module Locale::Driver::CGI

def charset
  req = Thread.current[:current_request]
  return nil unless req
  charsets = req[:accept_charset]
  if charsets and charsets.size > 0
    num = charsets.index(',')
    charset = num ? charsets[0, num] : charsets
    charset = nil if charset == "*"
  else
    charset = nil
  end
  charset
end

def clear_current_request
  Thread.current[:current_request] = nil
end

def locales
  req = Thread.current[:current_request]
  return nil unless req
  locales = []
  # QUERY_STRING "lang"
  if langs = req[:query_langs]
    langs.each do |lang|
      locales << Locale::Tag.parse(lang)
    end
  end
  unless locales.size > 0
    # COOKIE "lang"
    if langs = req[:cookie_langs]
      langs.each do |lang|
        locales << Locale::Tag.parse(lang) if lang.size > 0
      end
    end
  end
  unless locales.size > 0
    # HTTP_ACCEPT_LANGUAGE
    if lang = req[:accept_language] and lang.size > 0
      # 10.0 is for ruby-1.8.6 which have the bug of str.to_f. 
      # Normally, this should be 1.0.
      locales += lang.gsub(/\s/, "").split(/,/).map{|v| v.split(";q=")}.map{|j| [j[0], j[1] ? j[1].to_f : 10.0]}.sort{|a,b| -(a[1] <=> b[1])}.map{|v| Locale::Tag.parse(v[0])}
    end
  end
  locales.size > 0 ? Locale::TagList.new(locales.uniq) : nil
end

def set_request(query_langs, cookie_langs, accept_language, accept_charset)
  Locale.clear
  Thread.current[:current_request] = {
    :query_langs => query_langs.compact,
    :cookie_langs => cookie_langs.compact,
    :accept_language => accept_language,
    :accept_charset => accept_charset
  }
  self
end