yakan-hiko.rb

#!/usr/bin/env ruby
require 'mechanize'
require 'pry'

class Agent
  def initialize(login, password)
    @agent = Mechanize.new
    @agent.pluggable_parser['appilcation/epub+zip'] = Mechanize::Download
    @login, @password = login, password
  end

  def download(url)
    page = @agent.get 'https://yakan-hiko.com/login.php'
    form = page.form_with(:name => 'contact')
    form.login_id = @login
    form.pass = @password
    @agent.submit form

    page = @agent.get(url)
    page.save("/tmp/#{page.filename}")
  end
end

agent = Agent.new(ENV['YAKAN_HIKO_LOGIN'], ENV['YAKAN_HIKO_PASSWORD'])
agent.download(ARGV[0])