#!/bin/bash
set -e

# config options
# shellcheck disable=SC2034
declare -A keep
PR_SRC_USER=
BASE_BRANCH="main"
PR_PROJECT=
PR_REPO=
TOKEN=
PUSH_REMOTE="origin"

# command line only
verbose=0
cfg_file=
dryrun=
show_status=

###################
push_url=
did_push=

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

helpandquit()
{
	cat <<-EOF
		Usage: $0 [OPTIONS] [<module> ...]
		OPTIONS:
		  -h         help screen
	EOF
	exit 0
}

log_info()
{
	[ "$verbose" -gt 0 ] || return 0
	echo "$@"
}

request_pulls()
{
	curl -s -f "$pr_target?state=open" \
		-H "accept: application/json" \
		-H "Authorization: token $TOKEN" \
		-H "Content-Type: application/json"
}

getopttmp=$(getopt -o hc:v --long help,single,branch:,config:,date:,remote:,status,verbose,dry -n "${0##*/}" -- "$@")
eval set -- "$getopttmp"

while true ; do
        case "$1" in
                -h|--help) helpandquit; shift ;;
		-v|--verbose) verbose=$((++verbose)); shift ;;
                -c|--config) cfg_file="$2"; shift 2 ;;
		--status) show_status=1; shift ;;
		--dry) dryrun=1; shift ;;
                --) shift ; break ;;
                *) echo "Internal error!" ; exit 1 ;;
        esac
done

declare -A modules
for m in "$@"; do
	modules["$m"]=1
done

# shellcheck disable=SC1090
. "${cfg_file:-.settings}"

needed=(PR_SRC_USER PR_PROJECT PR_REPO TOKEN)
for i in "${needed[@]}"; do
	eval test -n "\"\$$i\"" || { echo "The following settings are mandatory: ${needed[*]}"; exit 1; }
done

push_url="$(git config --get remote."$PUSH_REMOTE".url)"
pr_target="https://gitea.opensuse.org/api/v1/repos/$PR_PROJECT/$PR_REPO/pulls"

# push queue
declare -A pq
while read -r cid _c ref; do
	m="${ref#refs/pq/}"
	pq["$m"]="$cid"
done < <(git for-each-ref 'refs/pq/*')
# request queue
declare -A rq
while read -r cid _c ref; do
	m="${ref#refs/remotes/"$PUSH_REMOTE"/update_}"
	[ "$m" != "$ref" ] || continue
	rq["$m"]="$cid"
done < <(git for-each-ref "refs/remotes/$PUSH_REMOTE/*")

declare -A pr
while read -r _id cid ref; do
	m="${ref#update_}"
	pr["$m"]="$cid"
	log_info "pr $m: $cid"
done < <(request_pulls | jq ".[]|select(.head.repo.owner.login == \"$PR_SRC_USER\")|[((.number|tostring)), .head.sha, .head.ref]|join(\" \")" -r)

log_info "to push: ${!pq[*]}"
log_info "remote: ${!rq[*]}"

if [ -n "$show_status" ]; then
	echo "# local remote  pr       package"
	if [ "${#modules[@]}" -eq 0 ]; then
		for m in "${!pq[@]}" "${!rq[@]}" "${!pr[@]}"; do
			modules["$m"]=1
		done
	fi
	for m in "${!modules[@]}"; do
		a=${pq[$m]:0:7}
		b=${rq[$m]:0:7}
		c=${pr[$m]:0:7}
		echo "${a:-       } ${b:-       } ${c:-       }  $m"
	done
	exit 0
fi

ret=0
for m in "${!pq[@]}"; do
	[ "${#modules[@]}" -eq 0 -o -n "${modules[$m]}" ] || continue
	cid="${pq[$m]}"
	[ -n "$cid" ]
	if [ -n "${rq[$m]}" ] && [ "$cid" = "${rq[$m]}" ]; then
		log_info "$m already pushed"
	else
		log_info "pushing $m: $cid"
		if ! git send-pack --force "$push_url" "${cid}:refs/heads/update_$m"; then
			echo "failed to push $m update" >&2
			ret=1
			continue
		fi
		did_push=1
	fi

	if [ -n "${pr[$m]}" ]; then
		if [ "$cid" = "${pr[$m]}" ]; then
			log_info "pr for $m exists, no update"
		else
			echo "Warning: exiting pr for $m with different content"
		fi
		continue
	fi

	title=$(git log -1 "--format=%s" "$cid")
	head="update_$m"
	[ "$PR_PROJECT" = "$PR_SRC_USER" ] || head="$PR_SRC_USER:$head"
	log_info "Filing pr '$title': $cid at $pr_target"
	[ -z "$dryrun" ] || continue
	#https://github.com/go-gitea/gitea/issues/18842
	if curl -s -f "$pr_target" \
		-H "accept: application/json" \
		-H "Authorization: token $TOKEN" \
		-H "Content-Type: application/json" \
		-d "{ \"base\": \"$BASE_BRANCH\", \"head\": \"$head\", \"title\": \"$title\"}" > "$tmpfile"; then
		prid=$(jq -r .number < "$tmpfile")
		echo "filed pr #$prid for $m"
	else
		echo "failed to file pr for $m"
		jq -r .message < "$tmpfile"
	fi
done

for m in "${!rq[@]}"; do
	[ "${#modules[@]}" -eq 0 -o -n "${modules[$m]}" ] || continue
	if [ -z "${pq[$m]}" ]; then
		log_info "delete remote request $m"
		if ! git send-pack --force "$push_url" ":refs/heads/update_$m"; then
			echo "failed to push $m update" >&2
			ret=1
			continue
		fi
		did_push=1
	fi
done

if [ -n "$did_push" ]; then
	log_info "Updating remote $PUSH_REMOTE"
	git remote update -p "$PUSH_REMOTE" > /dev/null
fi

exit "$ret"