# Should we better use sanitize library for this ?
require 'cgi'

def html2text html
  text = html.
    gsub(/( |\n|\s)+/im, ' ').squeeze(' ').strip.
    gsub(/<([^\s]+)[^>]*(src|href)=\s*(.?)([^>\s]*)\3[^>]*>\4<\/\1>/i,
'\4')

  links = []
  linkregex = /<[^>]*(src|href)=\s*(.?)([^>\s]*)\2[^>]*>\s*/i
  while linkregex.match(text)
    links << $~[3]
    text.sub!(linkregex, "[#{links.size}]")
  end

  text = CGI.unescapeHTML(
    text.
      gsub(/<(script|style)[^>]*>.*<\/\1>/im, '').
      gsub(/<!--.*-->/m, '').
      gsub(/<hr(| [^>]*)>/i, "___\n").
      gsub(/<li(| [^>]*)>/i, "\n* ").
      gsub(/<blockquote(| [^>]*)>/i, '> ').
      gsub(/<(br)(| [^>]*)>/i, "\n").
      gsub(/<(\/h[\d]+|p)(| [^>]*)>/i, "\n\n").
      gsub(/<[^>]*>/, '')
  ).lstrip.gsub(/\n[ ]+/, "\n") + "\n"

  for i in (0...links.size).to_a
    text = text + "\n  [#{i+1}] <#{CGI.unescapeHTML(links[i])}>" unless links[i].nil?
  end
  links = nil
  text
end