Filter routes by app guid in client

Turned out that filtering on client side does not work because the
paging results are changed. Instead Filtering the routes by app guid is
done in the KLient.

Filtering option is added and AppGUIDs column to CFRoute Table. In this
way by setting the app destination guids to CFRoute Annotations by
mutating webhook filtering the routes by app guid is possible without
affeceting the paging results

issue #4123

Author: uzabanov

api/repositories/filter/route_apps_filtering.go

@@ -0,0 +1,22 @@
+package filter
+
+import (
+	"slices"
+	"strings"
+
+	"github.com/BooleanCat/go-functional/v2/it"
+)
+
+func RoutesByAppGUIDsPredicate(appGuids []string) func(value any) bool {
+	return func(value any) bool {
+		destinationAppGUIDsStr := value.(string)
+		destinationAppGUIDs := strings.Split(destinationAppGUIDsStr, "\n")
+		return haveCommonElements(appGuids, destinationAppGUIDs)
+	}
+}
+
+func haveCommonElements(appGuids, destinationAppGUIDs []string) bool {
+	return it.Any(it.Map(slices.Values(appGuids), func(appGUID string) bool {
+		return slices.Contains(destinationAppGUIDs, appGUID)
+	}))
+}

api/repositories/filter/route_apps_filtering_test.go

@@ -0,0 +1,41 @@
+package filter_test
+
+import (
+	"github.com/google/uuid"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+
+	"code.cloudfoundry.org/korifi/api/repositories/filter"
+)
+
+var _ = Describe("RoutesByAppGUID", func() {
+	var (
+		appGUID1     string
+		appGUIDs     []string
+		filterResult bool
+	)
+
+	BeforeEach(func() {
+		appGUID1 = uuid.NewString()
+		appGUIDs = []string{appGUID1}
+	})
+
+	JustBeforeEach(func() {
+		appGUID2 := uuid.NewString()
+		filterResult = filter.RoutesByAppGUIDsPredicate(appGUIDs)(appGUID1 + "\n" + appGUID2)
+	})
+
+	It("returns true", func() {
+		Expect(filterResult).To(BeTrue())
+	})
+
+	When("guid is not in the list", func() {
+		BeforeEach(func() {
+			appGUIDs = []string{"some-other-guid"}
+		})
+
+		It("returns false", func() {
+			Expect(filterResult).To(BeFalse())
+		})
+	})
+})

api/repositories/filter/suite_test.go

@@ -0,0 +1,13 @@
+package filter_test
+
+import (
+	"testing"
+
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+func TestFiltering(t *testing.T) {
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "Filtering Suite")
+}

api/repositories/k8sklient/descriptors/client.go

@@ -16,6 +16,7 @@ import (
 type ResultSetDescriptor interface {
 	GUIDs() ([]string, error)
 	Sort(column string, desc bool) error
+	Filter(columnName string, filterFunc func(value any) bool) error
 }
 
 type Pluralizer interface {

api/repositories/k8sklient/descriptors/fake/result_set_descriptor.go

@@ -39,6 +39,19 @@ func (d *TableResultSetDescriptor) Sort(column string, desc bool) error {
 	return nil
 }
 
+func (d *TableResultSetDescriptor) Filter(columnName string, filterFunc func(value any) bool) error {
+	columnIndex, _, err := d.getColumn(columnName)
+	if err != nil {
+		return err
+	}
+
+	d.Table.Rows = slices.Collect(it.Filter(slices.Values(d.Table.Rows), func(row metav1.TableRow) bool {
+		return filterFunc(row.Cells[columnIndex])
+	}))
+
+	return nil
+}
+
 func (d *TableResultSetDescriptor) getColumn(column string) (int, metav1.TableColumnDefinition, error) {
 	for i, columnDef := range d.Table.ColumnDefinitions {
 		if columnDef.Name == column {

api/repositories/k8sklient/descriptors/table.go

@@ -1,6 +1,8 @@
 package descriptors_test
 
 import (
+	"slices"
+
 	"code.cloudfoundry.org/korifi/api/repositories/k8sklient/descriptors"
 	. "github.com/onsi/ginkgo/v2"
 	. "github.com/onsi/gomega"
@@ -11,6 +13,7 @@ var _ = Describe("TableResultSetDescriptor", func() {
 	var (
 		results  descriptors.TableResultSetDescriptor
 		guids    []string
+		column   string
 		guidsErr error
 	)
 
