module Msf
  class DBManager
    module Migration
      # Migrate database to latest schema version.
      #
      # @param verbose [Boolean] see ActiveRecord::Migration.verbose
      # @return [Array<ActiveRecord::MigrationProxy] List of migrations that
      #   ran.
      #
      # @see ActiveRecord::Migrator.migrate
      def migrate(verbose=false)
        ran = []
        ActiveRecord::Migration.verbose = verbose

        ActiveRecord::Base.connection_pool.with_connection do
          begin
            ran = ActiveRecord::Migrator.migrate(
                ActiveRecord::Migrator.migrations_paths
            )
          # ActiveRecord::Migrator#migrate rescues all errors and re-raises them
          # as StandardError
          rescue StandardError => error
            self.error = error
            elog("DB.migrate threw an exception: #{error}")
            dlog("Call stack:\n#{error.backtrace.join "\n"}")
          end
        end

        # Since the connections that existed before the migrations ran could
        # have outdated column information, reset column information for all
        # ActiveRecord::Base descendents to prevent missing method errors for
        # column methods for columns created in migrations after the column
        # information was cached.
        reset_column_information

        return ran
      end

      # Flag to indicate database migration has completed
      #
      # @return [Boolean]
      attr_accessor :migrated

      private

      # Resets the column information for all descendants of ActiveRecord::Base
      # since some of the migrations may have cached column information that
      # has been updated by later migrations.
      #
      # @return [void]
      def reset_column_information
        ActiveRecord::Base.descendants.each do |descendant|
          descendant.reset_column_information
        end
      end
    end
  end
end