Improve player name detection again

Now returns the whole bus name not just the last part and the
implementation assumption got documented.

Author: Kanjirito

src/player.rs

@@ -107,25 +107,21 @@ impl Player {
     }
 
     /// Returns the player name part of the player's D-Bus bus name.
-    /// This is the part after "org.mpris.MediaPlayer2.", not including Flatpak name parts and the instance part.
+    /// This is the part after "org.mpris.MediaPlayer2.", not including the instance part.
+    ///
+    /// **Note**: The instance part removal isn't guaranteed to work. It assumes that the player
+    /// implements it as mentioned in the MPRIS specification example.
     ///
     /// See: [MPRIS2 specification about bus names][bus_names].
     ///
     /// [bus_names]: https://specifications.freedesktop.org/mpris-spec/latest/#Bus-Name-Policy
     pub fn bus_name_player_name_part(&self) -> &str {
-        let bus_split: Vec<&str> = self
-            .bus_name
-            .trim_start_matches(MPRIS2_PREFIX)
-            .rsplit('.')
-            .collect();
-
-        if bus_split.len() == 1 || bus_split.len() == 3 {
-            // Safety in case a player's name actually starts with "instance"
-            bus_split[0]
-        } else if bus_split[0].starts_with("instance") {
-            bus_split[1]
+        let bus_trimmed = self.bus_name.trim_start_matches(MPRIS2_PREFIX);
+
+        if let Some(find_index) = bus_trimmed.rfind(".instance") {
+            &bus_trimmed[0..find_index]
         } else {
-            bus_split[0]
+            bus_trimmed
         }
     }