#!/bin/sh
# redirect stdout to stderr (stdout gets interpreted by make)
exec 1>&2
# create files in the same directory as this script
cd "$(dirname "$0")"
# do not run anything if make was run with -n (dry run)
# [ "${MAKEFLAGS#*n}" != "$MAKEFLAGS" ] && exit

touch_rm_exit_code() { [ $? -eq 0 ] && touch "$1" || rm -f "$1" ; }

# container image (initialized here, updated in makefile)
$CTR image exists "$CTR_IMG_TAG" 1> /dev/null 2> /dev/null
touch_rm_exit_code container_img

# check if all the submodules are initialized
test -z "$(git submodule status | grep '^-')"
touch_rm_exit_code submodules

rm -f auto.mk

# guess which device is the sd card by size (around 8GB)
for SDCARD_DISK in "$(lsblk --noheadings --bytes --output PATH,SIZE,TYPE | awk '
	$3 != "disk" { next }
	($2 < 7900000000) { next }
	($2 > 8000000000) { next }
	{ print $1 }')"
do
	[ -z "$SDCARD_DISK" ] && continue
	# check if the sd card is already correctly partitioned & formatted
	PARTS="$(lsblk "$SDCARD_DISK" --noheadings --output PATH,SIZE,TYPE,PTTYPE,FSTYPE,LABEL | awk '
		NR == 1 {
			if ($4 != "dos") exit(1)
		}
		NR == 2 {
			if ($6 != "BOOT") exit(1)
			if ($2 != "64M") exit(1)
			if ($5 != "vfat") exit(1)
			print $1
		}
		NR == 3 {
			if ($6 != "ROOTFS") exit(1)
			if ($5 != "ext4") exit(1)
			print $1
		}
		END { if (NR != 3) exit(1) }')" || continue
	SDCARD_PART_BOOT="$(echo "$PARTS" | sed '1!d')"
	SDCARD_PART_ROOTFS="$(echo "$PARTS" | sed '2!d')"
	break
done

if [ -n "$SDCARD_DISK" ]; then
	echo "SDCARD_DISK ?= $SDCARD_DISK" >> auto.mk
fi

if [ -n "$SDCARD_PART_BOOT" ] && [ -n "$SDCARD_PART_ROOTFS" ]; then
	echo "SDCARD_PART_BOOT ?= $SDCARD_PART_BOOT" >> auto.mk
	echo "SDCARD_PART_ROOTFS ?= $SDCARD_PART_ROOTFS" >> auto.mk
	touch sdcard_part_fmt
else
	rm -f sdcard_part_fmt
fi

# export all variables in auto.mk
echo "export" >> auto.mk