#!/bin/bash

# Storage device to install the linux.  
export DEV="/dev/sda"

# Whether you want to erase all contents of the storage device or not.
# 1 : Yes, I want to erase all.
# 0 : No, I want to add to the existing Linux distributions. 
export ERASEALL=1

# Logical Volume name for your Linux installation. Keep it unique from other distribution.
export LVROOTNAME="ubuntu"

# Logical volume size of the Linux installation.
# 30% mean, new logical volume will use 30% of the free space in the LVM volume group.
# For example, assume the free space is 100GB, and LVROOTSIZE is 30%FREE. Script will create 30GB logical volume.  
export LVROOTSIZE="50%FREE"

# Set the size of EFI partition and swap partition. The unit is Byte. you can use M,G... notation.
export EFISIZE="100M"
export LVSWAPSIZE="8G"

# Usually, these names can be left untouched. 
# If you change, keep them consistent through all distributions in your system.
export CRYPTPARTNAME="luks_volume"
export VGNAME="vg1"
export LVSWAPNAME="swap"

# ********************** DO NOT edit following lines ******************************

# Detect firmware type. 1 : EFI, 0 : BIOS
if [ -d /sys/firmware/efi ]; then
export ISEFI=1  # Yes, EFI
else
export ISEFI=0  # No, BIOS
fi # is EFI firmaare? 

# Set partition number based on the firmware type
if [  ${ISEFI} -eq 1  ] ; then 
# EFI firmware
export EFIPARTITION=1
export CRYPTPARTITION=2
else
# BIOS firmware
export CRYPTPARTITION=1
fi  # EFI firmware


# 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



# ----- Confirmations -----
# Distribution check
uname -a | grep ubuntu -i > /dev/null
if [ $? -eq 1  ] ; then	# "Ubuntu" is not found in the OS name.
	uname -a
	echo "This system seems to be netiher Ubuntu nor Ubuntu variants, while this script is dediated to the Ubuntu or its variants"
	echo "Are you sure you want to run this script for installation? [Y/N]"
	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 "Did you edit config.sys? Are you ready to install? [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


# ----- 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

# Finishing message
if [ ${ISEFI} -eq 1 ] ; then
	cat <<HEREDOC

****************** Pre-install process finished ******************

...Next, open the Ubiquity installer, map the /, swap, EFI partition( if needed ) and start installation.
...And then, execute "source 2-para-install.sh" during the Ubiquity copies files. 
HEREDOC
	cat <<HEREDOC

****************** Pre-install process finished ******************

...Next, open the Ubiquity installer, map the /, swap volume and start installation.
...And then, execute "source 2-para-install.sh" during the Ubiquity copies files. 
else
endif