Convert Firefox/Chromium Bookmarks HTML export files to Org-mode format

firefox_bookmarks_html_to_org.rb

#!/usr/bin/env ruby

# firefox_bookmarks_html_to_org.rb
# convert HTML files exported from Firefox/Chromium/Chrome/Brave/... Bookmarks
# to https://orgmode.org/ format
#
# Copyright (C) 2021 Juri Linkov  <juri@linkov.net>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

# Usage: ruby firefox_bookmarks_html_to_org.rb bookmarks-date.html > bookmarks-date.org
# where bookmarks-date.html is exported from Firefox by:
# 1. Type Control-Shift-O
# 2. Click "Import and Backup -> Export Bookmarks to HTML..." and "Save"

require 'nokogiri'
require 'cgi'

html = Nokogiri.HTML(ARGF.read.gsub(/\r$/,'').gsub(/<DT><A.+?<\/A>$/, '\\0</DT>').gsub(/<p>/,'').gsub(/\n+[ \t]*/,''))
STDERR.puts html.errors#.last

def process(html, level)
  html.children.each do |c|
    # DT A
    if (a=c.children[0])&.name == 'a'
      puts "- #{a.text}"
      puts "  #{begin CGI.unescape(a.attr('href')).gsub(/ /, '%20') rescue a.attr('href') end}"
      print "  [#{Time.at(a.attr('add_date').to_i)}]"
      print  " [#{Time.at(a.attr('last_modified').to_i)}]"
      puts
    elsif c.name == 'hr'
      puts ""
    end
  end
  html.children.each_with_index do |c, i|
    # DT H3
    if (h3=c.children[0])&.name == 'h3'
      puts "#{'*' * (level < 1 ? 1 : level)} #{h3.text}"
      print "  [#{Time.at(h3.attr('add_date').to_i)}]"
      print  " [#{Time.at(h3.attr('last_modified').to_i)}]"
      puts
      # DL
      process(html.children[i+1], level + 1)
    end
  end
end

process(html.css('html > body > dl'), 1)