#!/bin/bash

printf "This tool is for establishing sshfs links to transfer git-annex repo contents.\n"

printf "server or client?\n"
printf 'EITHER OF `s` or `c`\n'

read -p "?> "

case "$REPLY" in
	s)
		printf "[] ensure that port 22 is unfiltered\n"
		sudo iptables -A INPUT -p tcp --dport 22 -j ACCEPT

		printf "[] starting sshd\n"
		sudo systemctl start sshd

		WIRELESS_INTERFACE=$(
			nmcli --get-values GENERAL.DEVICE,GENERAL.TYPE device show |
			sed '/^wifi/!{h;d;};x' |
			head -n1)

		IP_OF_INTERFACE=$(
			ip address show dev $WIRELESS_INTERFACE |
			grep 'inet ' |
			awk -F' ' '{print $2}' |
			awk -F'/' '{print $1}')

		printf "[] instruct client to connect to %s\n" "$IP_OF_INTERFACE"

		printf "[] waiting to stop sshd\n"

		read

		sudo systemctl stop sshd

		printf "[] sshd stopped, but port 22 still open\n"
		;;
	c)
		printf "What IP to connect to?\n"
		printf "ENSURE THAT the IP is accessable on the current VLAN\n"

		printf 'ONE OF `ipv4 address`'

		read -p "?> " ADDRESS

		INFORMED_GUESS=$(ssh usr@$ADDRESS hostname)
		if [ -z "$INFORMED_GUESS" ]; then
			printf "What hostname?\n"

			mkdir -p ~/annex-remotes
			ls ~/annex-remotes

			read -p "?> " REMOTE_HOST
		else
			REMOTE_HOST=$INFORMED_GUESS
			printf "[] using hostname %s\n" "$INFORMED_GUESS"
		fi

		printf "[] mounting fs via sshfs\n"

		mkdir -p ~/annex-remotes/$REMOTE_HOST
		fusermount3 -qu ~/annex-remotes/$REMOTE_HOST
		sshfs usr@$ADDRESS:/home/usr/annex ~/annex-remotes/$REMOTE_HOST

		printf "[] mounted fs\n"

		# check if the fuse mount worked
		df_output=$(df -h | grep -c '/home/usr/annex')
		if [ "$df_output" -eq 0 ]; then
			printf "It seems the sshfs mount didn't work. Exiting.\n"
			exit 1
		fi

		# check if we need to make a copy of the annex on the new device
		if [ ! -d ~/annex-remotes/$REMOTE_HOST/.git ]; then
			printf "Should I do that with the current computer's git-annex store?\n\n"

			printf '`y`) initialize with the local store\n'
			printf '`n`) no, just mount the sshfs\n'

			read -p '?> '

			case $REPLY in
				y)
					cd ~/annex-remotes/$REMOTE_HOST
					printf "[] cloning the local git-annex store\n"
					git clone -v ~/annex

					shopt -s dotglob # include dotfiles and dotdirs in wildcard
					mv ./annex/* . # move everything up a dir

					if find "annex" -maxdepth 1 -type f -o -type d -empty; then # if annex is empty...
						printf "[] removing spurious ./annex directory\n"
						rm -r ./annex # ...remove it
					fi

					git annex init "$REMOTE_HOST"
					cd ~/annex
					git remote add $REMOTE_HOST ~/annex-remotes/$REMOTE_HOST
					;;
			esac # it's okay that the `n` and `*` cases fall-through
		fi

		printf "[] waiting to stop sshfs\n"

		read

		fusermount3 -u ~/annex-remotes/$REMOTE_HOST

		printf "[] unmounted sshfs\n"
		;;
	*)
		printf "unknown\n"
		;;
esac