refactor: make ReorderItems generic

sharedutil/sharedutil.go

@@ -115,67 +115,10 @@ const (
 	MoveDown
 )
 
-// TODO: it's a shame the below function is just duplicated for a slice of mediaprovider.MediaItem
+// Reorder items and return a new track slice.
-// Find out if there's a better way with refactoring.
-
-// Reorder tracks and return a new track slice.
 // idxToMove must contain only valid indexes into tracks, and no repeats
-func ReorderTracks(tracks []*mediaprovider.Track, idxToMove []int, op TrackReorderOp) []*mediaprovider.Track {
+func ReorderItems[T any](items []T, idxToMove []int, op TrackReorderOp) []T {
-	newTracks := make([]*mediaprovider.Track, len(tracks))
+	newItems := make([]T, len(items))
-	switch op {
-	case MoveToTop:
-		topIdx := 0
-		botIdx := len(idxToMove)
-		idxToMoveSet := ToSet(idxToMove)
-		for i, t := range tracks {
-			if _, ok := idxToMoveSet[i]; ok {
-				newTracks[topIdx] = t
-				topIdx++
-			} else {
-				newTracks[botIdx] = t
-				botIdx++
-			}
-		}
-	case MoveToBottom:
-		topIdx := 0
-		botIdx := len(tracks) - len(idxToMove)
-		idxToMoveSet := ToSet(idxToMove)
-		for i, t := range tracks {
-			if _, ok := idxToMoveSet[i]; ok {
-				newTracks[botIdx] = t
-				botIdx++
-			} else {
-				newTracks[topIdx] = t
-				topIdx++
-			}
-		}
-	case MoveUp:
-		first := firstIdxCanMoveUp(idxToMove)
-		copy(newTracks, tracks)
-		for _, i := range idxToMove {
-			if i < first {
-				continue
-			}
-			newTracks[i-1], newTracks[i] = newTracks[i], newTracks[i-1]
-		}
-	case MoveDown:
-		last := lastIdxCanMoveDown(idxToMove, len(tracks))
-		copy(newTracks, tracks)
-		for i := len(idxToMove) - 1; i >= 0; i-- {
-			idx := idxToMove[i]
-			if idx > last {
-				continue
-			}
-			newTracks[idx+1], newTracks[idx] = newTracks[idx], newTracks[idx+1]
-		}
-	}
-	return newTracks
-}
-
-// Reorder media items and return a new item slice.
-// idxToMove must contain only valid indexes into items, and no repeats
-func ReorderMediaItems(items []mediaprovider.MediaItem, idxToMove []int, op TrackReorderOp) []mediaprovider.MediaItem {
-	newTracks := make([]mediaprovider.MediaItem, len(items))
 	switch op {
 	case MoveToTop:
 		topIdx := 0
@@ -183,10 +126,10 @@ func ReorderMediaItems(items []mediaprovider.MediaItem, idxToMove []int, op Trac
 		idxToMoveSet := ToSet(idxToMove)
 		for i, t := range items {
 			if _, ok := idxToMoveSet[i]; ok {
-				newTracks[topIdx] = t
+				newItems[topIdx] = t
 				topIdx++
 			} else {
-				newTracks[botIdx] = t
+				newItems[botIdx] = t
 				botIdx++
 			}
 		}
@@ -196,34 +139,34 @@ func ReorderMediaItems(items []mediaprovider.MediaItem, idxToMove []int, op Trac
 		idxToMoveSet := ToSet(idxToMove)
 		for i, t := range items {
 			if _, ok := idxToMoveSet[i]; ok {
-				newTracks[botIdx] = t
+				newItems[botIdx] = t
 				botIdx++
 			} else {
-				newTracks[topIdx] = t
+				newItems[topIdx] = t
 				topIdx++
 			}
 		}
 	case MoveUp:
 		first := firstIdxCanMoveUp(idxToMove)
-		copy(newTracks, items)
+		copy(newItems, items)
 		for _, i := range idxToMove {
 			if i < first {
 				continue
 			}
-			newTracks[i-1], newTracks[i] = newTracks[i], newTracks[i-1]
+			newItems[i-1], newItems[i] = newItems[i], newItems[i-1]
 		}
 	case MoveDown:
 		last := lastIdxCanMoveDown(idxToMove, len(items))
-		copy(newTracks, items)
+		copy(newItems, items)
 		for i := len(idxToMove) - 1; i >= 0; i-- {
 			idx := idxToMove[i]
 			if idx > last {
 				continue
 			}
-			newTracks[idx+1], newTracks[idx] = newTracks[idx], newTracks[idx+1]
+			newItems[idx+1], newItems[idx] = newItems[idx], newItems[idx+1]
 		}
 	}
-	return newTracks
+	return newItems
 }
 
