#!/usr/bin/env ruby

require "uri"
require "digest"

filename, url = ARGV

unless filename && url
  warn "Please supply a filename and url"
  exit 1
end

path = filename.sub(File.basename(filename), "")
content = File.read(filename)

link_id = content.scan(/\[(\d+)\]: #{url}/).first.first

unless link_id
  warn "Link not found"
  exit 1
end

uri = URI.parse(url)

link_content = `w3m #{url}`

hash = Digest::MD5.base64digest(url + link_content)
  .scan(/[a-z0-9]/i)
  .first(6)
  .join
  .downcase

link_filename = "#{uri.host.gsub(".", "-")}-#{hash}.txt"

File.write("#{path}/#{link_filename}", link_content)

content.gsub!(/\[#{link_id}\]([^:])/, "[#{link_id}][^#{link_id}-backup]\\1")

File.write(filename, content)
File.write(filename, "\n[^#{link_id}-backup]: <a href=\"#{link_filename}\">Backed up #{Time.now}</a>", mode: "a+")