Get Dat NES Classic Brah

Stock Hunter

require 'json'
require 'open-uri'
require 'nokogiri'
require 'byebug'
require 'logger'

# OPTIONS #

# In Seconds
INTERVAL = 5

EMAIL = 'YOUR_EMAIL_HERE'

VERBOSE = ENV['VERBOSE']

USE_PROXY = ENV['PROXY']

# UA #

HEADERS = {
  'User-Agent' => 'Mozilla/5.0 (Windows NT 10.0; WOW64; rv:50.0) Gecko/20100101 Firefox/50.0'
}

# PRICE CHECKS #

# [ <Name (Just for logging & email)>, <Link to product page>, <Desired Price>]

AMAZON_PRICE_CHECKS = [
  # ['Amazon.ca: Clippers', 'https://www.amazon.ca/dp/B0009XH6ZA', 100.00]
]

# STOCK CHECKS #

# [ <Name (Just for logging & email)>, <Link to product page>]

AMAZON_CA = {
  'Amazon.ca: NES Classic' => 'https://www.amazon.ca/Nintendo-Entertainment-System-NES-Classic/dp/B01IFJBQ1E'
}

AMAZON_IT = {

}

AMAZON_DE = {

}

TRU = {

}

PROXIES = [
  ['207.99.118.74', 8080],
  ['45.63.48.26', 3128],
  ['71.205.192.36', 3128],
]

module StockHunter
  module_function

  def hunt
    attack
  rescue => e
    log_error(e, 'StandardError')
    hunt
  end

  def attack
    loop do
      check_amazon_ca_prices
      check_amazon_ca
      # check_amazon_it
      # check_amazon_de
    end
  end

  # PRICE CHECKING #

  def check_amazon_ca_prices
    AMAZON_PRICE_CHECKS.each do |name, url, target|
      doc = fetch_page(name, url)
      next unless doc

      text  = doc.search("span#priceblock_ourprice").text
      raw   = text.match(/\d+\..+/)
      price = raw[0]&.to_f if raw

      check_price(doc, name, url, price) do
        if price
          price < target
        else
          false
        end
      end

      snooze
    end
  end

  # STOCK CHECKING #

  def check_amazon_ca
    AMAZON_CA.each do |name, url|
      doc = fetch_page(name, url)
      next unless doc

      stock = doc.css('div#merchant-info').text if doc

      check_stock(doc, name, url) do
        stock.match('sold by Amazon')
      end

      snooze
    end
  end

  def check_amazon_it
    AMAZON_IT.each do |name, url|
      doc = fetch_page(name, url)
      next unless doc

      stock = doc.css('div#merchant-info').text if doc

      check_stock(doc, name, url) do
        stock.match('Venduto e spedito da Amazon')
      end

      snooze
    end
  end

  def check_amazon_de
    AMAZON_DE.each do |name, url|
      doc = fetch_page(name, url)
      next unless doc

      stock = doc.css('div#availability_feature_div').text if doc

      check_stock(doc, name, url) do
        stock.match('Verkauf und Versand durch') && stock.match('Amazon')
      end

      snooze
    end
  end

  def check_indigo
    INDIGO.each do |name, url|
      doc = fetch_page(name, url)
      next unless doc

      stock = doc.css('div.pricing-box').text if doc

      check_stock(doc, name, url) do
        stock.match('In stock online')
      end

      snooze
    end
  end

  def check_bb
    BB.each do |name, url|
      doc = fetch_page(name, url)
      next unless doc

      stock = doc.css('div#schemaorg-offer').text if doc

      check_stock(doc, name, url) do
        stock.match('In Stock')
      end

      snooze
    end
  end

  def check_tru
    TRU.each do |name, url|
      doc = fetch_page(name, url)
      next unless doc

      stock = doc.css('div#buy-interior').xpath('//comment()').text if doc

      check_stock(doc, name, url) do
        stock.match('In Stock')
      end

      snooze
    end
  end

  # PRICE CHECKING #

  def check_price(doc, name, url, price, &block)
    if doc && block.call
      alert_price(url, name, price)
    else
      log_not_cheaper(name, price)
    end
  end

  def alert_price(url, name, price)
    msg = "🎉  HOLY MOLY! #{name} is #{price}!!"
    logger.info msg
    puts msg if VERBOSE
    send_email(url, msg)
  end

  def log_not_cheaper(name, price)
    msg = "🙁  #{name} is still #{price}"
    logger.info msg
    puts msg if VERBOSE
  end

  # STOCK CHECKING #

  def check_stock(doc, name, url, &block)
    if doc && block.call
      alert_in_stock(url, name)
    else
      log_not_in_stock(name)
    end
  end

  def alert_in_stock(url, name)
    msg = "🎉  HOLY MOLY! #{name} is in stock!!"
    logger.info msg
    puts msg if VERBOSE
    send_email(url, msg)
  end

  def log_not_in_stock(name)
    msg = "🙁  #{name} is not in stock"
    logger.info msg
    puts msg if VERBOSE
  end

  # COMMON #

  def fetch_page(name, url)
    ip, port = PROXIES.rotate!.first

    file =
      if USE_PROXY
        open(url, HEADERS.merge(proxy: "http://#{ip}:#{port}"))
      else
        open(url, HEADERS)
      end

    Nokogiri::HTML(file)
  rescue => e
    log_error(e, name, ip)
    false
  end

  def send_email(url, msg)
    to = EMAIL
    subject = msg
    content = url

    `echo "#{content}" | mailx -s "#{subject}" #{to}`
  end

  def log_error(e, name, ip)
    msg = "#{ip} -- #{name} - #{e.message}"
    logger.error msg
    puts msg if VERBOSE
  end

  def logger
    Logger.new('stock_hunter.log')
  end

  def snooze
    sleep(INTERVAL)
  end
end

if __FILE__ == $0
  puts 'Running ...'
  StockHunter.hunt
end