#!/usr/bin/python

import os,sys,re
import traceback

from optparse import OptionParser


def main():
    
    usage = """
usage: pdftopngs [options] pdfname

  Converts a PDF file to a series of PNG images, one per page
  in the PDF file.  By default, the images are 512x512, which will
  probably be distorted from your PDF file, but is best suited for
  uploading as textures to Second Life.

  Prerequisites : you must have the ghostscript ("gs") and netpbm
  command-line utilities installed.
"""

    parser = OptionParser(usage = usage)
    parser.add_option("-x","--x-size", action="store", type="int",
                      dest="xsize", default=512,
                      help="Width of the resultant images (def: 512)")
    parser.add_option("-y","--y-size", action="store", type="int",
                      dest="ysize", default=512,
                      help="Height of the resultant images (def: 512)")
    parser.add_option("-r","--resolution", action="store", type="int",
                      dest="resolution", default=150,
                      help="DPI in the initial PDF conversion (def: 150)")
    parser.add_option("-g","--gs-args", action="store", type="string",
                      dest="gsargs", default=None,
                      help="Additional arguments to pass to ghostscript")

    options,args = parser.parse_args()

    try:
        if len(args) < 1:
            print "Please specify the name of a pdf file to convert"
            sys.exit(20)

        pdfname = args[0]
        res = options.resolution
        xsize = options.xsize
        ysize = options.ysize
        gsargs = ""
        if options.gsargs is not None: gsargs = options.gsargs

        pdfre = re.compile("^(.*)\.pdf")
        pdfmatch = pdfre.search(pdfname)
        if (pdfmatch is None):
            print "Error parsing %s as the name of a PDF file" % pdfname
            sys.exit(20)
        fnamebase = pdfmatch.group(1)

        cmd = "gs -q -sDEVICE=ppmraw -dNOPAUSE -sOutputFile=%s_%%02d.ppm " \
            "-r%s %s %s.pdf -c quit" % (fnamebase, res, gsargs, fnamebase)

        print cmd
        os.system(cmd)

        files = os.listdir(".")
        ppmre = re.compile("^%s_(\d+)\.ppm" % fnamebase)

        maxnum = 0
        for file in files:
            ppmmatch = ppmre.search(file)
            if (ppmmatch is not None):
                num = int(ppmmatch.group(1))
                if num > maxnum: maxnum = num
        if maxnum == 0:
            print "ERROR : no output from gs!"
            sys.exit(20)

        for i in range(1, maxnum+1):
            thisnamebase = "%s_%02d" % (fnamebase, i)
            cmd = "pnmscale -width %s -height %s %s.ppm | pnmtopng > %s.png" \
                % (xsize, ysize, thisnamebase, thisnamebase)
            print cmd
            os.system(cmd)
            try:
                os.unlink("%s.ppm" % thisnamebase)
            except OSError:
                pass

    except Exception:
        print "FAIL"
        traceback.print_exc()
        sys.exit(20)


# **********************************************************************

if __name__ == "__main__":
    sys.exit(main())