#!/bin/sh
#----------------------------------------------------------------------------
# /var/install/bin/remove-user-from-additional-group - remove user from additional group
#
# Creation:     2003-07-20  fm
# Last Update:  $Id$
#
# Copyright (c) 2001-@@YEAR@@ the eisfair team, team(at)eisfair(dot)org
#
# 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 2 of the License, or
# (at your option) any later version.
#----------------------------------------------------------------------------

# include eislib
. /var/install/include/eislib

#debug=true

if ${debug:-false}
then
    exec 2>/tmp/$(basename ${0})-trace$$.log
    set -x
    ask_debug=true
    export ask_debug
fi

ASK=/var/install/bin/ask
MKTEMP=/usr/bin/mktemp
RM=/usr/bin/rm
GREP=/usr/bin/grep
USERMOD=/usr/sbin/usermod

#----------------------------------------------------------------------------
# usage
#----------------------------------------------------------------------------
usage()
{
cat  <<EOF

 Usage:
 ${0}

        -u, --user            user to remove
        -g, --group           group to user remove from

                              or empty for interactive mode

 Example: ${0} --user mustermann --group users
 Example: ${0} -u mustermann -g users
 Example: ${0}

EOF
}

#----------------------------------------------------------------------------
# do exit
#----------------------------------------------------------------------------
do_exit()
{
    if "${interactive:-false}"
    then
        mecho
        anykey
    fi
    exit $1
}

#----------------------------------------------------------------------------
# myecho, do output to tty
#----------------------------------------------------------------------------
myecho()
{
    if ${interactive:-false}
    then
        mecho ${1} "${2}"
    else
        mecho "${2}" >&2
    fi
}

#----------------------------------------------------------------------------
# remove user from group
#----------------------------------------------------------------------------
remove_user_from_group()
{
    user=${1}
    rg=${2}

    #------------------------------------------------------------------------
    # get user name
    #------------------------------------------------------------------------
    if "${interactive}"
    then
        clrhome
        mecho --info "Remove user from additional group"
        mecho
        mecho

        _ask_tmpfile=$(${MKTEMP} -t XXXXXXXXXXXXX)
        ${ASK} "User:" '' '*' > ${_ask_tmpfile}
        rc=${?}
        read user < ${_ask_tmpfile}
        ${RM} -f ${_ask_tmpfile}
        if [ ${rc} = 255 ]
        then
            exit 1
        fi
    fi

    if [ -z "${user}" ]
    then
        mecho
        myecho --warn "Command aborted"
        do_exit 1
    fi

    mecho
    line=$(${GREP} "^${user}:" /etc/passwd)

    if [ -z "${line}" ]
    then
        mecho
        myecho --warn "User ${user} does not exist!"
        do_exit 1
    fi

    groups=''
    myecho "  Additional groups of user ${user}:"
    myecho
    oldifs="${IFS}"
    IFS=':'
    while read line
    do
       set -- ${line}
       g="${1}"
       u="${4}"

       IFS=','
       set -- ${u}
       for j in ${*}
       do
           if [ ${j} = ${user} ]
           then
               myecho --std "    ${g}"

               if [ -z "${groups}" ]
               then
                   groups="${g}"
               else
                   groups="${groups} "${g}
               fi
               break
           fi
       done

       IFS=':'
    done </etc/group
    IFS="${oldifs}"

    if [ -z "${groups}" ]
    then
        mecho
        myecho --warn "No additional group for ${user} found!"
        do_exit 1
    fi

    #------------------------------------------------------------------------
    # get group name
    #------------------------------------------------------------------------
    if "${interactive}"
    then
        mecho
        _ask_tmpfile=$(${MKTEMP} -t XXXXXXXXXXXXX)
        ${ASK} "Remove user ${user} from group:" '' '*' >${_ask_tmpfile}
        rc=${?}
        read rg <${_ask_tmpfile}
        ${RM} -f ${_ask_tmpfile}
        if [ ${rc} = 255 ]
        then
            exit 1
        fi
    fi
    mecho

    if [ -z "${rg}" ]
    then
        mecho
        myecho --warn "Command aborted"
        do_exit 1
    fi

    group_found=false

    for j in ${groups}
    do
        if [ ${rg} = ${j} ]
        then
            group_found=true
            break
        fi
    done

    if ! ${group_found:-false}
    then
        mecho
        myecho --warn "additional group ${rg} for user ${user} not found!"
        do_exit 1
    fi

    g=''

    for j in ${groups}
    do
        if [ ${j} != ${rg} ]
        then
             if [ -z "${g}" ]
             then
                 g=${j}
             else
                 g="${g},${j}"
             fi
        fi
    done

    ${USERMOD} -G "${g}" ${user}
}

#----------------------------------------------------------------------------
# main
#----------------------------------------------------------------------------
main()
{
    user=''
    group=''
    interactive=false


    if [ ${#} -eq 0 ]
    then
        interactive=true
        remove_user_from_group
        exit 0
    fi

    if [ ${#} -lt 4 ]
    then
        usage
        exit 1
    fi

    while [ ${#} -ne 0 ]
    do
        case ${1} in
        -u|--user)
            user="${2}"
            shift; shift
            ;;
        -g|--group)
            group="${2}"
            shift; shift
            ;;
        *)
            usage
            exit 1
            ;;
        esac
    done

    remove_user_from_group ${user} ${group}

    exit 0
}

#----------------------------------------------------------------------------
# call function main
#----------------------------------------------------------------------------
main "${@}"

#----------------------------------------------------------------------------
# end
#----------------------------------------------------------------------------