#!/bin/sh

# apk add abuild apk-tools alpine-conf busybox fakeroot xorriso

# FIXME: clean workdir out of unneeded sections
# FIXME: --release: cp/mv images to REPODIR/$ARCH/releases/
# FIXME: --update-latest: rewrite latest-releases.yaml with this build

set -e

# get abuild configurables
[ -e /usr/share/abuild/functions.sh ] || (echo "abuild not found" ; exit 1)
. /usr/share/abuild/functions.sh

# deduce aports directory
[ -n "$APORTS" ] || APORTS=$(realpath $(dirname $0)/../)
[ -e "$APORTS/main/build-base" ] || die "Unable to deduce aports base checkout"

# 
all_sections=""
all_profiles=""
all_checksums="sha256 sha512"
all_arches="armhf x86 x86_64"
all_dirs=""
build_date="$(date +%y%m%d)"
default_arch="$(apk --print-arch)"
_hostkeys=""
_simulate=""
_checksum=""

OUTDIR="$PWD"
RELEASE="${build_date}"

msg() {
	if [ -n "$quiet" ]; then return 0; fi
	local prompt="$GREEN>>>${NORMAL}"
	local name="${BLUE}mkimage${ARCH+-$ARCH}${NORMAL}"
	printf "${prompt} ${name}: %s\n" "$1" >&2
}

list_has() {
	local needle="$1"
	local i
	shift
	for i in $@; do
		[ "$needle" != "$i" ] || return 0
	done
	return 1
}

usage() {
	cat <<EOF

$0	[--tag RELEASE] [--outdir OUTDIR] [--workdir WORKDIR]
		[--arch ARCH] [--profile PROFILE] [--hostkeys] [--simulate]
$0	--help

options:
--arch		Specify which architecture images to build
		(default: $default_arch)
--hostkeys	Copy system apk signing keys to created images
--outdir	Specify directory for the created images
--profile	Specify which profiles to build
--simulate	Don't execute commands
--tag		Build images for tag RELEASE
--workdir	Specify temporary working directory (cache)

known profiles: $(echo $all_profiles | sort -u)

EOF
}

# helpers
load_plugins() {
	local f
	[ -e "$1" ] || return 0
	for f in "$1"/mkimg.*.sh; do
		[ -e "$f" ] || return 0
		break
	done
	all_profiles="$all_profiles $(sed -n -e 's/^profile_\(.*\)() {$/\1/p' $1/mkimg.*.sh)"
	all_sections="$all_sections $(sed -n -e 's/^section_\(.*\)() {$/\1/p' $1/mkimg.*.sh)"
	for f in "$1"/mkimg.*.sh; do
		. $f
	done
}

checksum() {
	sha1sum | cut -f 1 -d ' '
}

build_section() {
	local section="$1"
	local args="$@"
	local _dir="${args//[^a-zA-Z0-9]/_}"
	shift
	local args="$@"

	if [ -z "$_dir" ]; then
		_fail="yes"
		return 1
	fi

	if [ ! -e "$WORKDIR/${_dir}" ]; then
		DESTDIR="$WORKDIR/${_dir}.work"
		msg "--> $section $args"
		if [ -z "$_simulate" ]; then
			rm -rf "$DESTDIR"
			mkdir -p "$DESTDIR"
			if build_${section} "$@"; then
				mv "$DESTDIR" "$WORKDIR/${_dir}"
				_dirty="yes"
			else
				rm -rf "$DESTDIR"
				_fail="yes"
				return 1
			fi
		fi
	fi
	unset DESTDIR
	all_dirs="$all_dirs $_dir"
	_my_sections="$_my_sections $_dir"
}

build_profile() {
	local _id _dir _spec
	_my_sections=""
	_dirty="no"
	_fail="no"

	profile_$PROFILE
	list_has $ARCH $arch || return 0

	msg "Building $PROFILE"

	# Collect list of needed sections, and make sure they are built
	for SECTION in $all_sections; do
		section_$SECTION || return 1
	done
	[ "$_fail" = "no" ] || return 1

	# Defaults
	[ -n "$image_name" ] || image_name="alpine-${PROFILE}"
	[ -n "$output_filename" ] || output_filename="${image_name}-${RELEASE}-${ARCH}.${image_ext}"

	# Construct final image
	local _imgid=$(echo -n $_my_sections | sort | checksum)
	DESTDIR=$WORKDIR/image-$_imgid-$ARCH-$PROFILE
	if [ "$_dirty" = "yes" -o ! -e "$DESTDIR" ]; then
		msg "Creating $output_filename"
		if [ -z "$_simulate" ]; then
			# Merge sections
			rm -rf "$DESTDIR"
			mkdir -p "$DESTDIR"
			for _dir in $_my_sections; do
				for _fn in $WORKDIR/$_dir/*; do
					[ ! -e "$_fn" ] || cp -Lrs $_fn $DESTDIR/
				done
			done
			echo "${image_name}-${RELEASE} ${build_date}" > "$DESTDIR"/.alpine-release
		fi
	fi

	if [ "$_dirty" = "yes" -o ! -e "$output_filename" ]; then
		# Create image
		output_format="${image_ext//[:\.]/}"
		create_image_${output_format} || { _fail="yes"; false; }

		if [ "$_checksum" = "yes" ]; then
			for _c in $all_checksums; do
				${_c}sum "$output_filename" > "${output_filename}.${_c}"
			done
		fi
	fi
}

# load plugins
load_plugins "$(dirname $0)"
[ -z "$HOME" ] || load_plugins "$HOME/.mkimage"

# parse parameters
while [ $# -gt 0 ]; do
	opt="$1"
	shift
	case "$opt" in
	--repository) REPODIR="$1"; shift ;;
	--workdir) WORKDIR="$1"; shift ;;
	--outdir) OUTDIR="$1"; shift ;;
	--tag) RELEASE="$1"; shift ;;
	--arch) req_arch="$1"; shift ;;
	--profile) req_profiles="$1"; shift ;;
	--hostkeys) _hostkeys="--hostkeys";;
	--simulate) _simulate="yes";;
	--checksum) _checksum="yes";;
	--) break ;;
	-*) usage; exit 1;;
	esac
done

# setup defaults
if [ -z "$WORKDIR" ]; then
	WORKDIR="$(mktemp -d -t mkimage.XXXXXX)"
	trap 'rm -rf $WORKDIR' INT
	mkdir -p "$WORKDIR"
fi
req_profiles=${req_profiles:-${all_profiles}}
req_arch=${req_arch:-${default_arch}}
[ "$req_arch" != "all" ] || req_arch="${all_arch}"
[ "$req_profiles" != "all" ] || req_profiles="${all_profiles}"

# create images
for ARCH in $req_arch; do
	APKROOT="$WORKDIR/apkroot-$ARCH"
	if [ ! -e "$APKROOT" ]; then
		# create root for caching packages
		mkdir -p "$APKROOT/etc/apk/cache"
		cp -Pr /etc/apk/keys "$APKROOT/etc/apk/"
		abuild-apk --arch "$ARCH" --root "$APKROOT" add --initdb

		if [ -z "$REPODIR" ]; then
			warning "no repository set"
		fi
		echo "$REPODIR" > "$APKROOT/etc/apk/repositories"
	fi
	abuild-apk update --root "$APKROOT"

	for PROFILE in $req_profiles; do
		(build_profile) || exit 1
	done
done
