##
##  This file is part of shtool and 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.
##
##  This file 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
##  USA, or contact Ralf S. Engelschall <rse@engelschall.com>.
##

##
##  COMMON UTILITY CODE
##

#   commonly used ASCII values
ASC_TAB="	"
ASC_NL="
"

#   determine name of tool
if [ ".$tool" != . ]; then
    #   used inside shtool script
    toolcmd="$0 $tool"
    toolcmdhelp="shtool $tool"
    msgprefix="shtool:$tool"
else
    #   used as standalone script
    toolcmd="$0"
    toolcmdhelp="sh $0"
    msgprefix="$str_tool"
fi

#   parse argument specification string
eval `echo $arg_spec |\
      sed -e 's/^\([0-9]*\)\([+=]\)/arg_NUMS=\1; arg_MODE=\2/'`

#   parse option specification string
eval `echo h.$opt_spec |\
      sed -e 's/\([a-zA-Z0-9]\)\([.:+]\)/opt_MODE_\1=\2;/g'`

#   parse option alias string
eval `echo h:help,$opt_alias |\
      sed -e 's/-/_/g' -e 's/\([a-zA-Z0-9]\):\([^,]*\),*/opt_ALIAS_\2=\1;/g'`

#   interate over argument line
opt_PREV=''
while [ $# -gt 0 ]; do
    #   special option stops processing
    if [ ".$1" = ".--" ]; then
        shift
        break
    fi

    #   determine option and argument
    opt_ARG_OK=no
    if [ ".$opt_PREV" != . ]; then
        #   merge previous seen option with argument
        opt_OPT="$opt_PREV"
        opt_ARG="$1"
        opt_ARG_OK=yes
        opt_PREV=''
    else
        #   split argument into option and argument
        case "$1" in
            --[a-zA-Z0-9]*=*)
                eval `echo "x$1" |\
                      sed -e 's/^x--\([a-zA-Z0-9-]*\)=\(.*\)$/opt_OPT="\1";opt_ARG="\2"/'`
                opt_STR=`echo $opt_OPT | sed -e 's/-/_/g'`
                eval "opt_OPT=\${opt_ALIAS_${opt_STR}-${opt_OPT}}"
                ;;
            --[a-zA-Z0-9]*)
                opt_OPT=`echo "x$1" | cut -c4-`
                opt_STR=`echo $opt_OPT | sed -e 's/-/_/g'`
                eval "opt_OPT=\${opt_ALIAS_${opt_STR}-${opt_OPT}}"
                opt_ARG=''
                ;;
            -[a-zA-Z0-9]*)
                eval `echo "x$1" |\
                      sed -e 's/^x-\([a-zA-Z0-9]\)/opt_OPT="\1";/' \
                          -e 's/";\(.*\)$/"; opt_ARG="\1"/'`
                ;;
            -[a-zA-Z0-9])
                opt_OPT=`echo "x$1" | cut -c3-`
                opt_ARG=''
                ;;
            *)
                break
                ;;
        esac
    fi

    #   eat up option
    shift

    #   determine whether option needs an argument
    eval "opt_MODE=\$opt_MODE_${opt_OPT}"
    if [ ".$opt_ARG" = . ] && [ ".$opt_ARG_OK" != .yes ]; then
        if [ ".$opt_MODE" = ".:" ] || [ ".$opt_MODE" = ".+" ]; then
            opt_PREV="$opt_OPT"
            continue
        fi
    fi

    #   process option
    case $opt_MODE in
        '.' )
            #   boolean option
            eval "opt_${opt_OPT}=yes"
            ;;
        ':' )
            #   option with argument (multiple occurances override)
            eval "opt_${opt_OPT}=\"\$opt_ARG\""
            ;;
        '+' )
            #   option with argument (multiple occurances append)
            eval "opt_${opt_OPT}=\"\$opt_${opt_OPT}\${ASC_NL}\$opt_ARG\""
            ;;
        * )
            echo "$msgprefix:Error: unknown option: \`$opt_OPT'" 1>&2
            echo "$msgprefix:Hint:  run \`$toolcmdhelp -h' or \`man shtool' for details" 1>&2
            exit 1
            ;;
    esac
done
if [ ".$opt_PREV" != . ]; then
    echo "$msgprefix:Error: missing argument to option \`$opt_PREV'" 1>&2
    echo "$msgprefix:Hint:  run \`$toolcmdhelp -h' or \`man shtool' for details" 1>&2
    exit 1
fi

#   process help option
if [ ".$opt_h" = .yes ]; then
    echo "Usage: $toolcmdhelp $str_usage"
    exit 0
fi

#   complain about incorrect number of arguments
case $arg_MODE in
    '=' )
        if [ $# -ne $arg_NUMS ]; then
            echo "$msgprefix:Error: invalid number of arguments (exactly $arg_NUMS expected)" 1>&2
            echo "$msgprefix:Hint:  run \`$toolcmd -h' or \`man shtool' for details" 1>&2
            exit 1
        fi
        ;;
    '+' )
        if [ $# -lt $arg_NUMS ]; then
            echo "$msgprefix:Error: invalid number of arguments (at least $arg_NUMS expected)" 1>&2
            echo "$msgprefix:Hint:  run \`$toolcmd -h' or \`man shtool' for details" 1>&2
            exit 1
        fi
        ;;
esac

#   establish a temporary file on request
if [ ".$gen_tmpfile" = .yes ]; then
    #   create (explicitly) secure temporary directory
    if [ ".$TMPDIR" != . ]; then
        tmpdir="$TMPDIR"
    elif [ ".$TEMPDIR" != . ]; then
        tmpdir="$TEMPDIR"
    else
        tmpdir="/tmp"
    fi
    tmpdir="$tmpdir/.shtool.$$"
    ( umask 077
      rm -rf "$tmpdir" >/dev/null 2>&1 || true
      mkdir  "$tmpdir" >/dev/null 2>&1
      if [ $? -ne 0 ]; then
          echo "$msgprefix:Error: failed to create temporary directory \`$tmpdir'" 1>&2
          exit 1
      fi
    )

    #   create (implicitly) secure temporary file
    tmpfile="$tmpdir/shtool.tmp"
    touch "$tmpfile"
fi

#   utility function: map string to lower case
util_lower () {
    echo "$1" | tr 'ABCDEFGHIJKLMNOPQRSTUVWXYZ' 'abcdefghijklmnopqrstuvwxyz'
}

#   utility function: map string to upper case
util_upper () {
    echo "$1" | tr 'abcdefghijklmnopqrstuvwxyz' 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
}

#   cleanup procedure
shtool_exit () {
    rc="$1"
    if [ ".$gen_tmpfile" = .yes ]; then
        rm -rf "$tmpdir" >/dev/null 2>&1 || true
    fi
    exit $rc
}