patterns funcionais, alguns nomes estão ao contrário. mas o conteúdo agora está correto e fidedigno ao projeto.

assets/js/creations/state.js

@@ -6,10 +6,12 @@ import {
   getMainGainNode,
 } from "./audio.js";
 import { renderApp } from "./ui.js";
+import { getTotalSteps } from "./utils.js";
 
-// O "cérebro" da aplicação
 export let appState = {
   tracks: [],
+  activeTrackId: null,
+  activePatternIndex: 0, // <-- VOLTOU A SER GLOBAL
   isPlaying: false,
   playbackIntervalId: null,
   currentStep: 0,
@@ -20,19 +22,14 @@ export let appState = {
 };
 
 export async function loadAudioForTrack(track) {
-  if (!track.samplePath) {
-    console.warn("Track sem samplePath, pulando o carregamento de áudio.");
-    return track;
-  }
+  if (!track.samplePath) return track;
   try {
     const audioContext = getAudioContext();
     if (!audioContext) initializeAudioContext();
-
     const response = await fetch(track.samplePath);
     if (!response.ok) throw new Error(`Erro ao buscar o sample: ${response.statusText}`);
     const arrayBuffer = await response.arrayBuffer();
     track.audioBuffer = await audioContext.decodeAudioData(arrayBuffer);
-    console.log(`Áudio carregado para a trilha: ${track.name}`);
   } catch (error) {
     console.error(`Falha ao carregar áudio para a trilha ${track.name}:`, error);
     track.audioBuffer = null;
@@ -44,13 +41,18 @@ export function addTrackToState() {
   initializeAudioContext();
   const audioContext = getAudioContext();
   const mainGainNode = getMainGainNode();
+  const totalSteps = getTotalSteps();
+  const referenceTrack = appState.tracks[0];
 
   const newTrack = {
     id: Date.now(),
     name: "novo instrumento",
     samplePath: null,
     audioBuffer: null,
-    steps: [],
+    patterns: referenceTrack 
+      ? referenceTrack.patterns.map(p => ({ name: p.name, steps: new Array(p.steps.length).fill(false), pos: p.pos }))
+      : [{ name: "Pattern 1", steps: new Array(totalSteps).fill(false), pos: 0 }],
+    // activePatternIndex foi removido daqui
     volume: DEFAULT_VOLUME,
     pan: DEFAULT_PAN,
     gainNode: audioContext.createGain(),
@@ -62,12 +64,20 @@ export function addTrackToState() {
   newTrack.pannerNode.pan.value = newTrack.pan;
 
   appState.tracks.push(newTrack);
+  if (!appState.activeTrackId) {
+      appState.activeTrackId = newTrack.id;
+  }
   renderApp();
 }
 
 export function removeLastTrackFromState() {
-  appState.tracks.pop();
-  renderApp();
+  if (appState.tracks.length > 0) {
+    const removedTrack = appState.tracks.pop();
+    if (appState.activeTrackId === removedTrack.id) {
+        appState.activeTrackId = appState.tracks[0]?.id || null;
+    }
+    renderApp();
+  }
 }
 
 export async function updateTrackSample(trackId, samplePath) {
@@ -76,41 +86,43 @@ export async function updateTrackSample(trackId, samplePath) {
     track.samplePath = samplePath;
     track.name = samplePath.split("/").pop();
     track.audioBuffer = null;
-    renderApp();
     await loadAudioForTrack(track);
+    const trackLane = document.querySelector(`.track-lane[data-track-id="${trackId}"] .track-name`);
+    if (trackLane) {
+      trackLane.textContent = track.name;
+    }
   }
 }
 
 export function toggleStepState(trackId, stepIndex) {
   const track = appState.tracks.find((t) => t.id == trackId);
-  if (track) {
-    track.steps[stepIndex] = !track.steps[stepIndex];
+  if (track && track.patterns && track.patterns.length > 0) {
+    // Usa o índice GLOBAL para saber qual pattern modificar
+    const activePattern = track.patterns[appState.activePatternIndex];
+    if (activePattern && activePattern.steps.length > stepIndex) {
+      activePattern.steps[stepIndex] = !activePattern.steps[stepIndex];
+    }
   }
 }
 
 export function updateTrackVolume(trackId, volume) {
   const track = appState.tracks.find((t) => t.id == trackId);
-  const audioContext = getAudioContext();
   if (track) {
     const clampedVolume = Math.max(0, Math.min(1.5, volume));
     track.volume = clampedVolume;
     if (track.gainNode) {
-      track.gainNode.gain.setValueAtTime(
-        clampedVolume,
-        audioContext.currentTime
-      );
+      track.gainNode.gain.setValueAtTime(clampedVolume, getAudioContext().currentTime);
     }
   }
 }
 
 export function updateTrackPan(trackId, pan) {
   const track = appState.tracks.find((t) => t.id == trackId);
-  const audioContext = getAudioContext();
   if (track) {
     const clampedPan = Math.max(-1, Math.min(1, pan));
     track.pan = clampedPan;
     if (track.pannerNode) {
-      track.pannerNode.pan.setValueAtTime(clampedPan, audioContext.currentTime);
+      track.pannerNode.pan.setValueAtTime(clampedPan, getAudioContext().currentTime);
     }
   }
 }