#!/usr/bin/env bash

die() {
	>&2 printf '\e[1;31mdied: '"$*"'\e[0m\n'
	all_umounts
	exit 1
}

l() {
	>&2 printf '\e[1m'"$*"'\e[0m\n'
}

d() {
	>&2 printf '\e[1;34m# '"$*"'\e[0m\n'
	"$@" || die "$*"
}

baseimg="$1"

unpack_zip() {
	zip -p "$1" > "$2"
}

unzip_xz() {
	xz -d < "$1" > "$2"
}

unpack_bzip2() {
	bzip2 -d < "$1" > "$2"
}

unpack_gzip() {
	gzip -d < "$1" > "$2"
}

unpack_plain() {
	ln -sf "$1" "$2"
}

all_umounts() {
	umount base/root
	umount base/boot
	umount dest/root
	umount dest/boot
	vgchange -an raspi
	kpartx -d dest/image
	kpartx -d base/image
}

pii_mounts() {
	local dir="${1:-murks}"
	local img="${2:-$dir/image}"
	set -- `kpartx -l "$img" | sed -e 's/ : .*//'`
	local bootdev="/dev/mapper/$1"
	local rootdev="/dev/mapper/$2"
	[ -e "$bootdev" -a -e "$rootdev" ] || die "Cannot find devs [$bootdev] [$rootdev]"
	d mount "$bootdev" "$dir/boot"
	d mount "$rootdev" "$dir/root"
}

pii_mkfs() {
	local img="${1:-murks}"
	set -- `kpartx -l "$img" | sed -e 's/ : .*//'`
	local bootdev="/dev/mapper/$1"
	local rootdev="/dev/mapper/$2"
	[ -e "$bootdev" -a -e "$rootdev" ] || die "Cannot find devs [$bootdev] [$rootdev]"
	l format destination-boot
	d mkfs.fat -n boot -F 32 "$bootdev"
	l format destination-root
	d mkfs.xfs -L root "$rootdev"
}

case "$baseimg" in
*.zip) alias unpack=d\ unpack_zip ;;
*.xz)  alias unpack=d\ unpack_xz ;;
*.bz2) alias unpack=d\ unpack_bz2 ;;
*.gz)  alias unpack=d\ unpack_gz ;;
*)     alias unpack=d\ unpack_plain ;;
esac

# let's go...

d mkdir -p base/root base/boot dest/root dest/boot

l setup base-image-access
  #[ -e base/image ] && die "base/image already exists"
  #unpack "$baseimg" base/image
d kpartx -sar base/image
l mount base-partitions
  pii_mounts base

l create destination image
d dd if=/dev/zero of=dest/image seek=$((4800*256-1)) count=1 bs=4096
d parted dest/image -- \
		mklabel msdos \
		mkpart primary fat32   4MB 132MB \
		mkpart primary lvm   133MB   -1s \
		set 2 lba off \
		print
d kpartx -sa dest/image
  pii_mkfs dest/image
d parted dest/image print
l mount destination-partitions
  pii_mounts dest

l install it
d rsync -aHAX base/boot/ dest/boot/
d rsync -aHAX base/root/ dest/root/
d rsync kernel7.img initrd7.img dest/boot
if grep -q '^initramfs ' dest/boot/config.txt
then
	d sed -i -e 's!^initramfs .*!initramfs initrd7.img followkernel!' dest/boot/config.txt
else
	l "# echo initramfs initrd7.img followkernel >> dest/boot/config.txt"
	echo initramfs initrd7.img followkernel >> dest/boot/config.txt || die "echo initramfs initrd7.img followkernel >> dest/boot/config.txt"
fi
d sed -i -e 's!\<root=[^ ]*!root=/dev/raspi/root!;s!\<rootfstype=[^ ]*!rootfstype=xfs!;s!\<init=[^ ]* *!!' dest/boot/cmdline.txt
d touch dest/boot/ssh

l setup initramfs for updates in future
d sed -i -e 's!^COMPRESS=!COMPRESS=xz!' dest/root/etc/initramfs-tools/initramfs.conf

l deactivate resize2fs-init-script
d rm dest/root/etc/rc*.d/*resize2fs_once

l change user pi to deac
d sed -i -e 's!^pi:.*!deac:x:1000:1000:Denis Knauf,,,:/home/deac:/bin/bash!' dest/root/etc/passwd
d sed -i -e 's!^pi:.*!deac:$6$aZRhIfbP$6ELyvhfjXP2wiIuq5gIsDPFXFWM1E8KwGhKFWKtFwJZ8CLwHXmZECzpxslwLbvgtYCScTZBJBTjp.hVjd6.2l1:16958:0:99999:7:::!' dest/root/etc/shadow
d sed -i -e 's!\<pi\>!deac!' dest/root/etc/group
d mv dest/root/home/pi dest/root/home/deac

  all_umounts