Aw/pagination

Dfe.Data.SearchPrototype/Infrastructure/Builders/ISearchOptionsBuilder.cs

@@ -21,6 +21,18 @@ public interface ISearchOptionsBuilder
         /// </returns>
         ISearchOptionsBuilder WithSize(int? size);
 
+        /// <summary>
+        /// Sets the value used to define how many
+        /// records are skipped in the search response (if any).
+        /// </summary>
+        /// <param name="offset">
+        /// The number of initial search results to skip.
+        /// </param>
+        /// <returns>
+        /// The updated builder instance.
+        /// </returns>
+        ISearchOptionsBuilder WithOffset(int? offset);
+
         /// <summary>
         /// Sets the mode of search to invoke, i.e. All or Any.
         /// </summary>

Dfe.Data.SearchPrototype/Infrastructure/Builders/SearchOptionsBuilder.cs

@@ -16,6 +16,7 @@ public sealed class SearchOptionsBuilder : ISearchOptionsBuilder
 
         private SearchMode? _searchMode;
         private int? _size;
+        private int? _offset;
         private bool? _includeTotalCount;
         private IList<string>? _searchFields;
         private IList<string>? _facets;
@@ -53,6 +54,22 @@ public ISearchOptionsBuilder WithSize(int? size)
             return this;
         }
 
+        /// <summary>
+        /// Sets the value used to define how many
+        /// records are skipped in the search response (if any).
+        /// </summary>
+        /// <param name="offset">
+        /// The number of initial search results to skip.
+        /// </param>
+        /// <returns>
+        /// The updated builder instance.
+        /// </returns>
+        public ISearchOptionsBuilder WithOffset(int? offset)
+        {
+            _offset = offset;
+            return this;
+        }
+
         /// <summary>
         /// Sets the mode of search to invoke, i.e. All or Any.
         /// </summary>
@@ -139,6 +156,7 @@ public SearchOptions Build()
         {
             _searchOptions.SearchMode = _searchMode;
             _searchOptions.Size = _size;
+            _searchOptions.Skip = _offset;
             _searchOptions.IncludeTotalCount = _includeTotalCount;
             _searchFields?.ToList().ForEach(_searchOptions.SearchFields.Add);
             _facets?.ToList().ForEach(_searchOptions.Facets.Add);

Dfe.Data.SearchPrototype/Infrastructure/CognitiveSearchServiceAdapter.cs

@@ -19,7 +19,7 @@ namespace Dfe.Data.SearchPrototype.Infrastructure;
 public sealed class CognitiveSearchServiceAdapter<TSearchResult> : ISearchServiceAdapter where TSearchResult : class
 {
     private readonly ISearchByKeywordService _searchByKeywordService;
-    private readonly IMapper<Pageable<SearchResult<TSearchResult>>, EstablishmentResults> _searchResultMapper;
+    private readonly IMapper<(Pageable<SearchResult<TSearchResult>>, long?), EstablishmentResults> _searchResultMapper;
     private readonly IMapper<Dictionary<string, IList<AzureModels.FacetResult>>, EstablishmentFacets> _facetsMapper;
     private readonly AzureSearchOptions _azureSearchOptions;
     private readonly ISearchOptionsBuilder _searchOptionsBuilder;
@@ -46,7 +46,7 @@ public sealed class CognitiveSearchServiceAdapter<TSearchResult> : ISearchServic
     public CognitiveSearchServiceAdapter(
         ISearchByKeywordService searchByKeywordService,
         IOptions<AzureSearchOptions> azureSearchOptions,
-        IMapper<Pageable<SearchResult<TSearchResult>>, EstablishmentResults> searchResultMapper,
+        IMapper<(Pageable<SearchResult<TSearchResult>>, long?), EstablishmentResults> searchResultMapper,
         IMapper<Dictionary<string, IList<AzureModels.FacetResult>>, EstablishmentFacets> facetsMapper,
         ISearchOptionsBuilder searchOptionsBuilder)
     {
@@ -82,6 +82,7 @@ public async Task<SearchResults> SearchAsync(SearchServiceAdapterRequest searchS
             _searchOptionsBuilder
                 .WithSearchMode((SearchMode)_azureSearchOptions.SearchMode)
                 .WithSize(_azureSearchOptions.Size)
+                .WithOffset(searchServiceAdapterRequest.Offset)
                 .WithIncludeTotalCount(_azureSearchOptions.IncludeTotalCount)
                 .WithSearchFields(searchServiceAdapterRequest.SearchFields)
                 .WithFacets(searchServiceAdapterRequest.Facets)
@@ -100,7 +101,9 @@ await _searchByKeywordService.SearchAsync<TSearchResult>(
 
