Probably a dumb way to fix ugly latin1 garbage

unicoder.rb

class Unicoder
  @@char_map = {
    # (mostly cp1252) => utf8
    "\x80" => "\u20AC",    # EURO SIGN
    "\x82" => "\u201A",    # SINGLE LOW-9 QUOTATION MARK
    "\x83" => "\u0192",    # LATIN SMALL LETTER F WITH HOOK
    "\x84" => "\u201E",    # DOUBLE LOW-9 QUOTATION MARK
    "\x85" => "\u2026",    # HORIZONTAL ELLIPSIS
    "\x86" => "\u2020",    # DAGGER
    "\x87" => "\u2021",    # DOUBLE DAGGER
    "\x88" => "\u02C6",    # MODIFIER LETTER CIRCUMFLEX ACCENT
    "\x89" => "\u2030",    # PER MILLE SIGN
    "\x8A" => "\u0160",    # LATIN CAPITAL LETTER S WITH CARON
    "\x8B" => "\u2039",    # SINGLE LEFT-POINTING ANGLE QUOTATION MARK
    "\x8C" => "\u0152",    # LATIN CAPITAL LIGATURE OE
    "\x8E" => "\u017D",    # LATIN CAPITAL LETTER Z WITH CARON
    "\x91" => "\u2018",    # LEFT SINGLE QUOTATION MARK
    "\x92" => "\u2019",    # RIGHT SINGLE QUOTATION MARK
    "\x93" => "\u201C",    # LEFT DOUBLE QUOTATION MARK
    "\x94" => "\u201D",    # RIGHT DOUBLE QUOTATION MARK
    "\x95" => "\u2022",    # BULLET
    "\x96" => "\u2013",    # EN DASH
    "\x97" => "\u2014",    # EM DASH
    "\x98" => "\u02DC",    # SMALL TILDE
    "\x99" => "\u2122",    # TRADE MARK SIGN
    "\x9A" => "\u0161",    # LATIN SMALL LETTER S WITH CARON
    "\x9B" => "\u203A",    # SINGLE RIGHT-POINTING ANGLE QUOTATION MARK
    "\x9C" => "\u0153",    # LATIN SMALL LIGATURE OE
    "\x9E" => "\u017E",    # LATIN SMALL LETTER Z WITH CARON
    "\x9F" => "\u0178",    # LATIN CAPITAL LETTER Y WITH DIAERESIS
    "\xA0" => "\u00A0",    # NO-BREAK SPACE
    "\xA1" => "\u00A1",    # INVERTED EXCLAMATION MARK
    "\xA2" => "\u00A2",    # CENT SIGN
    "\xA3" => "\u00A3",    # POUND SIGN
    "\xA4" => "\u00A4",    # CURRENCY SIGN
    "\xA5" => "\u00A5",    # YEN SIGN
    "\xA6" => "\u00A6",    # BROKEN BAR
    "\xA7" => "\u00A7",    # SECTION SIGN
    "\xA8" => "\u00A8",    # DIAERESIS
    "\xA9" => "\u00A9",    # COPYRIGHT SIGN
    "\xAA" => "\u00AA",    # FEMININE ORDINAL INDICATOR
    "\xAB" => "\u00AB",    # LEFT-POINTING DOUBLE ANGLE QUOTATION MARK
    "\xAC" => "\u00AC",    # NOT SIGN
    "\xAD" => "\u00AD",    # SOFT HYPHEN
    "\xAE" => "\u00AE",    # REGISTERED SIGN
    "\xAF" => "\u00AF",    # MACRON
    "\xB0" => "\u00B0",    # DEGREE SIGN
    "\xB1" => "\u00B1",    # PLUS-MINUS SIGN
    "\xB2" => "\u00B2",    # SUPERSCRIPT TWO
    "\xB3" => "\u00B3",    # SUPERSCRIPT THREE
    "\xB4" => "\u00B4",    # ACUTE ACCENT
    "\xB5" => "\u00B5",    # MICRO SIGN
    "\xB6" => "\u00B6",    # PILCROW SIGN
    "\xB7" => "\u00B7",    # MIDDLE DOT
    "\xB8" => "\u00B8",    # CEDILLA
    "\xB9" => "\u00B9",    # SUPERSCRIPT ONE
    "\xBA" => "\u00BA",    # MASCULINE ORDINAL INDICATOR
    "\xBB" => "\u00BB",    # RIGHT-POINTING DOUBLE ANGLE QUOTATION MARK
    "\xBC" => "\u00BC",    # VULGAR FRACTION ONE QUARTER
    "\xBD" => "\u00BD",    # VULGAR FRACTION ONE HALF
    "\xBE" => "\u00BE",    # VULGAR FRACTION THREE QUARTERS
    "\xBF" => "\u00BF"     # INVERTED QUESTION MARK
  }

  class << self
    def zap(text)
      return text if !text
      text.force_encoding("BINARY").encode!('UTF-8', fallback: @@char_map)
    end
  end

  # Mangle all incoming parameters transcoding them to UTF-8
  class Middleware
    def initialize(app)
      @app = app
    end

    def call(env)
      req = Rack::Request.new(env)
      mangle(req.params)
      @app.call(req.env)
    end

    def mangle(hsh)
      hsh.each do |k,v|
        if v.respond_to?(:force_encoding)
          Unicoder.zap(v) unless v.valid_encoding?
        elsif v.kind_of?(Hash)
          mangle(v)
        end
      end
    end
  end
end