Files
gonic/server/ctrlsubsonic/specid/ids.go
2021-02-03 20:45:30 +00:00

77 lines
1.5 KiB
Go

package specid
// this package is at such a high level in the hierarchy because
// it's used by both `server/db` (for now) and `server/ctrlsubsonic`
import (
"encoding/json"
"errors"
"fmt"
"strconv"
"strings"
)
var (
ErrBadSeparator = errors.New("bad separator")
ErrNotAnInt = errors.New("not an int")
ErrBadPrefix = errors.New("bad prefix")
)
type IDT string
const (
Artist IDT = "ar"
Album IDT = "al"
Track IDT = "tr"
Podcast IDT = "pd"
PodcastEpisode IDT = "pe"
separator = "-"
)
type ID struct {
Type IDT
Value int
}
func New(in string) (ID, error) {
parts := strings.Split(in, separator)
if len(parts) != 2 {
return ID{}, ErrBadSeparator
}
partType := parts[0]
partValue := parts[1]
val, err := strconv.Atoi(partValue)
if err != nil {
return ID{}, fmt.Errorf("%q: %w", partValue, ErrNotAnInt)
}
switch IDT(partType) {
case Artist:
return ID{Type: Artist, Value: val}, nil
case Album:
return ID{Type: Album, Value: val}, nil
case Track:
return ID{Type: Track, Value: val}, nil
case Podcast:
return ID{Type: Podcast, Value: val}, nil
case PodcastEpisode:
return ID{Type: PodcastEpisode, Value: val}, nil
default:
return ID{}, fmt.Errorf("%q: %w", partType, ErrBadPrefix)
}
}
func (i ID) String() string {
if i.Value == 0 {
return "-1"
}
return fmt.Sprintf("%s%s%d", i.Type, separator, i.Value)
}
func (i ID) MarshalJSON() ([]byte, error) {
return json.Marshal(i.String())
}
func (i ID) MarshalText() ([]byte, error) {
return []byte(i.String()), nil
}