         var results = new SearchResults()
         {
-            Establishments = _searchResultMapper.MapFrom(searchResults.Value.GetResults()),
+            Establishments = 
+                _searchResultMapper.MapFrom(
+                    (searchResults.Value.GetResults(), searchResults.Value.TotalCount)),
             Facets = searchResults.Value.Facets != null
                 ? _facetsMapper.MapFrom(searchResults.Value.Facets.ToDictionary())
                 : null

Dfe.Data.SearchPrototype/Infrastructure/CompositionRoot.cs

@@ -44,7 +44,7 @@ public static void AddCognitiveSearchAdaptorServices(this IServiceCollection ser
 
         services.AddScoped(typeof(ISearchServiceAdapter), typeof(CognitiveSearchServiceAdapter<DataTransferObjects.Establishment>));
         services.AddScoped<ISearchOptionsBuilder, SearchOptionsBuilder>();
-        services.AddSingleton(typeof(IMapper<Pageable<SearchResult<DataTransferObjects.Establishment>>, EstablishmentResults>), typeof(PageableSearchResultsToEstablishmentResultsMapper));
+        services.AddSingleton(typeof(IMapper<(Pageable<SearchResult<DataTransferObjects.Establishment>>, long?), EstablishmentResults>), typeof(PageableSearchResultsToEstablishmentResultsMapper));
         services.AddSingleton<IMapper<Dictionary<string, IList<Azure.Search.Documents.Models.FacetResult>>, EstablishmentFacets>, AzureFacetResultToEstablishmentFacetsMapper>();
         services.AddSingleton<IMapper<DataTransferObjects.Establishment, Address>, AzureSearchResultToAddressMapper>();
         services.AddSingleton<IMapper<DataTransferObjects.Establishment, Establishment>, AzureSearchResultToEstablishmentMapper>();

Dfe.Data.SearchPrototype/Infrastructure/Mappers/PageableSearchResultsToEstablishmentResultsMapper.cs

@@ -8,11 +8,11 @@ namespace Dfe.Data.SearchPrototype.Infrastructure.Mappers;
 
 /// <summary>
 /// Facilitates mapping from the received <see cref="Models.SearchResults"/> 
-/// into the required <see cref="Models.EstablishmentResults"/>  object.
+/// into the required <see cref="Models.EstablishmentResults"/> object.
 /// </summary>
-public sealed class PageableSearchResultsToEstablishmentResultsMapper : IMapper<Pageable<SearchResult<DataTransferObjects.Establishment>>, Models.EstablishmentResults>
+public sealed class PageableSearchResultsToEstablishmentResultsMapper : IMapper<(Pageable<SearchResult<Establishment>>, long?), Models.EstablishmentResults>
 {
-    private readonly IMapper<DataTransferObjects.Establishment, Models.Establishment> _azureSearchResultToEstablishmentMapper;
+    private readonly IMapper<Establishment, Models.Establishment> _azureSearchResultToEstablishmentMapper;
 
