db: Create a DiscTable and Disc object

To represent each disc of an album. Discs may have different subtitles
that we want to display (or there may not be a subtitle at all). Casting
a Disc to a string either appends the subtitle to the album name or
returns the album name directly. This is intended to be used by the
ColumnView to display album names

Signed-off-by: Anna Schumaker <Anna@NoWheyCreamery.com>

db/__init__.py

@@ -13,9 +13,10 @@ executemany = Connection.executemany
 
 from . import artist
 from . import album
+from . import disc
 
 def reset():
-    mods = [ artist, album ]
+    mods = [ artist, album, disc ]
 
     for mod in mods: mod.Table.drop()
     for mod in mods: mod.Table.do_create()

db/disc.py

@@ -0,0 +1,67 @@
+# Copyright 2021 (c) Anna Schumaker.
+#
+# Table: discs
+# +--------+---------+--------+----------+
+# | discid | albumid | number | subtitle |
+# +--------+---------+--------+----------+
+from gi.repository import GObject
+from . import album
+from . import execute
+from . import objects
+
+class Disc(objects.Row):
+    def __gt__(self, rhs): return self.number > rhs.number
+    def __lt__(self, rhs): return self.number < rhs.number
+    def __str__(self):
+        if self.subtitle:
+            return f"{str(self.album)}: {self.subtitle}"
+        return f"{str(self.album)}"
+
+    def do_get_column(self, column):
+        return execute(f"SELECT {column} FROM discs "
+                        "WHERE discid=?", [ self.rowid ])
+
+    @GObject.Property
+    def album(self):
+        return album.Album(self.get_column("albumid"))
+
+    @GObject.Property
+    def number(self):
+        return self.get_column("number")
+
+    @GObject.Property
+    def subtitle(self):
+        return self.get_column("subtitle")
+
+
+class DiscTable(objects.Table):
+    def __init__(self):
+        objects.Table.__init__(self, "discs", Disc)
+
+    def do_create(self):
+        execute("CREATE TABLE IF NOT EXISTS discs "
+                    "(discid INTEGER PRIMARY KEY, "
+                    " albumid INTEGER, "
+                    " number INTEGER, "
+                    " subtitle TEXT, "
+                    " FOREIGN KEY(albumid) REFERENCES albums(albumid), "
+                    " UNIQUE(albumid, number))")
+
+    def do_insert(self, album, number, subtitle):
+        subtitle = subtitle if subtitle and len(subtitle) > 0 else None
+        return execute("INSERT INTO discs (albumid, number, subtitle) "
+                       "VALUES (?, ?, ?)", (int(album), number, subtitle))
+
+    def do_delete(self, disc):
+        return execute("DELETE FROM discs WHERE discid=?", [ int(disc) ])
+
+    def do_get(self, rowid):
+        return execute("SELECT discid FROM discs "
+                       "WHERE discid=?", [ rowid ])
+
+    def do_lookup(self, album, number, subtitle=None):
+        return execute("SELECT discid FROM discs "
+                       "WHERE (albumid=? AND number=?)", [ int(album), number ])
+
+
+Table = DiscTable()

db/test_disc.py

@@ -0,0 +1,72 @@
+# Copyright 2021 (c) Anna Schumaker.
+import db
+import sqlite3
+import unittest
+from gi.repository import GObject
+
+
+class TestDiscTable(unittest.TestCase):
+    def setUp(self):
+        db.reset()
+
+    def test_disc_table_init(self):
+        self.assertIsInstance(db.disc.Table, db.disc.DiscTable)
+        db.execute("SELECT discid,albumid,number,subtitle FROM discs")
+
+    def test_disc_table_insert(self):
+        artist = db.artist.Table.insert("Test Artist", "Test Sort")
+        album  = db.album.Table.insert(artist, "Test Album")
+        disc   = db.disc.Table.insert(album, 1, "subtitle")
+
+        self.assertIsInstance(disc, db.disc.Disc)
+        self.assertIsInstance(disc, db.objects.Row)
+
+        self.assertEqual(disc.album, album)
+        self.assertEqual(disc.number, 1)
+        self.assertEqual(disc.subtitle, "subtitle")
+        self.assertEqual(str(disc), "Test Album: subtitle")
+
+        disc2 = db.disc.Table.insert(album, 2, None)
+        self.assertEqual(disc2.subtitle, None)
+        self.assertEqual(str(disc2), "Test Album")
+
+        disc3 = db.disc.Table.insert(album, 3, "")
+        self.assertEqual(disc3.subtitle, None)
+        self.assertEqual(str(disc3), "Test Album")
+
+        with self.assertRaises(sqlite3.IntegrityError):
+            db.disc.Table.insert(album, 1, "subtitle")
+
+    def test_disc_table_delete(self):
+        artist = db.artist.Table.find("Test Artist", "Test Sort")
+        album  = db.album.Table.find(artist, "Test Album")
+        disc   = db.disc.Table.find(album, 1, "subtitle")
+
+        db.disc.Table.delete(disc)
+        self.assertIsNone(db.disc.Table.lookup(album, 1))
+
+    def test_disc_table_get(self):
+        artist = db.artist.Table.insert("Test Artist", "Test Sort")
+        album  = db.album.Table.insert(artist, "Test Album")
+        disc   = db.disc.Table.insert(album, 1, None)
+        self.assertEqual(db.disc.Table.get(1), disc)
+        self.assertIsNone(db.disc.Table.get(2))
+
+    def test_disc_table_lookup(self):
+        artist = db.artist.Table.insert("Test Artist", "Test Sort")
+        album  = db.album.Table.insert(artist, "Test Album")
+        disc   = db.disc.Table.insert(album, 1, None)
+        self.assertEqual(db.disc.Table.lookup(album, 1), disc)
+        self.assertIsNone(db.disc.Table.lookup(album, "none"))
+
+    def test_disc_compare(self):
+        artist = db.artist.Table.insert("Test Artist", "Test Sort")
+        album  = db.album.Table.insert(artist, "Test Album")
+        disc1  = db.disc.Table.insert(album, 1, "subtitle")
+        disc2  = db.disc.Table.insert(album, 2, "subtitle")
+
+        self.assertTrue(disc1 < disc2)
+        self.assertTrue(disc2 > disc1)
+
+        self.assertFalse(disc1 > disc2)
+        self.assertFalse(disc2 < disc1)