// app/static/js/services/bridgeAudioNode.js
// Audio sink: consumes 'bridge-audio' PCM frames (native bridge) and plays them
// through a ScriptProcessorNode into the WebAudio graph (track FX / master bus).
(function () {
  var RING_DEPTH = 8;           // 8 blocks * 256 samples ~= 46ms anti-underrun
  var SP_BUFFER = 4096;         // ScriptProcessor chunk (16 bridge blocks)
  var _queue = [];
  var _spn = null;
  var _gainNode = null;
  var _ctx = null;
  var _initialized = false;

  function _getCtx() {
    if (_ctx) return _ctx;
    if (typeof getAudioContext === 'function') _ctx = getAudioContext();
    else if (window.__sharedAudioCtx) _ctx = window.__sharedAudioCtx;
    else _ctx = new (window.AudioContext || window.webkitAudioContext)();
    return _ctx;
  }

  function init(audioCtx) {
    if (_initialized) return;
    _ctx = audioCtx || _getCtx();
    _gainNode = _ctx.createGain();
    _gainNode.gain.value = 1.0;
    _spn = _ctx.createScriptProcessor(SP_BUFFER, 0, 2);
    _spn.onaudioprocess = function (e) {
      var L = e.outputBuffer.getChannelData(0);
      var R = e.outputBuffer.getChannelData(1);
      L.fill(0); R.fill(0);
      if (!_queue.length) return;
      var f = _queue.shift();
      L.set(f.l); R.set(f.r);
    };
    _spn.connect(_gainNode);
    _initialized = true;
    console.log('[BridgeAudioNode] initialized (ring depth ' + RING_DEPTH + ')');
  }

  function onAudio(l, r) {
    if (!_initialized) init();
    _queue.push({ l: new Float32Array(l), r: new Float32Array(r) });
    if (_queue.length > RING_DEPTH) _queue.shift(); // drop oldest on overrun
  }

  function flush() { _queue = []; }

  function getOutputNode() { return _gainNode; }

  function disconnect() {
    flush();
    if (_spn && _gainNode) {
      try { _spn.disconnect(); } catch (e) {}
      try { _gainNode.disconnect(); } catch (e) {}
    }
    // Reset state so a later init() can rebuild (AudioRoutingEngine re-connect).
    _initialized = false;
    _spn = null;
    _gainNode = null;
    _ctx = null;
  }

  window.BridgeAudioNode = {
    init: init,
    onAudio: onAudio,
    flush: flush,
    getOutputNode: getOutputNode,
    connect: function (dest) { if (_gainNode) _gainNode.connect(dest); },
    disconnect: disconnect,
    isReady: function () { return _initialized; }
  };
})();