     /// <summary>
     /// The following mapping dependency provides the functionality to map from a raw Azure
@@ -22,7 +22,7 @@ public sealed class PageableSearchResultsToEstablishmentResultsMapper : IMapper<
     /// <param name="azureSearchResultToEstablishmentMapper">
     /// Mapper used to map from the raw Azure search result to a <see cref="Establishment"/> instance.
     /// </param>
-    public PageableSearchResultsToEstablishmentResultsMapper(IMapper<DataTransferObjects.Establishment, Models.Establishment> azureSearchResultToEstablishmentMapper)
+    public PageableSearchResultsToEstablishmentResultsMapper(IMapper<Establishment, Models.Establishment> azureSearchResultToEstablishmentMapper)
     {
         _azureSearchResultToEstablishmentMapper = azureSearchResultToEstablishmentMapper;
     }
@@ -44,23 +44,23 @@ public PageableSearchResultsToEstablishmentResultsMapper(IMapper<DataTransferObj
     /// <exception cref="ArgumentException">
     /// Exception thrown if the data cannot be mapped
     /// </exception>
-    public Models.EstablishmentResults MapFrom(Pageable<SearchResult<DataTransferObjects.Establishment>> input)
+    public Models.EstablishmentResults MapFrom((Pageable<SearchResult<Establishment>>, long?) input)
     {
         ArgumentNullException.ThrowIfNull(input);
+        Models.EstablishmentResults establishmentResults = new();
 
-        if (input.Any())
+        if (input.Item1.Any())
         {
-            var mappedResults = input.Select(result =>
+            var mappedResults = input.Item1.Select(result =>
                  result.Document != null
                     ? _azureSearchResultToEstablishmentMapper.MapFrom(result.Document)
                     : throw new InvalidOperationException(
-                        "Search result document object cannot be null.")
-                );
-            return new Models.EstablishmentResults(mappedResults);
-        }
-        else
-        {
-            return new Models.EstablishmentResults();
+                        "Search result document object cannot be null."));
+
+            establishmentResults =
+                new Models.EstablishmentResults(mappedResults, input.Item2);
         }
+
+        return establishmentResults;
     }
 }

Dfe.Data.SearchPrototype/Infrastructure/Tests/Builders/SearchOptionsBuilderTests.cs

@@ -29,6 +29,22 @@ public void Build_WithSize_SearchOptionsWithCorrectSize()
             searchOptions.Size.Should().Be(100);
         }
 
+        [Fact]
+        public void Build_WithOfset_SearchOptionsWithCorrectOffset()
+        {
+            // arrange
+            ISearchFilterExpressionsBuilder mockSearchFilterExpressionsBuilder = new FilterExpressionBuilderTestDouble().Create();
+
+            ISearchOptionsBuilder searchOptionsBuilder = new SearchOptionsBuilder(mockSearchFilterExpressionsBuilder);
+
+            // act
+            SearchOptions searchOptions = searchOptionsBuilder.WithOffset(offset: 39).Build();
+
+            // assert
+            searchOptions.Should().NotBeNull();
+            searchOptions.Skip.Should().Be(39);
+        }
+
         [Fact]
         public void Build_WithSearchMode_SearchOptionsWithCorrectSearchMode()
         {

Dfe.Data.SearchPrototype/Infrastructure/Tests/CognitiveSearchServiceAdapterAndMapperTests.cs

@@ -14,7 +14,7 @@ namespace Dfe.Data.SearchPrototype.Infrastructure.Tests;
 
 public sealed class CognitiveSearchServiceAdapterAndMapperTests
 {
-    private readonly IMapper<Pageable<SearchResult<DataTransferObjects.Establishment>>, EstablishmentResults> _searchResponseMapper;
+    private readonly IMapper<(Pageable<SearchResult<DataTransferObjects.Establishment>>, long?), EstablishmentResults> _searchResponseMapper;
     private readonly IMapper<Dictionary<string, IList<Azure.Search.Documents.Models.FacetResult>>, EstablishmentFacets> _facetsMapper;
     private readonly ISearchOptionsBuilder _searchOptionsBuilder = SearchOptionsBuilderTestDouble.MockFor(new Azure.Search.Documents.SearchOptions());
 
