import maya.cmds as cmds

def createAndConnectTex(nodeName, path, fileAttr, matAttr, isRaw=False, isAlphaAsLum=False):
	baseColFile = cmds.shadingNode('file', asTexture=True, isColorManaged=True, n=nodeName)#create file node
	cmds.setAttr(baseColFile + '.fileTextureName', path, type='string')#set file path
	if isRaw:
		gammaNode = cmds.shadingNode('gammaCorrect', n='%s_gammaCorrect' % nodeName, asUtility=True)
		cmds.setAttr(gammaNode + '.gamma', 2.2, 2.2, 2.2, type='double3')
		cmds.connectAttr(baseColFile + '.outColor', gammaNode + '.value', force=True)
		cmds.connectAttr(gammaNode + '.outValueX', matAttr, force=True)
		cmds.setAttr(baseColFile + '.colorSpace', 'Raw', type='string')
	else:
		cmds.connectAttr(baseColFile + fileAttr, matAttr, force=True)#connect file to material
	if isAlphaAsLum:
		cmds.setAttr(baseColFile + '.alphaIsLuminance', True)

def getMapPath(diffPath, newMap):
	splitFile = diffPath.split('_')
	baseFile = '_'.join(splitFile[:-1])#get path without end
	mapTyp = splitFile[len(splitFile)-1]

	mapTypSplit = mapTyp.split('.')
	fileTyp = mapTypSplit[len(mapTypSplit)-1]#get file type

	newFile = baseFile+'_'+newMap+'.'+fileTyp#combine parts
	return newFile

def setupMaterial(mat, baseFile):
	selMat = cmds.optionMenu(mat, query=True, value=True)#get material name
	selFile = cmds.textField(baseFile, query=True, text=True)#get selected file
	if selMat and selFile:
		createAndConnectTex('%s_Diffuse_file' % selMat, selFile, '.outColor', selMat + '.color')
		createAndConnectTex('%s_Specular_file' % selMat, getMapPath(selFile, 'Specular'), '.outColor', selMat + '.KsColor')
		createAndConnectTex('%s_Roughness_file' % selMat, getMapPath(selFile, 'Roughness'), '.outAlpha', selMat + '.specularRoughness', True, True)
		createAndConnectTex('%s_f0_file' % selMat, getMapPath(selFile, 'f0'), '.outAlpha', selMat + '.Ksn', True, True)

		nmlNode = cmds.shadingNode('bump2d', n='%s_Normal_B2D' % selMat, asUtility=True)
		nmlFileNode = cmds.shadingNode('file', asTexture=True, isColorManaged=True, n='%s_Normal_file' % selMat)#create file node
		cmds.setAttr(nmlFileNode + '.fileTextureName', getMapPath(selFile, 'Normal'), type='string')#set file path
		cmds.setAttr(nmlFileNode + '.colorSpace', 'Raw', type='string')
		cmds.connectAttr(nmlNode + '.outNormal', selMat + '.normalCamera', force=True)
		cmds.connectAttr(nmlFileNode + '.outAlpha', nmlNode + '.bumpValue', force=True)
		cmds.setAttr(nmlNode + '.bumpInterp', 1)#Set Tangent Space Normals

	cmds.select(selMat)

def browseForFile(baseFile):
	selFile = cmds.fileDialog2(ds=2, fileMode=1, fileFilter='Image file (*.*)')
	if selFile:
		cmds.textField(baseFile, edit=True, text=selFile[0])

winID = 'SubToRedUI'

if cmds.window(winID, exists=True, resizeToFitChildren=True):
	cmds.deleteUI(winID)
cmds.window( winID, title='Substance -> Arnold')

cmds.columnLayout()

matOption = cmds.optionMenu( label='Materials' )
for mat in cmds.ls(type='aiStandard', long=True):
	cmds.menuItem(label=mat)

cmds.separator(height=16)
cmds.text(label='BaseColour texture:')

cmds.rowLayout(numberOfColumns=2)
baseFile = cmds.textField(width=256)
cmds.button(label='Browse', command='browseForFile(baseFile)')
cmds.setParent('..')

cmds.separator(height=16)

cmds.button(label='Go!', command='setupMaterial(matOption, baseFile)')

cmds.showWindow( winID )