module YoutubeToRss

# File lib/youtube_to_rss.rb, line 6
def convert(url)
  url = remove_query_strings(url)
  base_url = 'https://www.youtube.com/feeds/videos.xml?'

  if url.include?('/channel/')
    "#{base_url}channel_id=#{extract_param(url, '/channel/')}"
  elsif url.include?('/user/')
    "#{base_url}user=#{extract_param(url, '/user/')}"
  else
    raise 'URL should have channel or user param.'
  end
end

# File lib/youtube_to_rss.rb, line 21
def extract_param(url, param)
  url.split(param).last
end

# File lib/youtube_to_rss.rb, line 25
def remove_query_strings(url)
  url.split('?').first.split('&').first
end