#!/bin/sh
#
# vuescan
#
# Wrapper script for the vuescan scan software from http://www.hamrick.com/
# This fixes some shortcomings vuescan doesn't or hasn't yet addressed.
#
# INSTALL:
# - Put this script into your $PATH.
# - Create an empty directory, e.g. /usr/local/pckg/vuescan,
#   and unpack the vuescan tar file into it.
#   Edit variable installdir below to the location of this directory.
# - Create another empty directory, e.g. /usr/local/pckg/vuescan-bin,
#   and in it create a symbolic link (ln -s)
#   called netscape, pointing to this "vuescan" wrapper script.
#   Edit variable browserbindir below to the location of this directory.
#   Don't put any other binaries in here.
# - Edit variable browser below to the browser you wish to use.
#
# Copyright (C) by Volker Kuhlmann <VolkerKuhlmann@gmx.de>
# Released under the terms of the GNU General Public License (GPL) Version 2.
# See http://www.gnu.org/ for details.
#
# Volker Kuhlmann
#   5, 8 Jan; 24 Dec 2003
#   7 Jan; 20 Oct 2004
#   12 Sep; 9 Nov 2005
#   28 May 3006
#


VERSION="2.4, 28 May 2006"
AUTHOR="Volker Kuhlmann <VolkerKuhlmann@gmx.de>"
COPYRIGHT="Copyright (C) 2003 - 2006"


####
#### Constants and initialised variables
#

# The directory where the vuescan tar file has been unpacked into.
# That's the tar file from:  http://www.hamrick.com/files/vuesca83.tgz
installdir="/usr/local/pckg/vuescan"

# The browser you want to use with the vuescan help
browser="konqueror"

# Directory which must contain a binary called "netscape", which will be called
# by vuescan. Make this a symlink to this wrapper script, i.e. make a symlink
# in this directory called netscape which points to this wrapper script.
browserbindir="/usr/local/pckg/vuescan-bin"

# Directory which contains the user's vuescan.ini
inidir="$HOME/.vuescan"

# Name of vuescan's ini file (this must match what's compiled into vuescan!)
inifile="vuescan.ini"


####
#### Version, Usage, Help
#
# Call only these from application: Version, Usage, Help
#
show_version() {
    echo "`basename $0` wrapper version $VERSION
$COPYRIGHT by $AUTHOR"
}
Version() { show_version; exitwith ErrVersion; }
Help() { show_help; exitwith ErrHelp; }

show_help() {
    echo "
Usage: `basename $0` [OPTIONS]
Wrapper version $VERSION
$COPYRIGHT by $AUTHOR

Wrapper script for the vuescan scan software from http://www.hamrick.com/
This fixes some shortcomings VueScan doesn't address, namely:
1) User's preferences are splattered all over the filesystem instead of being
   kept in the same place, like all other well-behaved *ix-applications do it.
   Since version 8.3, vuescan puts its vuescan.ini into \$HOME - arrrgh,
   using \$HOME/.vuescan/ would have been fine.
   Since version 8.3.40, it uses \$HOME/.vuescan/.
2) The help files are only read with a browser 'netscape' which has been history
   for a few years now. Now it's browser 'mozilla', 'firefox', 'konqueror' or a
   number of others, and vuescan still doesn't allow you to specify which
   browser you want to use.
3) Vuescan doesn't find its auxiliary files unless they're in the same
   directory; using a wrapper fixes this as a side-effect.
   (Fixed at some point.)

OPTIONS (for the wrapper script, not vuescan itself!):
  -h|--help           Show help. Note: vuescan itself doesn't have any --help.
  --version           Show version
  --browser PROGRAM   Use browser PROGRAM instead (e.g. mozilla)
"
}


####
#### Error/Exit codes
#
CALL_WITH_HELP_TEXT="Call with --help for help."
exitwith() {
    exec 1>&2  # write stdout on stderr instead
  case "$1" in
    ErrVersion|ErrUsage|ErrHelp)
	# usage already displayed
	exit 1;;
  esac
}


