playlist: Create a Runtime label

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

playlist/footer.py

@@ -10,3 +10,22 @@ class VisibleTracks(Gtk.Label):
     def set_count(self, n):
         s = 's' if n != 1 else ''
         self.set_text(f"Showing {n} track{s}")
+
+
+class Runtime(Gtk.Label):
+    def __init__(self):
+        Gtk.Label.__init__(self)
+        self.set_halign(Gtk.Align.END)
+        self.set_hexpand(True)
+
+    def set_runtime(self, seconds):
+        (min,  sec) = divmod(seconds, 60)
+        (hour, min) = divmod(min, 60)
+        (day, hour) = divmod(hour, 24)
+        (week, day) = divmod(day, 7)
+
+        vals = [ ("week", week), ("day", day), ("hour", hour),
+                 ("minute", min), ("second", sec) ]
+        text = [ f"{v} {k}{'s' if v != 1 else ''}" for (k, v) in vals if v != 0 ]
+
+        self.set_text(', '.join(text) if len(text) > 0 else "0 seconds")

playlist/test_footer.py

@@ -18,3 +18,26 @@ class TestVisibleTracks(unittest.TestCase):
         self.assertEqual(visible.get_text(), "Showing 1 track")
         visible.set_count(2)
         self.assertEqual(visible.get_text(), "Showing 2 tracks")
+
+
+class TestRuntime(unittest.TestCase):
+    def test_init(self):
+        runtime = footer.Runtime()
+        self.assertIsInstance(runtime, Gtk.Label)
+        self.assertEqual(runtime.get_halign(), Gtk.Align.END)
+        self.assertTrue(runtime.get_hexpand())
+
+    def test_runtime(self):
+        runtime = footer.Runtime()
+        runtime.set_runtime(0)
+        self.assertEqual(runtime.get_text(), "0 seconds")
+        runtime.set_runtime(61)
+        self.assertEqual(runtime.get_text(), "1 minute, 1 second")
+        runtime.set_runtime(3720)
+        self.assertEqual(runtime.get_text(), "1 hour, 2 minutes")
+        runtime.set_runtime(93600)
+        self.assertEqual(runtime.get_text(), "1 day, 2 hours")
+        runtime.set_runtime(777600)
+        self.assertEqual(runtime.get_text(), "1 week, 2 days")
+        runtime.set_runtime(1209600)
+        self.assertEqual(runtime.get_text(), "2 weeks")