Tidy up saving database

app/models.py

@@ -2,6 +2,7 @@
 #
 import os.path
 import re
+import stackprinter
 #
 from dbconfig import Session
 #
@@ -417,7 +418,7 @@ class PlaylistRows(Base):
         return (
             f"<PlaylistRow(id={self.id}, playlist_id={self.playlist_id}, "
             f"track_id={self.track_id}, "
-            f"note={self.note} row_number={self.row_number}>"
+            f"note={self.note}, row_number={self.row_number}>"
         )
 
     def __init__(self,
@@ -452,7 +453,7 @@ class PlaylistRows(Base):
                          plr.note)
 
     @staticmethod
-    def delete_higher_rows(session: Session, playlist_id: int, row: int) \
+    def delete_higher_rows(session: Session, playlist_id: int, maxrow: int) \
             -> None:
         """
         Delete rows in given playlist that have a higher row number
@@ -463,7 +464,7 @@ class PlaylistRows(Base):
         rows_to_go = session.execute(
             select(PlaylistRows)
             .where(PlaylistRows.playlist_id == playlist_id,
-                   PlaylistRows.row_number > row)
+                   PlaylistRows.row_number > maxrow)
         ).scalars().all()
         if not rows_to_go:
             return
@@ -472,11 +473,6 @@ class PlaylistRows(Base):
             log.debug(f"Should delete: {row}")
             # If needed later:
             # session.delete(row)
-        rows_to_go = session.execute(
-            select(PlaylistRows)
-            .where(PlaylistRows.playlist_id == playlist_id,
-                   PlaylistRows.row_number > row)
-        ).scalars().all()
 
     @staticmethod
     def delete_rows(session: Session, ids: List[int]) -> None:
@@ -509,6 +505,42 @@ class PlaylistRows(Base):
         # Ensure new row numbers are available to the caller
         session.commit()
 
+    @classmethod
+    def get_plr(session: Session, row_number: int,
+                playlist_id: int) -> "PlaylistRows":
+        """Return playlistrows object matching passed parameters"""
+
+        return (
+            select(PlaylistRows)
+            .where(
+                PlaylistRows.row_number == row_number,
+                PlaylistRows.playlist_id == playlist_id)
+            .limit(1)
+        ).first()
+
+    @staticmethod
+    def get_track_plr(session: Session, track_id: int,
+                      playlist_id: int) -> Optional["PlaylistRows"]:
+        """Return first matching PlaylistRows object or None"""
+
+        return session.scalars(
+            select(PlaylistRows)
+            .where(
+                PlaylistRows.track_id == track_id,
+                PlaylistRows.playlist_id == playlist_id
+            )
+            .limit(1)
+        ).first()
+
+    @staticmethod
+    def get_last_used_row(session: Session, playlist_id: int) -> Optional[int]:
+        """Return the last used row for playlist, or None if no rows"""
+
+        return session.execute(
+            select(func.max(PlaylistRows.row_number))
+            .where(PlaylistRows.playlist_id == playlist_id)
+        ).scalar_one()
+
     @classmethod
     def get_played_rows(cls, session: Session,
                         playlist_id: int) -> List[int]:
@@ -547,15 +579,6 @@ class PlaylistRows(Base):
 
         return plrs
 
-    @staticmethod
-    def get_last_used_row(session: Session, playlist_id: int) -> Optional[int]:
-        """Return the last used row for playlist, or None if no rows"""
-
-        return session.execute(
-            select(func.max(PlaylistRows.row_number))
-            .where(PlaylistRows.playlist_id == playlist_id)
-        ).scalar_one()
-
     @classmethod
     def get_unplayed_rows(cls, session: Session,
                           playlist_id: int) -> List[int]:

app/musicmuster.py

@@ -739,6 +739,7 @@ class Window(QMainWindow, Ui_MainWindow):
                 helpers.set_track_metadata(session, track)
                 helpers.normalise_track(track.path)
                 self.visible_playlist_tab().insert_track(session, track)
+            self.visible_playlist_tab().save_playlist(session)
 
     def insert_header(self) -> None:
         """Show dialog box to enter header text and add to playlist"""
@@ -758,6 +759,7 @@ class Window(QMainWindow, Ui_MainWindow):
         if ok:
             with Session() as session:
                 playlist_tab.insert_header(session, dlg.textValue())
+                self.save_playlist(session)
 
     def insert_track(self) -> None:
         """Show dialog box to select and add track from database"""
@@ -828,13 +830,13 @@ class Window(QMainWindow, Ui_MainWindow):
 
