Add feature flag for deprecating a package with many versions (#7285)

Author: Scott Bommarito

src/NuGetGallery/Controllers/ManageDeprecationJsonApiController.cs

@@ -81,12 +81,6 @@ public virtual async Task<JsonResult> Deprecate(
                 status |= PackageDeprecationStatus.Other;
             }
 
-            var currentUser = GetCurrentUser();
-            if (!_featureFlagService.IsManageDeprecationEnabled(GetCurrentUser()))
-            {
-                return DeprecateErrorResponse(HttpStatusCode.Forbidden, Strings.DeprecatePackage_Forbidden);
-            }
-
             if (versions == null || !versions.Any())
             {
                 return DeprecateErrorResponse(HttpStatusCode.BadRequest, Strings.DeprecatePackage_NoVersions);
@@ -102,6 +96,12 @@ public virtual async Task<JsonResult> Deprecate(
                     string.Format(Strings.DeprecatePackage_MissingRegistration, id));
             }
 
+            var currentUser = GetCurrentUser();
+            if (!_featureFlagService.IsManageDeprecationEnabled(GetCurrentUser(), registration))
+            {
+                return DeprecateErrorResponse(HttpStatusCode.Forbidden, Strings.DeprecatePackage_Forbidden);
+            }
+
             if (ActionsRequiringPermissions.DeprecatePackage.CheckPermissionsOnBehalfOfAnyAccount(currentUser, registration) != PermissionsCheckResult.Allowed)
             {
                 return DeprecateErrorResponse(HttpStatusCode.Forbidden, Strings.DeprecatePackage_Forbidden);

src/NuGetGallery/Controllers/PackagesController.cs

@@ -751,7 +751,7 @@ public virtual async Task<ActionResult> DisplayPackage(string id, string version
             model.SymbolsPackageValidationIssues = _validationService.GetLatestPackageValidationIssues(model.LatestSymbolsPackage);
             model.IsCertificatesUIEnabled = _contentObjectService.CertificatesConfiguration?.IsUIEnabledForUser(currentUser) ?? false;
             model.IsAtomFeedEnabled = _featureFlagService.IsPackagesAtomFeedEnabled();
-            model.IsPackageDeprecationEnabled = _featureFlagService.IsManageDeprecationEnabled(currentUser);
+            model.IsPackageDeprecationEnabled = _featureFlagService.IsManageDeprecationEnabled(currentUser, package.PackageRegistration);
 
             if(model.IsGitHubUsageEnabled = _featureFlagService.IsGitHubUsageEnabled(currentUser))
             {
@@ -1467,6 +1467,7 @@ public virtual async Task<ActionResult> Manage(string id, string version = null)
             // Load all versions of the package.
             var packages = _packageService.FindPackagesById(
                 id, PackageDeprecationFieldsToInclude.DeprecationAndRelationships);
+
             if (version != null)
             {
                 // Try to find the exact version if it was specified.
@@ -1492,7 +1493,7 @@ public virtual async Task<ActionResult> Manage(string id, string version = null)
                 ReportMyPackageReasons,
                 Url,
                 await _readMeService.GetReadMeMdAsync(package),
-                _featureFlagService.IsManageDeprecationEnabled(currentUser));
+                _featureFlagService.IsManageDeprecationEnabled(currentUser, package.PackageRegistration));
 
             if (!model.CanEdit && !model.CanManageOwners && !model.CanUnlistOrRelist)
             {

src/NuGetGallery/Services/FeatureFlagService.cs

@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
+using System.Linq;
 using NuGet.Services.Entities;
 using NuGet.Services.FeatureFlags;
 using NuGetGallery.Features;
@@ -22,6 +23,7 @@ public class FeatureFlagService : IFeatureFlagService
         private const string PackagesAtomFeedFeatureName = GalleryPrefix + "PackagesAtomFeed";
 
         private const string ManageDeprecationFeatureName = GalleryPrefix + "ManageDeprecation";
+        private const string ManageDeprecationForManyVersionsFeatureName = GalleryPrefix + "ManageDeprecationMany";
         private const string ODataReadOnlyDatabaseFeatureName = GalleryPrefix + "ODataReadOnlyDatabase";
 
         private readonly IFeatureFlagClient _client;
@@ -46,9 +48,20 @@ public bool IsPackagesAtomFeedEnabled()
             return _client.IsEnabled(PackagesAtomFeedFeatureName, defaultValue: false);
         }
 
-        public bool IsManageDeprecationEnabled(User user)
+        /// <summary>
+        /// The number of versions a package needs to have before it should be flighted using <see cref="ManageDeprecationForManyVersionsFeatureName"/> instead of <see cref="ManageDeprecationFeatureName"/>.
+        /// </summary>
+        private const int _manageDeprecationForManyVersionsThreshold = 500;
+
+        public bool IsManageDeprecationEnabled(User user, PackageRegistration registration)
         {
-            return _client.IsEnabled(ManageDeprecationFeatureName, user, defaultValue: false);
+            if (!_client.IsEnabled(ManageDeprecationFeatureName, user, defaultValue: false))
+            {
+                return false;
+            }
+
+            return registration.Packages.Count() < _manageDeprecationForManyVersionsThreshold 
+                || _client.IsEnabled(ManageDeprecationForManyVersionsFeatureName, user, defaultValue: true);
         }
 
         public bool AreEmbeddedIconsEnabled(User user)

src/NuGetGallery/Services/IFeatureFlagService.cs

@@ -33,9 +33,7 @@ public interface IFeatureFlagService
         /// Whether or not users can manage their package's deprecation state.
         /// If disabled, 
         /// </summary>
-        /// <param name="user"></param>
-        /// <returns></returns>
-        bool IsManageDeprecationEnabled(User user);
+        bool IsManageDeprecationEnabled(User user, PackageRegistration registration);
 
         /// <summary>
         /// Whether the user is allowed to publish packages with an embedded icon.