🔷 add PlayingFrom component to right sidebar

🔷 move upNext card into separate component
🔷 a lot of refactors

server/app/models.py

@@ -2,11 +2,12 @@
 Contains all the models for objects generation and typing.
 """
 
-from dataclasses import dataclass
+from dataclasses import dataclass, field
 from datetime import date
 from typing import List
 from app import api
 from app import settings
+from app.exceptions import TrackExistsInPlaylist
 
 
 @dataclass
@@ -99,10 +100,11 @@ class Playlist:
 
     playlistid: str
     name: str
-    description: str
     image: str
     tracks: List[Track]
+    _pre_tracks: list = field(init=False, repr=False)
     lastUpdated: int
+    description: str = ""
     count: int = 0
     """A list of track objects in the playlist"""
 
@@ -111,8 +113,29 @@ class Playlist:
         self.name = data["name"]
         self.description = data["description"]
         self.image = ""
-        self.tracks = create_playlist_tracks(data["tracks"])
+        self._pre_tracks = data["pre_tracks"]
+        self.tracks = []
         self.lastUpdated = data["lastUpdated"]
+        self.count = len(self._pre_tracks)
+
+    def get_tracks(self) -> List[Track]:
+        """
+        Generates and returns Track objects from pre_tracks
+        """
+        return create_playlist_tracks(self._pre_tracks)
+
+    def update_count(self):
+        self.count = len(self.tracks)
+
+    def add_track(self, track):
+        if track not in self._pre_tracks:
+            self._pre_tracks.append(track)
+            self.update_count()
+        else:
+            raise TrackExistsInPlaylist("Track already exists in playlist")
+
+    def update_desc(self, desc):
+        self.description = desc
 
 
 @dataclass