#!/bin/bash
set -e

allatonce=

helpandquit()
{
	cat <<-EOF
		Usage: $0 [OPTIONS] [<module> ...]
		OPTIONS:
		  -allatonce create dir from filename before extracting
		  -h         help screen
	EOF
	exit 0
}

getopttmp=$(getopt -o h --long help,allatonce -n "${0##*/}" -- "$@")
eval set -- "$getopttmp"

while true ; do
        case "$1" in
                -h|--help) helpandquit; shift ;;
                --allatonce) allatonce=1; shift ;;
                --) shift ; break ;;
                *) echo "Internal error!" ; exit 1 ;;
        esac
done

. .settings

modules=("$@")
origin="$(git config --get remote.origin.url)"
now="$(date "+%s %z")"
# FIXME: hardcoded to avoid changing commits for now
now="$(stat -c %Y token) +0100"
export GIT_AUTHOR_NAME="Auto"
export GIT_AUTHOR_EMAIL="auto@suse.de"
export GIT_AUTHOR_DATE="$now"
export GIT_COMMITTER_NAME="Auto"
export GIT_COMMITTER_EMAIL="auto@suse.de"
export GIT_COMMITTER_DATE="$now"
commit_base="origin/main"

tmpfile=$(mktemp updatemodules.XXXXXX)
cleanup()
{
	rm -f "$tmpfile"
}
trap cleanup EXIT

# read all submodules
declare -A revs
while read -r m t cid p; do
	[ "$t" = "commit" ] || continue
	revs["$p"]="$cid"
done < <(git cat-file -p "$commit_base^{tree}")

if [ -z "$modules" ]; then
       modules=("${!revs[@]}")
fi

# check remotes for updates
declare -A commits
treetext=$(git cat-file -p "$commit_base^{tree}")
gitmodules=$(git cat-file -p "$commit_base":.gitmodules)
for m in "${modules[@]}"; do
	path="$(echo "$gitmodules" | git config -f /dev/stdin --get "submodule.$m.path")"
	url="$(echo "$gitmodules" | git config -f /dev/stdin --get "submodule.$m.url")"
	branch="$(echo "$gitmodules" | git config -f /dev/stdin --get "submodule.$m.branch")"
	if [ -z "$path" ] || [ -z "$url" ]; then
		echo "$m unknown" >&2
		continue
	fi
	if [ "${url:0:3}" = '../' ]; then
		url="$origin/$url"
	fi
	read -r cid _d < <(git ls-remote "$url" "${branch:-HEAD}")
	if [ -z "${revs[$path]}" ]; then
		echo "$path unknown" >&2
		continue
	fi
	# create a new commit for this package
	if [ "${revs[$path]}" != "$cid" ]; then
		echo "Needs update: $path@${revs[$path]} -> $cid"
		if [ "$allatonce" = 1 ]; then
			treetext="${treetext/${revs[$path]}	$path/$cid	$path}"
		else
			newtree="$(git cat-file -p "$commit_base^{tree}" | sed -e "s/${revs[$path]}\t$path/$cid\t$path/" | git mktree)"
			newcid="$(git commit-tree -p "$commit_base" -m "Update $m" "$newtree")"
			commits["$m"]="$newcid"
		fi
	fi
done

if [ "$allatonce" = 1 ]; then
	newtree="$(echo "$treetext" | git mktree)"
	newcid="$(git commit-tree -p "$commit_base" -m "Update all" "$newtree")"
	commits["all"]="$newcid"
fi

for m in "${!commits[@]}"; do
	mkdir -p ".scripts/push"
	if [ -e ".scripts/push/$m" ]; then
		read -r cid < ".scripts/push/$m"
		[ "$cid" = "${commits[$m]}" ] || echo "Warning: previous commit $cid for $m" >&2
	fi
	echo "${commits[$m]}" > ".scripts/push/$m"
done