#!/bin/sh

# dexconf: Debian X server configuration file writer for failsafe mode
#
# This tool is a backend which uses debconf database values.  It writes an
# XFree86 X server configuration file based on the information in the database.
#
# This script is derived from the dexconf program, written by
# Branden Robinson

# Copyright 2007--2008 Canonical, Ltd.
# Copyright 2000--2004 Progeny Linux Systems, Inc.
#
# This is free software; you may redistribute it and/or modify
# it under the terms of the GNU General Public License as
# published by the Free Software Foundation; either version 2,
# or (at your option) any later version.
#
# This 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.
#
# You should have received a copy of the GNU General Public License with
# the Debian operating system, in /usr/share/common-licenses/GPL;  if
# not, write to the Free Software Foundation, Inc., 59 Temple Place,
# Suite 330, Boston, MA 02111-1307 USA

set -e

# source debconf library
. /usr/share/debconf/confmodule

# display a usage message
usage () {
  cat <<EOF
Usage: $PROGNAME [OPTION ...]
  write an Xorg X server configuration file based on debconf database values
Options:
  -h, --help                                 display this usage message and exit
  -o FILE, --output=FILE                        write configuration file to FILE
This help message is intended only as a quick reference.  For a description of
the usage of $PROGNAME, see the $PROGNAME(1) manual page.
EOF
}

# the error-out function
bomb () {
  echo "$PROGNAME: error: $*" | fold -s -w "${COLUMNS:-80}" >&2
  exit 1
}

# wrapper around db_get to ensure that the info we try to retrieve exists; it
# is (almost) always a fatal error for the values to be null
fetch () {
  db_get "$1" || true
  if [ -z "$RET" ]; then
    ERRMSG="cannot generate configuration file; $1 not set.  Aborting."
    ERRMSG="$ERRMSG  Reconfigure the X server with \"dpkg-reconfigure"
    ERRMSG="$ERRMSG xserver-xorg\" to correct this problem."
    bomb "$ERRMSG"
  fi
}

# convert a debconf comma-delimited list to a shell whitespace-delimited list
list_convert () {
  echo $(IFS=", "; set -- $RET; while [ $# -gt 0 ]; do echo \"$1\"; shift; done)
}

SERVER="xorg"
XF86CONFIG=/etc/X11/xorg.conf.failsafe
PROGNAME=${0##*/}
SHOWHELP=
EARLYEXIT=

GETOPT_OUTPUT=$(getopt --options ho: \
                       --longoptions help,output: \
                       -n "$PROGNAME" -- "$@")

if [ $? -ne 0 ]; then
    bomb "error while getting options; use \"$PROGNAME --help\" for help"
fi

eval set -- "$GETOPT_OUTPUT"

while :; do
    case "$1" in
        -f|--format)
          bomb "This option, and XFree86 3.x output, are no longer supported."
          ;;
        -h|--help) SHOWHELP=yes EARLYEXIT=yes ;;
        -o|--output) XF86CONFIG="$2"; shift ;;
        --) shift; break ;;
        *)
          bomb "unrecognized option \"$1\"; use \"$PROGNAME --help\" for help"
          ;;
    esac
    shift
done

if [ -n "$SHOWHELP" ]; then
    usage
fi

if [ -n "$EARLYEXIT" ]; then
    exit 0
fi

DEXCONFTMPDIR=

trap 'if [ -e "$DEXCONFTMPDIR/backup" ] && [ -n "$XF86CONFIG" ]; then \
        cat "$DEXCONFTMPDIR/backup" >"$XF86CONFIG"; \
      fi; \
      exec 4<&-; \
      rm -rf "$DEXCONFTMPDIR"; \
      bomb "received signal; aborting"' HUP INT QUIT TERM


# Set up a temporary directory for the files we'll be writing.
TDIR_PARENT="${TMPDIR:-/tmp}"
TDIR="${TMPDIR:-/tmp}/dexconf-tmp-$$"

if [ ! -d "$TDIR_PARENT" ]; then
  bomb "cannot create temporary work directory; \"$TDIR_PARENT\" does not" \
    "exist or is not a directory"
fi

if [ ! -w "$TDIR_PARENT" ]; then
  bomb "cannot create temporary work directory in \"$TDIR_PARENT\"; directory" \
    "not writable"
fi

rm -rf "$TDIR"

if mkdir -m 0700 "$TDIR"; then
  DEXCONFTMPDIR="$TDIR"
else
  bomb "creation of temporary work directory \"$TDIR\" failed"
fi

# xorg.conf sections:
#   Files          File pathnames
#   ServerFlags    Server flags                      NOT USED BY DEXCONF
#   Module         Dynamic module loading            NOT USED BY DEXCONF
#   InputDevice    Input device description
#   Device         Graphics device description
#   VideoAdaptor   Xv video adaptor description      NOT USED BY DEXCONF
#   Monitor        Monitor description
#   Modes          Video modes descriptions          NOT USED BY DEXCONF
#   Screen         Screen configuration
#   ServerLayout   Overall layout                    NOT USED BY DEXCONF
#   DRI            DRI-specific configuration        NOT USED BY DEXCONF
#   Vendor         Vendor-specific configuration     NOT USED BY DEXCONF

### HEADER

# Because debconf hijacks standard output and its confmodule uses file
# descriptor 3 for its own purposes, we will write our output to file descriptor
# 4 instead of standard output.

