help

#!/bin/bash
# @parseArger-begin
# @parseArger-help "I send an SOS to the world" --option "help" --short-option "h"
# @parseArger-version "0.1" --option "version" --short-option "v"
# @parseArger-verbose --option "verbose" --level "0"
# @parseArger-declarations
# @parseArger pos arg-name "positional argument name"
# @parseArger pos description "positional argument description"
# @parseArger opt short "short form" --short s
# @parseArger opt no-name "value for the negation"
# @parseArger opt alias "flag alias" --repeat
# @parseArger opt no-alias "flag negation alias" --repeat
# @parseArger flag on "on by default"
# @parseArger-declarations-end

# @parseArger-utils
_helpHasBeenPrinted=1;
_SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd -P)";
# @parseArger-utils-end

# @parseArger-parsing
die()
{
	local _ret="${2:-1}"
	test "${_PRINT_HELP:-no}" = yes && print_help >&2
	log "$1" -3 >&2
	exit "${_ret}"
}


begins_with_short_option()
{
	local first_option all_short_options=''
	first_option="${1:0:1}"
	test "$all_short_options" = "${all_short_options/$first_option/}" && return 1 || return 0
}

# POSITIONALS ARGUMENTS
_positionals=();
_arg_arg_name="";
_arg_description="";
# OPTIONALS ARGUMENTS
_arg_short=
_arg_no_name=
_arg_alias=()
_arg_no_alias=()
# FLAGS
_arg_on="off"
_verbose_level="0";



print_help()
{
	_triggerSCHelp=1;

	if [[ "$_helpHasBeenPrinted" == "1" ]]; then
		_helpHasBeenPrinted=0;
		echo -e "I send an SOS to the world:"
	echo -e "	arg-name: positional argument name"
	echo -e "	description: positional argument description"
	echo -e "	-s, --short <short>: short form"
	echo -e "	--no-name <no-name>: value for the negation"
	echo -e "	--alias <alias>: flag alias, repeatable"
	echo -e "	--no-alias <no-alias>: flag negation alias, repeatable"
	echo -e "	--on|--no-on: on by default"
	echo -e "Usage :
	$0 <arg-name> <description> [--short <value>] [--no-name <value>] [--alias <value>] [--no-alias <value>] [--[no-]on]";
	fi

}

log() {
	local _arg_msg="${1}";
	local _arg_level="${2:0}";
	if [ "${_arg_level}" -le "${_verbose_level}" ]; then
		case "$_arg_level" in
			-3)
				_arg_COLOR="\033[0;31m";
				;;
			-2)
				_arg_COLOR="\033[0;33m";
				;;
			-1)
				_arg_COLOR="\033[1;33m";
				;;
			1)
				_arg_COLOR="\033[0;32m";
				;;
			2)
				_arg_COLOR="\033[1;36m";
				;;
			3)
				_arg_COLOR="\033[0;36m";
				;;
			*)
				_arg_COLOR="\033[0m";
				;;
		esac
		echo -e "${_arg_COLOR}${_arg_msg}\033[0m";
	fi
}

parse_commandline()
{
	_positionals_count=0
	while test $# -gt 0
	do
		_key="$1"
		case "$_key" in
			-s|--short)
				test $# -lt 2 && die "Missing value for the option: '$_key'" 1
				_arg_short="$2"
				shift
				;;
			--short=*)
				_arg_short="${_key##--short=}"
				;;
			-s*)
				_arg_short="${_key##-s}"
				;;
			
			--no-name)
				test $# -lt 2 && die "Missing value for the option: '$_key'" 1
				_arg_no_name="$2"
				shift
				;;
			--no-name=*)
				_arg_no_name="${_key##--no-name=}"
				;;
			
			--alias)
				test $# -lt 2 && die "Missing value for the option: '$_key'" 1
				_arg_alias+=("$2")
				shift
				;;
			--alias=*)
				_arg_alias+=("${_key##--alias=}")
				;;
			
			--no-alias)
				test $# -lt 2 && die "Missing value for the option: '$_key'" 1
				_arg_no_alias+=("$2")
				shift
				;;
			--no-alias=*)
				_arg_no_alias+=("${_key##--no-alias=}")
				;;
			
