// js/audio/audio_audio.js
import { appState } from "../state.js";
import { updateAudioEditorUI, updatePlayheadVisual, resetPlayheadVisual } from "./audio_ui.js";
import { initializeAudioContext, getAudioContext } from "../audio.js";
import { getPixelsPerSecond } from "../utils.js";

// --- Configurações do Scheduler ---
const LOOKAHEAD_INTERVAL_MS = 25.0;
const SCHEDULE_AHEAD_TIME_SEC = 0.5; // 500ms

// --- Estado Interno do Engine ---
let audioCtx = null;
let isPlaying = false;
let schedulerIntervalId = null;
let animationFrameId = null;

// Sincronização de Tempo
let startTime = 0; 
let seekTime = 0; 
let logicalPlaybackTime = 0; 

// Configurações de Loop
let isLoopActive = false;
let loopStartTimeSec = 0;
let loopEndTimeSec = 8; 

const runtimeClipState = new Map();
const scheduledNodes = new Map();
let nextEventId = 0; 

const callbacks = {
  onClipScheduled: null,
  onClipPlayed: null,
};

// --- Funções Auxiliares de Tempo (sem alterações) ---
function _getBpm() {
  const bpmInput = document.getElementById("bpm-input");
  return parseFloat(bpmInput.value) || 120;
}
function _getSecondsPerBeat() { return 60.0 / _getBpm(); }
function _convertBeatToSeconds(beat) { return beat * _getSecondsPerBeat(); }
function _convertSecondsToBeat(seconds) { return seconds / _getSecondsPerBeat(); }


function _initContext() {
  if (!audioCtx) {
    initializeAudioContext();
    audioCtx = getAudioContext();
  }
}

// --- Lógica Principal do Scheduler (sem alterações) ---

function _scheduleClip(clip, absolutePlayTime, durationSec) {
  if (!clip.buffer) {
    console.warn(`Clip ${clip.id} não possui áudio buffer carregado.`);
    return;
  }
  if (!clip.gainNode || !clip.pannerNode) {
    console.warn(`Clip ${clip.id} não possui gainNode ou pannerNode.`);
    return;
  }

  const source = new Tone.BufferSource(clip.buffer);
  source.connect(clip.gainNode);
  
  // --- CORREÇÃO: Aplica o pitch (que pode ser de stretch ou wheel) ---
  if (clip.pitch && clip.pitch !== 0) {
      source.playbackRate.value = Math.pow(2, clip.pitch / 12);
  } else {
      source.playbackRate.value = 1.0; // Garante que o modo 'trim' toque normal
  }
  // --- FIM DA CORREÇÃO ---

  const eventId = nextEventId++;
  const clipOffset = clip.offsetInSeconds || clip.offset || 0;
  source.start(absolutePlayTime, clipOffset, durationSec);
  scheduledNodes.set(eventId, { sourceNode: source, clipId: clip.id });

  if (callbacks.onClipScheduled) {
    callbacks.onClipScheduled(clip);
  }

  source.onended = () => {
    _handleClipEnd(eventId, clip.id);
    source.dispose();
  };
}

function _handleClipEnd(eventId, clipId) {
  scheduledNodes.delete(eventId);
  runtimeClipState.delete(clipId); 

  if (callbacks.onClipPlayed) {
    const clip = appState.audio.clips.find(c => c.id == clipId);
    if(clip) callbacks.onClipPlayed(clip);
  }
}

function _schedulerTick() {
  if (!isPlaying || !audioCtx) return;

  const now = audioCtx.currentTime;
  const logicalTime = (now - startTime) + seekTime;
  const scheduleWindowStartSec = logicalTime;
  const scheduleWindowEndSec = logicalTime + SCHEDULE_AHEAD_TIME_SEC;

  for (const clip of appState.audio.clips) {
    const clipRuntime = runtimeClipState.get(clip.id) || { isScheduled: false };
    
    if (clipRuntime.isScheduled) {
      continue;
    }
    if (!clip.buffer) { 
      continue;
    }

    const clipStartTimeSec = clip.startTimeInSeconds;
    const clipDurationSec = clip.durationInSeconds;

    if (typeof clipStartTimeSec === 'undefined' || typeof clipDurationSec === 'undefined') {
      continue;
    }

    let occurrenceStartTimeSec = clipStartTimeSec;

    if (isLoopActive) {
      const loopDuration = loopEndTimeSec - loopStartTimeSec;
      if (loopDuration <= 0) continue; 
      if (occurrenceStartTimeSec < loopStartTimeSec && logicalTime >= loopStartTimeSec) {
         const offsetFromLoopStart = (occurrenceStartTimeSec - loopStartTimeSec) % loopDuration;
         occurrenceStartTimeSec = loopStartTimeSec + (offsetFromLoopStart < 0 ? offsetFromLoopStart + loopDuration : offsetFromLoopStart);
      }
      if (occurrenceStartTimeSec < logicalTime) {
        const loopsMissed = Math.floor((logicalTime - occurrenceStartTimeSec) / loopDuration) + 1;
        occurrenceStartTimeSec += loopsMissed * loopDuration;
      }
    }
    if (
      occurrenceStartTimeSec >= scheduleWindowStartSec &&
      occurrenceStartTimeSec < scheduleWindowEndSec
    ) {
      const absolutePlayTime = startTime + (occurrenceStartTimeSec - seekTime);
      _scheduleClip(clip, absolutePlayTime, clipDurationSec);
      clipRuntime.isScheduled = true;
      runtimeClipState.set(clip.id, clipRuntime);
    }
  }
}