@@ -47,7 +50,6 @@ var _ = Describe("TableResultSetDescriptor", func() {
 
 	Describe("Sort", func() {
 		var (
-			column  string
 			desc    bool
 			sortErr error
 		)
@@ -171,4 +173,35 @@ var _ = Describe("TableResultSetDescriptor", func() {
 			})
 		})
 	})
+
+	Describe("Filter", func() {
+		var filterErr error
+		BeforeEach(func() {
+			column = "Hobbies"
+		})
+
+		JustBeforeEach(func() {
+			filterErr = results.Filter(column, func(value any) bool {
+				hobbies := value.([]string)
+				return slices.Contains(hobbies, "hiking") || slices.Contains(hobbies, "gaming")
+			})
+			guids, guidsErr = results.GUIDs()
+			Expect(guidsErr).NotTo(HaveOccurred())
+		})
+
+		It("filters the table by specified column", func() {
+			Expect(filterErr).NotTo(HaveOccurred())
+			Expect(guids).To(Equal([]string{"Alice", "Bob"}))
+		})
+
+		When("filter column is not found", func() {
+			BeforeEach(func() {
+				column = "NonExistentColumn"
+			})
+
+			It("returns an error", func() {
+				Expect(filterErr).To(MatchError(ContainSubstring("not found")))
+			})
+		})
+	})
 })

api/repositories/k8sklient/descriptors/table_test.go

@@ -126,7 +126,7 @@ func (k *K8sKlient) List(ctx context.Context, list client.ObjectList, opts ...re
 }
 
 func isSimpleList(listOpts repositories.ListOptions) bool {
-	return listOpts.Sort == nil && listOpts.Paging == nil
+	return listOpts.Sort == nil && listOpts.Paging == nil && listOpts.Filter == nil
 }
 
 func (k *K8sKlient) listViaUserClient(ctx context.Context, list client.ObjectList, opts ...client.ListOption) (descriptors.PageInfo, error) {

api/repositories/k8sklient/klient.go

@@ -359,6 +359,22 @@ var _ = Describe("Klient", func() {
 			})
 		})
 
+		When("filtering is requested", func() {
+			BeforeEach(func() {
+				listOpts = append(listOpts, repositories.WithFiltering("foo", func(value any) bool {
+					return value == "bar"
+				}))
+			})
+
+			It("delegates to the descriptor based lister", func() {
+				Expect(err).NotTo(HaveOccurred())
+				Expect(descriptorBasedLister.ListCallCount()).To(Equal(1))
+				_, _, actualListOptions := descriptorBasedLister.ListArgsForCall(0)
+				Expect(actualListOptions.Filter.By).To(Equal("foo"))
+				Expect(actualListOptions.Filter.FilterFunc("bar")).To(BeTrue())
+			})
+		})
+
 		When("a list option errors", func() {
 			BeforeEach(func() {
 				listOpts = []repositories.ListOption{repositories.ErroringListOption("list-opt-err")}

api/repositories/k8sklient/klient_test.go

@@ -100,6 +100,12 @@ func (k *DescriptorsBasedLister) fetchObjectGUIDs(ctx context.Context, listObjec
 		}
 	}
 
+	if listOpts.Filter != nil {
+		if err = objectDescriptors.Filter(listOpts.Filter.By, listOpts.Filter.FilterFunc); err != nil {
+			return nil, fmt.Errorf("failed to filter object descriptors: %w", err)
+		}
+	}
+
 	objectGUIDs, err := objectDescriptors.GUIDs()
 	if err != nil {
 		return nil, fmt.Errorf("failed to get sorted object GUIDs: %w", err)