criação de novas patterns de composição, com indice correto, nos projetos

assets/js/creations/main.js

@@ -213,24 +213,27 @@ document.addEventListener("DOMContentLoaded", () => {
     }
   });
 
-  // --- Criar/Remover Pattern (toolbar) ---
-  const addPatternBtn = document.getElementById("add-pattern-btn");
-  const removePatternBtn = document.getElementById("remove-pattern-btn");
+  function getNextPatternIndex() {
+    const nonBass = (appState.pattern.tracks || []).filter(t => t.type !== "bassline");
+
+    const maxFromNonBass = nonBass.reduce(
+      (m, t) => Math.max(m, (t.patterns?.length || 0) - 1),
+      -1
+    );
+
+    const maxFromBass = (appState.pattern.tracks || [])
+      .filter(t => t.type === "bassline" && Number.isFinite(Number(t.patternIndex)))
+      .reduce((m, t) => Math.max(m, Number(t.patternIndex)), -1);
+
+    return Math.max(maxFromNonBass, maxFromBass) + 1;
+  }
 
   addPatternBtn?.addEventListener("click", () => {
-    const refTrack = (appState.pattern.tracks || []).find(t => t.type !== "bassline");
-    const nextIndex = refTrack?.patterns?.length ?? 0;
-
-    const defaultName = `Pattern ${nextIndex + 1}`;
+    const idx = getNextPatternIndex();
+    const defaultName = `Pattern ${idx + 1}`;
     const name = (prompt("Nome do novo pattern:", defaultName) || defaultName).trim();
 
-    // cria e já seleciona
-    sendAction({ type: "ADD_PATTERN", patternIndex: nextIndex, name, select: true });
-  });
-
-  // opcional (se quiser implementar remover depois)
-  removePatternBtn?.addEventListener("click", () => {
-    sendAction({ type: "REMOVE_LAST_PATTERN" });
+    sendAction({ type: "ADD_PATTERN", patternIndex: idx, name, select: true });
   });
 
   //Seleção de pattern