#!/bin/sh
set -eu

# Port allocation for zero-downtime deployments
#
# Reads remote state to determine next available port.
# State files:
#   $base/$project/base_port           - starting port number
#   $base/$project/releases/*/assigned_port - port for each release
#
# Algorithm:
#   1. read base_port (default 3100)
#   2. find all assigned_port files in releases/
#   3. return smallest unused port >= base_port

ssh=deploy-peoplesgrocers-website
base=/home/peoplesgrocers
project=salience

ssh $ssh "
set -eu

base=$base
project=$project

test -d \$base/\$project || { echo 'project dir does not exist' >&2; exit 1; }

# read or initialize base_port
if test -f \$base/\$project/base_port; then
	base_port=\$(cat \$base/\$project/base_port)
else
	base_port=3100
	echo \$base_port > \$base/\$project/base_port
fi

# find all assigned ports
assigned=\$(find \$base/\$project/releases -name assigned_port -exec cat {} \; 2>/dev/null | sort -n || true)

# find first unused port
port=\$base_port
while true; do
	found=0
	for p in \$assigned; do
		test \$p -eq \$port && { found=1; break; }
	done
	test \$found -eq 0 && break
	port=\$((port + 1))
done

echo \$port
"