#! /bin/sh
# See https://stackoverflow.com/a/69193032/7976758

set -e
share=group

while getopts agh opt; do
   case $opt in
      a) share=all ;;
      g) share=group ;;
      h) ;;
   esac
done
shift `expr $OPTIND - 1`

if [ $# -gt 1 -o "$1" = -h ]; then
    echo "Usage: $0 [-a|-g] [group]"
    if [ $# -gt 1 ]; then
        exit 1
    fi
fi

git config core.sharedRepository $share

# Fix group
if [ -n "$1" ]; then
    chgrp -R $1 . # Use desired group name
    # Make FS to inherit group on creating subdirectories or files
    find . -type d -exec chmod g+s '{}' \+
fi

# Fix file/directory permissions throughout the entire tree
if [ $share = all ]; then
    chmod -R ug=rwX,o=rX . # Please note **uppercase** X
    # Git object DB files are read-only
    find .git/objects -type f -exec chmod a=r '{}' \+
else # share = group
    chmod -R ug=rwX,o= .
    find .git/objects -type f -exec chmod ug=r '{}' \+
fi