{{
	def is_alpine:
		env.variant | startswith("alpine")
	;
	def is_slim:
		env.variant | startswith("slim-")
-}}
{{ if is_alpine then ( -}}
FROM alpine:{{ env.variant | ltrimstr("alpine") }}
{{ ) elif is_slim then ( -}}
FROM debian:{{ env.variant | ltrimstr("slim-") }}-slim
{{ ) else ( -}}
FROM buildpack-deps:{{ env.variant }}
{{ ) end -}}

{{ if is_alpine then ( -}}
RUN set -eux; \
	apk add --no-cache \
		bzip2 \
		ca-certificates \
		gmp-dev \
		libffi-dev \
		procps \
		yaml-dev \
		zlib-dev \
	;

{{ ) elif is_slim then ( -}}
RUN set -eux; \
	apt-get update; \
	apt-get install -y --no-install-recommends \
		bzip2 \
		ca-certificates \
		libffi-dev \
		libgmp-dev \
		libssl-dev \
		libyaml-dev \
		procps \
		zlib1g-dev \
	; \
	rm -rf /var/lib/apt/lists/*

{{ ) else "" end -}}
# skip installing gem documentation
RUN set -eux; \
	mkdir -p /usr/local/etc; \
	{ \
		echo 'install: --no-document'; \
		echo 'update: --no-document'; \
	} >> /usr/local/etc/gemrc

ENV LANG C.UTF-8
ENV RUBY_MAJOR {{ env.version }}
ENV RUBY_VERSION {{ .version }}
ENV RUBY_DOWNLOAD_SHA256 {{ .sha256 }}

