/* Notes to Rests by Warren Porter "restStaff.js"
   After downloading this file, when setting it up in NWC User Tools create this command line:

   wscript "'Browse can insert the path for you' \restStaff.js" 

   This can help create a new staff when one is needed for layering.  First, copy an entire staff to the clipboard, create a new staff,
   then cut the clipboard to the new staff.  Run this command on that new staff.  Clefs, time signatures, and key signatures will be
   left alone on the new staff, but all notes, chords, and restchords will be replaced by rests.  Bars with "full measures" (the norm,
   it has as many beats as the time signature dictates) will be replaced with whole rests, a measure with more or fewer (like a pickup)
   will be replaced with rests of the same durations (and order if necessary) or the original notes, rests, chords, or restchords.

   The new staff may then be used for layered notes for the original staff.  It can be run through the MMR tool with the "LayerHide"
   option so unneeded parts won't display.
   
   This is not suited to creating a "tempo" or "conductor" staff.  To create a tempo staff which could be layered into all other parts
   to print parts, the clef or keys should not be copied while tempos or tempo variences should be.
 */

var rc=0, errMsg=""
function getNoteLength(notelet) {  // Returns duration of note , whole = 768
var NoteLengths = { "16th":48, "32nd":24, "4th":192, "64th":12, "8th":96, "Half":384, "Whole":768 }
parts = notelet.split(",");
var  noteLength= -1;
noteLength = NoteLengths[parts[0]];
var noteLength = ( NoteLengths[parts[0]] === undefined ) ? -1 : NoteLengths[parts[0]];
  if (noteLength == -1)
    return -1;

  for (var i = 1; i < parts.length; i++) {
    if (parts[i].substr(0,9) == "DblDotted") {
	  noteLength = noteLength * 7 / 4; }
	else
      if (parts[i].substr(0,6) == "Dotted") {
	    noteLength = noteLength * 3 / 2; }
	  else
	    if (parts[i].substr(0,7) == "Triplet") {
	      noteLength = noteLength * 2 / 3; } }
  return noteLength;
}
function calculate(clip) {
  var i, j=0, dsi;
  var lines = new Array(), result = new Array(), nlines = new Array, mt=0, measureTab = new Array, beatletCount=0, targetMeasure = 768;
  var thisDur, thisNote, durSplit;
  lines = clip.split("\r\n");
  for (i=0; i < lines.length; i++) {
	if (lines[i].slice(1,5) == "Text" || lines[i].slice(1,14) == "TempoVariance")
	  continue;
    if (lines[i].slice(1,5) == "Fake" || lines[i].slice(1,8) == "Context" ) {  // For these items, pass them thru and ignore them.
	  nlines[j++] = lines[i]; continue; }
	if (lines[i].slice(1,8) == "TimeSig") {	
	  if (beatletCount == targetMeasure)  // Measure exactly full
	    nlines[j++] = "|Rest|Dur:Whole|Visibility:Never";  // Insert whole rest
	  else {
	    for (mt = 0; mt < measureTab.length; mt++)
		  nlines[j++] = "|Rest|Dur:" + measureTab[mt] + "|Visibility:Never";}
	  beatletCount = 0, measureTab.length = 0; mt=0;
	  result = lines[i].match(/ture:(\d+)\/(\d+)/);  // Read the time signature
	  if (result == null)  //In case it is C or cut time
	    targetMeasure = 768;
	  else
	    targetMeasure = 768 * result[1] / result[2];    // Calculate length of measure	  
	  nlines[j++] = lines[i]; continue; }	  
	if (/Grace/.test(lines[i]))
	  continue;
	result = lines[i].match(/Dur:([^\|\r\n]+)/)   // Looking for anything with a duration
	if (result != null) {  // Duration loop
	  thisDur = result[1];
	  thisNote = getNoteLength(thisDur);
	  if (thisNote == -1) {
	    errMsg += "Invalid duration of " + lines[i] + "\r\n";
		rc=1;
		continue; }
	  durSplit = thisDur.split(",");
	  for (dsi=1; dsi < durSplit.length; dsi++)
	    if (!(durSplit[dsi].substr(0,9) == "DblDotted" || durSplit[dsi].substr(0,6) == "Dotted" || durSplit[dsi].substr(0,7) == "Triplet")) {
		  durSplit.length = dsi; break; }
	  measureTab[mt++] = durSplit.join(",");
	  if (lines[i].slice(1,15) == "Rest|Dur:Whole")  //So existing whole rest in , e.g., 3/4 time won't be treated as having 4 beats.
	    thisNote = targetMeasure;
	  beatletCount += thisNote;
	  continue; }   // End duration loop
	if (lines[i].slice(1,4) == "Bar" || lines[i].slice(1,5) == "Flow" || lines[i].slice(1,7) == "Ending"  || lines[i].slice(0,1) == "!"|| 
	      lines[i].slice(1,13) == "RestMultiBar" || lines[i].slice(1,9) == "Boundary" || lines[i].slice(1,11) == "Instrument" ||
		  lines[i].slice(1,4) == "MPC" || lines[i].slice(1,5) == "Clef" || lines[i].slice(1,4) == "Key" ) {  //Bar loop, flow, & spec. endings
	  if (beatletCount == targetMeasure)  // Measure exactly full
	    nlines[j++] = "|Rest|Dur:Whole|Visibility:Never";  // Insert whole rest
	  else {
	    for (mt = 0; mt < measureTab.length; mt++)
		  nlines[j++] = "|Rest|Dur:" + measureTab[mt] + "|Visibility:Never";}
	  beatletCount = 0, measureTab.length = 0; mt=0;  // Get set up for next measure
	  if (lines[i].slice(1,6) != "Tempo")
	    nlines[j++] = lines[i]; }  //End bar loop
  }  //End main processing loop
  return nlines;
}

var myLines=calculate(WScript.StdIn.ReadAll()).join("\r\n");
if (rc == 0)
  WScript.StdOut.Write(myLines);
else
  WScript.StdErr.Write(errMsg);
WScript.quit(rc);