#!/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
#   15 May 2011
#
chr0(){ echo @;};chr1(){ echo .;}


VERSION="2.5, 15 May 2011"
AUTHOR="Volker Kuhlmann <VolkerKuhlmann`chr0`gmx`chr1`de>"
COPYRIGHT="Copyright (C) 2003 - 2011"


####
#### 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
# (from http://www.hamrick.com/vsm.html)
installdir="/usr/local/pckg/vuescan"
if [ -d "$installdir/vuescan" ]; then
    installdir="$installdir/vuescan"
fi

# 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.
# NOTE: No longer used with current version of vuescan!
browserbindir="/usr/local/pckg/vuescan-bin"
if [ ! -d "$browserbindir" ]; then
    browserbindir="/usr/local/pckg/vuescan/vuescan-bin"
fi

# 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.
   (Fixed at some point.)
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";;
	*)
	    no_browser_override=1; 
	    # Not sure exactly from which version this should be set.
    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
    if [ -z "$no_browser_override" ]; then
	PATH="$browserbindir:$PATH"
	export PATH
    fi
    "$installdir"/vuescan "$@"
    ret=$?
    backup_ini
    exit $ret

fi