fix: allow playing long songs

This is actually an unsigned short, not a short.
See https://noteblock.world/song/b91BWfUTnH for an example

src/main/java/land/chipmunk/chipmunkmod/song/Instrument.java

@@ -30,24 +30,20 @@ public class Instrument {
     public final int offset;
     public final String sound;
 
-    private Instrument (final int id, final String name, final int offset, final String sound) {
+    protected Instrument (final int id, final String name, final int offset, final String sound) {
         this.id = id;
         this.name = name;
         this.offset = offset;
         this.sound = sound;
     }
 
-    private Instrument (final int id, final String name, final int offset) {
+    protected Instrument (final int id, final String name, final int offset) {
         this.id = id;
         this.name = name;
         this.offset = offset;
         this.sound = "block.note_block." + name;
     }
 
-    public static Instrument of (final String sound) {
-        return new Instrument(-1, null, 0, sound);
-    }
-
     public static Instrument fromId (final int id) {
         return VALUES[id];
     }

src/main/java/land/chipmunk/chipmunkmod/song/NBSConverter.java

@@ -4,6 +4,9 @@ import java.io.IOException;
 import java.nio.ByteBuffer;
 import java.nio.ByteOrder;
 import java.util.ArrayList;
+
+import net.minecraft.resources.Identifier;
+import net.minecraft.util.Util;
 import net.minecraft.world.phys.Vec3;
 
 public class NBSConverter {
@@ -75,9 +78,9 @@ public class NBSConverter {
         }
 
         final ArrayList<NBSNote> nbsNotes = new ArrayList<>();
-        short tick = -1;
+        int tick = -1;
         while (true) {
-            final int tickJumps = buffer.getShort();
+            final int tickJumps = Short.toUnsignedInt(buffer.getShort());
             if (tickJumps == 0) break;
             tick += tickJumps;
 
@@ -120,12 +123,12 @@ public class NBSConverter {
         if (buffer.hasRemaining()) {
             final byte customInstrumentCount = buffer.get();
             for (int i = 0; i < customInstrumentCount; i++) {
-                final NBSCustomInstrument customInstrument = new NBSCustomInstrument();
+                final String name = getString(buffer, bytes.length);
-                customInstrument.name = getString(buffer, bytes.length);
+                final String file = getString(buffer, bytes.length);
-                customInstrument.file = getString(buffer, bytes.length);
+                final byte pitch = buffer.get();
-                customInstrument.pitch = buffer.get();
+                final boolean visible = buffer.get() != 0; // "Press piano key"
-                customInstrument.key = buffer.get() != 0;
+
-                customInstruments.add(customInstrument);
+                customInstruments.add(new NBSCustomInstrument(name, file, pitch, visible));
             }
         }
 
@@ -145,12 +148,10 @@ public class NBSConverter {
                 key = (double) ((note.key * 100) + note.pitch) / 100;
             } else {
                 final int index = note.instrument - vanillaInstrumentCount;
-
                 if (index >= customInstruments.size()) continue;
-
                 final NBSCustomInstrument customInstrument = customInstruments.get(index);
-                instrument = Instrument.of(customInstrument.name);
 
+                instrument = customInstrument;
                 key = (note.key) + (customInstrument.pitch + (double) note.pitch / 100);
             }
 
@@ -220,10 +221,26 @@ public class NBSConverter {
         public byte stereo = 100;
     }
 
-    private static class NBSCustomInstrument {
+    private static class NBSCustomInstrument extends Instrument {
-        public String name;
+        public final byte pitch;
-        public String file;
+        public final boolean visible;
-        public byte pitch = 0;
+
-        public boolean key = false;
+        public NBSCustomInstrument(final String name, final String optionalPath, final byte pitch, final boolean visible) {
+            // some implementations straight up just don't save the path, so we perform conversions on name on those
+            final String path = optionalPath.isBlank() ? name : optionalPath;
+            String sound = Util.sanitizeName(path, Identifier::isAllowedInIdentifier)
+                .replaceFirst("\\.ogg$", "")
+                .replaceFirst("^minecraft/", "")
+                .replaceFirst("\\d+$", "")
+                .replace('/', '.');
+
+            // if there's no path, it's probably a note block sound
+            // this happens when you have trumpets saved in a v5 format NBS for example
+            if (!sound.contains(".")) sound = "block.note_block." + sound;
+
+            super(-1, name, 0, sound);
+            this.pitch = pitch;
+            this.visible = visible;
+        }
     }
 }