//
// This JavaScript program creates an M3U audio playlist
// of MP3 WMV and WAV files in the current directory
// and all subdirectories individually.
// Written by Zsolt Nagy-Perge in April 2021,
// Pensacola, Fla. <zsnp@juno.com>
//

try
{
  var FSO = new ActiveXObject('Scripting.FileSystemObject');
}
catch(e) { Exit("ERROR:\nCannot access File System."); }

SELF = WScript.ScriptFullName;
CURDIR = cut(SELF, "\\", 0x10010);
MYNAME = $b;
ABOUT = cut(ReadFile(SELF), "\r\n\r\n", 0x10).replace(/\/\/\s*/g, "");
Exit_If_Cancel("M3U Playlist Creator", MYNAME + "\n\n" + ABOUT + "\nClick on OK to run this script...");
WalkDIR(CURDIR);
Alert("DONE");
Exit();

//////////////////////////////////////////////////

function Alert(s) { WScript.Echo(s); }
function Exit(s) { if (typeof(s) == "string") Alert(s); WScript.Quit(0); }

//////////////////////////////////////////////////
// This function reads all files in a directory
// and processes each file, then does the same with
// each subdirectory as well.
// Usage: ARRAY = ReadDIR(PATH)
//
function WalkDIR(PATH)
{
  var FC, EXT, File, FullName, FileName, FILELIST = [],
  OUTPUT_FILE = PATH + "\\PLAY.M3U",
  F = FSO.GetFolder(PATH);
  for (FC = new Enumerator(F.files); !FC.atEnd(); FC.moveNext())
  {
    FullName = FC.item();
    FileName = cut(FullName, "\\", 0x10001);
    EXT = cut(FileName, ".", 0x10001).toUpperCase();
    if (EXT == "MP3" || EXT == "WMV" || EXT == "WAV")
      FILELIST.push(FullName);
    if (FILELIST.length > 1)
      CreateFile(OUTPUT_FILE, "#EXTM3U\r\n" + FILELIST.join("\r\n"));
  }
  FILELIST = 0;

  // Check each sub-directory...
  for (FC = new Enumerator(F.SubFolders); !FC.atEnd(); FC.moveNext())
    WalkDIR(FC.item());
}
//////////////////////////////////////////////////
// This function splits string into two parts
// along the first occurrence of substring.
// Returns the first part if CMD is 0x10.
// Returns the second part if CMD is 1.
// If substring is not found, returns the original
// string if CMD is 0x100. Ignores case when
// CMD is 0x1000. Starts searching from end of
// string when CMD is 0x10000.
//
function cut(STR, SUB, CMD)
{
  if (typeof(CMD) === "undefined") CMD = 0x111;
  STR += "";
  SUB += "";
  var P;
  if (CMD & 0x1000)
    P = (CMD & 0x10000) ? STR.toUpperCase().lastIndexOf(SUB) : STR.toUpperCase().indexOf(SUB);
  else
    P = (CMD & 0x10000) ? STR.lastIndexOf(SUB) : STR.indexOf(SUB);
  $a = $b = "";
  if (P < 0) return (CMD & 256) ? STR : "";
  $a = STR.substr(0, P);
  $b = STR.slice(P + SUB.length);
  return (CMD & 16 ? $a : '') + (CMD & 1 ? $b : '');
}
//////////////////////////////////////////////////
//                                      v2021.4.11
// Creates and overwrites a file and with a string.
// Retuns 0 on success or 1 if an error occurred.
// Usage: INTEGER = CreateFile(FILENAME, STRING)
//
function CreateFile(FILENAME, STRING)
{
  try
  {
    var FSO = new ActiveXObject("Scripting.FileSystemObject");
    var F = FSO.CreateTextFile(FILENAME, 1, 0);
    //
    // Usage: FILE_HANDLE = FSO.CreateTextFile(FILENAME, OVERWRITE, FORMAT)
    //   OVERWRITE: 0=Don't overwrite file if it exists
    //              1=Overwrite file if it already exists
    //      FORMAT: 0=ASCII
    //              1=UNICODE
    //
    F.Write(STRING);
    F.Close();
    return 0;
  }
  catch (e) {}
  return 1;
}
//////////////////////////////////////////////////
//                                      v2021.4.11
// Returns the entire contents of a text or binary file.
// Usage: STRING = ReadFile(FILENAME)
//
function ReadFile(FILENAME)
{
  var F, FSO, DATA = "";
  try
  {
    FSO = new ActiveXObject("Scripting.FileSystemObject");
    F = FSO.OpenTextFile(FILENAME, 1);  // Read UNICODE format
    DATA = F.ReadAll();
    F.Close();
    return DATA;
  }
  catch (e) {}
  return "";
}
//////////////////////////////////////////////////
//
// This function will display an OK-OR-CANCEL popup
// window with some message. If the user clicks
// Cancel, the script terminates.
// Usage: Exit_If_Cancel(TITLE, MESSAGE)
//
function Exit_If_Cancel(Title, Msg)
{
  var A = 0;
  try
  {
    var WshShell = WScript.CreateObject("WScript.Shell");
    A = WshShell.Popup(Msg, 1000, Title, 33);
  }
  catch(e) { Alert(Msg); }
  if (A == 2) Exit();
}
//////////////////////////////////////////////////