# some of ruby's build scripts are written in ruby
#   we purge system ruby later to make sure our final image uses what we just built
RUN set -eux; \
	\
{{ if is_alpine then ( -}}
# readline-dev vs libedit-dev: https://bugs.ruby-lang.org/issues/11869 and https://github.com/docker-library/ruby/issues/75
	apk add --no-cache --virtual .ruby-builddeps \
		autoconf \
		bison \
		bzip2 \
		bzip2-dev \
		ca-certificates \
		coreutils \
		dpkg-dev dpkg \
		g++ \
		gcc \
		gdbm-dev \
		glib-dev \
		libc-dev \
		libffi-dev \
		libxml2-dev \
		libxslt-dev \
		libucontext-dev \
		linux-headers \
		make \
		ncurses-dev \
		openssl \
		openssl-dev \
		patch \
		procps \
		readline-dev \
		ruby \
		tar \
		xz \
		yaml-dev \
		zlib-dev \
	; \
{{ ) else ( -}}
	savedAptMark="$(apt-mark showmanual)"; \
	apt-get update; \
	apt-get install -y --no-install-recommends \
		bison \
		dpkg-dev \
		libgdbm-dev \
		ruby \
{{ if is_slim then ( -}}
		autoconf \
		g++ \
		gcc \
		libbz2-dev \
		libgdbm-compat-dev \
		libglib2.0-dev \
		libncurses-dev \
		libreadline-dev \
		libxml2-dev \
		libxslt-dev \
		make \
		wget \
		xz-utils \
{{ ) else "" end -}}
	; \
	rm -rf /var/lib/apt/lists/*; \
{{ ) end -}}
	\
	wget -O ruby.tar.xz "https://cache.ruby-lang.org/pub/ruby/${RUBY_MAJOR%-rc}/ruby-$RUBY_VERSION.tar.xz"; \
	echo "$RUBY_DOWNLOAD_SHA256 *ruby.tar.xz" | sha256sum --check --strict; \
	\
	mkdir -p /usr/src/ruby; \
	tar -xJf ruby.tar.xz -C /usr/src/ruby --strip-components=1; \
	rm ruby.tar.xz; \
	\
	cd /usr/src/ruby; \
	\
{{ if is_alpine then ( -}}
# https://github.com/docker-library/ruby/issues/196
# https://bugs.ruby-lang.org/issues/14387#note-13 (patch source)
# https://bugs.ruby-lang.org/issues/14387#note-16 ("Therefore ncopa's patch looks good for me in general." -- only breaks glibc which doesn't matter here)
	wget -O 'thread-stack-fix.patch' 'https://bugs.ruby-lang.org/attachments/download/7081/0001-thread_pthread.c-make-get_main_stack-portable-on-lin.patch'; \
	echo '3ab628a51d92fdf0d2b5835e93564857aea73e0c1de00313864a94a6255cb645 *thread-stack-fix.patch' | sha256sum --check --strict; \
	patch -p1 -i thread-stack-fix.patch; \
	rm thread-stack-fix.patch; \
	\
{{
	{
		"2.6": {
			url: "https://github.com/ruby/ruby/pull/3773",
			commit: "fcc88da5eb162043adcba552646677d2ab5adf55",
		},
	}[env.version] | if . and env.variant != "alpine3.13" then (
-}}
# https://bugs.ruby-lang.org/issues/17723 (building with autoconf 2.70+ fails)
# {{ .url }}
	wget -O 'autoconf-2.70.patch' 'https://github.com/ruby/ruby/commit/{{ .commit }}.patch'; \
	patch -p1 -i autoconf-2.70.patch; \
	rm autoconf-2.70.patch; \
	\
{{ ) else "" end -}}
# the configure script does not detect isnan/isinf as macros
	export ac_cv_func_isnan=yes ac_cv_func_isinf=yes; \
	\
{{ ) else "" end -}}
# hack in "ENABLE_PATH_CHECK" disabling to suppress:
#   warning: Insecure world writable dir
	{ \
		echo '#define ENABLE_PATH_CHECK 0'; \
		echo; \
		cat file.c; \
	} > file.c.new; \
	mv file.c.new file.c; \
	\
	autoconf; \
	gnuArch="$(dpkg-architecture --query DEB_BUILD_GNU_TYPE)"; \
{{ if is_alpine and env.version == "2.7" then ( -}}
	export LIBS='-lucontext'; \
{{ ) else "" end -}}
	./configure \
		--build="$gnuArch" \
		--disable-install-doc \
		--enable-shared \
	; \
	make -j "$(nproc)"; \
	make install; \
	\
{{ if is_alpine then ( -}}
	runDeps="$( \
		scanelf --needed --nobanner --format '%n#p' --recursive /usr/local \
			| tr ',' '\n' \
			| sort -u \
			| awk 'system("[ -e /usr/local/lib/" $1 " ]") == 0 { next } { print "so:" $1 }' \
	)"; \
	apk add --no-network --virtual .ruby-rundeps $runDeps; \
	apk del --no-network .ruby-builddeps; \
{{ ) else ( -}}
	apt-mark auto '.*' > /dev/null; \
	apt-mark manual $savedAptMark > /dev/null; \
	find /usr/local -type f -executable -not \( -name '*tkinter*' \) -exec ldd '{}' ';' \
		| awk '/=>/ { print $(NF-1) }' \
		| sort -u \
		| grep -vE '^/usr/local/lib/' \
		| xargs -r dpkg-query --search \
		| cut -d: -f1 \
		| sort -u \
		| xargs -r apt-mark manual \
	; \
	apt-get purge -y --auto-remove -o APT::AutoRemove::RecommendsImportant=false; \
{{ ) end -}}
	\
	cd /; \
	rm -r /usr/src/ruby; \
# verify we have no "ruby" packages installed
{{ if is_alpine then ( -}}
	if \
		apk --no-network list --installed \
			| grep -v '^[.]ruby-rundeps' \
			| grep -i ruby \
	; then \
		exit 1; \
	fi; \
{{ ) else ( -}}
	if dpkg -l | grep -i ruby; then exit 1; fi; \
{{ ) end -}}
	[ "$(command -v ruby)" = '/usr/local/bin/ruby' ]; \
# rough smoke test
	ruby --version; \
	gem --version; \
	bundle --version

# don't create ".bundle" in all our apps
ENV GEM_HOME /usr/local/bundle
ENV BUNDLE_SILENCE_ROOT_WARNING=1 \
	BUNDLE_APP_CONFIG="$GEM_HOME"
ENV PATH $GEM_HOME/bin:$PATH
# adjust permissions of a few directories for running "gem install" as an arbitrary user
RUN mkdir -p "$GEM_HOME" && chmod 777 "$GEM_HOME"

CMD [ "irb" ]