#!/bin/sh -e

resolve_package() {
	for pkg in "$@"
	do
		apk info "$pkg" | head -n1 | awk '{print $1}'
	done
}

strip_version_from_pkg_name() {
	for pkg in "$@"
	do
		echo "$pkg" | sed 's,-[0-9a-zA-Z.]\+-r[0-9]\+$,,'
	done
}

find_runtime_dependency_pkgs() {
	for p in "$@"
	do
		ldd "$p" 2>/dev/null |\
		grep '=> .\+\.so' |\
		awk '{print $3}' |\
		sort |\
		uniq |\
		while read -r so
		do
			apk info --who-owns $so
		done |\
		awk '{print $5}' |\
		awk -F- '{print $1}'
	done
}

find_devel_pkg() {
	# shellcheck disable=SC2046
	strip_version_from_pkg_name $(
		apk list -d "$1" |\
		grep dev |\
		sort |\
		uniq |\
		awk '{print $1}'
	)
}

# retrieve configure args of already packaged nginx
NGINX_CONFIGURE_ARGS="$(nginx -V 2>&1 | grep -o '^configure arguments: .*$' | sed 's,^configure arguments: ,,g')"
# remove preconfigured dynamic modules so only ours will be placed in the objs folder
NGINX_CONFIGURE_ARGS="$(printf '%s' "$NGINX_CONFIGURE_ARGS" | sed 's,--with-[^=]\+module=dynamic,,g')"

apk update

# Determine all dependencies used for the packaged nginx and install them
DEPENDENCIES="$(
	find_runtime_dependency_pkgs /usr/lib/nginx/modules/*.so
	# shellcheck disable=SC2046
	strip_version_from_pkg_name $(resolve_package $(apk info -R nginx | tail -n+2))
)"
DEVPACKAGES="$(for dep in $DEPENDENCIES; do find_devel_pkg "$dep"; done | sort | uniq)"
apk add --virtual .build-deps \
	gcc \
	libc-dev \
	make \
	linux-headers \
	$DEVPACKAGES
tar -zx -f nginx.tar.gz
rm nginx.tar.gz
cd nginx-*/

./configure $NGINX_CONFIGURE_ARGS --add-dynamic-module=../module --with-debug
make modules

. /etc/os-release
versionsuffix="$ID$VERSION_ID-nginx$NGINX_VERSION"

find_runtime_dependency_pkgs objs/*.so > "../required_packages-$versionsuffix.txt"
for so in objs/*.so
do
	name="$(basename "$so" .so)-$versionsuffix.so"
	install -m644 "$so" "../$name"
done