#!/bin/bash

target="${1%/}"
[ -z "$target" ] && {
	echo "Wrapper for chroot to set up variables and after use cleanup."
	echo "Usage: $0 target [script]"
	exit 1
}
target="$(realpath "$target")"
[ -d "$target" ] || {
	echo "Target $target does not exist or is not a directory";
	exit 1
}
[ -d "$target/dev" ] && [ -d "$target/run" ] && [ -d "$target/proc" ] && [ -d "$target/sys" ] && [ -d "$target/tmp" ] || {
	echo "Required directories (dev,run,proc,sys,tmp) missing in $target"
	exit 1
}

script="${2%/}"
[ ! -z "$script" ] && {
	if [ -e "$script" ] ; then	
		if [ -x "$script" ] ; then 
			echo "Using script: $script"
			[ -L "$script" ] && {
				echo "Warning: Script $script is a symlink. Proper symlink handling is not yet implemented"
			}
		else  
			echo "Error: Script $script is not an executable" 
			exit 1
		fi
	else
		echo "Error: Script $script does not exist"
		exit 1
	fi
}
echo Setting up chroot...
mount -v --rbind /dev $target/dev
mount -v --make-rslave $target/dev
#mount -v --bind /dev/tty $target/dev/tty
echo Copying files...
mkdir -p $target/root/tmp
cp -L /etc/resolv.conf $target/root/tmp/resolv.conf
[ ! -z "$script" ] && cp -L "$script" "$target/root/tmp/$(basename "$script")"
echo Entering chroot...
chroot $target /bin/bash -c "echo Initial cleanup
find /run -not -path /run -print -delete
find /proc -not -path /proc -print -delete
find /sys -not -path /sys -print -delete
find /tmp -not -path /tmp -print -delete
[ -d /var/tmp ] && find /var/tmp -not -path /var/tmp -print -delete
echo Setting up mounts
mount -vt tmpfs none /run
mount -vt proc none /proc
mount -vt sysfs none /sys
#mount -vt devpts devpts /dev/pts
#mount -vt tmpfs none /dev/shm
mount -vt tmpfs none /tmp
[ -d /var/tmp ] && mount -vt tmpfs none /var/tmp
echo Setting up variables
export LC_ALL=C
echo $target > /etc/debian_chroot
[ -h /var/lock ] && mkdir -vp \"\$(readlink -f /var/lock)\"
if ( type dbus-uuidgen >/dev/null 2>&1 ) ; then
	if [ ! -f \"/var/lib/dbus/machine-id\" ] ; then
		echo Generating dbus machine id.
		dbus-uuidgen --ensure
	else
		echo Skipping dbus machine id generation.
	fi
else
	echo No dbus-uuidgen on this system.
fi
if ( type systemd-machine-id-setup >/dev/null 2>&1 ) ; then
	if [ ! -f \"/etc/machine-id\" ] ; then
		systemd-machine-id-setup
	else
		echo Skipping systemd machine id setup.
	fi
else
	echo No systemd-machine-id-setup on this system.
fi
if [ ! -e \"/etc/resolv.conf\" ] ; then
	echo Creating new resolv.conf file
	if [ -L \"/etc/resolv.conf\" ] ; then
		file=\$(readlink \"/etc/resolv.conf\")
		echo Creating dir \$(dirname \$file)
		mkdir -p \$(dirname \$file)
		echo Creating file \$file
		touch \$file
	fi 
	cp /root/tmp/resolv.conf -v /etc/resolv.conf
elif [ -f /etc/resolv.conf ] ; then
	echo *Found an old resolv.conf on $target*
	du -h /etc/resolv.conf
	cat /etc/resolv.conf
	echo *To be replaced with*
	du -h /root/tmp/resolv.conf
	cat /root/tmp/resolv.conf
	cp -vi /root/tmp/resolv.conf /etc/resolv.conf
fi
if ( type dhclient >/dev/null 2>&1 ) ; then
	read -p \"Dhcp client detected. Enter \\\"y\\\" to run: \" ch
	[ \"\$ch\" == \"y\" ] && dhclient -v
else
	echo No dhclient on this system
fi
if [ ! -z \"$script\" -a -e \"/root/tmp/\$(basename \"$script\")\" ] ; then
	script=\$(basename \"$script\")
	echo \"\$(basename \"$script\")\" > /tmp/chroot_script
	echo Running /root/tmp/\$script
	/root/tmp/\$script
	echo Cleaning temporary files...
	rm /tmp/chroot_script
	rm /root/tmp/ -rf
else
	echo Cleaning temporary files...
	rm /root/tmp/ -rf
	#if [ -n \"$user\" ]; then
	#	echo Running shell for user $user...
	#	su - $user
	#else
		echo Running root shell...
		su -
	#fi
fi
echo Cleaning up...
if [ -f \"/var/lib/dbus/machine-id\" ] ; then
	read -p \"Dbus machine id file present. Enter \\\"y\\\" to delete it: \" ch
	[ \"\$ch\" == \"y\" ] && rm -vf /var/lib/dbus/machine-id
fi
if [ -f \"/etc/machine-id\" ] ; then
	read -p \"Systemd machine id file is present. Enter \\\"y\\\" to delete it: \" ch
	[ \"\$ch\" == \"y\" ] && rm -vf /etc/machine-id
fi
if [ -f \"\$HOME/.bash_history\" ] ; then
	read -p \"Bash history file is present. Enter \\\"y\\\" to delete it: \" ch
	[ \"\$ch\" == \"y\" ] && rm -vf \$HOME/.bash_history
fi
rm /etc/debian_chroot
[ -d /var/tmp ] && umount -lfv /var/tmp
umount -lfv /tmp
#umount -lfv /dev/shm
#umount -lfv /dev/pts
umount -lfv /sys
umount -lfv /run
umount -lfv /proc
echo Leaving chroot..."
#umount -lfv $target/dev/tty
umount -lfv $target/dev
rm -rfv $target/run/*
pstokill="$(lsof 2>/dev/null | grep $target | tr -s "[:space:]" | grep -v ^chroot\- | cut -d\  -f2 | uniq )"
[ -z "$pstokill" ] || {
	echo Terminating remaining processes...
	kill $pstokill
}
pstokill="$(lsof 2>/dev/null | grep $target | tr -s "[:space:]" | grep -v ^chroot\- | cut -d\  -f2 | uniq )"
[ -z "$pstokill" ] || {
	echo Killing remaining processes...
	kill -9 $pstokill
}