Downloads videos from nsscreencast (requires paid account)

nsscreencast_downloader.rb

# Using this script downloads ALL the videos in NSScreencast.
# Usage: `EMAIL=your email PASSWORD=your password.`

require 'HTTParty'
require 'Nokogiri'
require 'pry'
require "mechanize"
require "parallel"

class Scraper

  def initialize

    mechanize = Mechanize.new
    mechanize.post("https://www.nsscreencast.com/user_sessions", {"email" => ENV["EMAIL"], "password" => ENV["PASSWORD"]})
    mechanize.pluggable_parser.default = Mechanize::Download

    total_pages = 16
    failed_downloads = Array.new

    1.upto(total_pages) do |i|

      doc = HTTParty.get("https://nsscreencast.com/episodes?page=#{i}#episodes")
      parse_page ||= Nokogiri::HTML(doc)

      links = parse_page.css("div.episode").css("div.episode_thumbnail").css("a")

      # Parallel.each(links) do |link|
      links.each do |link|
        path = link.attributes['href'].value.sub('/episodes/', '')
        episode_id = path.match(/^([0-9]*)/)[1]
        video_url = "https://nsscreencast.com/episodes/#{path}.mp4"

        file_name = "#{path}.mp4"
        if File.file?(file_name)
          puts "[EXISTS] #{file_name} has already been downloaded for video at URL:\n#{video_url}\n\n"
        else
          puts "[DOWNLOADING] #{video_url}\n"

          begin
            video = mechanize.get(video_url)
          rescue Mechanize::ResponseCodeError => e
            failed_downloads.push(video_url)
          else
            video.save("#{path}.mp4")
            puts "Saved #{video_url}\n\n"
          end
        end
      end
    end

    puts("\n\nThe following downloads failed: \n[\n#{failed_downloads.join("\n")}\n]")
  end
end

_scraper = Scraper.new