require 'mongoid/compatibility'

module Mongoid
  module Locker
    # Normalizes queries between Mongoid 2 and 3.
    module Wrapper
      # Update the document for the provided Class matching the provided query with the provided setter.
      #
      # @param [Class] The model class
      # @param [Hash] The Mongoid query
      # @param [Hash] The Mongoid setter
      # @return [Boolean] true if the document was successfully updated, false otherwise
      def self.update(klass, query, setter)
        if Mongoid::Compatibility::Version.mongoid5?
          !klass.with(safe: true).collection.find(query).find_one_and_update(setter).nil?
        elsif Mongoid::Compatibility::Version.mongoid2?
          klass.collection.update(query, setter, safe: true)['n'] == 1
        else
          klass.with(safe: true).collection.find(query).update(setter)['n'] == 1
        end
      end

      # Determine whether the provided document is locked in the database or not.
      #
      # @param [Class] The model instance
      # @return [Time] The timestamp of when the document is locked until, nil if not locked.
      def self.locked_until(doc)
        existing_query = {
          _id: doc.id,
          locked_until: { '$exists' => true }
        }

        if Mongoid::Compatibility::Version.mongoid2?
          existing = doc.class.collection.find_one(existing_query, fields: { locked_until: 1 })
          existing ? existing['locked_until'] : nil
        else
          existing = doc.class.where(existing_query).limit(1).only(:locked_until).first
          existing ? existing.locked_until : nil
        end
      end
    end
  end
end