#!/bin/bash
#emacs: -*- mode: shell-script; c-basic-offset: 4; tab-width: 4; indent-tabs-mode: nil -*-
#ex: set sts=4 ts=4 sw=4 et:

# play safe
set -e
set -u

############
# Defaults #
############

nd_autoinstall_version=0.1

# To be set by cmdline args
ai_envfile=
ai_package=
ai_verbose=
ai_dialog_title=
ai_force=0
ai_file=

print_verbose()
{
	[ -z "$ai_verbose" ] || echo "I: $*"
}

print_version()
{
cat << EOT
nd-autoinstall $nd_autoinstall_version

Copyright (C) 2010 Yaroslav Halchenko <debian@onerussian.com>

Licensed under GNU Public License version 3 or later.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

Written by Yaroslav Halchenko for the NeuroDebian project.

EOT
}


print_help()
{
cat << EOT

Usage:  nd-autoinstall [options] COMMAND [command_options]

Runs the COMMAND if it is available, otherwise installs PACKAGE first,
and then runs the command.  If an environment file is specified, it
gets sourced first (PACKAGE gets installed if environment file is not
available).

Options:

  -p, --package=PACKAGE
    Name of the package to be installed if named differently than
    COMMAND.

  -e, --environment-file=FILE
    File to be sourced before invocation of the COMMAND.  If not found,
    PACKAGE gets installed first.

  -f, --force
    Skip all checks and install package(s) provided via --package.

  -F, --file=FILE
    If specified file is not present, install the PACKAGE and run
    the COMMAND.

  -v, --verbose
    Enable additional progress messages.

  -t, --title
    Optinal title of the installation dialog.

  -h, --help
    Print short description, usage summary and option list.

  --version
    Print version information and exit.

Exit status:

  exit status of the COMMAND -
      if COMMAND is available (or got sucesfully installed)
  2 - incorrect invocation of nd-autoinstall
  3 - PACKAGE installation failure
EOT
}

################################
# Commandline options handling #
################################

# Parse commandline options (taken from the getopt examples from the Debian util-linux package)
# Note that we use `"$@"' to let each command-line parameter expand to a
# separate word. The quotes around `$@' are essential!
# We need CLOPTS as the `eval set --' would nuke the return value of getopt.
CLOPTS=`getopt -o h,e:,p:,t:,f,F:,v --long help,version,environment-file:,package:,title:,verbose,force,file: -n 'nd-autoinstall' -- "$@"`

if [ $? != 0 ] ; then
  echo "Terminating..." >&2
  exit 2
fi

# Note the quotes around `$CLOPTS': they are essential!
eval set -- "$CLOPTS"

while true ; do
  case "$1" in
	  -e|--environment-file) shift; ai_envfile="$1"; shift;;
	  -f|--force) ai_force=1; shift;;
	  -F|--file) shift; ai_file="$1"; shift;;
	  -p|--package) shift; ai_package="$1"; shift;;
	  -t|--title) shift; ai_dialog_title="$1"; shift;;
	  -v|--verbose) ai_verbose=1; shift;;
	  -h|--help) print_help; exit 0;;
	  --version) print_version; exit 0;;
	  --) shift ; break ;;
	  *) echo "Internal error! ($1)"; exit 1;;
  esac
done


if [ $# -lt 1 ] ; then
    print_help >&2
    exit 2
fi

ai_command="$1"; shift
[ -z "$ai_package" ] && ai_package=$(basename "$ai_command")

[ -z "$ai_dialog_title" ] && ai_dialog_title="Package installation"

ai_envfile_failed=
if [ ! -z "$ai_envfile" ]; then
	source "$ai_envfile" || ai_envfile_failed=1
fi

#
# Decide either installation is necessary
#
do_install=0
if [ ! -z "$ai_envfile_failed" ]; then
    print_verbose "Environment file $ai_envfile failed to source. Install $ai_package"
	do_install=1
fi
if [ ! -z "$ai_file" ] && [ ! -e "$ai_file" ]; then
    print_verbose "File $ai_file absent. Install $ai_package"
    do_install=1
fi
if ! which "$ai_command" > /dev/null && [ ! -e "$ai_command" ]; then
    print_verbose "Command $ai_command is not available. Install $ai_package"
	do_install=1
fi
if [ $ai_force -eq 1 ]; then
    print_verbose "Force installation of $ai_package"
	do_install=1
fi

if [ $do_install -eq 1 ]; then
    # Figure out amount of space to download/occupy
    space_info="$(LC_ALL=C apt-get --trivial-only --print-uris install $ai_package 2>/dev/null \
        | grep -e '^\(Need to get \|After this\)' || : )"
    if [ $ai_force -eq 0 ]; then
		if ! zenity --question \
			--text="To run '$ai_command', $ai_package package needs to be installed.

$space_info

Do you want to proceed?"; then
			exit 2
		fi
	fi

    print_verbose "Need to install $ai_package to run $ai_command"

    logfile=$(mktemp -u /tmp/nd-autoinstall-XXXXXX.log)

    { SUDO_ASKPASS="/usr/bin/ssh-askpass" /usr/bin/sudo -A \
		DEBIAN_FRONTEND=gnome /usr/bin/apt-get install -y $ai_package 2>&1 \
        && rm -f $logfile; } \
        | tee $logfile \
        | zenity --title="$ai_dialog_title" \
		         --text="Installing $ai_package
$space_info" \
                 --progress --pulsate --auto-close --auto-kill
    if [ -e $logfile ] ; then
        zenity --title="Installation of $ai_package has failed: see $logfile" \
            --window-icon=error \
            --width=800 --height=600 \
            --text-info --filename=$logfile
        exit 3
    fi
	[ -z "$ai_envfile_failed" ] || source "$ai_envfile" || {
		zenity --text="Failed to source $ai_envfile even after installing $ai_package" \
			--window-icon=error --error
		exit 1
	}
fi

if which $ai_command > /dev/null 2>&1; then
	# only run if executable
	print_verbose "Running $ai_command"
	$ai_command "$@"
fi