####
#### Parse command line parameters
#


####
#### Functions
#

# Obtain the vuescan version, and where it keeps its ini file
# As this software doesn't have a --version, we have to pull a trick.
get_vuescan_version() {
    vuescan_version="`strings "$installdir/vuescan" | grep -i 'vuescan .* linux'`"
    vuescan_version="${vuescan_version#* }"
    vuescan_version="${vuescan_version% *}"
    
    vuescan_inidir="$HOME/.vuescan" # default to the latest version
    case "$vuescan_version" in
    	7.*|8.[012].*)	vuescan_inidir=".";;
	8.3.[0-3]*)  	vuescan_inidir="$HOME";;
    esac
}

# Create user's ini dir if necessary
create_ini_dir() {
    if [ ! -d "$inidir" ]; then
	echo 1>&2 "Creating user's .ini-file directory: '$inidir'"
	mkdir -p "$inidir"
	if [ $? -ne 0 ]; then
    	    echo 1>&2 "There was an error creating '$inidir'!"
	    false
	fi
    fi
}

# Copy the user's vuescan.ini into the directory from which the wrapper was
# started.
# (vuescan can only handle its .ini file in the current directory.)
restore_ini() {
    inifilehome="$inidir/$inifile"
    
    # Do nothing if vuescan's vuescan.ini-directory is $inidir.
    test "$vuescan_inidir" = "$inidir" && return
    
    # Create user's ini dir if necessary
    create_ini_dir
    
    # Copy .ini file into its active directory
    if [ -e "$inifilehome" ]; then
    	cp -p "$inifilehome" "$vuescan_inidir"
	if [ $? -ne 0 ]; then
    	    echo 1>&2 "Couldn't restore '$inifilehome' to '$vuescan_inidir'!!"
	fi
	# vuescan needs to write this file
	chmod 2>/dev/null u+w "$vuescan_inidir/$inifile"
    else
    	echo 1>&2 "Can't access '$inifilehome'!"
	echo 1>&2 "\
If vuescan runs for the first time, it will create an .ini file automatically."
	false
    fi
}

# Save the .ini file for the next time
backup_ini() {
    # Do nothing if vuescan's vuescan.ini-directory is $inidir.
    test "$vuescan_inidir" = "$inidir" && return
    
    # Create user's ini dir if necessary
    create_ini_dir
    
    # Copy .ini file from its active location into user's directory
    if [ -d "$inidir" ]; then
    	if [ -f "$vuescan_inidir/$inifile" ]; then
	    cp -p "$vuescan_inidir/$inifile" "$inidir"
	    rm "$vuescan_inidir/$inifile"
	else
    	    echo 1>&2 "There's no '$vuescan_inidir/$inifile'!!"
	fi
    else
	echo 1>&2 "Can't backup '$vuescan_inidir/$inifile'!"
    fi
}

# Start the configured browser. This function never returns.
run_browser() {
    exec "$browser" "$@"
    exit $?
}


####
#### Main
#

case "`basename "$0"`" in
    mozilla|netscape)	run_browser "$@";;
esac

debug=
while [ $# -gt 0 ]; do
    case "$1" in
	-h|-help|--help)	Help;;
	--version)	    	Version;;
	--browser)	    	browser="$2"; shift 2;;
	--install)	    	installdir="$2"; shift 2;;

	__browser)	    	shift; run_browser "$@";;   # test only
	--debug)    	    	shift; debug="--debug"; set -x;;
    esac
done

if [ ! -d "$installdir" ]; then
    echo 1>&2 "
Vuescan directory $installdir
  doesn't exist.
"
    exit 9
fi

backgroundflag__="5e8ba6e8d338bedf77a5c1fb52a1dbc3"
if [ "$backgroundflag" != "$backgroundflag__" ]; then

    # Re-run ourselves in the background, returning the shell prompt
    export backgroundflag="$backgroundflag__"
    $0 $debug --browser "$browser" --install "$installdir" "$@" &
    sleep 1

else

    installdir="`cd "$installdir"; pwd`"

    get_vuescan_version
    restore_ini
    PATH="$browserbindir:$PATH"
    export PATH
    "$installdir"/vuescan "$@"
    ret=$?
    backup_ini
    exit $ret

fi