#!/bin/bash

# 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 source *****
Execute as following : 
source 1-pre-install.sh

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

# Load configuration parameter
source config.sh

# ******************************************************************************* 
#                        Confirmation and Passphrase setting 
# ******************************************************************************* 

# Distribution check
uname -a | grep ubuntu -i > /dev/null
if [ $? -eq 1  ] ; then	# "Ubuntu" 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 # "Ubuntu" is not found in the OS name.

# For surre ask the config.sh is edited
echo "Are you ready to install? The destination logical volume label is \"${LVROOTNAME}\" [Y/N]"
read YESNO
if [ ${YESNO} != "Y" -a ${YESNO} != "y" ] ; then
	cat <<HEREDOC 1>&2

Installation terminated.
HEREDOC
	return
fi	# if YES

# For sure ask ready to erase. 
if [ ${ERASEALL} -eq 1 ] ; then
	echo "Are you sure you want to erase entire ${DEV}? [Y/N]"
	read YESNO
	if [ ${YESNO} != "Y" -a ${YESNO} != "y" ] ; then
		cat <<HEREDOC 1>&2
Check config.sh. The variable ERASEALL is ${ERASEALL}.

Installation terminated.
HEREDOC
		return
	fi	# if YES
fi	# if erase all

# ----- Set Passphrase -----
# Input passphrase
echo "Type passphrase for the disk encryption."
read -sr PASSPHRASE
export PASSPHRASE

echo "Type passphrase again, to confirm."
read -sr PASSPHRASE_C

# Validate whether both are indentical or not
if [ ${PASSPHRASE} != ${PASSPHRASE_C} ] ; then
	cat <<HEREDOC 1>&2
***** ERROR : Passphrase doesn't match *****
Installation terminated.
HEREDOC
	return
fi	# passphrase validation


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


# ----- Erase entire disk, create partitions, format them  and encrypt the LUKS partition -----
if [ ${ERASEALL} -eq 1 ] ; then

	# Assign specified space and rest of disk to the EFI and LUKS partition, respectively.
	if [  ${ISEFI} -eq 1 ] ; then
		# Zap existing partition table and create new GPT
		echo "...Initialize ${DEV} with GPT."
		sgdisk --zap-all "${DEV}"
		# Create EFI partition and format it
		echo "...Create an EFI partition on ${DEV}."
		sgdisk --new=${EFIPARTITION}:0:+${EFISIZE} --change-name=${EFIPARTITION}:"EFI System"  --typecode=${EFIPARTITION}:ef00 "${DEV}"  
		echo "...Format the EFI parttion."
		mkfs.vfat -F 32 -n EFI-SP "${DEV}${EFIPARTITION}"
		# Create Linux partition
		echo "...Create a Linux partition on ${DEV}."
		sgdisk --new=${CRYPTPARTITION}:0:0    --change-name=${CRYPTPARTITION}:"Linux LUKS" --typecode=${CRYPTPARTITION}:8309 "${DEV}"
		# Then print them
		sgdisk --print "${DEV}"
	else
		# Zap existing partition table
		echo "...Erase partition table of ${DEV}."
		dd if=/dev/zero of=${DEV} bs=512 count=1
		# Create MBR and allocate max storage for Linux partition
		echo "...Create a Linux partition on ${DEV} with MBR."
		sfdisk ${DEV} <<HEREDOC
2M,,L
HEREDOC
	fi	# if EFI firmware

	# Encrypt the partition to install Linux
	echo "...Initialize ${DEV}${CRYPTPARTITION} as crypt partition"
	printf %s "${PASSPHRASE}" | cryptsetup luksFormat --type=luks1 --key-file - --batch-mode "${DEV}${CRYPTPARTITION}"

fi	# if erase all

# ----- Open the LUKS partition -----
# Open the crypt partition. 
echo "...Open a crypt partition ${DEV}${CRYPTPARTITION} as \"${CRYPTPARTNAME}\""
printf %s "${PASSPHRASE}" | cryptsetup open -d - "${DEV}${CRYPTPARTITION}" ${CRYPTPARTNAME}

# Check whether successful open. If mapped, it is successful. 
if [ ! -e /dev/mapper/${CRYPTPARTNAME} ] ; then 
	cat <<HEREDOC 1>&2
***** ERROR : Cannot open LUKS volume "${CRYPTPARTNAME}" on ${DEV}${CRYPTPARTITION}. *****
Check passphrase and config.txt