// --- Loop de Animação (sem alterações) ---
function _animationLoop() {
  if (!isPlaying) {
    animationFrameId = null;
    return;
  }
  const now = audioCtx.currentTime;
  let newLogicalTime = (now - startTime) + seekTime;
  if (isLoopActive) {
    if (newLogicalTime >= loopEndTimeSec) {
      const loopDuration = loopEndTimeSec - loopStartTimeSec;
      newLogicalTime = loopStartTimeSec + ((newLogicalTime - loopStartTimeSec) % loopDuration);
      startTime = now;
      seekTime = newLogicalTime;
    }
  }
  logicalPlaybackTime = newLogicalTime; 
  if (!isLoopActive) {
    let maxTime = 0;
    appState.audio.clips.forEach(clip => {
        const clipStartTime = clip.startTimeInSeconds || 0;
        const clipDuration = clip.durationInSeconds || 0;
        const endTime = clipStartTime + clipDuration;
        if (endTime > maxTime) maxTime = endTime;
    });
    
    if (maxTime > 0 && logicalPlaybackTime >= maxTime) {
        stopAudioEditorPlayback(true); // Rebobina no fim
        resetPlayheadVisual();
        return; 
    }
  }
  const pixelsPerSecond = getPixelsPerSecond();
  const newPositionPx = logicalPlaybackTime * pixelsPerSecond;
  updatePlayheadVisual(newPositionPx);
  animationFrameId = requestAnimationFrame(_animationLoop);
}

// --- API Pública ---

export function updateTransportLoop() {
  isLoopActive = appState.global.isLoopActive;
  loopStartTimeSec = appState.global.loopStartTime;
  loopEndTimeSec = appState.global.loopEndTime;

  runtimeClipState.clear();
  
  scheduledNodes.forEach(nodeData => {
    // --- CORREÇÃO BUG 1: Remove a linha 'onended = null' ---
    nodeData.sourceNode.stop(0);
    nodeData.sourceNode.dispose();
  });
  scheduledNodes.clear();
}

export function startAudioEditorPlayback() {
  if (isPlaying) return;
  
  _initContext();
  if (audioCtx.state === 'suspended') {
      audioCtx.resume();
  }

  isPlaying = true;
  // --- CORREÇÃO BUG 2: Atualiza o estado global ---
  appState.global.isAudioEditorPlaying = true;
  
  startTime = audioCtx.currentTime;
  
  updateTransportLoop(); 
  
  console.log("%cIniciando Playback...", "color: #3498db;");

  _schedulerTick(); 
  schedulerIntervalId = setInterval(_schedulerTick, LOOKAHEAD_INTERVAL_MS);
  animationFrameId = requestAnimationFrame(_animationLoop);
  updateAudioEditorUI();
  const playBtn = document.getElementById("audio-editor-play-btn");
  if (playBtn) {
    playBtn.className = 'fa-solid fa-pause';
  }
}

export function stopAudioEditorPlayback(rewind = false) {
  if (!isPlaying) return;

  isPlaying = false;
  // --- CORREÇÃO BUG 2: Atualiza o estado global ---
  appState.global.isAudioEditorPlaying = false;
  
  console.log(`%cParando Playback... (Rewind: ${rewind})`, "color: #d9534f;");

  clearInterval(schedulerIntervalId);
  schedulerIntervalId = null;
  cancelAnimationFrame(animationFrameId);
  animationFrameId = null;

  seekTime = logicalPlaybackTime;
  logicalPlaybackTime = 0; 
  
  if (rewind) {
      seekTime = 0;
  }
  
  scheduledNodes.forEach(nodeData => {
    // --- CORREÇÃO BUG 1: Remove a linha 'onended = null' ---
    nodeData.sourceNode.stop(0);
    nodeData.sourceNode.dispose();
  });
  scheduledNodes.clear();
  runtimeClipState.clear();

  updateAudioEditorUI();
  const playBtn = document.getElementById("audio-editor-play-btn");
  if (playBtn) {
    playBtn.className = 'fa-solid fa-play';
  }
  
  if (rewind) {
      resetPlayheadVisual();
  }
}

export function restartAudioEditorIfPlaying() {
  if (isPlaying) {
    stopAudioEditorPlayback(false); // Pausa
    startAudioEditorPlayback();
  }
}

export function seekAudioEditor(newTime) {
  const wasPlaying = isPlaying;
  if (wasPlaying) {
    stopAudioEditorPlayback(false); // Pausa
  }
  seekTime = newTime;
  logicalPlaybackTime = newTime; 
  const pixelsPerSecond = getPixelsPerSecond();
  const newPositionPx = newTime * pixelsPerSecond;
  updatePlayheadVisual(newPositionPx);
  if (wasPlaying) {
    startAudioEditorPlayback();
  }
}

export function registerCallbacks(newCallbacks) {
    if (newCallbacks.onClipScheduled) {
        callbacks.onClipScheduled = newCallbacks.onClipScheduled;
    }
    if (newCallbacks.onClipPlayed) {
        callbacks.onClipPlayed = newCallbacks.onClipPlayed;
    }
}