			--on)
				_arg_on="on"
				;;
			--no-on)
				_arg_on="off"
				;;
			-h|--help)
				print_help;
				exit 0;
				;;
			-h*)
				print_help;
				exit 0;
				;;
			-v|--version)
				print_version;
				exit 0;
				;;
			-v*)
				print_version;
				exit 0;
				;;
			--verbose)
				if [ $# -lt 2 ];then
					_verbose_level="$((_verbose_level + 1))";
				else
					_verbose_level="$2";
					shift;
				fi
				;;
			
			*)
				_last_positional="$1"
				_positionals+=("$_last_positional")
				_positionals_count=$((_positionals_count + 1))
				;;
		esac
		shift
	done
}


handle_passed_args_count()
{
	local _required_args_string="arg-name description"
	if [ "${_positionals_count}" -gt 2 ] && [ "$_helpHasBeenPrinted" == "1" ];then
		_PRINT_HELP=yes die "FATAL ERROR: There were spurious positional arguments --- we expect at most 2 (namely: $_required_args_string), but got ${_positionals_count} (the last one was: '${_last_positional}').\n\t${_positionals[*]}" 1
	fi
	if [ "${_positionals_count}" -lt 2 ] && [ "$_helpHasBeenPrinted" == "1" ];then
		_PRINT_HELP=yes die "FATAL ERROR: Not enough positional arguments - we require at least 2 (namely: $_required_args_string), but got only ${_positionals_count}.
	${_positionals[*]}" 1;
	fi
}


assign_positional_args()
{
	local _positional_name _shift_for=$1;
	_positional_names="_arg_arg_name _arg_description ";
	shift "$_shift_for"
	for _positional_name in ${_positional_names};do
		test $# -gt 0 || break;
		eval "if [ \"\$_one_of${_positional_name}\" != \"\" ];then [[ \"\${_one_of${_positional_name}[*]}\" =~ \"\${1}\" ]];fi" || die "${_positional_name} must be one of: $(eval "echo \"\${_one_of${_positional_name}[*]}\"")" 1;
		eval "$_positional_name=\${1}" || die "Error during argument parsing, possibly an ParseArger bug." 1;
		shift;
	done
}

print_debug()
{
	print_help
	# shellcheck disable=SC2145
	echo "DEBUG: $0 $@";
	
	echo -e "\targ-name: ${_arg_arg_name}";
	echo -e "\tdescription: ${_arg_description}";
	echo -e "\tshort: ${_arg_short}";
	echo -e "\tno-name: ${_arg_no_name}";
	echo -e "\talias: ${_arg_alias[*]}";
	echo -e "\tno-alias: ${_arg_no_alias[*]}";
	echo -e "\ton: ${_arg_on}";

}

print_version()
{
	echo "0.1";
}

on_interrupt() {
	die Process aborted! 130;
}

parse_commandline "$@";
handle_passed_args_count;
assign_positional_args 1 "${_positionals[@]}";
trap on_interrupt INT;



# @parseArger-parsing-end
# print_debug "$@"
# @parseArger-end

if [ "$_arg_no_name" == "" ]; then
	_arg_no_name="no-${_arg_arg_name}";
fi
optHelp="--${_arg_arg_name}|--${_arg_no_name}: ${_arg_description}";

if [ "$_arg_short" != "" ]; then
  optHelp="-${_arg_short}|${optHelp}";
fi
if [ "$_arg_on" != "off" ]; then
  optHelp="$optHelp, on by default (use --${_arg_no_name} to turn it off)";
fi
if [ "${#_arg_alias[@]}" -gt 0 ]; then
	optHelp+="
		aliases:";
	for ali in "${_arg_alias[@]}"; do
		optHelp+=" --${ali},";
	done
fi
if [ "${#_arg_no_alias[@]}" -gt 0 ]; then
	optHelp+="
		no-aliases:";
	for ali in "${_arg_no_alias[@]}"; do
		optHelp+=" --${ali},";
	done
fi

echo -e "	echo -e \"\t${optHelp}\"";