require 'yaml'

module VCR
  class Cassette
    class Serializers
      # The YAML serializer. This will use either Psych or Syck, which ever your
      # ruby interpreter defaults to. You can also force VCR to use Psych or Syck by
      # using one of those serializers.
      #
      # @see JSON
      # @see Psych
      # @see Syck
      module YAML
        extend self
        extend EncodingErrorHandling
        extend SyntaxErrorHandling

        # @private
        ENCODING_ERRORS = [ArgumentError]

        # @private
        SYNTAX_ERRORS = [::Psych::SyntaxError]

        # The file extension to use for this serializer.
        #
        # @return [String] "yml"
        def file_extension
          "yml"
        end

        # Serializes the given hash using YAML.
        #
        # @param [Hash] hash the object to serialize
        # @return [String] the YAML string
        def serialize(hash)
          handle_encoding_errors do
            result = ::YAML.dump(hash)
            result.gsub!(": \n", ": null\n") # set canonical null value in order to avoid trailing whitespaces
            result
          end
        end

        # Deserializes the given string using YAML.
        #
        # @param [String] string the YAML string
        # @return [Hash] the deserialized object
        def deserialize(string)
          handle_encoding_errors do
            handle_syntax_errors do
              if ::YAML.respond_to?(:unsafe_load)
                ::YAML.unsafe_load(string)
              else
                ::YAML.load(string)
              end
            end
          end
        end
      end
    end
  end
end