module BSON::Hash

def as_extended_json(**options)
  transform_values { |value| value.as_extended_json(**options) }
end

def serialize_key(buffer, key)
  buffer.put_cstring(key)
rescue ArgumentError => e
  raise ArgumentError, "Error serializing key #{key}: #{e.class}: #{e}"
rescue EncodingError => e
  # Note this may convert exception class from a subclass of
  # EncodingError to EncodingError itself
  raise EncodingError, "Error serializing key #{key}: #{e.class}: #{e}"
end

def serialize_key_value_pairs(buffer)
  each do |field, value|
    unless value.respond_to?(:bson_type)
      raise Error::UnserializableClass,
            "Hash value for key '#{field}' does not define its BSON serialized type: #{value}"
    end
    buffer.put_byte(value.bson_type)
    key = field.to_bson_key
    serialize_key(buffer, key)
    value.to_bson(buffer)
  end
end

def serialize_to_buffer(buffer)
  position = buffer.length
  buffer.put_int32(0)
  serialize_key_value_pairs(buffer)
  buffer.put_byte(NULL_BYTE)
  buffer.replace_int32(position, buffer.length - position)
end

def to_bson(buffer = ByteBuffer.new)
  # If the native buffer version has an optimized version, we'll call
  # it directly. Otherwise, we'll serialize the hash the hard way.
  if buffer.respond_to?(:put_hash)
    buffer.put_hash(self)
  else
    serialize_to_buffer(buffer)
  end
end

def to_bson_normalized_value
  Document.new(self)
end