#!/bin/bash -u

function main() {
	# Load configuration parameter
	source config.sh

	# Load functions
	source common/confirmation.sh
	source common/preinstall.sh
	source common/parainstall.sh
	source common/parainstall_msg.sh


	# This is the mount point of the install target. 
	export TARGETMOUNTPOINT="/target"
	# 1 : Show message during GUI/TUI installer, 0 : Do not show.
	export PARAINSTMSG=1

	# Distribution check
	if ! uname -a | grep ubuntu -i > /dev/null  ; then	# "Ubuntu" is not found in the OS name.
		echo "*******************************************************************************"
		uname -a
		cat <<- HEREDOC 
		*******************************************************************************
		This system seems to be not Ubuntu, while this script is dediated to the Ubuntu.
		Are you sure you want to run this script? [Y/N]
		HEREDOC
		read YESNO
		if [ ${YESNO} != "Y" -a ${YESNO} != "y" ] ; then
			cat <<- HEREDOC 1>&2

			Installation terminated.
			HEREDOC
			return 1
		fi	# if YES

	fi # "Ubuntu" is not found in the OS name.

	# ******************************************************************************* 
	#                                Confirmation before installation 
	# ******************************************************************************* 

	# Common part of the parameter confirmation
	if ! confirmation ; then
		return 1
	fi

	# ******************************************************************************* 
	#                                Pre-install stage 
	# ******************************************************************************* 

	# Common part of the pre-install stage
	if ! pre_install ; then
		return 1
	fi


	# ******************************************************************************* 
	#                                Para-install stage 
	# ******************************************************************************* 

	# Show common message to let the operator focus on the critical part
	parainstall_msg

	# Ubuntu dependent message
	cat <<- HEREDOC

	************************ CAUTION! CAUTION! CAUTION! ****************************
	
	Make sure to click "Continue Testing",  at the end of the Ubiquity installer.
	Just exit the installer without rebooting.

	Type return key to start Ubiquity.
	HEREDOC

	# waitfor a console input
	read dummy_var

	# Start Ubiquity installer 
	ubiquity &

	# Record the PID of the installer. 
	installer_pid=$!

	# Common part of the para-install. 
	# Record the install PID, modify the /etc/default/grub of the target, 
	# and then, wait for the end of sintaller. 
	if ! parainstall ; then
		return 1
	fi

	# ******************************************************************************* 
	#                                Post-install stage 
	# ******************************************************************************* 

	## Mount the target file system
	# ${TARGETMOUNTPOINT} is created by the GUI/TUI installer
	echo "...Mount /dev/mapper/${VGNAME}-${LVROOTNAME} on ${TARGETMOUNTPOINT}."
	mount /dev/mapper/${VGNAME}-${LVROOTNAME} ${TARGETMOUNTPOINT}

	# And mount other directories
	echo "...Mount all other dirs."
	for n in proc sys dev etc/resolv.conf; do mount --rbind "/$n" "${TARGETMOUNTPOINT}/$n"; done

	# Change root and create the keyfile and ramfs image for Linux kernel. 
	echo "...Chroot to ${TARGETMOUNTPOINT}."
	cat <<- HEREDOC | chroot ${TARGETMOUNTPOINT} /bin/bash
	# Mount the rest of partitions by target /etc/fstab
	mount -a

	# Set up the kernel hook of encryption
	echo "...Install cryptsetup-initramfs package."
	apt -qq install -y cryptsetup-initramfs

	# Prepare a key file to embed in to the ramfs.
	echo "...Prepair key file."
	mkdir /etc/luks
	dd if=/dev/urandom of=/etc/luks/boot_os.keyfile bs=4096 count=1 status=none
	chmod u=rx,go-rwx /etc/luks
	chmod u=r,go-rwx /etc/luks/boot_os.keyfile

	# Add a key to the key file. Use the passphrase in the environment variable. 
	echo "...Add a key to the key file."
	printf %s "${PASSPHRASE}" | cryptsetup luksAddKey -d - "${DEV}${CRYPTPARTITION}" /etc/luks/boot_os.keyfile

	# Add the LUKS volume information to /etc/crypttab to decrypt by kernel.  
	echo "...Add LUKS volume info to /etc/crypttab."
	echo "${CRYPTPARTNAME} UUID=$(blkid -s UUID -o value ${DEV}${CRYPTPARTITION}) /etc/luks/boot_os.keyfile luks,discard" >> /etc/crypttab

	# Putting key file into the ramfs initial image
	echo "...Register key file to the ramfs"
	echo "KEYFILE_PATTERN=/etc/luks/*.keyfile" >> /etc/cryptsetup-initramfs/conf-hook
	echo "UMASK=0077" >> /etc/initramfs-tools/initramfs.conf

	# Finally, update the ramfs initial image with the key file. 
	echo "...Upadte initramfs."
	update-initramfs -uk all

	# Leave chroot
	HEREDOC

	# Unmount all
	echo "...Unmount all."
	umount -R ${TARGETMOUNTPOINT}

	# Finishing message
	cat <<- HEREDOC
	****************** Post-install process finished ******************

	...Ready to reboot.
	HEREDOC

	# Normal end
	return 0
}

# Execute
main