install.sh

#!/usr/bin/env bash
# Install scripts
export PATH="$PATH:$HOME/.local/bin/:$HOME/.bin/"
export PATH_USER_LIB="$HOME/.local/lib/"

usage() {
	cat >&2 <<EOF
Usage:	${0##*/} [OPTIONS] [<configuration file>]]

OPTIONS:
  -h			  help
EOF
}

main() {
	# flags
	local -i enable_verbose=0
	local -i enable_quiet=0
	local -i enable_debug=0

	local -a options
	local -a args
	local installer="./tools/install.py"
	local setup_config="setup.ini"

	check_dependencies
	# parse input args
	parse_options "$@"
	# set leftover options parsed local input args
	set -- ${args[@]}
	# remove args array
	unset -v args
	check_input_args "$@"

	set_signal_handlers
	prepare_env
	pre_run
	run "$@"
	post_run
	unset_signal_handlers
}

################################################################################
# script internal execution functions
################################################################################

run() {
	local command=$1
	if [[ $(type -t _${command}) == "function" ]]; then
		echo ran $command
		_${command}
	else
		python3 "$installer" "$setup_config" || exit 1
	fi
}

check_dependencies() {
	if ! hash stow 2>&1 | logger -t install -p user.info; then
		error "'stow' is required for installation."
	fi
	! command -v "$installer" && installer="install.py"
	! command -v "$installer" && error "Could not find $installer in PATH." && exit 1
}

check_input_args() {
	:
}

prepare_env() {
	set_descriptors
	[[ -n $1 ]] && setup_config=$1
	pushd "$HOME"
	mkdir -p .local/{bin,lib}
	popd
}

prepare() {
	export PATH_USER_LIB=${PATH_USER_LIB:-"$HOME/.local/lib/"}
	local parent_path=$(
		cd "$(dirname "${BASH_SOURCE[0]}")"
		pwd -P
	)
	cd "$parent_path"
}

set_descriptors() {
	if (($enable_verbose)); then
		exec {fdverbose}>&2
	else
		exec {fdverbose}>/dev/null
	fi
	if (($enable_debug)); then
		set -xv
		exec {fddebug}>&2
	else
		exec {fddebug}>/dev/null
	fi
}

set_signal_handlers() {
	trap sigh_abort SIGABRT
	trap sigh_alarm SIGALRM
	trap sigh_hup SIGHUP
	trap sigh_cont SIGCONT
	trap sigh_usr1 SIGUSR1
	trap sigh_usr2 SIGUSR2
	trap sigh_cleanup SIGINT SIGQUIT SIGTERM EXIT
}

unset_signal_handlers() {
	trap - SIGABRT
	trap - SIGALRM
	trap - SIGHUP
	trap - SIGCONT
	trap - SIGUSR1
	trap - SIGUSR2
	trap - SIGINT SIGQUIT SIGTERM EXIT
}

pre_run() {
	:
}
post_run() {
	:
}

parse_options() {
	# exit if no options left
	[[ -z $1 ]] && return 0
	log "parse \$1: $1" 2>&$fddebug

	local do_shift=0
	case $1 in
	-d | --debug)
		enable_debug=1
		;;
	-v | --verbose)
		enable_verbose=1
		;;
	-q | --quiet)
		enable_quiet=1
		;;
	-h | --help)
		usage
		exit 0
		;;
	-p | --path)
		path=$2
		do_shift=2
		;;
	--)
		do_shift=3
		;;
	*)
		do_shift=1
		;;
	esac
	if (($do_shift == 1)); then
		args+=("$1")
	elif (($do_shift == 2)); then
		# got option with argument
		shift
	elif (($do_shift == 3)); then
		# got --, use all arguments left as options for other commands
		shift
		options+=("$@")
		return
	fi
	shift
	parse_options "$@"
}

sigh_abort() {
	trap - SIGABRT
}

sigh_alarm() {
	trap - SIGALRM
}

sigh_hup() {
	trap - SIGHUP
}

sigh_cont() {
	trap - SIGCONT
}

sigh_usr1() {
	trap - SIGUSR1
}

sigh_usr2() {
	trap - SIGUSR2
}

sigh_cleanup() {
	trap - SIGINT SIGQUIT SIGTERM EXIT
	local active_jobs=$(jobs -p)
	for p in $active_jobs; do
		if [[ -e "/proc/$p" ]]; then
			kill "$p" >/dev/null 2>&1
			wait "$p"
		fi
	done
}

mkdir() {
	! [[ -e $1 ]] && command mkdir "$@"
}

if [[ $(type -t error) != "function" ]]; then
	echo() (
		IFS=" "
		printf '%s\n' "$*"
	)
	out() { echo "$1 $2" "${@:3}"; }
	error() { out "==> ERROR:" "$@"; } >&2
fi

prepare
main "$@"