exec 4>"$DEXCONFTMPDIR/Header"
cat >&4 <<SECTION
# xorg.conf.failsafe (X.Org X Window System server configuration file)
#
# This file was generated by dexconf, the Debian X Configuration tool, using
# values from the debconf database.
#
# Edit this file with caution, and see the xorg.conf manual page.
# (Type "man xorg.conf" at the shell prompt.)
#
# This file is automatically updated on xserver-xorg package upgrades *only*
# if it has not been modified since the last upgrade of the xserver-xorg
# package.
#
# If you have edited this file but would like it to be automatically updated
# again, run the following command:
#   sudo dpkg-reconfigure -phigh xserver-xorg
SECTION

### DEVICE

db_get xserver-$SERVER/config/device/driver
DEVICE_DRIVER="$RET"
db_get xserver-$SERVER/config/device/bus_id
DEVICE_BUSID="$RET"
db_get xserver-$SERVER/config/device/use_fbdev
DEVICE_USE_FBDEV="$RET"

# Override device driver
DEVICE_DRIVER=${1:-"vesa"}

QEMU_KVM=$(grep "QEMU Virtual CPU" /proc/cpuinfo || true)
if [ -n "$QEMU_KVM" ]; then
    DEVICE_DRIVER="cirrus"
fi

# Added by Ryan Hamilton to fix failsafe mode vbox issues
VBOX_VIDEO=$(grep "vbox" /proc/modules || true)
if [ -n "$VBOX_VIDEO" ]; then
	DEVICE_DRIVER="vboxvideo"
fi


exec 4>"$DEXCONFTMPDIR/Device"
cat >&4 <<SECTION
Section "Device"
	Identifier	"Configured Video Device"
SECTION
if [ -n "$DEVICE_DRIVER" ]; then
  printf "\tDriver\t\t\"$DEVICE_DRIVER\"\n" >&4
fi
PS3_FB=$(grep -i PS3 /proc/fb 2>/dev/null || true)
if [ -n "$PS3_FB" ]; then
  printf "\tOption\t\t\"ShadowFB\"\t\t\"false\"\n" >&4
fi
if [ -n "$DEVICE_BUSID" ]; then
  printf "\tBusID\t\t\"$DEVICE_BUSID\"\n" >&4
fi
if [ "$DEVICE_USE_FBDEV" = "true" ]; then
  printf "\tOption\t\t\"UseFBDev\"\t\t\"$DEVICE_USE_FBDEV\"\n" >&4
fi
printf "EndSection\n" >&4

### MONITOR

exec 4>"$DEXCONFTMPDIR/Monitor"
cat >&4 <<SECTION
Section "Monitor"
	Identifier	"Configured Monitor"
SECTION

if [ -n "$QEMU_KVM" ]; then
  printf "\tHorizSync\t30-70\n" >&4
  printf "\tVertRefresh\t50-160\n" >&4
fi
cat >&4 <<SECTION
EndSection
SECTION

### SCREEN

exec 4>"$DEXCONFTMPDIR/Screen"
cat >&4 <<SECTION
Section "Screen"
	Identifier	"Default Screen"
	Monitor		"Configured Monitor"
	Device		"Configured Video Device"
SECTION
if [ -n "$PS3_FB" ]; then
  printf "\tDefaultFbBpp 32\n" >&4
fi
#if [ -n "$QEMU_KVM" ]; then
cat >&4 <<SUBSECTION
	DefaultDepth	24
	SubSection "Display"
		Depth	24
		Modes	"1280x1024" "1280x800" "1152x768" "1024x768" "800x600" "640x480"
	EndSubSection
SUBSECTION
#fi
printf "EndSection\n" >&4

# Close file descriptor 4 before we delete temporary files
exec 4<&-

# Tell debconf to stop listening to us.
db_stop

# Write the configuration file.  Put a blank line before every section we write
# except the first.

OUTFILE="$DEXCONFTMPDIR/dexconf-out"
umask 022
: >"$OUTFILE"

SPACER=
for SECTION in Header Files InputDeviceKeyboard InputDeviceMouse \
               Device Monitor Screen; do
  if [ -e "$DEXCONFTMPDIR/$SECTION" ]; then
    eval $SPACER
    cat "$DEXCONFTMPDIR/$SECTION" >>"$OUTFILE"
    SPACER='echo "" >>"$OUTFILE"'
  fi
done

# Ensure we can write to our destination if it already exits.
if [ -e "$XF86CONFIG" ]; then
  if [ ! -w "$XF86CONFIG" ]; then
    bomb "unable to write to \"$XF86CONFIG\""
  fi
fi

BACKUP=
# Create a backup of the existing configuration file if it already exists.
if [ -e "$XF86CONFIG" ]; then
  cat "$XF86CONFIG" >"$DEXCONFTMPDIR/backup"
  BACKUP=true
fi

# Move the new file into place.
if ! cat "$OUTFILE" >"$XF86CONFIG"; then
  # Failed; try to restore the backup.
  if [ -n "$BACKUP" ]; then
    cat "$DEXCONFTMPDIR/backup" >"$XF86CONFIG"
  fi
fi

rm -rf "$DEXCONFTMPDIR"

exit 0

# vim:set ai et sts=2 sw=2 tw=80: