migrate homepage items to homepage routine

+ add Mix db model

app/lib/playlistlib.py

@@ -10,7 +10,6 @@ from typing import Any
 from PIL import Image, ImageSequence
 
 from app import settings
-from app.db.libdata import TrackTable
 from app.models.track import Track
 from app.store.albums import AlbumStore
 from app.store.tracks import TrackStore

app/lib/recipes/__init__.py

@@ -0,0 +1,66 @@
+"""
+Recipes are a way to create mixes.
+"""
+
+from abc import ABC, abstractmethod
+from typing import Any, Dict, List
+
+from app.db.userdata import UserTable
+from app.models.mix import Mix
+from app.plugins.mixes import MixesPlugin
+from app.store.homepage import HomepageStore
+
+
+class HomepageRoutine(ABC):
+    """
+    A routine creates a row of homepage items.
+    """
+
+    title: str
+    description: str
+
+    items: List[Mix]
+    extra: Dict[str, Any]
+
+    @property
+    @abstractmethod
+    def is_valid(self) -> bool: ...
+
+    def __init__(self) -> None:
+        if not self.is_valid:
+            return
+
+        self.items = self.run()
+
+    @abstractmethod
+    def run(self) -> List[Mix]:
+        """
+        Creates the homepage items and saves them to the
+        homepage store if self.is_valid is true.
+        """
+        ...
+
+
+class ArtistMixes(HomepageRoutine):
+    items: List[Mix] = []
+    extra: Dict[str, Any] = {}
+    store_key = "artist_mixes"  
+
+    @property
+    def is_valid(self):
+        return MixesPlugin().enabled
+
+    def run(self):
+        users = UserTable.get_all()
+
+        for user in users:
+            mix = MixesPlugin()
+            mixes = mix.create_artist_mixes(user.id)
+
+            if not mixes:
+                continue
+
+            HomepageStore.set_mixes(mixes, mixkey=self.store_key, userid=user.id)
+
+    def __init__(self) -> None:
+        super().__init__()