# frozen_string_literal: true

module Mutations
  module Todos
    class RestoreMany < ::Mutations::Todos::Base
      graphql_name 'TodoRestoreMany'

      MAX_UPDATE_AMOUNT = 50

      argument :ids,
               [GraphQL::ID_TYPE],
               required: true,
               description: 'The global ids of the todos to restore (a maximum of 50 is supported at once)'

      field :updated_ids, [GraphQL::ID_TYPE],
            null: false,
            description: 'The ids of the updated todo items'

      def resolve(ids:)
        check_update_amount_limit!(ids)

        todos = authorized_find_all_pending_by_current_user(model_ids_of(ids))
        updated_ids = restore(todos)

        {
            updated_ids: gids_of(updated_ids),
            errors: errors_on_objects(todos)
        }
      end

      private

      def gids_of(ids)
        ids.map { |id| ::URI::GID.build(app: GlobalID.app, model_name: Todo.name, model_id: id, params: nil).to_s }
      end

      def model_ids_of(ids)
        ids.map do |gid|
          parsed_gid = ::URI::GID.parse(gid)
          parsed_gid.model_id.to_i if accessible_todo?(parsed_gid)
        end.compact
      end

      def accessible_todo?(gid)
        gid.app == GlobalID.app && todo?(gid)
      end

      def todo?(gid)
        GlobalID.parse(gid)&.model_class&.ancestors&.include?(Todo)
      end

      def raise_too_many_todos_requested_error
        raise Gitlab::Graphql::Errors::ArgumentError, 'Too many todos requested.'
      end

      def check_update_amount_limit!(ids)
        raise_too_many_todos_requested_error if ids.size > MAX_UPDATE_AMOUNT
      end

      def errors_on_objects(todos)
        todos.flat_map { |todo| errors_on_object(todo) }
      end

      def authorized_find_all_pending_by_current_user(ids)
        return Todo.none if ids.blank? || current_user.nil?

        Todo.for_ids(ids).for_user(current_user).done
      end

      def restore(todos)
        TodoService.new.mark_todos_as_pending(todos, current_user)
      end
    end
  end
end
