class String
  # simple markdown
  def as_html
    ret = self
    ret = ret.gsub(/([\w\.])\n(\w)/,"\\1<br/>\\2")
    ret
  end

  # convert escaped strings, remove scritpts
  def to_html(opts={})
    value = self.gsub(/&lt;/, '<').gsub(/&gt;/, '>').gsub(/&amp;/,'&')
    value = value.gsub(/<script/,'&lt;script') unless opts[:script]
    value = value.gsub(/<link/,'&lt;link') unless opts[:link]
    value
  end

  def trim(len)
    return self if self.length<len
    data = self.dup[0,len]+'&hellip;'
    data
  end

  def sanitize
    Sanitize.clean(self, :elements=>%w[span ul ol li b bold i italic u underline hr br p], :attributes=>{'span'=>['style']} )
  end

  def tag(node_name, opts={})
    opts.tag(node_name, self)
  end

  def wrap(node_name, opts={})
    return self unless node_name
    opts.tag(node_name, self)
  end

  def fix_ut8
    self.encode('UTF-8', 'binary', invalid: :replace, undef: :replace, replace: '?')
  end

  def parse_erb
    self.gsub(/<%=([^%]+)%>/) { eval $1; }
  end

  def parameterize
    self.downcase.gsub(/[^\w]+/,'-')
  end

  def to_url
    # str_from = 'šđč枊ĐČĆŽäÄéeöÖüüÜß'
    # str_to   = 'sdcczSDCCZaAeeoOuuUs'
    # self.downcase.gsub(/\s+/,'-').tr(str_from, str_to).gsub(/[^\w\-]/,'')
    self.gsub('&',' and ').gsub('.',' dot ').parameterize.gsub('-dot-','.').downcase[0, 50]
  end

  def css_to_hash
    self.split('&').inject({}) do |h,line|
      el = line.split('=', 2)
      h[el[0]] = el[1]
      h
    end
  end

  def to_a
    self.split(/\s*,\s*/)
  end

  def starts_with?(prefix)
    prefix.respond_to?(:to_str) && self[0, prefix.length] == prefix
  end

  def last(num=1)
    len = self.length
    self[len-num, len]
  end

  def span_green
    %[<span style="color: #080;">#{self}</span>]
  end

  def span_red
    %[<span style="color: #800;">#{self}</span>]
  end

  def constantize
    klass = self
    obj = Object.const_get(klass)
    obj.to_s == klass.sub(/^::/,'') ? obj : raise(NameError, 'Cant find class %s' % klass)
  end
end