@@ -57,7 +57,8 @@ await cognitiveSearchServiceAdapter.SearchAsync(
                 new SearchServiceAdapterRequest(
                     searchKeyword: "SearchKeyword",
                     searchFields: ["FIELD1", "FIELD2", "FIELD2"],
-                    facets: ["FACET1", "FACET2", "FACET3"]));
+                    facets: ["FACET1", "FACET2", "FACET3"],
+                    offset: 99));
 
         // assert
         response.Should().NotBeNull();
@@ -94,7 +95,8 @@ await cognitiveSearchServiceAdapter.SearchAsync(
                 new SearchServiceAdapterRequest(
                     searchKeyword: "SearchKeyword",
                     searchFields: ["FIELD1", "FIELD2", "FIELD2"],
-                    facets: ["FACET1", "FACET2", "FACET3"]));
+                    facets: ["FACET1", "FACET2", "FACET3"],
+                    offset: 0));
 
         // assert
         response.Should().NotBeNull();
@@ -128,7 +130,8 @@ await cognitiveSearchServiceAdapter.SearchAsync(
                 new SearchServiceAdapterRequest(
                     searchKeyword: "SearchKeyword",
                     searchFields: ["FIELD1", "FIELD2", "FIELD2"],
-                    facets: ["FACET1", "FACET2", "FACET3"]));
+                    facets: ["FACET1", "FACET2", "FACET3"],
+                    offset: 0));
 
         // assert
         response.Should().NotBeNull();

Dfe.Data.SearchPrototype/Infrastructure/Tests/CognitiveSearchServiceAdapterTests.cs

@@ -21,7 +21,7 @@ public sealed class CognitiveSearchServiceAdapterTests
     private readonly IMapper<Dictionary<string, IList<Azure.Search.Documents.Models.FacetResult>>, EstablishmentFacets> _mockFacetsMapper
         = AzureFacetResultToEstablishmentFacetsMapperTestDouble.DefaultMock();
     private readonly AzureSearchOptions _options  = AzureSearchOptionsTestDouble.Stub();
-    private readonly IMapper<Pageable<SearchResult<DataTransferObjects.Establishment>>, EstablishmentResults> _mockEstablishmentResultsMapper
+    private readonly IMapper<(Pageable<SearchResult<DataTransferObjects.Establishment>>, long?), EstablishmentResults> _mockEstablishmentResultsMapper
         = PageableSearchResultsToEstablishmentResultsMapperTestDouble.DefaultMock();
     private readonly ISearchByKeywordService _mockSearchService;
     private readonly ISearchOptionsBuilder _mockSearchOptionsBuilder =
@@ -30,7 +30,7 @@ public sealed class CognitiveSearchServiceAdapterTests
     private static CognitiveSearchServiceAdapter<DataTransferObjects.Establishment> CreateServiceAdapterWith(
         ISearchByKeywordService searchByKeywordService,
         IOptions<AzureSearchOptions> searchOptions,
-        IMapper<Pageable<SearchResult<DataTransferObjects.Establishment>>, EstablishmentResults> searchResponseMapper,
+        IMapper<(Pageable<SearchResult<DataTransferObjects.Establishment>>, long?), EstablishmentResults> searchResponseMapper,
         IMapper<Dictionary<string, IList<Azure.Search.Documents.Models.FacetResult>>, EstablishmentFacets> facetsMapper,
         ISearchOptionsBuilder searchOptionsBuilder
        ) =>

Dfe.Data.SearchPrototype/Infrastructure/Tests/Mappers/PageableSearchResultsToEstablishmentResultsMapperTests.cs

