require 'getoptlong'

class CommandLineArgumentParser
  WEB_CRAWLER = 'web'
  DOMAIN_CRAWLER = 'domain'

  attr_reader :crawl_type, :crawl_depth, :page_limit, :url_file

  def initialize
    unless ARGV.length >= 1
      display_usage
      exit
    end

    @opts = GetoptLong.new(
                          ["--crawl", "-c", GetoptLong::REQUIRED_ARGUMENT],
                          ["--crawl-depth", "-d", GetoptLong::OPTIONAL_ARGUMENT],
                          ["--page-limit", "-p", GetoptLong::OPTIONAL_ARGUMENT],
                          ["--url-file", "-f", GetoptLong::OPTIONAL_ARGUMENT]
    )
    @crawl_depth = 3
    @crawl_type = "data.txt"
    @page_limit = 100
    @url_file = 'urls.txt'
  end

  def display_usage
    p "simple usage:"
    p "ruby search-engine-main.rb -c web -d 3 -p 100 -f 'urls.txt'"
    p "-c must be either 'web' or 'domain', will default to 'web' is your type garbage"
  end

  def parse_arguments
    @opts.each do |opt, arg|
      case opt
      when '--crawl'
        ensure_crawl_type_correct(arg)
      when '--crawl-depth'
        @crawl_depth = arg
      when '--page-limit'
        @page_limit = arg
      when '--url-file'
        @url_file = arg
      end
    end
  end

  def ensure_crawl_type_correct(value)
    if value != WEB_CRAWLER && value != DOMAIN_CRAWLER
      @crawl_type = WEB_CRAWLER
    else
      @crawl_type = value
    end
  end
end