#!/usr/bin/python
#
# mk-rescueimage.i386 - builds a rescue image from an existing tree
#                       which can be converted into a isolinux bootable
#                       iso and used as a sysadmin rescue image.
#
#
# Usage: mk-rescueimage.i386 <src-tree> <dest-dir> <productname>
#
# the rescue image will be created as <dest-dir>/i386-rescueimage
#

import os
import sys
import string

def usage():
    print "usage: mk-rescueimage.i386 <toplevel> <dest-dir> <productname> <default>"
    sys.exit(0)


if len(sys.argv) < 5:
    usage()
    sys.exit(1)
    
if not os.access("%s/i386" % (sys.argv[2],), os.F_OK):
    print "ERROR - Destination directory %s does not contain an i386 directory!" % (srcdir,)
    sys.exit(1)

srcdir  = sys.argv[1]
destdir = sys.argv[2]+"/i386-rescueimage"
productname = sys.argv[3]
default = sys.argv[4]

# clean and create destination directory
os.system("rm -rf %s" % (destdir,))
os.system("mkdir %s" % (destdir,))

# copy documentation
for pat in ["*eula*", "*EULA*", "README*", "RELEASE*", "GPL", "RPM-*"]:
    try:
	os.system("cp -p %s/%s       %s/" % (srcdir, pat, destdir))
    except:
	print "Unable to find pattern %s" % (pat,)


# cp isolinux boot image
os.system("cp -a %s/isolinux     %s/" % (srcdir, destdir))

# cp stage image
os.system("mkdir -p %s/%s/base" % (destdir,default))
os.system("cp -a %s/%s/base/stage2.img %s/%s/base" % (srcdir, default, destdir,default,))

# munge syslinux config to have a default of rescue mode
cfgfile = open("%s/isolinux/isolinux.cfg" % (destdir,), "r")
cfglines = cfgfile.readlines()
cfgfile.close()

# backup old one
os.system("cp %s/isolinux/isolinux.cfg %s/isolinux/isolinux.cfg.backup" % (destdir,destdir))

cfgfile = open("%s/isolinux/isolinux.cfg" % (destdir,), "w+")
fndit = 0
indefault = 0
defaultimg = None
for l in cfglines:
    if string.find(l, "default ") != -1:
	defaultimg = string.strip(string.split(l,' ')[1])
	cfgfile.write("default rescue\n")
	continue
    elif string.find(l, "label ") != -1:
	# see if we've left default stanza and entered a new one
	if fndit and indefault:
	    indefault = 0
	    cfgfile.write(rescuestanza)
	    
	if defaultimg is not None:
	    curimg = string.strip(string.split(l, ' ')[1])
	    if curimg == defaultimg:
		fndit = 1
		indefault = 1

		# build up the rescue stanza based on whats in the
		# default stanza as we echo it out
		rescuestanza = "label rescue\n"

	# if we fall through then write it out
	cfgfile.write(l)
    else:
	# we're writing out the matching stanza - if we hit the append
	# line put rescue on the end of it, otherwise just echo line
	if fndit and indefault:
	    if string.find(l, "append ") != -1:
		rescuestanza = rescuestanza + string.rstrip(l)+" rescue\n"
	    else:
		rescuestanza = rescuestanza + l

	cfgfile.write(l)

cfgfile.close()

if not fndit:
    print "Could not find default stanza, did not modify isolinux.cfg"
    os.system("mv -f %s/isolinux/isolinux.cfg.backup %s/isolinux/isolinux.cfg" % (destdir,destdir))
else:
    os.system("rm -f %s/isolinux/isolinux.cfg.backup" % (destdir,))

# synthesize a new syslinux screen
#

msgfile = open("%s/isolinux/boot.msg" % (destdir,), "w+")

msgfile.write(" \n")
msgfile.write("splash.lss\n")

# make "Red Hat" RED!
idx = string.find(productname, "Red Hat")
if idx != -1:
    productstr = productname[:idx]
    productstr = productstr + "02Red Hat07"
    productstr = productstr + productname[idx+7:]
else:
    productstr = productname

msgfile.write("This is the %s Rescue CD.\n" % (productstr,))
msgfile.write("\n")
msgfile.write(" -  To enter rescue mode press the 0f<ENTER>07 key.\n")
msgfile.write("\n")
msgfile.write(" -  To install or upgrade %s type \"linux\" and then the 0f<ENTER>07 key.\n" % (productstr, ))
msgfile.write("\n")
msgfile.write(" -  Use the function keys listed below for more information.\n")
msgfile.write("\n")
msgfile.write("02[F1-Main] [F2-Options] [F3-General] [F4-Kernel] [F5-Rescue]07\n")
msgfile.close()