module AppleSystemStatus
  require "capybara"
  require 'capybara/poltergeist'

  class Crawler
    USER_AGENT = "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_9_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/43.0.2357.134 Safari/537.36"

    def initialize
      Capybara.register_driver :poltergeist do |app|
        Capybara::Poltergeist::Driver.new(app)
      end
      @session = Capybara::Session.new(:poltergeist)
      @session.driver.headers = { "User-Agent" => USER_AGENT }
    end

    def perform(country = nil)
      @session.visit(apple_url(country))

      title_parts = [
        @session.find("#key_date_text").text,
        @session.find("#key_date").text,
        @session.find("#key_date_post").text,
      ]

      response = {
        title:    title_parts.join(" ").strip,
        statuses: [],
      }

      @session.all("#dashboard td").each_with_object(response[:statuses]) do |td, statuses|
        begin
          statuses << {
            title:       td.find("p[role='text']").text,
            description: td.find("p[role='text']")["aria-label"],
            status:      td.find("span")["class"],
          }
        rescue Capybara::ElementNotFound
          # NOTE: Capybara::Node::Matchers#has_css? is very slow!
        end
      end

      response
    end

    private

    def apple_url(country)
      if country
        "https://www.apple.com/#{country}/support/systemstatus/"
      else
        "https://www.apple.com/support/systemstatus/"
      end
    end
  end
end