How can remove http(s), www(n) and public suffixes in ruby? - ruby-on-rails

Question

Input => Expected Output
https://mail.google.com.au => mail.google
http://www.google.in => google
https://www9.calendar.google.co.uk => calendar.google
https://www12.stage.calendar.google.co.uk => stage.calendar.google
www.blog.botreetechnologies.com => blog.botreetechnologies
Update
t = URI.parse 'http://www.google.com'
t.host
#=> "www.google.com"
URI.split 'http://www.google.com'
#=> ["http", nil, "www.google.com", nil, nil, "", nil, nil, nil]
uri = URI.parse("http://www.google.co.uk")
#=> #<URI::HTTP http://www.google.co.uk>
domain = PublicSuffix.parse(uri.host)
#=> #<PublicSuffix::Domain:0x00000003c538e0 #sld="google", #tld="co.uk", #trd="www">
domain.sld
#=> "google"
uri = URI.parse("http://www.mail.google.co.uk")
#=> #<URI::HTTP http://www.mail.google.co.uk>
domain = PublicSuffix.parse(uri.host)
#=> #<PublicSuffix::Domain:0x00000002e97bc0 #sld="google", #tld="co.uk", #trd="www.mail">
domain.sld
#=> "google"
%w[http://www.example.com/page http://blog.example.com/page].each do |u|
puts URI.parse(u).host.sub(/^www\./, '')
end
# example.com
# blog.example.com
uri = URI.parse("www.pinkpoodles.com.au")
#=> #<URI::Generic www.pinkpoodles.com.au>
uri.host
#=> nil

Answer 1

I can't think of a "one-liner", but something like this would work:
require 'uri'
require 'public_suffix'
def simple_host(uri)
uri = URI(uri)
uri = URI("http://#{uri}") unless uri.scheme
domain = PublicSuffix.parse(uri.host)
trd = domain.trd
if trd
trd = trd.split('.')
trd.shift if trd.first.start_with?('www')
end
[*trd, domain.sld].join('.')
end
simple_host('https://mail.google.com.au') #=> "mail.google"
simple_host('http://www.google.in') #=> "google"
simple_host('https://www9.calendar.google.co.uk') #=> "calendar.google"
simple_host('https://www12.stage.calendar.google.co.uk') #=> "stage.calendar.google"
simple_host('www.blog.botreetechnologies.com') #=> "blog.botreetechnologies"

Answer 2

Not a job for one line. But here's a function that does some string manipulation that at least satisfies the test cases you have provided.
def foo(url)
url = url.split("//").last.split(".")
url = url.each do |word|
if word.include?("http") || word.include?("www") || word.length < 3
url.delete(word)
end
end
if url.length > 1
if url.length >= 3 && url[2].length > 3
url = [url[0], url[1], url[2]].join('.')
else
url = [url[0], url[1]].join(".")
end
else
url = url.first
end
end
foo 'http://www.google.in'
# => 'google'
foo 'https://www9.calendar.google.co.uk'
# => 'calendar.google'
foo 'https://mail.google.com.au'
# => 'mail.google'
foo 'https://www12.stage.calendar.google.co.uk'
# => 'stage.calendar.google'
foo 'www.blog.botreetechnologies.com'
# => 'blog.botreetechnologies'

Answer 3

Here how I fixed that then. On a toe so pasting quickly
def filename(website_domain)
domain = website_domain.starts_with?('http') ? website_domain : "https://#{website_domain}"
uri = URI.parse domain
suffix = PublicSuffix.parse(uri.host)
name = uri.host.sub(/^www\d*\./i, '').sub(/\.#{suffix.tld}/, '')
"#{name}.filtered.xml"
end