// ===========================================================================
// Copyright 2018 Autodesk, Inc. All rights reserved.
//
// Use of this software is subject to the terms of the Autodesk license
// agreement provided at the time of installation or download, or which
// otherwise accompanies this software in either electronic or hard copy form.
// ===========================================================================

global proc int blendShapeCreateEmptyDirectory(string $bsdName, int $tgtIndex)
//
// Description:
//   Create an empty directory under this blendShape $bsdName,
//   the new directory shares the same parent directory of the given $tgtIndex.
//   This function does not support to create directory 0 yet.
// 
// Input:
//   $tgtIndex    >= 0 means it is a target, 
//                < 0 means it is a target directory.
//                == 0, it is treated as a target not directory 0,
//                since there is no brother/sister directory at the same level of directory 0.
// 
// Return: 
//   the new directory index which > 0, 0 means fail.
// 
{
	int $newDirectoryIndex = blendShapeUnusedTargetDirectoryIndex($bsdName);
	
	if ($newDirectoryIndex <= 0)
		return 0; 
		
	if ($tgtIndex >= 0)
	{
		// this is a target.
		
		// TODO. this path is not used yet so no implement.
	}	
	else
	{
		// this is a target directory
		
		// make sure this new directory does not have childIndices.
		$tempAttr = $bsdName + ".targetDirectory[" + $newDirectoryIndex + "].childIndices";
		$cmd = "setAttr " + $tempAttr + " -type Int32Array 0";
		eval($cmd);
		
		// update this new directory's the parent directory
		$tempAttr = $bsdName + ".targetDirectory[" + -$tgtIndex + "].parentIndex";
		$parentDir = `getAttr $tempAttr`;
		
		$tempAttr = $bsdName + ".targetDirectory[" + $newDirectoryIndex + "].parentIndex";
		setAttr $tempAttr $parentDir;
		
		// update parent directory's childIndices
		$tempAttr = $bsdName + ".targetDirectory[" + $parentDir + "].childIndices";
		int $childIndices[] = `getAttr $tempAttr`;
		
		intArrayInsertAtIndex(size($childIndices), $childIndices, -$newDirectoryIndex);
		
		$tempAttr = $bsdName + ".targetDirectory[" + $parentDir + "].childIndices";
		$cmd = "setAttr " + $tempAttr + " -type Int32Array " + size($childIndices);
		for ($idx in $childIndices)
			$cmd += " " + $idx;
		eval($cmd);
	}
	
	return $newDirectoryIndex;
}