Installation terminated.
HEREDOC
	return
fi	# if crypt volume is unable to open

# ----- Configure the LVM in LUKS volume -----
# Check volume group ${VGNAME} exist or not
vgdisplay -s ${VGNAME} &> /dev/null
if  [ $? -eq 0 ] ; then		# is return value 0? ( exist ?)
	echo "...Volume group ${VGNAME} already exist. Skipped to create. No problem."
else
	echo "...Initialize a physical volume on \"${CRYPTPARTNAME}\""
	pvcreate /dev/mapper/${CRYPTPARTNAME}
	echo "...And then create Volume group \"${VGNAME}\"."
	vgcreate ${VGNAME} /dev/mapper/${CRYPTPARTNAME}
fi # if /dev/volume-groupt not exist

# Create a SWAP Logical Volume on VG, if it doesn't exist
if [ -e /dev/mapper/${VGNAME}-${LVSWAPNAME} ] ; then 
	echo "...Swap volume already exist. Skipped to create. No problem."
else
	echo "...Create logical volume \"${LVSWAPNAME}\" on \"${VGNAME}\"."
	lvcreate -L ${LVSWAPSIZE} -n ${LVSWAPNAME} ${VGNAME} 
fi	# if /dev/mapper/swap volume already exit. 

# Create a ROOT Logical Volume on VG. 
if [ -e /dev/mapper/${VGNAME}-${LVROOTNAME} ] ; then 
	cat <<HEREDOC 1>&2
***** ERROR : Logical volume "${VGNAME}-${LVROOTNAME}" already exists. *****
Check LVROOTNAME environment variable in config.txt.

Installation terminated.
HEREDOC
	return
else
	echo "...Create logical volume \"${LVROOTNAME}\" on \"${VGNAME}\"."
	lvcreate -l ${LVROOTSIZE} -n ${LVROOTNAME} ${VGNAME}
fi	# if the root volun already exist

# ******************************************************************************* 
#                                Para-install stage 
# ******************************************************************************* 
cat <<HEREDOC
******************************************************************************
The pre-install process is done. We are ready to install the Linux to the 
target storage device. By pressing return key, Ubuntu Ubiquity installer 
starts.

Please pay attention to the partition mapping configuration. In this 
installation, you have to map the previously created partitions/logical
volumes to the appropriate directory of the target system. 

Host Volume            | Target Directory | Comment
-----------------------|------------------|-----------------------------------
/dev/sda1              | /boot/efi        | Only EFI system needs.
/dev/mapper/vg1-ubuntu | /                | Host volume name is up to your 
                       |                  | configuration parameter.
/dev/mapper/swap       | swap             | Only the first distribution 
                       |                  | installation requires this mapping.

************************ CAUTION! CAUTION! CAUTION! ****************************
 
Make sure to click "Continue Testing",  at the end of the Ubiquity installer.

Type return key to start Ubiquity.
HEREDOC

# waitfor a console input
read dummy_var

# Start GUI installer 
ubiquity &
# Record the PID
ubiquity_pid=$!

# While the /etc/default/grub in the install target is NOT existing, keep sleeping.
# If ubiquity terminated without installation, this script also terminates.
while [ ! -e /target/etc/default/grub ]
do
	sleep 1 # 1sec.

	ps $ubiquity_pid  > /dev/null # ps return 0 if process exists.
	if [ $? -ne 0 ] ; then	# If not exists
	cat <<HEREDOC 1>&2
The ubiquity installer terminated unexpectedly. 

Installation process terminated.
HEREDOC
	return

	fi
done

# Perhaps, too neuvous. Wait 1 more sectond to avoid the rece condition.
sleep 1 # 1sec.

# Make target GRUB aware to the crypt partition
# This must do it after start of the file copy by ubiquity, but before the end of the file copy.
echo "...Add GRUB_ENABLE_CRYPTODISK entry to /target/etc/default/grub "
echo "GRUB_ENABLE_CRYPTODISK=y" >> /target/etc/default/grub


# And then, wait for the end of Ubiquity process
echo "...Waiting the end of Ubiquity installer."
wait $ubiquity_pid

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

# 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 source *****
Execute as following : 
source 3-post-install.sh

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

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

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

# Change root and create the keyfile and ramfs image for Linux kernel. 
echo "...Chroot to /target."
cat <<HEREDOC | chroot /target /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
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

# 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

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

# Leave chroot
exit
HEREDOC

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

...Ready to reboot.
HEREDOC