module Roda::RodaPlugins::ErrorMail::InstanceMethods

def _error_mail(e)
  email_opts = self.class.opts[:error_mail]
  subject = if e.respond_to?(:message)
    "#{e.class}: #{e.message}"
  else
    e.to_s
  end
  subject = "#{email_opts[:prefix]}#{subject}"
  filter = email_opts[:filter]
  format = lambda do |h|
    h = h.map{|k, v| "#{k.inspect} => #{filter.call(k, v) ? 'FILTERED' : v.inspect}"}
    h.sort!
    h.join("\n")
  end 
  begin
    params = request.params
    params = (format[params] unless params.empty?)
  rescue
    params = 'Invalid Parameters!'
  end
  message = String.new
  message << <<END
request.path}
  if e.respond_to?(:backtrace)
    message << <<END
e:
trace.join("\n")}
  end
  message << <<END
[env]}
  if params
    message << <<END
}
  end
  if env['rack.session']
    message << <<END

[session]}
  end
  Mail.new do
    from email_opts[:from]
    to email_opts[:to]
    subject subject
    body message
    if headers = email_opts[:headers]
      headers.each do |k,v|
        header[k] = v
      end
    end
  end
end