class ContactForm
  LIMITS = {
    "email" => 254,
    "name" => 128,
    "subject" => 200,
    "message" => 5000
  }.freeze

  def initialize(params)
    @params = params
  end

  def spam?
    !@params["website"].to_s.empty?
  end

  def valid?
    fields_valid = LIMITS.all? do |key, max|
      value = @params[key]

      value.is_a?(String) &&
        value.valid_encoding? &&
        !value.strip.empty? &&
        value.strip.length <= max
    end

    return false unless fields_valid

    email_valid = @params["email"].strip.match?(/\A[^\s@]+@[^\s@]+\.[^\s@]+\z/)
    headers_valid = %w[name subject].none? do |key|
      @params[key].match?(/[\r\n]/)
    end

    email_valid && headers_valid
  end
end