module Moneta
  class Transformer
    # Available key/value transformers
    TRANSFORMER = {
      # Name:   [ Type,       Load,                           Dump,                              Library        Test      ],
      bencode:  [ :serialize, '::BEncode.load(%s)',           '::BEncode.dump(%s)',              'bencode'      ],
      bert:     [ :serialize, '::BERT.decode(%s)',            '::BERT.encode(%s)',               'bert'         ],
      bson:     [ :serialize, 'Helper::BSON.load(%s)',        'Helper::BSON.dump(%s)',           'bson'         ],
      json:     [ :serialize, '::MultiJson.load(%s)',         '::MultiJson.dump(%s)',            'multi_json'   ],
      marshal:  [ :serialize, '::Marshal.load(%s)',           '::Marshal.dump(%s)',              nil            ],
      msgpack:  [ :serialize, '::MessagePack.unpack(%s)',     '::MessagePack.pack(%s)',          'msgpack'      ],
      ox:       [ :serialize, '::Ox.parse_obj(%s)',           '::Ox.dump(%s)',                   'ox'           ],
      php:      [ :serialize, '::PHP.unserialize(%s)',        '::PHP.serialize(%s)',             'php_serialize'],
      tnet:     [ :serialize, '::TNetstring.parse(%s).first', '::TNetstring.dump(%s)',           'tnetstring'   ],
      yaml:     [ :serialize, '::YAML.load(%s)',              '::YAML.dump(%s)',                 'yaml'         ],
      bzip2:    [ :compress,  'Helper.bunzip2(%s)',           'Helper.bzip2(%s)',                'rbzip2'       ],
      lz4:      [ :compress,  '::LZ4.uncompress(%s)',         '::LZ4.compress(%s)',              'lz4-ruby'     ],
      lzma:     [ :compress,  '::LZMA.decompress(%s)',        '::LZMA.compress(%s)',             'lzma'         ],
      lzo:      [ :compress,  '::LZO.decompress(%s)',         '::LZO.compress(%s)',              'lzoruby'      ],
      snappy:   [ :compress,  '::Snappy.inflate(%s)',         '::Snappy.deflate(%s)',            'snappy'       ],
      quicklz:  [ :compress,  '::QuickLZ.decompress(%s)',     '::QuickLZ.compress(%s)',          'qlzruby'      ],
      zlib:     [ :compress,  '::Zlib::Inflate.inflate(%s)',  '::Zlib::Deflate.deflate(%s)',     'zlib'         ],
      base64:   [ :encode,    "%s.unpack('m0').first",        "[%s].pack('m0')"                                 ],
      urlsafe_base64: [
        :encode,
        'Base64.urlsafe_decode64(%s)',
        'Base64.urlsafe_encode64(%s)',
        'base64'
      ],
      escape:   [ :encode,    'Helper.unescape(%s)',          'Helper.escape(%s)'                               ],
      hex:      [ :encode,    "[%s].pack('H*')",              "%s.unpack('H*').first"                           ],
      qp:       [ :encode,    "%s.unpack('M').first",         "[%s].pack('M')"                                  ],
      uuencode: [ :encode,    "%s.unpack('u').first",         "[%s].pack('u')"                                  ],
      hmac:     [
        :hmac,
        'Helper.hmacverify(%s, options[:secret] || @secret)',
        'Helper.hmacsign(%s, options[:secret] || @secret)',
        'openssl'
      ],
      prefix:   [
        :prefix,
        "%s.sub(@prefix, '')",
        '(options[:prefix] || @prefix)+%s',
        nil,
        "%s.start_with?(@prefix)"
      ],
      truncate: [ :truncate,  nil,                            'Helper.truncate(%s, @maxlen)',    'digest/md5'   ],
      md5:      [ :digest,    nil,                            '::Digest::MD5.hexdigest(%s)',     'digest/md5'   ],
      rmd160:   [ :digest,    nil,                            '::Digest::RMD160.hexdigest(%s)',  'digest/rmd160'],
      sha1:     [ :digest,    nil,                            '::Digest::SHA1.hexdigest(%s)',    'digest/sha1'  ],
      sha256:   [ :digest,    nil,                            '::Digest::SHA256.hexdigest(%s)',  'digest/sha2'  ],
      sha384:   [ :digest,    nil,                            '::Digest::SHA384.hexdigest(%s)',  'digest/sha2'  ],
      sha512:   [ :digest,    nil,                            '::Digest::SHA512.hexdigest(%s)',  'digest/sha2'  ],
      city32:   [ :digest,    nil,                            '::CityHash.hash32(%s).to_s(16)',  'cityhash'     ],
      city64:   [ :digest,    nil,                            '::CityHash.hash64(%s).to_s(16)',  'cityhash'     ],
      city128:  [ :digest,    nil,                            '::CityHash.hash128(%s).to_s(16)', 'cityhash'     ],
      spread:   [ :spread,    nil,                            'Helper.spread(%s)'                               ],
      to_s:     [ :string,    nil,                            '%s.to_s'                                         ],
      inspect:  [ :string,    nil,                            '%s.inspect'                                      ]
    }.freeze

    # Allowed value transformers (Read it like a regular expression!)
    VALUE_TRANSFORMER = 'serialize? compress? hmac? encode?'.freeze

    # Allowed key transformers (Read it like a regular expression!)
    KEY_TRANSFORMER = '(serialize | string)? prefix? ((encode? truncate?) | (digest spread?))?'.freeze

    # Key transformers that can be "loaded" (e.g. reversed) and can be used by the key enumeration feature
    LOAD_KEY_TRANSFORMER = 'serialize? prefix? encode?'.freeze

    # Key transformers that can be "tested for success" with a dumped key and can be used by the key enumeration feature
    TEST_KEY_TRANSFORMER = 'serialize? prefix? encode?'.freeze
  end
end
