#!/bin/bash

# Load configuration parameter
source config.sh

# Varidate whether script is executed as sourced or not
(return 0 2>/dev/null) && sourced=1 || sourced=0
if [ $sourced -eq 0 ] ; then
	cat <<HEREDOC 1>&2
***** ERROR : Must execute as "sourced" *****
Execute as following : 
source void-kaiten-yaki.sh

Installation terminated.
HEREDOC
	exit    # use "exit" instead of "return", if not "sourced" execusion
fi # "sourced" validation

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

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

Installation terminated.
HEREDOC
		return
	fi	# if YES

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

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

# Common part of the parameter confirmation
source common/_confirmation.sh

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

# Install essential packages.
# If GUI environment, also install xterm to run the void-installer in a window
if [ ${GUIENV} -eq 1 ] ; then  
	xbps-install -y -Su xbps gptfdisk xterm
else
	xbps-install -y -Su xbps gptfdisk
fi

# Common part of the pre-install stage
source common/_preinstall.sh

# ADD "rd.auto=1 cryptdevice=/dev/sda2:${LUKS_NAME} root=/dev/mapper/${VGNAME}-${ROOTNAME}" to GRUB.
# This is magical part. I have not understood why this is required. 
# Anyway, without this modification, Void Linux doesn't boot. 
# Refer https://wiki.voidlinux.org/Install_LVM_LUKS#Installation_using_void-installer
echo "...Modify /etc/default/grub."
sed -i "s#loglevel=4#loglevel=4 rd.auto=1 cryptdevice=/dev/sda2:${LUKS_NAME} root=/dev/mapper/${VGNAME}-${LVROOTNAME}#" /etc/default/grub

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

# Show common message to let the operator focus on the critical part
source common/_parainstall_msg.sh

# Ubuntu dependent message
cat <<HEREDOC

************************ CAUTION! CAUTION! CAUTION! ****************************
 
Make sure to click "NO", if the void-installer ask you to reboot.
Just exit the installer without rebooting.

Type return key to start void-installer.
HEREDOC

# waitfor a console input
read dummy_var

# Start void-installer 
if [ $GUIENV -eq 1 ]; then
	xterm -fa monospace -fs ${XTERMFONTSIZE} -e void-installer &
else
	void-installer &
fi

# 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. 
source common/_parainstall.sh

# ******************************************************************************* 
#                                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."
xbps-install -y lvm2 cryptsetup

# 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 'install_items+=" /etc/luks/boot_os.keyfile /etc/crypttab " ' > /etc/dracut.conf.d/10-crypt.conf

# Finally, update the ramfs initial image with the key file. 
echo "...Upadte initramfs."
xbps-reconfigure -fa
echo "...grub-mkconfig."
grub-mkconfig -o /boot/grub/grub.cfg
echo "...update-grub."
update-grub

# Leave chroot
HEREDOC

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

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

...Ready to reboot.
HEREDOC