@@ -1,7 +1,6 @@
 using Azure;
 using Azure.Search.Documents.Models;
 using Dfe.Data.SearchPrototype.Common.Mappers;
-using Dfe.Data.SearchPrototype.Infrastructure.DataTransferObjects;
 using Dfe.Data.SearchPrototype.Infrastructure.Mappers;
 using Dfe.Data.SearchPrototype.Infrastructure.Tests.TestDoubles;
 using Dfe.Data.SearchPrototype.Infrastructure.Tests.TestHelpers;
@@ -13,7 +12,7 @@ namespace Dfe.Data.SearchPrototype.Infrastructure.Tests.Mappers;
 
 public sealed class PageableSearchResultsToEstablishmentResultsMapperTests
 {
-    IMapper<Pageable<SearchResult<DataTransferObjects.Establishment>>, EstablishmentResults> _searchResultsMapper;
+    IMapper<(Pageable<SearchResult<DataTransferObjects.Establishment>>, long?), EstablishmentResults> _searchResultsMapper;
 
     public PageableSearchResultsToEstablishmentResultsMapperTests()
     {
@@ -29,14 +28,16 @@ public void MapFrom_WithValidSearchResults_ReturnsConfiguredEstablishments()
         // arrange
         List<SearchResult<DataTransferObjects.Establishment>> searchResultDocuments =
             SearchResultFake.SearchResults();
+
         var pageableSearchResults = PageableTestDouble.FromResults(searchResultDocuments);
 
         // act
-        EstablishmentResults? mappedResult = _searchResultsMapper.MapFrom(pageableSearchResults);
+        EstablishmentResults? mappedResult = _searchResultsMapper.MapFrom((pageableSearchResults, 100));
 
         // assert
         mappedResult.Should().NotBeNull();
-        mappedResult.Establishments.Should().HaveCount(searchResultDocuments.Count());
+        mappedResult.Establishments.Should().HaveCount(searchResultDocuments.Count);
+
         foreach (var searchResult in searchResultDocuments)
         {
             searchResult.ShouldHaveMatchingMappedEstablishment(mappedResult);
@@ -47,7 +48,7 @@ public void MapFrom_WithValidSearchResults_ReturnsConfiguredEstablishments()
     public void MapFrom_WithEmptySearchResults_ReturnsEmptyList()
     {
         // act
-        EstablishmentResults? result = _searchResultsMapper.MapFrom(PageableTestDouble.FromResults(SearchResultFake.EmptySearchResult()));
+        EstablishmentResults? result = _searchResultsMapper.MapFrom((PageableTestDouble.FromResults(SearchResultFake.EmptySearchResult()), 100));
 
         // assert
         result.Should().NotBeNull();
@@ -60,10 +61,10 @@ public void MapFrom_WithNullSearchResults_ThrowsArgumentNullException()
         // act.
         _searchResultsMapper
             .Invoking(mapper =>
-                mapper.MapFrom(null!))
+                mapper.MapFrom((null!, 0)))
                     .Should()
                         .Throw<ArgumentNullException>()
-                        .WithMessage("Value cannot be null. (Parameter 'input')");
+                        .WithMessage("Value cannot be null. (Parameter 'source')");
     }
 
     [Fact]
@@ -77,7 +78,7 @@ public void MapFrom_WithANullSearchResult_ThrowsInvalidOperationException()
         // act.
         _searchResultsMapper
             .Invoking(mapper =>
-                mapper.MapFrom(PageableTestDouble.FromResults(searchResultDocuments)))
+                mapper.MapFrom((PageableTestDouble.FromResults(searchResultDocuments), 100)))
                     .Should()
                         .Throw<InvalidOperationException>()
                         .WithMessage("Search result document object cannot be null.");

Dfe.Data.SearchPrototype/Infrastructure/Tests/TestDoubles/PageableSearchResultsToEstablishmentResultsMapperTestDouble.cs

