#!/bin/sh

tmp="$(mktemp)"
test "$(id -u)" != "0" && sudo="sudo"

die ()
{
	echo "$@" >&2
}

# Read one character
read_char ()
{
	die -n ">"
	old_stty_cfg=$(stty -g)
	stty raw
	dd ibs=1 count=${1:-1} 2> /dev/null
	stty $old_stty_cfg
	die ""
}

get_dev ()
{
	grep "^$1\." "$tmp" | cut -f 2- -d ' '
}

# mount the device with $1 as the choice
mount ()
{
	dev="$(get_dev "$1")"
	test -z "$dev" && exit 1

	die "Mounting /dev/$dev on /media/$dev"
	mkdir -p /media/$dev
	$sudo mount /dev/$dev /media/$dev > /dev/null 2>&1 ||
		return 1
}

# umount the device with $1 as the choice
umount ()
{
	mountpoint="$(sed -n "${1}p" "$tmp" |
		awk '{print $3}')"
	test -z "$mountpoint" && exit 1

	die "Unmounting $mountpoint"
	$sudo umount "$mountpoint" ||
		return 1
}

ejekt ()
{
	dev="$(get_dev "$1" | sed 's/.$//')"
	test -z "$dev" && exit 1

	die "Ejecting /dev/$dev"
	$sudo eject /dev/$dev > /dev/null 2>&1 ||
		return 1
}

# print lsblk, use $1 to print only devices with mountpoints or without
pr_lsblk ()
{
	clear
	lsblk -o name,size,type,mountpoint
	die "───────────────────────────────────"
	lsblk --ascii -o name,mountpoint |
		grep '^.-' |
		while read line
	do
		words="$(printf "$line" | wc -w)"
		test $words -eq ${1:-1} && continue 
		printf "%s\n" "$line"
	done |
		cut -f 2- -d "-" |
		awk '{print NR ". " $0}' |
		tee "$tmp" >&2
}

cleanup ()
{
	rm -f "$tmp"
}

trap cleanup EXIT INT

die "m(ount) u(mount) (e)ject ?"
choice="$(read_char)"

case $choice in
	"m") i=2; cmd=mount ;;
	"u") i=1; cmd=umount ;;
	"e") i=2; cmd=ejekt ;;
	*) exit 1 ;;
esac

pr_lsblk $i
choice="$(read_char)"
printf "$choice" | grep -q "[0-9]" || exit 1
$cmd $choice &&
	die "Successful." ||
	die "Failed."