#!@PYTHON@
#
# Check the free space available on a writable DVD
# Should always exit with 0 status, otherwise it indicates a serious error.
# (wrong number of arguments, Python exception...)
#
#  called:  dvd-freespace <dvd-device-name>
#
#
# returns:
# Prints on the first output line the free space available in bytes.
# If an error occurs, prints a negative number (-errno), followed,
# on the second line, by an error message.
# 
# $Id$

# Configurable values:
df="@DF@"
dvdrwmediainfo="@DVDRWMEDIAINFO@"

margin=10485760 # 10 mb security margin


# end of configurable values

import popen2
import os
import errno
import sys

if len(sys.argv) < 2:
   print "Wrong number of arguments."
   sys.exit(1)

device=sys.argv[1]

def gettotalsize():
   cmd=dvdrwmediainfo + " " + device
   processi = popen2.Popen4(cmd)
   status = processi.wait()
   if not os.WIFEXITED(status):
      print -errno.EPIPE
      print dvdrwmediainfo + " process did not exit correctly."
      sys.exit(0)
   if os.WEXITSTATUS(status) != 0:
      print -errno.EPIPE
      print "Cannot get media info from " + dvdrwmediainfo
      sys.exit(0)
   while 1:
      result = processi.fromchild.readline()
      if result.find("Track Size:") > -1:
	 index = result.find("*2KB")
	 if index > 0: 
	    return long(result[12:index]) * 2048
	 else:
	    print -errno.EPIPE
	    print "Invalid format in media info lead-out line from " + dvdrwmediainfo
	    sys.exit(0)
      if result.find("Legacy lead-out at:") > -1:
	 index = result.find("=")
	 if index > -1:
	    res = result[index+1:-1]
	    if not res.isdigit():
	       print -errno.EPIPE
	       print "Invalid format in media info lead-out line from " + dvdrwmediainfo
	       sys.exit(0)
	    return long(res)
	 else:
	    print -errno.EPIPE
	    print "Invalid format in media info lead-out line from " + dvdrwmediainfo
	    sys.exit(0)
      if not result:
	 print -errno.EPIPE
	 print "Cannot get media lead-out index from " + dvdrwmediainfo
	 sys.exit(0)

cmd=df + " " + device
process = popen2.Popen4(cmd)
status = process.wait()
if not os.WIFEXITED(status):
   print -errno.EPIPE
   print df + " process did not not exit correctly."
   sys.exit(0)

exitstat = os.WEXITSTATUS(status) & ~0x80
if exitstat == errno.ENOSPC:
   print "0"
   print os.strerror(exitstat)
   sys.exit(0)
if exitstat != 0:
   print -exitstat
   print os.strerror(exitstat)
   sys.exit(0)
size = 0
while 1:
   result = process.fromchild.readline()
   if not result:
      print -errno.EPIPE
      print "Cannot get output from " + df
      sys.exit(0)
   index = result.find(device)
   if index > -1: 
      while result[index] != ' ':
	 index += 1
      while result[index] == ' ':
	 index += 1
      eindex = index;
      while result[eindex] != ' ':
	 eindex += 1
      res = result[index:eindex] 
      if not res.isdigit():
	 print -errno.EPIPE;
	 print "Could not find size in df output"
	 sys.exit(0)
      size = long(res)*1024
      break

size = gettotalsize()-(size+margin)
if size < 0:
   size = 0
print size
print "No error occurred"
sys.exit(0)