dlimg

#!/usr/bin/env ruby

require 'optparse'
require 'fileutils'
require 'open-uri'

require 'nokogiri'

# = Options =
options = {}
OptionParser.new do |opts|
  opts.banner = "Usage: dl.rb [options]"

  opts.on("-u VALUE", "--url VALUE", "Target url") do |v|
    options[:url] = v
  end

  opts.on("-p VALUE", "--parent_css_selector VALUE", "Parent css selector") do |v|
    options[:parent_css_selector] = v
  end

  opts.on("-d VALUE", "--dir VALUE", "Save dir") do |v|
    options[:dir] = v
  end
end.parse!

[:url, :parent_css_selector, :dir].each do |required_key|
  raise OptionParser::MissingArgument, "missing argument: --#{required_key}. this is required" if options[required_key].nil?
end

# = Execute =
FileUtils.mkdir_p(options[:dir]) unless File.exists?(options[:dir])

document = Nokogiri::HTML(open(options[:url]))
img_selector = "#{options[:parent_css_selector]} img"

document.css(img_selector).each_with_index do |img, index|
  src = img[:src]
  ext = src.split('.').last
  filepath = File.join(options[:dir], "#{index}.#{ext}")

  File.open(filepath, 'wb') { |f|
    f.puts open(src).read
  }
end