#!/usr/bin/env bash

# git-develacc -- manage repositories in develacc NFS share

# Copyright (C) 2018 Sean Whitton
#
# 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 3 of the License, or (at
# your option) any later version.
#
# This program 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, see <https://www.gnu.org/licenses/>.

set -e

# sanity check
if [ "$(hostname)" = develacc ]; then
    echo >&2 "$0: this script should be run outside the develacc container by my normal user"
    exit 1
fi

# set variables
outside_home="$HOME"
# inside_home="$(getent passwd spw | cut -d: -f6)"
inside_home="/home/spwhitton/local/develacc"
outside="$(pwd)"
inside="${outside/$outside_home/$inside_home}"
parent="$(dirname $inside)"
short="$(basename $outside)"

# clone the repo if needed
if ! [ -d "$inside" ]; then
    mkdir -p "$parent"
    # here we rely on setgid on ~spw
    git -C "$parent" clone --mirror "$outside" "$short"
    git -C "$inside" init --bare --shared=group
    git -C "$inside" unbare
fi

# sync remotes from outside develacc into develacc
git remote | while read remote; do
    if ! [ "$remote" = "develacc" ] && ! [ "$remote" = "dgit" ]; then
        # this is to disable `git remote update` and therefore my `mr update`
        git -C "$inside" config --local --bool "remote.$remote.skipdefaultupdate" true

        # we need a url on the origin remote so that `mr register`
        # works.  And then we might as well set an url on all the
        # remotes (except 'outside') for a nicer display in magit.
	url="$(git config --local remote.$remote.url)"
	git -C "$inside" config --local "remote.$remote.url" "$url"

        git -C "$inside" config --local --unset "remote.$remote.mirror" || true
        git -C "$inside" config --local "remote.$remote.fetch" "+refs/heads/*:refs/remotes/$remote/*"
    fi
done

# ensure we have a remote for the outside repo
git -C "$inside" config --local --bool "remote.outside.skipdefaultupdate" true
git -C "$inside" config --local "remote.outside.url" "$outside" # magit cosmetics
git -C "$inside" config --local "remote.outside.fetch" "+refs/heads/*:refs/remotes/outside/*"

# update all remote-tracking refs inside develacc
git -C "$inside" fetch --prune --tags "$outside" \
    '+refs/remotes/*:refs/remotes/*' \
    '+refs/heads/*:refs/remotes/outside/*'
git -C "$inside" update-ref -d 'refs/remotes/develacc/*'

# prune old remotes
git -C "$inside" remote | while read remote; do
    if ! [ "$remote" = "origin" ] && ! [ "$remote" = "outside" ]; then
	if ! git remote | grep --quiet "$remote"; then
	    git -C "$inside" remote rm "$remote"
	fi
    fi
done

# update develacc-tracking refs outside develacc
if ! [ "$(git remote | grep develacc)" ]; then
    git remote add -f develacc "$inside"
else
    git fetch develacc
fi