#!/bin/bash

# Company:  PowerCraft Technology
# Author:   Copyright Jelle de Jong <jelledejong@powercraft.nl>
# Note:     Please send me an email if you enhanced the script
# Date:     2008-11-22 / 2008-12-07 / ... / 2009-02-15 / 2009-06-13

# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# This program 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
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
# MA 02110-1301, USA.

TEXTDOMAINDIR=/usr/share/locale
TEXTDOMAIN=pct-support-login

SYSCONF="/etc/pct-support-scripts.conf"
SYSDIR="/etc/pct-support-scripts.conf.d/"
SECURITY="-o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -o NumberOfPasswordPrompts=13"

version="0.1.6"
author="Jelle de Jong <jelledejong@powercraft.nl>"
donation="http://www.tuxcrafter.net/pages/contact.html#paypal-donation"
homepage="https://secure.powercraft.nl/svn/packages/trunk/source/pct-support-scripts/"
licence="http://www.gnu.org/licenses/gpl-3.0.html"

unset USERNAME
unset SERVER
unset PORT
unset SCAN
unset CONFIG

function version()
{
    echo $"Usage:    $0 --help"
    echo $"Version:  $version"
    echo $"Author:   $author"
    echo $"Donation: $donation"
    echo $"Homepage: $homepage"
    echo $"Licence:  $licence"
}

function usage()
{
    echo "Program to establish a remote support session"
    echo
    echo "Usage:    $0 [options]"
    echo
    echo "Options:"
    echo "  -u, --user ...   user"
    echo "  -s, --server ... server"
    echo "  -p, --port ...   server port to connect to"
    echo "  -n, --scan ...   scanning for support screen session (yes, no)"
    echo "  -c, --config ... name of id-string used in configuration file"
    echo "  -h, --help, -?   show this help information"
    echo "  -v, --version    show the version and author information"
    echo
    echo "Example:"
    echo "  pct-support-login"
    echo "  pct-support-login --user support01 --server powercraft.nl"
    echo "  pct-support-login --scan yes"
    echo "  pct-support-login -u support01 -s powercraft.nl -n"
    echo "  pct-support-login --config config2"
    echo
    echo "Configuration:"
    echo "  $SYSCONF"
    echo "  $SYSDIR"
    echo
    echo "  In the configuration files the default user, server and port"
    echo "  can be set. Pleae look inside the files to get a better idea"
    echo "  of how to configure them. The --config option can be used to"
    echo "  select additional configurations. For example using"
    echo "  --config config2 will use the section [config2]."
    echo
    echo "  It is always possible to use the command options, or the"
    echo "  configuration system to make profiles for the servers you"
    echo "  want to contact for remote support, it is a generic system"
    echo "  by design."
    echo
    echo "  This program can be used to request a remote support ticket"
    echo "  at PowerCraft Technology. You can find contact data on our"
    echo "  main website. We give support from everywere to everywere."
    echo
    echo "Website:"
    echo "  https://secure.powercraft.nl/svn/packages/"
    echo "Mailinglist:"
    echo "  http://www.powercraft.nl/cgi-bin/mailman/listinfo/packages-commit"
    echo "  http://www.powercraft.nl/cgi-bin/mailman/listinfo/packages-devel"
}

while [[ "$1" == -* ]]; do
    case "$1" in
        -h|--help|-\?) usage; exit 0;;
        -u|--user) USERNAME="$2"; shift; shift;;
        -s|--server) SERVER="$2"; shift; shift;;
        -p|--port) PORT="$2"; shift; shift;;
        -n|--scan) SCAN="$2"; shift; shift;;
        -c|--config) CONFIG="$2"; shift; shift;;
        -v|--version) version; exit 0;;
        --) shift; break;;
        -*) echo 1>&2 $"invalid option: $1"; usage; exit 1;;
    esac
done

function scan_configuration()
{
    file="$1"
    unset options

    [ ! -z "$USERNAME" ] && options+=("USERNAME")
    [ ! -z "$SERVER" ] && options+=("SERVER")
    [ ! -z "$PORT" ] && options+=("PORT")
    [ ! -z "$SCAN" ] && options+=("SCAN")

    for value in "${options[@]}"
    do
        sed -n -i -e "/$value/!p" "$file"
    done
}

function get_configuration()
{
    section="$1"

    if [ ! -z "$section" ] && [ ! -z "$CONFIG" ]; then
        section+="-$CONFIG"
    elif [ -z "$section" ] && [ ! -z "$CONFIG" ]; then
        section="$CONFIG"
    fi

    [ ! -d "$SYSDIR" ] && mkdir --parents --verbose "$SYSDIR"
    tempfile=$(mktemp -p "/tmp/" tempfile.XXXXXXXXXX)
    trap "rm -f $tempfile" 0 1 2 3 15
    #~ trap "rm -f $tempfile" EXIT SIGHUP SIGINT SIGQUIT SIGTERM

    [ -z "$tempfile" ] && exit 1

    files="$SYSCONF"
    files+=$'\n'
    files+=$(run-parts --list "$SYSDIR" )

    if [ -n "$files" ]; then
        while read file; do
            set +e
            [ ! -r "$file" ] && continue
            sed -n '/^\['"$section"'\]$/,/^\[.*\]$/{//!p}' "$file" > "$tempfile"
            scan_configuration "$tempfile"
            . "$tempfile"
            set -e
        done < <(echo "$files")
    fi
}

if [ ! -z $CONFIG ]; then
    get_configuration
else
    get_configuration pct-support-login
fi

if [ -z "$USERNAME" ]; then
    echo 1>&2 $"user not set, try adding --user support01, closing now"
    exit 1
fi
if [ -z "$SERVER" ]; then
    echo 1>&2 $"server not set, try adding --server powercraft.nl, closing now"
    exit 1
fi
if [ -z "$PORT" ]; then
    echo 1>&2 $"port not set, try adding --port 9999, closing now"
    exit 1
fi

if [ -z $(which screen) ] || [ -z $(which ssh) ] || [ -z $(whereis -b sshd | cut -d : -f 2) ]
then
    echo 1>&2 $"please install the openssh-client openssh-server screen packages"
    exit 1
fi

if [ -z "$(pidof sshd)" ]; then
    echo $"trying to start the openssh-server..."
    sudo invoke-rc.d ssh start
fi

echo $"trying to initialize ssh tunnel to make remote support possible:"
echo $"- enter the provided password from your administrator"
echo $"- the password will not show up when you type the characters"
echo $"- just type the password and press the [enter] key"
ssh $SECURITY -q -f -N -R $PORT:127.0.0.1:22 $USERNAME@$SERVER

if [ "$?" -ne 0 ]; then
    echo 1>&2 $"connection failed, please try again and contact your administrator"
    exit 1
else
    echo $"connection successful, please wait for your administrator to login"
fi

unset active
maximum=600
count=0
while [ -z "$active" ] && [ "$count" -lt "$maximum" ] && [ "$SCAN" != "0" ] && [ "$SCAN" != "no" ]
do
    count=$(($count+1))
    if [ -z "$(ps aux | grep support | grep SCREEN | grep --invert-match $SERVER)" ]; then
        sleep 1 &&  echo -ne $"...scanning for support session, please standby... $count/$maximum \r"
    else
        active="yes"
    fi
done

if [ "$active" == "yes" ]; then
    echo $"trying to enter the screen session..."
    screen -x support
    echo $"support session ended, closing now..."
fi

echo $"this window will close after 30 seconds, please standby..."
sleep 30s

echo $"bye"
exit 0