#!/bin/sh
#
# Create minimal xorg.conf extracted from Xorg.<DISPLAY>.log
#
# -c <configfile> (use to specify configfile to create)
# -e (edit file with $EDITOR after creation)
# -f (overwrite existing <configfile>)
# -l <logfile> (use to specify X logfile to read)
#

if [ $UID -ne 0 ]; then
  echo "You must be root"
  exit 1
fi

configfile=/etc/X11/xorg.conf
editor=false
overwrite=false
logfile=/var/log/Xorg.0.log

while getopts ":c:efl:" opt; do
    case $opt in
	c ) configfile=${OPTARG}
	    ;;
	e ) editor=true
	    ;;
	f ) overwrite=true
	    ;;
	l ) logfile=${OPTARG}
	    ;;
	* ) echo 'usage: minimal-xconfig [-c <configfile>] [-e] [-f] [-l <logfile>]'
	    exit 1
	    ;;
   esac
done

if [ ! -f $logfile ]; then
    echo "$logfile does not exist."
    echo "Use \"-l <logfile>\" to specify a different logfile."
    exit 1
fi

if ! grep -q -- "(==) --- Start of built-in configuration ---" $logfile; then
    echo "$logfile does not contain the required xorg.conf section."
    echo "Probably it uses a regular xorg.conf."
    echo "Use \"-l <logfile>\" to specify a different logfile."
    exit 1
fi

if [ -f $configfile -a "$overwrite" == "false" ]; then
    echo "$configfile already exists."
    echo "Use \"-f\" to overwrite or \"-c <configfile>\" to specify a different configfile."
    exit 1
fi

begin=false

cat $logfile | \
while read line; do
    if [ "$begin" == "true" ]; then
	if echo $line | grep -q -- "(==) --- End of built-in configuration ---"; then
	    break
	else
	    if ! echo $line | grep -q ^Section; then
		if ! echo $line | grep -q ^EndSection; then
		    echo -n "  "
		fi
	    fi
	    echo $line
	    test "$line" == "EndSection" && echo
	fi
    elif echo $line | grep -q -- "(==) --- Start of built-in configuration ---"; then
	begin=true
    fi
done > $configfile

if [ "$editor" == "true" ]; then
    $EDITOR $configfile
else
    echo "created $configfile"
fi

exit 0