#!/usr/bin/env python
# pdf2ps.py
# filter for using pdf2ps (gs toolkit) instead of pdftops (xpdf toolkit) in CUPS
# 
# Copyright (C) 2008  Yury Yurevich <the.pythy@gmail.com>
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation, version 2
# of the License.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.

"""
Wrapper script for pdf2ps (gs-common package)
"""
import os
import sys
import tempfile
import subprocess

pdf2ps = "/usr/bin/pdf2ps"

def parse_args(args):
    if len(args) < 5:
        raise ValueError("Wrong number of arguments %d instead of 5" % len(args))
    job_id, username, title, copies, options, pdf_file = args
    return job_id, username, title, copies, options, pdf_file

def get_input_file(pdf_file):
    if pdf_file:
        return pdf_file, False
    # read from stdin to temp file
    fd, t_pdf_file = tempfile.mkstemp('.pdf')
    buf = sys.stdin.read(1024)
    while buf:
        os.write(fd, buf)
        buf = sys.stdin.read(1024)
    os.close(fd)
    return t_pdf_file, True

def call_pdf2ps(input_file, output_file):
    return subprocess.call([pdf2ps, input_file, output_file])

def write_to_stdout(fd):
    buf = os.read(fd, 1024)
    while buf:
        sys.stdout.write(buf)
        buf = os.read(fd, 1024)
    sys.stdout.flush()
    os.close(fd)

def convert(args):
    files_to_delete = []
    job_id, username, title, copies, options, _pdf = parse_args(args)
    pdf_file, need_delete = get_input_file(_pdf)
    if need_delete:
        files_to_delete.append(pdf_file)
    fd, ps_file = tempfile.mkstemp('.ps')
    returncode = call_pdf2ps(pdf_file, ps_file)
    if returncode == 0:
        files_to_delete.append(ps_file)
        write_to_stdout(fd)
    for f in files_to_delete:
        os.unlink(f)
    if returncode != 0:
        raise RuntimeError("pdf2ps returns non-zero code %d" % returncode)

def main(args):
    try:
        convert(args)
    except ValueError, e:
        sys.stderr.write("Usage: pdf2ps <job_id> <username> <title> <copies> <options> [pdf_file]\n")
        sys.stderr.write("Err: %s\n" % e)
        sys.exit(2)
    except RuntimeError, e:
        sys.stderr.write("Err: %s\n" % e)
        sys.exit(1)

if __name__ == "__main__":
    main(sys.argv[1:])