A separate MostListenedSong struct is not needed anymore.

internal/radio/mostlistened.go

@@ -1,97 +0,0 @@
-package radio
-
-import (
-	"bytes"
-	"strconv"
-	"sync"
-	"time"
-
-	"github.com/pkg/errors"
-)
-
-const MostListenedDateFormat string = "02 January 2006 at 15:04:05 MST"
-
-// MostListenedSong holds a metadata for a most listened song.
-type MostListenedSong struct {
-	mutex     sync.RWMutex
-	Date      time.Time `json:"date"`
-	Listeners int       `json:"listeners"`
-	Song      string    `json:"song"`
-	changed   bool
-}
-
-func (mls *MostListenedSong) Update(song Song) {
-	mls.mutex.Lock()
-	defer mls.mutex.Unlock()
-	if song.Artist == "" {
-		return
-	}
-	if song.MaxListeners > mls.Listeners {
-		mls.Listeners = song.MaxListeners
-		mls.Date = song.StartAt
-		mls.Song = song.Artist + " - " + song.Title
-		mls.changed = true
-	}
-}
-
-func (mls *MostListenedSong) Get() *MostListenedSong {
-	mls.mutex.RLock()
-	defer mls.mutex.RUnlock()
-
-	if mls.Date.Year() == 1 {
-		return nil
-	}
-
-	return &MostListenedSong{
-		Date:      mls.Date,
-		Listeners: mls.Listeners,
-		Song:      mls.Song}
-}
-
-// Load parses given data and fill a MostListenedSong.
-func (mls *MostListenedSong) Load(data []byte) (err error) {
-	mls.mutex.Lock()
-	defer mls.mutex.Unlock()
-
-	lines := bytes.Split(data, []byte{'\n'})
-	if len(lines) != 3 {
-		return errors.New("lines count mismatch, should be 3")
-	}
-
-	var date time.Time
-	if date, err = time.Parse(time.RFC3339, string(lines[0])); err != nil {
-		return errors.Wrap(err, "wrong date/time format")
-	}
-
-	var listeners int
-	if listeners, err = strconv.Atoi(string(lines[1])); err != nil {
-		return errors.Wrap(err, "a listeners number failed to parse")
-	}
-
-	if len(lines[2]) == 0 {
-		return errors.New("a song is empty")
-	}
-
-	mls.Date = date
-	mls.Listeners = listeners
-	mls.Song = string(lines[2])
-	return nil
-}
-
-// Store returns a byte slice of a marshalled to text MostListenedSong.
-func (mls *MostListenedSong) Store() []byte {
-	if !mls.changed {
-		return nil
-	}
-
-	buf := make([]byte, 0, 30+len(mls.Song))
-	b := bytes.NewBuffer(buf)
-
-	b.WriteString(mls.Date.Format(time.RFC3339))
-	b.WriteByte('\n')
-	b.WriteString(strconv.Itoa(mls.Listeners))
-	b.WriteByte('\n')
-	b.WriteString(mls.Song)
-
-	return b.Bytes()
-}