# Copyright 2013 Intel Corporation
# Author: Artem Bityutskiy
# License: GPLv2

# This file contains common functions for setup-ivi-* programs

# Own name
__PROG="${PROG:-installerfw-sh-functions}"

# Installer framework variables are saved in this file
__installerfw_file="/etc/installerfw-environment"
# The OS release information file
__osrelease_file="/etc/os-release"
# EFI System Partition PARTUUID
__esp_ptypeid="C12A7328-F81F-11D2-BA4B-00A0C93EC93B"

# Mount prefix is assumed to be "/" if it is not defined
[ -n "${INSTALLERFW_MOUNT_PREFIX:-}" ] || export INSTALLERFW_MOUNT_PREFIX="/"

__fatal()
{
	IFS= printf "%s\n" "$__PROG: error: $*" 1>&2
	exit 1
}

__verbose()
{
	if [ -n "$verbose" ]; then
		IFS= printf "%s\n" "$__PROG (verbose): $*" >&2
	fi
}

# Verify that an environment variable is defined
installerfw_verify_defined()
{
	local variable="$1"

	printenv "$variable" > /dev/null ||
		__fatal "cannot find required environment variable" \
		        "\"$variable\""
}

# Add the INSTALLERFW_MOUNT_PREFIX prefix to a path. This does not really
# require a separate function unless we want to be fancy and avoid double or
# tripple "/" in the resulting path.
installerfw_mnt_prefix()
{
	installerfw_verify_defined "INSTALLERFW_MOUNT_PREFIX"

	local path="$INSTALLERFW_MOUNT_PREFIX/$1"

	printf "%s" "$path" | LC_ALL=C sed -e 's/\/\+/\//g'
}

# Return full path to the file which contains the installer framework
# environment variables.
installerfw_get_env_file_name()
{
	printf "%s" "$(installerfw_mnt_prefix "$__installerfw_file")"
}

# Save installer framework environment variables. Note, all the variables can
# be split on 2 classes - those which make sense only inside the particular
# installer and those which make sense in the OS environment. We only save the
# latter.
installerfw_save_env()
{
	local file="$(installerfw_get_env_file_name)"
	local opts="\
-e '^INSTALLERFW_KERNEL_OPTS=' \
-e '^INSTALLERFW_PART[[:digit:]]\+_ALIGN=' \
-e '^INSTALLERFW_PART[[:digit:]]\+_BOOTFLAG=' \
-e '^INSTALLERFW_PART[[:digit:]]\+_FSOPTS=' \
-e '^INSTALLERFW_PART[[:digit:]]\+_FSTYPE=' \
-e '^INSTALLERFW_PART[[:digit:]]\+_LABEL=' \
-e '^INSTALLERFW_PART[[:digit:]]\+_MOUNTPOINT=' \
-e '^INSTALLERFW_PART[[:digit:]]\+_PARTUUID=' \
-e '^INSTALLERFW_PART[[:digit:]]\+_SIZE=' \
-e '^INSTALLERFW_PART[[:digit:]]\+_TYPE_ID=' \
-e '^INSTALLERFW_PART[[:digit:]]\+_UUID=' \
-e '^INSTALLERFW_PART_COUNT=' \
-e '^INSTALLERFW_PTABLE_FORMAT=' \
"

	local variables="$(printenv | eval "LC_ALL=C grep $opts")"

	if [ "$(printf "%s" "$variables" | wc -l)" -eq "0" ]; then
		__fatal "no installer framework environment variables" \
		        "found, nothing to save"
	fi

	printf "%s" "$variables" | LC_ALL=C sed -n -e \
		"s/\(^INSTALLERFW_[^=]\+\)=\(.*\)/\1=\"\2\"/p" > "$file"
	__verbose "installerfw_save_env(): saved installer framework" \
	          "environment in \"$file\""
}

# Restore installer framework environment variables.
installerfw_restore_env()
{
	local file="$(installerfw_get_env_file_name)"

	[ -f "$file" ] || \
		__fatal "installerfw_restore_env(): can't restore the" \
		        "installer framework environment: can't find" \
			"\"$file\""

	while IFS= read -r line; do
		eval "export $line"
	done < "$file"

	__verbose "installerfw_restore_env(): restored installer" \
		  "framework environment from \"$file\""
}

# Check whether installer framework variables are defined
installerfw_available()
{
	printenv | LC_ALL=C grep -q "^INSTALLERFW_[^[:blank:]]\+"
}

# Check if the system is an EFI boot system by checking whether the boot
# partition is a FAT 32 partition with the magic EFI type GUID.
installerfw_is_efi_boot_system()
{
	installerfw_get_part_info "/boot" "TYPE_ID" "__ptypeid"

	# Make sure the UUID uses capital letters
	__ptypeid="$(printf "%s" "$__ptypeid" | tr "[:lower:]" "[:upper:]")"

	installerfw_verify_defined "INSTALLERFW_PTABLE_FORMAT"

	if [ "${INSTALLERFW_PTABLE_FORMAT:-}" = "gpt" ] && \
	   [ "$__ptypeid" = "$__esp_ptypeid" ]; then
		__verbose "installerfw_is_efi_boot_system(): /boot is" \
		          "the EFI system partition (type is" "\"$__ptypeid\")"
		return 0
	else
		__verbose "installerfw_is_efi_boot_system(): no EFI" \
		          "system partition found (type is" "\"$__ptypeid\")"
		return 1
	fi
}

# Get a piece of installer framework data for a partition. At the moment the
# partition is specified by it's mount point (in $1), but this can be extended
# to also accept the partition number, if needed.
#
# The second parameter ($2) is the a partial installer framework variable name
# which should be returned. For example, "PARTUUID" would correspond to
# "INSTALLERFW_PARTx_PARTUUID", and so on.
#
# The third parameter ($3) is name of the variable to store the result at. If
# the requested installer framework variable is undefined or null, the shell
# variable with name stored in $3 will have null value upon exit.
installerfw_get_part_info()
{
	local __mntpoint="$1"; shift
	local __var="$1"; shift
	local __res_var="$1"; shift
	local __pnum="0"

	installerfw_verify_defined "INSTALLERFW_PART_COUNT"

	while [ "$__pnum" -lt "$INSTALLERFW_PART_COUNT" ]; do
		local __mp="INSTALLERFW_PART${__pnum}_MOUNTPOINT"
		installerfw_verify_defined "$__mp"

		__mp="$(eval printf "%s" "\"\$$__mp\"")"

		[ "$__mp" != "$__mntpoint" ] || break

		__pnum="$((__pnum+1))"
	done

	local installerfw_var="INSTALLERFW_PART${__pnum}_${__var}"

	local __value=
	if printenv "$installerfw_var" > /dev/null; then
		__value="$(eval printf "%s" "\"\$$installerfw_var\"")"
	fi

	__verbose "installerfw_get_part_info(): $__res_var=$__value"
	eval "$__res_var"="\"\$__value\""
}