Support user prompts in Fizzy do, move parsing logic to context

app/models/command/parser/context.rb

@@ -28,6 +28,29 @@ class Command::Parser::Context
     viewing_cards_index? || viewing_search_results?
   end
 
+  def find_user(string)
+    if string.starts_with?("gid://")
+      User.find_by_id(GlobalID::Locator.locate(string).id)
+    else
+      string_without_at = string.delete_prefix("@")
+      User.all.find { |user| user.mentionable_handles.include?(string_without_at.downcase) }
+    end
+  end
+
+  def find_workflow_stage(string)
+    candidate_stages.find do |stage|
+      stage.name.downcase.include?(combined_arguments.downcase)
+    end
+  end
+
+  def find_tag(string)
+    Tag.find_by_title(string)
+  end
+
+  def find_collection(string)
+    Collection.where("lower(name) like ?", "%#{name.downcase}%").first
+  end
+
   private
     attr_reader :controller, :action, :params
 
@@ -57,4 +80,8 @@ class Command::Parser::Context
       @action = route[:action]
       @params =  ActionController::Parameters.new(Rack::Utils.parse_nested_query(uri.query).merge(route.except(:controller, :action)))
     end
+
+    def candidate_stages
+      Workflow::Stage.where(workflow_id: cards.joins(:collection).select("collections.workflow_id").distinct)
+    end
 end