gistfile1.txt

type MediaType int

const (
	MediaUnknown MediaType = iota
	MediaImage
	MediaVideo
	MediaAudio
	MediaDocument
	MediaPresslyComment
)

var mediaTypes = []string{
	"unknown", "image", "video", "audio", "document",
}

func (mt MediaType) String() string {
	return mediaTypes[mt]
}

func (mt MediaType) MarshalText() ([]byte, error) {
	return []byte(mt.String()), nil
}

func (mt *MediaType) UnmarshalText(text []byte) error {
	*mt = MediaUnknown
	enum := string(text)
	for i, k := range mediaTypes {
		if enum == k {
			*mt = MediaType(i)
			return nil
		}
	}
	return nil
}