3 files changed, 127 insertions, 0 deletions
diff --git a/app/graphql/mutations/design_management/base.rb b/app/graphql/mutations/design_management/base.rb
new file mode 100644
index 00000000000..918e5709b94
--- /dev/null
+++ b/app/graphql/mutations/design_management/base.rb
@@ -0,0 +1,23 @@
+# frozen_string_literal: true
+
+module Mutations
+  module DesignManagement
+    class Base < ::Mutations::BaseMutation
+      include Mutations::ResolvesIssuable
+
+      argument :project_path, GraphQL::ID_TYPE,
+               required: true,
+               description: "The project where the issue is to upload designs for"
+
+      argument :iid, GraphQL::ID_TYPE,
+               required: true,
+               description: "The iid of the issue to modify designs for"
+
+      private
+
+      def find_object(project_path:, iid:)
+        resolve_issuable(type: :issue, parent_path: project_path, iid: iid)
+      end
+    end
+  end
+end
diff --git a/app/graphql/mutations/design_management/delete.rb b/app/graphql/mutations/design_management/delete.rb
new file mode 100644
index 00000000000..d2ef2c9bcca
--- /dev/null
+++ b/app/graphql/mutations/design_management/delete.rb
@@ -0,0 +1,66 @@
+# frozen_string_literal: true
+
+module Mutations
+  module DesignManagement
+    class Delete < Base
+      Errors = ::Gitlab::Graphql::Errors
+
+      graphql_name "DesignManagementDelete"
+
+      argument :filenames, [GraphQL::STRING_TYPE],
+               required: true,
+               description: "The filenames of the designs to delete",
+               prepare: ->(names, _ctx) do
+                 names.presence || (raise Errors::ArgumentError, 'no filenames')
+               end
+
+      field :version, Types::DesignManagement::VersionType,
+            null: true, # null on error
+            description: 'The new version in which the designs are deleted'
+
+      authorize :destroy_design
+
+      def resolve(project_path:, iid:, filenames:)
+        issue = authorized_find!(project_path: project_path, iid: iid)
+        project = issue.project
+        designs = resolve_designs(issue, filenames)
+
+        result = ::DesignManagement::DeleteDesignsService
+          .new(project, current_user, issue: issue, designs: designs)
+          .execute
+
+        {
+          version: result[:version],
+          errors: Array.wrap(result[:message])
+        }
+      end
+
+      private
+
+      # Here we check that:
+      #  * we find exactly as many designs as filenames
+      def resolve_designs(issue, filenames)
+        designs = issue.design_collection.designs_by_filename(filenames)
+
+        validate_all_were_found!(designs, filenames)
+
+        designs
+      end
+
+      def validate_all_were_found!(designs, filenames)
+        found_filenames = designs.map(&:filename)
+        missing = filenames.difference(found_filenames)
+
+        if missing.present?
+          raise Errors::ArgumentError, <<~MSG
+            Not all the designs you named currently exist.
+            The following filenames were not found:
+            #{missing.join(', ')}
+
+            They may have already been deleted.
+          MSG
+        end
+      end
+    end
+  end
+end
diff --git a/app/graphql/mutations/design_management/upload.rb b/app/graphql/mutations/design_management/upload.rb
new file mode 100644
index 00000000000..1ed7f8e49e6
--- /dev/null
+++ b/app/graphql/mutations/design_management/upload.rb
@@ -0,0 +1,38 @@
+# frozen_string_literal: true
+
+module Mutations
+  module DesignManagement
+    class Upload < Base
+      graphql_name "DesignManagementUpload"
+
+      argument :files, [ApolloUploadServer::Upload],
+               required: true,
+               description: "The files to upload"
+
+      authorize :create_design
+
+      field :designs, [Types::DesignManagement::DesignType],
+            null: false,
+            description: "The designs that were uploaded by the mutation"
+
+      field :skipped_designs, [Types::DesignManagement::DesignType],
+            null: false,
+            description: "Any designs that were skipped from the upload due to there " \
+                         "being no change to their content since their last version"
+
+      def resolve(project_path:, iid:, files:)
+        issue = authorized_find!(project_path: project_path, iid: iid)
+        project = issue.project
+
+        result = ::DesignManagement::SaveDesignsService.new(project, current_user, issue: issue, files: files)
+                   .execute
+
+        {
+          designs: Array.wrap(result[:designs]),
+          skipped_designs: Array.wrap(result[:skipped_designs]),
+          errors: Array.wrap(result[:message])
+        }
+      end
+    end
+  end
+end