# :stopdoc:

# Stolen from ruby core's uri/common.rb, with modifications to support 1.8.x
#
# https://github.com/ruby/ruby/blob/trunk/lib/uri/common.rb
#
#

module URI
  TBLENCWWWCOMP_ = {} # :nodoc:
  TBLDECWWWCOMP_ = {} # :nodoc:

  # Encode given +str+ to URL-encoded form data.
  #
  # This method doesn't convert *, -, ., 0-9, A-Z, _, a-z, but does convert SP
  # (ASCII space) to + and converts others to %XX.
  #
  # This is an implementation of
  # http://www.w3.org/TR/html5/forms.html#url-encoded-form-data
  #
  # See URI.decode_www_form_component, URI.encode_www_form
  def self.encode_www_form_component(str)
    if RUBY_VERSION < "1.9" && $KCODE =~ /u/i
      str.gsub(/([^ a-zA-Z0-9_.-]+)/) do
        '%' + $1.unpack('H2' * Rack::Utils.bytesize($1)).join('%').upcase
      end.tr(' ', '+')
    else
      if TBLENCWWWCOMP_.empty?
        tbl = {}
        256.times do |i|
          tbl[i.chr] = '%%%02X' % i
        end
        tbl[' '] = '+'
        begin
          TBLENCWWWCOMP_.replace(tbl)
          TBLENCWWWCOMP_.freeze
        rescue
        end
      end
      str = str.to_s
      str.gsub(/[^*\-.0-9A-Z_a-z]/) {|m| TBLENCWWWCOMP_[m]}
    end
  end

  # Decode given +str+ of URL-encoded form data.
  #
  # This decods + to SP.
  #
  # See URI.encode_www_form_component, URI.decode_www_form
  def self.decode_www_form_component(str, enc=nil)
    if TBLDECWWWCOMP_.empty?
      tbl = {}
      256.times do |i|
        h, l = i>>4, i&15
        tbl['%%%X%X' % [h, l]] = i.chr
        tbl['%%%x%X' % [h, l]] = i.chr
        tbl['%%%X%x' % [h, l]] = i.chr
        tbl['%%%x%x' % [h, l]] = i.chr
      end
      tbl['+'] = ' '
      begin
        TBLDECWWWCOMP_.replace(tbl)
        TBLDECWWWCOMP_.freeze
      rescue
      end
    end
    raise ArgumentError, "invalid %-encoding (#{str})" unless /\A(?:%[0-9a-fA-F]{2}|[^%]+)*\z/ =~ str
    str.gsub(/\+|%[0-9a-fA-F]{2}/) {|m| TBLDECWWWCOMP_[m]}
  end
end
