#!/bin/sh
# Example P2P network transit program for git-annex.
#
# This simulates a multi-node P2P network using unix 
# socket files in /tmp.
#
# Copyright 2025 Joey Hess; icenced under the GNU GPL version 3 or higher.

set -e

if [ "$1" = address ]; then
	# Output the local P2P network address.
	#
	# For the purposes of this example, a new address is made up each
	# time this is run. Using the current unix second to get a fairly
	# unique address.
	myaddress=$(date +%s)
	echo "$myaddress"
else
	socketfile="$2"
	if [ -z "$socketfile" ]; then
		# Connect to the peer's address and relay stdin and stdout.
		peeraddress="$1"
		# For the purposes of this demo, socat is used, and simply
		# connects stdio to the unix socket file in /tmp.
		socat - UNIX-CONNECT:"/tmp/$peeraddress"
	else
		# Arrange for incoming connections from peers to connect to
		# the unix socket provided by git-annex. The local
		# P2P network address is also available to use.
		myaddress="$1"
		# For the purposes of this demo, the socket file provided
		# by git-annex is symlinked to the location in /tmp.
		ln -sf $(realpath "$socketfile") "/tmp/$myaddress"
	fi
fi