gistfile1.rb

require 'open-uri'
require 'amazon/ecs'

jans = []
url = 'http://www.bookoffonline.co.jp/display/L001,sk=10,bg=120902,row=50,pr=u-108,st=u,'

1.upto(30).map {|i| url + "p=#{i},"}.each do |url|
  doc = Nokogiri::HTML(open(url), nil, 'CP932')
  doc.css('.itemttl').each do |link|
    path = link.xpath('a')[0].attributes['href'].value
    book_url = "http://www.bookoffonline.co.jp#{path}"
    $stdout = StringIO.new
    doc = Nokogiri::HTML(open(book_url), nil, 'CP932')
    jan = doc.css('.infotxt/table').map do |infotxt|
      infotxt.xpath('tr')[2].xpath('td')[0].text rescue nil
    end.compact.first || nil
    $stdout = STDOUT
    jans << jan if jan
    sleep 10
  end
end


Amazon::Ecs.options = {
    AWS_access_key_id: ENV['AWS_ACCESS_KEY_ID'],
    AWS_secret_key: ENV['AWS_SECRET_KEY'],
    associate_tag: ENV['ASSOCIATE_TAG'],
    country: 'jp',
}

jans.each_slice(10).each do |ids|

  p ids
  res = Amazon::Ecs.item_lookup(
    ids.join(','),
    id_type: 'EAN',
    search_index: 'Books',
    response_group: 'OfferSummary,ItemAttributes',
  )

  res.items.each do |item|
    item_attributes = item.get_element('ItemAttributes')
    title = item_attributes.get_unescaped('Title')
    jan   = item_attributes.get_unescaped('EAN')

    offer_summary = item.get_element('OfferSummary')
    new_price  = offer_summary.get_unescaped('LowestNewPrice/Amount') rescue nil
    used_price = offer_summary.get_unescaped('LowestUsedPrice/Amount') rescue nil

    p "jan: #{jan} new_price: #{new_price} used_price: #{used_price} title: #{title}" if used_price.to_i > 300
  end
  sleep 10
end