railscasts_fetch.rb

require "net/http"
require "pry"

# Parameters for episode looping.
#
# Note that 404 seems to be reserved for whining.
MIN_EPISODE_NUMBER = 001
MAX_EPISODE_NUMBER = 417

FORMAT = ".ogv"

(MIN_EPISODE_NUMBER..MAX_EPISODE_NUMBER).each do |episode_number|
	puts ">> Now on episode #{episode_number}"

	print " >> Sending request..."

	# RailsCasts server will handle redirects.
	#
	# So if we just knock on the route, providing it only the number, it'll
	# give us a redirect.
	uri = URI.parse("http://railscasts.com/episodes/#{episode_number}")

	# Create a request, spoof user-agent to make people think we're s00p3r
	# l33t with our curly awesomeness.
	request = Net::HTTP::Get.new(uri.to_s, {"User-Agent" => "curl/7.37.0"})

	response = Net::HTTP.start(uri.host, uri.port) do |http|
		http.request(request)
	end

	print " #{response.code}!\n"

	prefetch_hash = response.to_hash

	response_location = response["location"]

	puts " >> Have location #{response_location}, parsing..."
	match = response_location.match(/(\d+)\-(.+)$/)

	episode_number = "%03d" % [match[1]]
	episode_title_safe = match[2]

	puts "  #{episode_number} <=> #{episode_title_safe}"

	puts " >> Generating media url..."

	media_url = "http://media.railscasts.com/assets/episodes/videos/#{episode_number}-#{episode_title_safe}#{FORMAT}"

	puts ""

	puts ">> Downloading video from #{media_url}..."

	media_uri = URI.parse(media_url)

	media_request = Net::HTTP::Get.new(media_uri.to_s, {"User-Agent" => "curl/7.37.0"})

	media_response = Net::HTTP.start(media_uri.host, media_uri.port) do |http|
		http.request(media_request)
	end

	puts " >> Done! Writing..."

	open("#{episode_number}-#{episode_title_safe}#{FORMAT}", "wb") do |io|
		io.write media_response.body
	end

	puts ">> DONE!", "", "", ""
end