         # Update destination playlist_tab if visible (if not visible, it
         # will be re-populated when it is opened)
-        destionation_playlist_tab = None
+        destination_playlist_tab = None
         for tab in range(self.tabPlaylist.count()):
             if self.tabPlaylist.widget(tab).playlist_id == dlg.playlist.id:
-                destionation_playlist_tab = self.tabPlaylist.widget(tab)
+                destination_playlist_tab = self.tabPlaylist.widget(tab)
                 break
-        if destionation_playlist_tab:
+        if destination_playlist_tab:
-            destionation_playlist_tab.populate(session, dlg.playlist.id)
+            destination_playlist_tab.populate(session, dlg.playlist.id)
 
     def move_selected(self) -> None:
         """
@@ -1500,8 +1502,8 @@ class DbDialog(QDialog):
 
         self.parent().visible_playlist_tab().insert_track(
             self.session, track, note=self.ui.txtNote.text())
-        # Commit session to get correct row numbers if more tracks added
+        # Save to database (which will also commit changes)
-        self.session.commit()
+        self.parent().visible_playlist_tab().save_playlist(self.session)
         # Clear note field and select search text to make it easier for
         # next search
         self.ui.txtNote.clear()

app/playlists.py

@@ -1,5 +1,5 @@
 import re
-import stackprinter
+import stackprinter                         # type: ignore
 import subprocess
 import threading
 
@@ -199,7 +199,7 @@ class PlaylistTab(QTableWidget):
         # self.setSortingEnabled(True)
 
         # Now load our tracks and notes
-        self.populate(session, self.playlist_id)
+        self.populate_display(session, self.playlist_id)
 
     def __repr__(self) -> str:
         return f"<PlaylistTab(id={self.playlist_id}>"
@@ -623,7 +623,7 @@ class PlaylistTab(QTableWidget):
             # Add track details to items
             try:
                 start_gap = row_data.track.start_gap
-            except:
+            except AttributeError:
                 return
             start_gap_item = QTableWidgetItem(str(start_gap))
             if start_gap and start_gap >= 500:
@@ -771,10 +771,10 @@ class PlaylistTab(QTableWidget):
         self._clear_current_track_row()
         self.current_track_start_time = None
 
-    def populate(self, session: Session, playlist_id: int,
+    def populate_display(self, session: Session, playlist_id: int,
                  scroll_to_top: bool = True) -> None:
         """
-        Populate from the associated playlist ID
+        Populate display from the associated playlist ID
         """
 
         # Sanity check row numbering before we load
@@ -1344,9 +1344,8 @@ class PlaylistTab(QTableWidget):
         Delete mutliple rows
 
         Actions required:
-        - Delete the rows from the PlaylistRows table
-        - Correct the row numbers in the PlaylistRows table
         - Remove the rows from the display
+        - Save the playlist
         """
 
         # Delete rows from database
@@ -1359,14 +1358,11 @@ class PlaylistTab(QTableWidget):
                           f"Really delete {row_count} row{plural}?"):
             return
 
-        with Session() as session:
-            PlaylistRows.delete_rows(session, plr_ids)
-
-            # Fix up row numbers left in this playlist
-            PlaylistRows.fixup_rownumbers(session, self.playlist_id)
-            # Remove selected rows from display
         self.remove_selected_rows()
 
+        with Session() as session:
+            self.save_playlist(session)
+
     def _drop_on(self, event):
         """
         https://stackoverflow.com/questions/26227885/drag-and-drop-rows-within-qtablewidget