buildopts

#!/bin/bash
#
# A script to query and manipulate Mu2e Offline build options.
# Andrei Gaponenko, 2015

if [[ $(basename $0) != buildopts ]]; then
    echo "ERROR: The buildopts script should be executed, not sourced" >&2
    return 1
fi


#================================================================
# known keywords
kkw=(build g4vis g4mt trigger)
# a list of allowed values, the first one is the default
opts_build() {
    echo prof debug
}
# a list of allowed values, the first one is the default
opts_g4vis() {
    echo none ogl qt
}
# a list of allowed values, the first one is the default
opts_g4mt() {
    echo on off
}
# a list of allowed values, the first one is the default
opts_trigger(){
    echo off on
}
#================================================================
# the --help option overrides everything else on the command line
help=0
for arg in "${@}"; do
    case "$arg" in
        ( -h | --help ) help=1 ;;
    esac
done

if [[ $help == 1 ]]; then
    cat <<EOF
Usage:

  $0                     prints the current config

  $0 --<option>          prints the current value for the option

  $0 --<option>=<value>  sets the new value

  $0 --<option>=default  resets the option

  $0 --reset             resets all options

  $0 --help               prints this message

The recognized options are:

EOF
    for opt in "${kkw[@]}"; do
        echo "    --$opt, allowed values are: "$(opts_$opt)
        echo ""
    done

cat <<EOF
The first value on each list of option values is the default.
EOF
    exit 0
fi

#================================================================
optdb=$(dirname $0)/.buildopts

## We want to allow modifications of build config only when buildopts
## is called from the base release directory and not from a satellite.
assert_writes_allowed() {
    # Get the physical path to .buildopts
    CONFDIR=`dirname $(readlink -f $optdb)`
    if [[ $(/bin/pwd) != $CONFDIR ]]; then
        (
            echo "Error: modifying build options must be done from the top of the base Offline directory."
            echo "       Base release: $CONFDIR"
            echo "       You  are  in: $(/bin/pwd)"
        ) >& 2
        exit 2
    fi
}

## mu2e_getopt <keyword> <default_value>
mu2e_getopt() {
    keyword="$1"
    default="$2"
    ##echo "# verbose: querying $keyword, default is $default" >&2
    val=$(awk -F= '/^'$keyword'/{print $2}' $optdb 2>/dev/null)
    if [[ x$val == x ]]; then val="$default";fi
    echo $val
}

# synopsis: mu2e_setopt <keyword> <new_value>
mu2e_setopt() {
    keyword="$1"
    value="$2"
    ##echo "# verbose: setting $keyword to $value" >&2
    assert_writes_allowed
    grep -v ^"$keyword" $optdb > $optdb.$$ 2>/dev/null
    echo "$keyword=$value" >> $optdb.$$
    /bin/mv -f $optdb.$$ $optdb
}

# synopsis: mu2e_resetopt <keyword>
mu2e_resetopt() {
    keyword="$1"
    ##echo "# verbose: resetting $keyword" >&2
    assert_writes_allowed
    grep -v ^"$keyword" $optdb > $optdb.$$ 2>/dev/null
    /bin/mv -f $optdb.$$ $optdb
}

noargs=1
while [[ x"$1" != x  ]]; do
    noargs=0
    matched=0
    for kw in "${kkw[@]}"; do
        if [[ "$1" =~  --${kw}.* ]]; then
            if [[ "$1" == --$kw ]]; then
                matched=1
                mu2e_getopt $kw $(opts_$kw)
            else
                if [[ "$1" =~ --$kw=(.*) ]]; then
                    matched=1
                    val="${BASH_REMATCH[1]}"
                    if [[ $val == default ]]; then
                        mu2e_resetopt $kw
                    else
                        allowed=0
                        for opt in $(opts_$kw); do
                            #echo "# verbose: kw = $kw testing allowed val = $opt" >&2
                            if [[ $opt == $val ]]; then
                                allowed=1
                            fi
                        done
                        if [[ $allowed = 0 ]]; then
                            echo "ERROR: the value of '$val' is not allowed for the --$kw option" >&2
                            exit 1
                        fi
                        mu2e_setopt $kw "$val"
                    fi
                fi
            fi
        fi
    done

    if [[ $matched == 0 ]]; then
        if [[ $1 == --reset ]]; then
            assert_writes_allowed
            /bin/rm -f $optdb
        else
            echo "ERROR: unrecognized option $1.  Try $0 --help" >&2
            exit 1
        fi
    fi

    shift
done

#================================================================
if [[ $noargs == 1 ]]; then
    #echo "# The current settings are:"
    for i in "${kkw[@]}"; do
        echo "$i=$(mu2e_getopt $i $(opts_$i) )"
        #echo "$i  ${!i[0]}"
    done
fi