#!/bin/sh

# Unmount USB drives or Android phones. Replaces the older `dmenuumount`. Fewer
# prompt and also de-decrypts LUKS drives that are unmounted.

set -e

mounteddroids="$(grep simple-mtpfs /etc/mtab | awk '{print "📱" $2}')"
lsblkoutput="$(lsblk -nrpo "name,type,size,mountpoint")"
mounteddrives="$(echo "$lsblkoutput" | awk '($2=="part"||$2="crypt")&&$4!~/\/boot|\/home$|SWAP/&&length($4)>1{printf "💾%s (%s)\n",$4,$3}')"

allunmountable="$(echo "$mounteddroids
$mounteddrives" | sed "/^$/d;s/ *$//")"
test -n "$allunmountable"

chosen="$(echo "$allunmountable" | dmenu -i -p "Unmount which drive?")"
chosen="${chosen%% *}"
test -n "$chosen"

sudo -A umount -l "/${chosen#*/}"
notify-send "Device unmounted." "$chosen has been unmounted."

# Close the chosen drive if decrypted.
cryptid="$(echo "$lsblkoutput" | grep "/${chosen#*/}$")"
cryptid="${cryptid%% *}"

test -b /dev/mapper/"${cryptid##*/}" &&
	sudo -A cryptsetup close "$cryptid" &&
	notify-send "🔒Device dencryption closed." "Drive is now securely locked again."

# Ask to eject drive if possible.
mntline=$(echo "$lsblkoutput" | tac | grep -m1 -n "/${chosen#*/}" | cut -d':' -f1)
[ -n "$mntline" ] &&
	devlabel=$(echo "$lsblkoutput" | tac | tail -n +"$mntline" | grep -m1 '[^ ]* disk' | cut -d'/' -f3 | cut -d' ' -f1) &&
	samedrivemounts=$(echo "$lsblkoutput" | tac | awk '$1~/'"$devlabel"'/&&!cnt{cnt=1}cnt{if($2~/disk/||cnt>2){cnt-=1;print cnt;exit}if($4){cnt+=1}}') &&
	[ "$samedrivemounts" = 1 ] &&
		[ $(printf "No\nYes" | dmenu -p 'Device fully unmounted. Eject this drive?') == 'Yes' ] &&
			sudo -A sh -c "echo offline > /sys/block/$devlabel/device/state; echo 1 > /sys/block/$devlabel/device/delete" &&
			notify-send "Device ejected." "Drive can now be removed safely."