ar-rebar3

#!/bin/bash
set -e
set -x

if [ $# -ne 2 ]
then
	echo "ar-rebar3 <profile> <command>"
	exit 1
fi

SYSTEM=$(uname -s)
SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
PROFILE=$1
COMMAND=$2
OVERLAY_TARGET="${SCRIPT_DIR}/_vars.config"

# helper function to create erlang like value from the shell
# and stored them into a specific file.
create_overlay_var() {
	local target="${OVERLAY_TARGET}"
	local name="${1}"
	local value="$(eval ${2} 2>/dev/null || echo undefined)"

	if ! echo "${name}" | grep -E '^[a-z]+[0-9A-Za-z_]+$' >/dev/null
	then
		echo "invalid variable ${name}" 1>&2
		return 1
	fi

	if ! echo "${value}" | grep -E '^[[:print:]]+$' >/dev/null
	then
		echo "invalid value ${value}" 1>&2
		return 1
	fi

	if test -e "${target}"
	then
		printf '{%s, "%s"}.\n' "${name}" "${value}" >> "${target}"
		return 0
	fi

	printf '{%s, "%s"}.\n' "${name}" "${value}" > "${target}"
	return 0
}

# create variables required for the overlay, it will contain
# various information regarding the build and will be 
# hardcoded in the final release.
rebar3_overlay_variables() {
	echo "Crafting overlay variables..."
	if test "${SYSTEM}" = "Linux"
	then
		create_overlay_var git_rev "git rev-parse HEAD"
		create_overlay_var datetime "date -u '+%Y-%m-%dT%H:%M:%SZ'"
		create_overlay_var cc_version "cc --version | head -n1"
		create_overlay_var gmake_version "gmake --version | head -n1"
		create_overlay_var cmake_version "cmake --version | head -n1"
	else
		touch $OVERLAY_TARGET
	fi
}

# remove old artifacts that must be recreated everytime.
rebar3_clean_artifacts() {
	echo Removing build artifacts...
	rm -vf "_vars.config"
	rm -vf "${SCRIPT_DIR}/lib"
	rm -vf "${SCRIPT_DIR}/releases"
}

# execute rebar3 using the profile and the command previously
# configured
rebar3_invocation() {
	echo "Executing rebar3 as ${PROFILE} ${COMMAND}"
	${SCRIPT_DIR}/rebar3 as ${PROFILE} ${COMMAND}
}

# create artifacts required to run the code locally, only useful
# in case of release.
rebar3_create_artifacts() {
	echo Copying and linking build artifacts
	ln -vsf ${RELEASE_PATH}/arweave/releases ${SCRIPT_DIR}/releases
	ln -vsf ${RELEASE_PATH}/arweave/lib ${SCRIPT_DIR}/lib
}

######################################################################
# main script
######################################################################
rebar3_clean_artifacts
rebar3_overlay_variables
rebar3_invocation

if [ "${COMMAND}" = "release" ]
then
	RELEASE_PATH=$(${SCRIPT_DIR}/rebar3 as ${ARWEAVE_BUILD_TARGET:-default} path --rel)
	rebar3_create_artifacts
fi