#!/usr/bin/env bash
#
# Copyright (c) 2018-2023 Intel Corporation
#
# SPDX-License-Identifier: Apache-2.0
#

set -e

typeset -r script_name=${0##*/}

# shellcheck disable=SC2034,SC2155
typeset -r cidir=$(dirname "$0")

function usage() {
	cat <<EOF
Description: Display host architecture name in various formats.

Usage: ${script_name} [options]

Options:

 -d, --default         : Show arch(1) architecture (this is the default).
 -g, --golang          : Show architecture name using golang naming.
 -r, --rust            : Show architecture name using rust naming
 -h, --help            : Show this help.
 -k, --kernel          : Show architecture name compatible with Linux* build system.

EOF
}

# Convert architecture to the name used by golang
function arch_to_golang() {
	local -r arch="$1"

	case "${arch}" in
		aarch64) echo "arm64";;
		ppc64le) echo "${arch}";;
		x86_64) echo "amd64";;
		s390x) echo "s390x";;
		*) die "unsupported architecture: ${arch}";;
	esac
}

# Convert architecture to the name used by rust
function arch_to_rust() {
	local arch="$1"

	if [[ "${arch}" == "ppc64le" ]]; then
		arch="powerpc64le"
	fi

	echo "${arch}"
}

# Convert architecture to the name used by the Linux kernel build system
function arch_to_kernel() {
	local -r arch="$1"

	case "${arch}" in
		aarch64) echo "arm64";;
		ppc64le) echo "powerpc";;
		x86_64) echo "${arch}";;
		s390x) echo "s390x";;
		*) die "unsupported architecture: ${arch}";;
	esac
}

function main() {
	local type="default"

	local getopt_cmd="getopt"

	# macOS default getopt does not recognize GNU options
	[[ "$(uname -s)" == "Darwin" ]] && getopt_cmd="/usr/local/opt/gnu-getopt/bin/${getopt_cmd}"

	local args
	args=$("${getopt_cmd}" \
		-n "${script_name}" \
		-a \
		--options="dgrhk" \
		--longoptions="default golang  rust help kernel" \
		-- "$@")

	eval set -- "${args}"
	# The eval+set above will always succeed; $? here reflects `getopt` exit status
	# which was already captured. This guard is a legacy no-op kept for safety.
	# shellcheck disable=SC2181
	[[ $? -ne 0 ]] && { usage >&2; exit 1; }

	while [[ $# -gt 1 ]]
	do
		case "$1" in
			-d|--default) ;;

			-g|--golang) type="golang";;

			-r|--rust) type="rust";;

			-h|--help)
				usage
				exit 0
				;;

			-k|--kernel) type="kernel";;

			--)
				shift
				break
				;;
		esac
		shift
	done

	local -r arch=$(uname -m)

	case "${type}" in
		default) echo "${arch}";;
		golang) arch_to_golang "${arch}";;
		rust) arch_to_rust "${arch}";;
		kernel) arch_to_kernel "${arch}";;
	esac
}

main "$@"