#!/bin/bash -u
# ******************************************************************************* 
#                                Pre-install stage 
# ******************************************************************************* 

function pre_install_common() {


	# ----- 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 [  "${ISEFI}" -eq 1 ] ; then
			# Zap existing partition table and create new GPT
			echo "...Initializing \"${DEV}\" with GPT."
			sgdisk --zap-all "${DEV}"
			# Create EFI partition and format it
			echo "...Creating an EFI partition on \"${DEV}\"."
			sgdisk --new="${EFIPARTITION}":0:+"${EFISIZE}" --change-name="${EFIPARTITION}":"EFI System"  --typecode="${EFIPARTITION}":ef00 "${DEV}"  
			echo "...Formatting the EFI parttion."
			mkfs.vfat -F 32 -n EFI-SP "${DEV}${EFIPARTITION}"
			# Create Linux partition
			echo "...Creating 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 "...Erasing partition table of \"${DEV}\"."
			dd if=/dev/zero of="${DEV}" bs=512 count=1
			# Create MBR and allocate max storage for Linux partition
			echo "...Creating a Linux partition on ${DEV} with MBR."
			sfdisk "${DEV}" <<- HEREDOC
			2M,,L
			HEREDOC
		fi	# if EFI firmware

		# Encrypt the partition to install Linux
		echo "...Initializing \"${DEV}${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 "...Opening 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/"${CRYPTPARTNAME}" ] ; then 
		cat <<- HEREDOC 
		***** ERROR : Cannot open LUKS volume "${CRYPTPARTNAME}" on "${DEV}${CRYPTPARTITION}". *****
		...Check passphrase and your config.txt

		...Installation process terminated..
		HEREDOC
		return 1 # with error status
	fi	# if crypt volume is unable to open

	# ----- Configure the LVM in LUKS volume -----
	# Check volume group ${VGNAME} exist or not
	if  vgdisplay -s "${VGNAME}" &> /dev/null ; then		# if exist
		echo "...Volume group \"${VGNAME}\" already exist. Skipped to create. No problem."
		echo "...Activating all logical volumes in volume group \"${VGNAME}\"."
		vgchange -ay
	else
		echo "...Initializing a physical volume on \"${CRYPTPARTNAME}\""
		pvcreate /dev/mapper/"${CRYPTPARTNAME}"
		echo "...And then creating Volume group \"${VGNAME}\"."
		vgcreate "${VGNAME}" /dev/mapper/"${CRYPTPARTNAME}"
	fi # if /dev/volume-groupt 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 "...Creating 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 # exist
		if [ "${OVERWRITEINSTALL}" -eq 1 ] ; then # exist and overwrite install
			echo "...Logical volume \"${VGNAME}-${LVROOTNAME}\" already exists. OK."
		else	# exist and not overwriteinstall
			cat <<- HEREDOC 
			***** ERROR : Logical volume "${VGNAME}-${LVROOTNAME}" already exists. *****
			...Check LVROOTNAME environment variable in your config.txt.
			HEREDOC
			echo "...Deactivating all logical volumes in volume group \"${VGNAME}\"."
			vgchange -a n "${VGNAME}"
			echo "...Closing LUKS volume \"${CRYPTPARTNAME}\"."
			cryptsetup close  "${CRYPTPARTNAME}"
			cat <<- HEREDOC 

			...Installation process terminated..
			HEREDOC
			return 1 # with error status
		fi
	else	# not exsit
		if [ "${OVERWRITEINSTALL}" -eq 1 ] ; then
			cat <<- HEREDOC 
			***** ERROR : Logical volume "${VGNAME}-${LVROOTNAME}" doesn't exist while overwrite install. *****
			...Check consistency of your config.txt.
			HEREDOC
			echo "...Deactivate all logical volumes in volume group \"${VGNAME}\"."
			vgchange -a n "${VGNAME}"
			echo "...Closing LUKS volume \"${CRYPTPARTNAME}\"."
			cryptsetup close  "${CRYPTPARTNAME}"
			cat <<- HEREDOC 

			...Installation process terminated..
			HEREDOC
			return 1 # with error status
		else # not exist and not overwrite install
			echo "...Creating logical volume \"${LVROOTNAME}\" on \"${VGNAME}\"."
			lvcreate -l "${LVROOTSIZE}" -n "${LVROOTNAME}" "${VGNAME}"
		fi
	fi


	# successful return
	return 0
}