configure

#!/bin/sh

name='MakeMeHappy'
datadir="/usr/share/$name"
etcdir="/etc/$name"
parseCHANGES='
if (m/^\* v[^v]*(v[0-9]+\.[0-9]+[^ ]*) +\(released/) {
    print $1;
    exit 0
}'
version="no-version-yet"
python=''

if test "x$1" = "x--help"; then
    cat <<EOF
Fine tuning of the installation directories:
--datadir=DIR         Configure distribution data directory
--etcdir=DIR          Configure installation-wide data directory
--python=FILE         Configure Python-3 binary name
EOF
    exit 0
fi

findprg() {
    _prg="$1"
    REPLY=''
    _oldifs="$IFS"
    IFS=':'
    for dir in $PATH; do
        f="$dir/$_prg"
        if [ -x "$f" ]; then
            printf 'Looking up %s program in $PATH: %s\n' "$_prg" "$f"
            REPLY="$f"
            IFS="$_oldifs"
            return 0
        fi
    done
    IFS="$_oldifs"
    printf 'Could not find binary: %s\n' "$_prg"
    return 1
}

gotgit=1
findprg git || {
    printf 'Version will be set to %s\n' "$version"
    gotgit=0
}
git="$REPLY"

while [ "$#" -gt 0 ]; do
    case "$1" in
    --datadir=*) datadir="${1#*=}" ;;
    --etcdir=*) etcdir="${1#*=}" ;;
    --python=*) python="${1#*=}" ;;
    *) printf 'Unknown option: "%s"\n' "$1"
       exit 1 ;;
    esac
    shift
done

if [ -z "$python" ]; then
    findprg python3 || exit 1
    python="$REPLY"
fi

if [ "$gotgit" -gt 0 ]; then
    if [ "$("$git" rev-parse --is-inside-work-tree 2>/dev/null)" = 'true' ]
    then
        version="$(git describe --always)"
        version=${version#v}
        if test -n "$(git diff-index --name-only HEAD --)"; then
            version=${version}-dirty
        fi
    else
        printf 'Running outside of git repository!\n'
    fi
fi

if [ "$version" = "no-version-yet" ]; then
    # Either, there's no git installed, or we don't have git repository infor-
    # mation while trying to figure out the project's version. Fall back the to
    # the version in the latest release note in CHANGES.
    version=$(perl -ne "$parseCHANGES" < CHANGES)
fi

printf 'Version will be set to %s\n' "$version"

printf 'Generating mmh from mmh.in...\n'
sed -e "s|@@DATADIR@@|${datadir}|" \
    -e "s|@@ETCDIR@@|${etcdir}|"   \
    -e "s|@@PYTHON@@|${python}|"   \
    -e "s|@@VERSION@@|${version}|" \
    < mmh.in > mmh

chmod 0755 mmh