module Prick
  module Migra
    def self.migrate(from_name, to_name, file)
      args = urls(from_name, to_name).join(" ")
      options = OPTIONS.join(" ")
      Command.command %(
        status=0
        migra #{options} #{args} >#{file} || { status=$?; }
        [ $status = 2 ] || exit 1
      )
    end

  private
    OPTIONS = %w(--unsafe --with-privileges)

    def self.urls(*args)
      args = Array(args).flatten
      args.map { |name| "postgresql:///#{name}" }
    end
  end
end