hbakhtiyor/rcore-ext

class String
  @@common_formats = {bin: 'B*', hex: 'H*'}
  
  # Decode string with various formats.
  # Supported formats: :bin, :hex, :base32, :base64
  #
  # You can also pass options for Base64 to use
  # * <tt>:strict</tt>
  # * <tt>:url_safe</tt>
  #
  #   "hello world!".decode_string(:hex)  #=> 68656c6c6f20776f726c6421
  #   "hi".decode_string(:bin)            #=> 0110100001101001
  #
  #   "NBSWY3DPEB3W64TMMQQQ====".decode_string(:base32)   #=> hello world!
  #   "aGVsbG8gd29ybGQh\n".decode_string(:base64)         #=> hello world!  
  #
  #   "aGVsbG8gd29ybGQh".decode_string(:base64, strict: true) #=> hello world!
  def decode_string(format, options={})
    raise ArgumentError, "Format can't be empty" if format.nil? 
    format = format.to_sym    
    @options = options || {}

    case format
    when :base32
      base32_decode
    when :base64
      base64_decode
    else
      raise ArgumentError, "Unsupported format: #{format}" unless @@common_formats.has_key?(format)
      common_decode(format)
    end
  end

  # Encode string with various formats.
  # Supported formats: :bin, :hex, :base32, :base64
  #
  # You can also pass options for Base64 to use
  # * <tt>:strict</tt>
  # * <tt>:url_safe</tt>
  #
  #   "68656c6c6f20776f726c6421".decode_string(:hex)  #=> hello world!
  #   "0110100001101001".decode_string(:bin)          #=> hi
  #
  #   "hello world!".decode_string(:base32)   #=> NBSWY3DPEB3W64TMMQQQ====
  #   "hello world!".decode_string(:base64)   #=> aGVsbG8gd29ybGQh\n  
  #
  #   "hello world!".decode_string(:base64, strict: true) #=> aGVsbG8gd29ybGQh
  def encode_string(format, options={})
    raise ArgumentError, "Format can't be empty" if format.nil?
    format = format.to_sym
    @options = options || {}

    case format
    when :base32
      base32_encode
    when :base64
      base64_encode
    else
      raise ArgumentError, "Unsupported format: #{format}" unless @@common_formats.has_key?(format)
      common_encode(format)
    end
  end

  private
    def common_encode(format)
      [self].pack(@@common_formats[format])
    end

    def common_decode(format)
      self.unpack(@@common_formats[format]).first
    end

    def base32_encode
      require 'base32'
      Base32.encode(self)
    end

    def base32_decode
      require 'base32'
      Base32.decode(self)
    end

    def base64_encode
      require 'base64'
      if @options[:strict]
        Base64.strict_encode64(self)
      elsif @options[:url_safe]
        Base64.urlsafe_encode64(self)
      else
        Base64.encode64(self)
      end
    end

    def base64_decode
      require 'base64'
      if @options[:strict]
        Base64.strict_decode64(self)
      elsif @options[:url_safe]
        Base64.urlsafe_decode64(self)
      else
        Base64.decode64(self)
      end
    end

end