@@ -9,24 +9,24 @@ namespace Dfe.Data.SearchPrototype.Infrastructure.Tests.TestDoubles;
 
 internal static class PageableSearchResultsToEstablishmentResultsMapperTestDouble
 {
-    public static IMapper<Pageable<SearchResult<DataTransferObjects.Establishment>>, EstablishmentResults> DefaultMock() =>
-        Mock.Of<IMapper<Pageable<SearchResult<DataTransferObjects.Establishment>>, EstablishmentResults>>();
+    public static IMapper<(Pageable<SearchResult<DataTransferObjects.Establishment>>, long?), EstablishmentResults> DefaultMock() =>
+        Mock.Of<IMapper<(Pageable<SearchResult<DataTransferObjects.Establishment>>, long?), EstablishmentResults>>();
 
-    public static Expression<Func<IMapper<Pageable<SearchResult<DataTransferObjects.Establishment>>, EstablishmentResults>, EstablishmentResults>> MapFrom() =>
-        mapper => mapper.MapFrom(It.IsAny<Pageable<SearchResult<DataTransferObjects.Establishment>>>());
+    public static Expression<Func<IMapper<(Pageable<SearchResult<DataTransferObjects.Establishment>>, long?), EstablishmentResults>, EstablishmentResults>> MapFrom() =>
+        mapper => mapper.MapFrom(It.IsAny<(Pageable<SearchResult<DataTransferObjects.Establishment>>, long ?)>());
 
-    public static IMapper<Pageable<SearchResult<DataTransferObjects.Establishment>>, EstablishmentResults> MockFor(EstablishmentResults establishments)
+    public static IMapper<(Pageable<SearchResult<DataTransferObjects.Establishment>>, long?), EstablishmentResults> MockFor(EstablishmentResults establishments)
     {
-        var mapperMock = new Mock<IMapper<Pageable<SearchResult<DataTransferObjects.Establishment>>, EstablishmentResults>>();
+        var mapperMock = new Mock<IMapper<(Pageable<SearchResult<DataTransferObjects.Establishment>>, long?), EstablishmentResults>>();
 
         mapperMock.Setup(MapFrom()).Returns(establishments);
 
         return mapperMock.Object;
     }
 
-    public static IMapper<Pageable<SearchResult<DataTransferObjects.Establishment>>, EstablishmentResults> MockMapperThrowingArgumentException()
+    public static IMapper<(Pageable<SearchResult<DataTransferObjects.Establishment>>, long?), EstablishmentResults> MockMapperThrowingArgumentException()
     {
-        var mapperMock = new Mock<IMapper<Pageable<SearchResult<DataTransferObjects.Establishment>>, EstablishmentResults>>();
+        var mapperMock = new Mock<IMapper<(Pageable<SearchResult<DataTransferObjects.Establishment>>, long?), EstablishmentResults>>();
 
         mapperMock.Setup(MapFrom()).Throws(new ArgumentException());
 

Dfe.Data.SearchPrototype/Infrastructure/Tests/TestDoubles/SearchOptionsBuilderTestDouble.cs

@@ -14,6 +14,8 @@ public static ISearchOptionsBuilder MockFor(SearchOptions searchOptions)
 
             mockSearchOptionsBuilder.Setup(searchOptionsBuilder =>
                 searchOptionsBuilder.WithSize(It.IsAny<int?>())).Returns(mockSearchOptionsBuilder.Object);
+            mockSearchOptionsBuilder.Setup(searchOptionsBuilder =>
+                searchOptionsBuilder.WithOffset(It.IsAny<int?>())).Returns(mockSearchOptionsBuilder.Object);
             mockSearchOptionsBuilder.Setup(searchOptionsBuilder =>
                 searchOptionsBuilder.WithSearchMode(It.IsAny<SearchMode>())).Returns(mockSearchOptionsBuilder.Object);
             mockSearchOptionsBuilder.Setup(searchOptionsBuilder =>