-- © Dieter May, Jun 2020 
use scripting additions

try
	tell application "Adobe Acrobat" to set pdfPath to file alias of active doc
	set pdfPath to POSIX path of pdfPath
on error errMess
	display alert errMess
	return
end try

--- wenn hier etwas geändert wird, muss ~/Library/Caches/watermark-applescript.py gelöscht werden.
set theProperties to "xOffset, yOffset, angle, scale, opacity = 70.0, 600.0, 35.0, 1.0, 0.1"
set theFont to "Chalkduster" -- in Schriftsammlung mit Apfel-I den PostScript-Namen anzeigen
set theFontSize to "120.0"
--------------------


set tmpFolder to (path to "cach" from user domain as string)
set pyScript to POSIX path of (tmpFolder & "watermark-applescript.py" as string)

if not CheckExistence(pyScript) then
	writeToFile(pyScript, pythonScript(theProperties, theFont, theFontSize))
end if

display dialog "Wasserzeichen" default answer "Kopie" buttons {"Abbrechen", "OK"} default button 2
copy the result as list to {buttonPressed, textReturned}

set theCMD to "/usr/bin/python " & quoted form of pyScript & space & quoted form of pdfPath & space & quoted form of textReturned
set outFile to (do shell script theCMD)
--delay 1
set hfsFile to POSIX file outFile
--tell application "Finder" to reveal hfsFile
tell application "Adobe Acrobat"
	open hfsFile
	activate
end tell

on writeToFile(filePath, theData)
	try
		set f to open for access (filePath as text) with write permission
		set eof f to 0
		write (theData) to f starting at eof as «class utf8»
		close access f
	on error theError
		try
			close access f
		end try
		return theError
	end try
end writeToFile

on CheckExistence(FileOrFolderToCheckString)
	try
		alias FileOrFolderToCheckString
		return true
	on error
		return false
	end try
end CheckExistence

on pythonScript(theProperties, theFont, theFontSize)
	return "#!/usr/bin/python
# coding: utf-8
import sys
import os
import math
import Quartz.CoreGraphics as Quartz
from CoreText import (kCTFontAttributeName, CTFontCreateWithName, CTLineDraw, CTLineCreateWithAttributedString, kCTFontAttributeName, CTLineGetImageBounds)
from CoreFoundation import (CFAttributedStringCreate, CFURLCreateFromFileSystemRepresentation, kCFAllocatorDefault)
def createPDFDocumentFromPath(path):
	return Quartz.CGPDFDocumentCreateWithURL(Quartz.CFURLCreateFromFileSystemRepresentation(kCFAllocatorDefault, path, len(path), False))
def createOutputContextWithPath(path):
	return Quartz.CGPDFContextCreateWithURL(Quartz.CFURLCreateFromFileSystemRepresentation(kCFAllocatorDefault, path, len(path), False), None, None)
def contextDone(context):
	if context:
		Quartz.CGPDFContextClose(context)
		del context
def drawWatermarkText(writeContext, line, xOffset, yOffset, angle, scale, opacity):
	if line:
		rect = CTLineGetImageBounds(line, writeContext)
		imageWidth = rect.size.width
		imageHeight = rect.size.height
		Quartz.CGContextSaveGState(writeContext)
		Quartz.CGContextSetAlpha(writeContext, opacity)
		Quartz.CGContextTranslateCTM(writeContext,  xOffset, yOffset)
		Quartz.CGContextTranslateCTM(writeContext, imageWidth / 2, imageHeight / 2)
		Quartz.CGContextRotateCTM(writeContext, angle * math.pi / 180)
		Quartz.CGContextTranslateCTM(writeContext, -imageWidth / 2, -imageHeight / 2)
		Quartz.CGContextScaleCTM(writeContext, scale, scale)
		Quartz.CGContextSetTextPosition(writeContext, 0.0, 0.0)
		CTLineDraw(line, writeContext)
		Quartz.CGContextRestoreGState(writeContext)
if __name__ == '__main__':
	" & theProperties & "
	font = CTFontCreateWithName('" & theFont & "', " & theFontSize & ", None)
	text = sys.argv[2]
	filename = sys.argv[1]
	shortName = os.path.splitext(filename)[0]
	outFilename = shortName + '_' + text + '.pdf'
	pdf = createPDFDocumentFromPath(filename)
	writeContext = createOutputContextWithPath(outFilename)
	pages = Quartz.CGPDFDocumentGetNumberOfPages(pdf)
	if pdf:
		for i in range(1, (pages+1)):
			page = Quartz.CGPDFDocumentGetPage(pdf, i)
			if page:
				mbox = Quartz.CGPDFPageGetBoxRect(page, Quartz.kCGPDFMediaBox)
				Quartz.CGContextBeginPage(writeContext, mbox)
				Quartz.CGContextDrawPDFPage(writeContext, page)
				astr = CFAttributedStringCreate(kCFAllocatorDefault, text, { kCTFontAttributeName : font })
				line = CTLineCreateWithAttributedString(astr)
				drawWatermarkText(writeContext, line, xOffset , yOffset, angle, scale, opacity)
				Quartz.CGContextEndPage(writeContext)
	del pdf
	contextDone(writeContext)
	print (outFilename)
"
end pythonScript