#!/bin/sh
# Written by Didier Spâier, Paris France.
# Public domain.
# shellcheck source=/dev/null
export TEXTDOMAIN=slint-scripts
if [ "$(id -u)" -ne 0 ]; then
        gettext "This script should be run as root."; echo
        exit
fi
to_lower() {
	echo "$1"|tr '[:upper:]' '[:lower:]'
}
RESCUE=$(mktemp -d)
MEGA=$((1024*1024))
rescuebootstick(){
		ISORESCUE=$RESCUE/isorescue
	echo
	gettext "Do you want to make a rescue boot stick of an USB flash drive? "; echo
	while true; do
		gettext "Please type yes or no: "
		read -r ANSWER
		case $(to_lower "$ANSWER") in
			yes) break;;
			no) return;;
			*) :
		esac
	done
	while true; do
		lsblk -lno serial,name,type|grep disk|grep ' sd'|sed "s@[[:space:]].*@@" >"$RESCUE/before"
		gettext "Plug in the USB boot stick, then press Enter."
		read -r
		sleep 3
		lsblk -lno serial,name,type|grep disk|grep ' sd'|sed "s@[[:space:]].*@@"  >"$RESCUE/after"
		# Lines found in after but not in before are added
		rm -f "$RESCUE/added"
		while read -r added; do
			if ! grep -q "$added" "$RESCUE/before"; then
				echo "$added" >> "$RESCUE/added"
			fi
		done < "$RESCUE/after"
		if [ ! -f "$RESCUE/added" ]; then
		echo
			gettext "We didn't find a newly inserted USB flash drive."; echo
			gettext "Maybe it was already inserted?"; echo
			while true; do
				gettext "If you want to try again remove it then type yes, else type no: "
				read -r ANSWER
				case $(to_lower "$ANSWER") in
					yes) continue 2;;
					no) return;;
					*) :
				esac
			done
		else
			NBADDED=$(wc -l "$RESCUE"/added|cut -d" " -f 1)
		fi
		if [ "$NBADDED" -eq 1 ]; then
			SERIAL=$(cat "$RESCUE/added")
			lsblk -bpPo serial,name,size,vendor,model,type|grep "SERIAL=\"$SERIAL\"" > "$RESCUE/rescuebootstick"
			. "$RESCUE/rescuebootstick"
			echo
			RESCUEPATH="$NAME"
			gettext "This drive will be used as rescue boot stick."; echo
			echo "$NAME $VENDOR $MODEL ($((SIZE/MEGA))M)"
			gettext  "If you accept all data currently stored on it will be lost!"; echo
			gettext "You will confirm that want to use this one, choose another one or give up."; echo
			while true; do
				gettext "Type yes to use it, no to try another one or q to give up: "
				read -r ANSWER
					case $(to_lower "$ANSWER") in
						yes) break 2;;
						no) gettext "Remove this USB flash drive, then press Enter: "; read -r; continue 2;;
						q) return;;
						*) :
					esac
			done
		fi
		if [ "$NBADDED" -gt 1 ]; then
			echo
			gettext "Several newly inserted drives have been detected!"; echo
			gettext "No rescue boot disk can be made now."; echo
			gettext "Press Enter to continue."; echo
			read -r
			return
		fi
	done
	echo
	gettext "Please wait while we prepare the booting equipment..."; echo
	KERNELPATH=$(find /boot -name "vmlinuz-generic-*")
	VERSION=$(sed  "s&[[:space:]].*&&;s&.*-&&" /proc/cmdline)
	INITRD="initramfs-${VERSION}.img"
	mkdir -p "$ISORESCUE/boot/grub"
	grub-mkconfig -o "$ISORESCUE/boot/grub/grub.cfg"
	cp "$KERNELPATH" "$ISORESCUE/" || exit 1
	cp "/boot/$INITRD" "$ISORESCUE/" || exit 1
	gettext "Writing the booting equipment on the stick..."; echo
	grub-mkrescue --locales='' \
	--themes='' --compress=xz -V "ISORESCUE" -iso_mbr_part_type 0x83 \
	-o "$RESCUE/rescue.iso"  -partition_offset 16 -J \
	--xorriso=grub-mkrescue-sed.sh "$ISORESCUE" 1>>"$RESCUE/makerescueiso.log" 2>>"$RESCUE/makerescueiso.log"
	cp "$RESCUE/rescue.iso" "$RESCUEPATH"
	sync
	rm -r "$RESCUE"
	gettext "Done. You may now remove the rescue boot stick."; echo
	echo
}
rescuebootstick