 func firstIdxCanMoveUp(idxs []int) int {

sharedutil/sharedutil_test.go

@@ -7,7 +7,7 @@ import (
 	"github.com/dweymouth/supersonic/backend/mediaprovider"
 )
 
-func Test_ReorderTracks(t *testing.T) {
+func Test_ReorderItems(t *testing.T) {
 	tracks := []*mediaprovider.Track{
 		{ID: "a"}, // 0
 		{ID: "b"}, // 1
@@ -27,7 +27,7 @@ func Test_ReorderTracks(t *testing.T) {
 		{ID: "b"},
 		{ID: "e"},
 	}
-	newTracks := ReorderTracks(tracks, idxToMove, MoveToTop)
+	newTracks := ReorderItems(tracks, idxToMove, MoveToTop)
 	if !tracklistsEqual(t, newTracks, want) {
 		t.Error("ReorderTracks: MoveToTop order incorrect")
 	}
@@ -42,7 +42,7 @@ func Test_ReorderTracks(t *testing.T) {
 		{ID: "c"},
 		{ID: "f"},
 	}
-	newTracks = ReorderTracks(tracks, idxToMove, MoveToBottom)
+	newTracks = ReorderItems(tracks, idxToMove, MoveToBottom)
 	if !tracklistsEqual(t, newTracks, want) {
 		t.Error("ReorderTracks: MoveToBottom order incorrect")
 	}
@@ -57,7 +57,7 @@ func Test_ReorderTracks(t *testing.T) {
 		{ID: "f"},
 		{ID: "e"},
 	}
-	newTracks = ReorderTracks(tracks, idxToMove, MoveUp)
+	newTracks = ReorderItems(tracks, idxToMove, MoveUp)
 	if !tracklistsEqual(t, newTracks, want) {
 		t.Error("ReorderTracks: MoveUp order incorrect")
 	}
@@ -72,7 +72,7 @@ func Test_ReorderTracks(t *testing.T) {
 		{ID: "e"},
 		{ID: "f"},
 	}
-	newTracks = ReorderTracks(tracks, idxToMove, MoveDown)
+	newTracks = ReorderItems(tracks, idxToMove, MoveDown)
 	if !tracklistsEqual(t, newTracks, want) {
 		t.Error("ReorderTracks: MoveDown order incorrect")
 	}

ui/browsing/nowplayingpage.go

@@ -462,7 +462,7 @@ func (a *NowPlayingPage) doSetNewTrackOrder(trackIDs []string, op sharedutil.Tra
 			idxs = append(idxs, i)
 		}
 	}
-	newTracks := sharedutil.ReorderMediaItems(a.queue, idxs, op)
+	newTracks := sharedutil.ReorderItems(a.queue, idxs, op)
 	a.pm.UpdatePlayQueue(newTracks)
 }
 

ui/browsing/playlistpage.go

@@ -187,7 +187,7 @@ func (a *PlaylistPage) doSetNewTrackOrder(op sharedutil.TrackReorderOp) {
 			idxs = append(idxs, i)
 		}
 	}
-	newTracks := sharedutil.ReorderTracks(a.tracks, idxs, op)
+	newTracks := sharedutil.ReorderItems(a.tracks, idxs, op)
 	ids := sharedutil.TracksToIDs(newTracks)
 	if err := a.sm.Server.ReplacePlaylistTracks(a.playlistID, ids); err != nil {
 		log.Printf("error updating playlist: %s", err.Error())