Add /reopen command

app/models/command/reopen.rb

@@ -0,0 +1,35 @@
+class Command::Reopen < Command
+  include Command::Cards
+
+  store_accessor :data, :reopened_card_ids
+
+  def title
+    "Reopen #{cards_description}"
+  end
+
+  def execute
+    reopened_card_ids = []
+
+    transaction do
+      cards.find_each do |card|
+        reopened_card_ids << card.id
+        card.reopen(user: user)
+      end
+
+      update! reopened_card_ids: reopened_card_ids
+    end
+  end
+
+  def undo
+    transaction do
+      reopened_cards.find_each do |card|
+        card.close(user: user)
+      end
+    end
+  end
+
+  private
+    def reopened_cards
+      user.accessible_cards.where(id: reopened_card_ids)
+    end
+end