1 files changed, 60 insertions, 0 deletions
diff --git a/app/models/design_management/design_collection.rb b/app/models/design_management/design_collection.rb
index 96d5f4c2419..c48b36588c9 100644
--- a/app/models/design_management/design_collection.rb
+++ b/app/models/design_management/design_collection.rb
@@ -6,8 +6,34 @@ module DesignManagement
 
     delegate :designs, :project, to: :issue
 
+    state_machine :copy_state, initial: :ready, namespace: :copy do
+      after_transition any => any, do: :update_stored_copy_state!
+
+      event :start do
+        transition ready: :in_progress
+      end
+
+      event :end do
+        transition in_progress: :ready
+      end
+
+      event :error do
+        transition in_progress: :error
+      end
+
+      event :reset do
+        transition any => :ready
+      end
+    end
+
     def initialize(issue)
+      super() # Necessary to initialize state_machine
+
       @issue = issue
+
+      if stored_copy_state = get_stored_copy_state
+        @copy_state = stored_copy_state
+      end
     end
 
     def ==(other)
@@ -30,5 +56,39 @@ module DesignManagement
     def designs_by_filename(filenames)
       designs.current.where(filename: filenames)
     end
+
+    private
+
+    def update_stored_copy_state!
+      # As "ready" is the initial copy state we can clear the cached value
+      # rather than persist it.
+      if copy_ready?
+        unset_store_copy_state!
+      else
+        set_stored_copy_state!
+      end
+    end
+
+    def copy_state_cache_key
+      "DesignCollection/copy_state/issue=#{issue.id}"
+    end
+
+    def get_stored_copy_state
+      Gitlab::Redis::SharedState.with do |redis|
+        redis.get(copy_state_cache_key)
+      end
+    end
+
+    def set_stored_copy_state!
+      Gitlab::Redis::SharedState.with do |redis|
+        redis.set(copy_state_cache_key, copy_state)
+      end
+    end
+
+    def unset_store_copy_state!
+      Gitlab::Redis::SharedState.with do |redis|
+        redis.del(copy_state_cache_key)
+      end
+    end
   end
 end