (page {PageNumber}) results for query '{SearchQuery}'")]
+	private static partial void LogSearchResults(ILogger logger, int pageSize, int pageNumber, string searchQuery, [LogProperties] SearchResultsLogProperties result);
+
+	private sealed record SearchResultsLogProperties(string[] Urls);
 }
 
 public record SearchRequest