update

core/playback/queue.go

@@ -0,0 +1,136 @@
+package playback
+
+import (
+	"fmt"
+	"math/rand"
+
+	"github.com/navidrome/navidrome/log"
+	"github.com/navidrome/navidrome/model"
+)
+
+type Queue struct {
+	Index int
+	Items model.MediaFiles
+}
+
+func NewQueue() *Queue {
+	return &Queue{
+		Index: -1,
+		Items: model.MediaFiles{},
+	}
+}
+
+func (pd *Queue) String() string {
+	filenames := ""
+	for idx, item := range pd.Items {
+		filenames += fmt.Sprint(idx) + ":" + item.Path + " "
+	}
+	return fmt.Sprintf("#Items: %d, idx: %d, files: %s", len(pd.Items), pd.Index, filenames)
+}
+
+// returns the current mediafile or nil
+func (pd *Queue) Current() *model.MediaFile {
+	if pd.Index == -1 {
+		return nil
+	}
+	if pd.Index >= len(pd.Items) {
+		log.Error("internal error: current song index out of bounds", "idx", pd.Index, "length", len(pd.Items))
+		return nil
+	}
+
+	return &pd.Items[pd.Index]
+}
+
+// returns the whole queue
+func (pd *Queue) Get() model.MediaFiles {
+	return pd.Items
+}
+
+func (pd *Queue) Size() int {
+	return len(pd.Items)
+}
+
+func (pd *Queue) IsEmpty() bool {
+	return len(pd.Items) < 1
+}
+
+// set is similar to a clear followed by a add, but will not change the currently playing track.
+func (pd *Queue) Set(items model.MediaFiles) {
+	pd.Clear()
+	pd.Items = append(pd.Items, items...)
+}
+
+// adding mediafiles to the queue
+func (pd *Queue) Add(items model.MediaFiles) {
+	pd.Items = append(pd.Items, items...)
+	if pd.Index == -1 && len(pd.Items) > 0 {
+		pd.Index = 0
+	}
+}
+
+// empties whole queue
+func (pd *Queue) Clear() {
+	pd.Index = -1
+	pd.Items = nil
+}
+
+// idx Zero-based index of the song to skip to or remove.
+func (pd *Queue) Remove(idx int) {
+	current := pd.Current()
+	backupID := ""
+	if current != nil {
+		backupID = current.ID
+	}
+
+	pd.Items = append(pd.Items[:idx], pd.Items[idx+1:]...)
+
+	var err error
+	pd.Index, err = pd.getMediaFileIndexByID(backupID)
+	if err != nil {
+		// we seem to have deleted the current id, setting to default:
+		pd.Index = -1
+	}
+}
+
+func (pd *Queue) Shuffle() {
+	current := pd.Current()
+	backupID := ""
+	if current != nil {
+		backupID = current.ID
+	}
+
+	rand.Shuffle(len(pd.Items), func(i, j int) { pd.Items[i], pd.Items[j] = pd.Items[j], pd.Items[i] })
+
+	var err error
+	pd.Index, err = pd.getMediaFileIndexByID(backupID)
+	if err != nil {
+		log.Error("Could not find ID while shuffling: %s", backupID)
+	}
+}
+
+func (pd *Queue) getMediaFileIndexByID(id string) (int, error) {
+	for idx, item := range pd.Items {
+		if item.ID == id {
+			return idx, nil
+		}
+	}
+	return -1, fmt.Errorf("ID not found in playlist: %s", id)
+}
+
+// Sets the index to a new, valid value inside the Items. Values lower than zero are going to be zero,
+// values above will be limited by number of items.
+func (pd *Queue) SetIndex(idx int) {
+	pd.Index = max(0, min(idx, len(pd.Items)-1))
+}
+
+// Are we at the last track?
+func (pd *Queue) IsAtLastElement() bool {
+	return (pd.Index + 1) >= len(pd.Items)
+}
+
+// Goto next index
+func (pd *Queue) IncreaseIndex() {
+	if !pd.IsAtLastElement() {
+		pd.SetIndex(pd.Index + 1)
+	}
+}