amazon_order.rb

# -*- coding: utf-8 -*-
require 'mechanize'

class AmazonOrder
    def initialize
        @agent = WWW::Mechanize.new
        @agent.user_agent_alias = 'Windows IE 7'
    end

    def login id, password
        page = @agent.get('https://www.amazon.co.jp/gp/sign-in.html')
        page.forms[1].fields_with(:name => 'email').first.value = id
        page.forms[1].fields_with(:name => 'password').first.value = password
        page = page.forms[1].click_button
    end

    def get_items
        page = @agent.get 'https://www.amazon.co.jp/gp/css/history/orders/view.html'
        years = page.search('#orderFilter option @value').select{|x| x.value =~ /year-/}.map{|x| x.value.split('-')[1]}

        years.reduce([]){|r, year| r + get_items_by(year) }.uniq{|x| x[:isbn10]}
    end

    def get_items_by year
        sleep(1)

        a_url = "https://www.amazon.co.jp/gp/css/history/orders/view.html?opt=ab&groupID=0&orderFilter=year-#{year}&x=20&y=4"
        page = @agent.get a_url
        len = (page.at('/html/body/table[3]/tbody/tr/td/div/b[2]').text.to_f / 10).ceil

        (1..len).reduce([]) do |r, i|
           page = @agent.get a_url + "&startAtIndex=#{i*10}"
           page.encoding = 'sjis'
           r + to_items(page)
        end
    end

    def parse page
        next_btn = page.at('/html/body/table[3]/tbody/tr/td[2]/a/@href')
        to_items(page) + if next_btn
             parse page.links.select{|link| link.href == next_btn.text}.first.click
        else
            [] 
        end
    end

    def to_items page
        page.search('li.item').map do |item|
            {
            name:item.at('a').text,
            isbn10:item.at('a @href').value.split('/')[5]
            }
        end
    end
end