#!/bin/sh -ue
exec 4>&1 1>&2
usage() {
	cat <<EOF
Usage: $0 SPOOL_NAME | lk f -i | ...

spools are a file and folder for batch processing linkpoints
any command can append to \$LK_SPOOLS[=$LK_SPOOLS]/SPOOL_NAME (or use pio-spool-reader.sh)
This script takes that spool and whenever the pio browser app connects it receives the batch of unprocess points
$1
EOF
	exit 1
}

[ "${2+isset}" = isset ] && export PIO_TOKEN="$2"
. "$(dirname "$0")/set-env.sh"

mkdir -p "$LK_SPOOLS" || usage "can't mkdir $LK_SPOOLS"
cd "$LK_SPOOLS"
export spool="$PWD/${1:-default}"
case "$spool" in
*..*) usage "$spool cant contain .." ;;
esac

touch "$spool" || usage "can't write to $spool"
[ -f "$spool" ] || usage "something other than a file: $spool"
touch "$spool"

spool_dir="$spool.d"
mkdir -p "$spool_dir"

if ! ln -s "$spool" "$spool_dir/lock" 2>/dev/null; then
	echo "lock $spool_dir/lock exists. (PIO_NOLOCK=$PIO_NOLOCK)"
  [ -z "${PIO_NOLOCK+isset}" ] && exit 1
else
	echo locked "$spool_dir/lock"
fi

cleanup() {
	trap '' TERM
	[ -n "$pid" ] && kill $pid
	echo "releasing $spool_dir/lock"
	rm -f "$spool_dir/lock" || true
	exit 0
}
trap 'cleanup' TERM INT

echo "$PIO_TOKEN"
echo "$URL"

count=0
while true; do
	pid=""
	date=$(date +"%Y%m%d%H%M%S")
	out="$spool_dir/$date.$count"
	touch "$spool"
	ws-stdio -a "0.0.0.0:$PORT" -t "$PIO_TOKEN" -- /bin/sh -x -c 'tail -f $spool' >&4 &
	pid=$!
	wait $pid
	mv "$spool" "$out" #warm: potential race condition - irrelevant while not ACKing in ws-stdio & browser app
	[ -s "$out" ] || rm "$out"
	count=$((count + 1))
done
cleanup