#!/usr/bin/bash
# SPDX-License-Identifier: GPL-2.0-or-later

set -euo pipefail

function spdlog() {
	local level="${1}" messages=("${@:2}")

	case "${level}" in
	info)
		level="$(printf "%s%s%s" "\033[32m" "info" "\e[0m")"
		;;
	warn)
		level="$(printf "%s%s%s" "\033[33m\033[1m" "warning" "\e[0m")"
		;;
	error)
		level="$(printf "%s%s%s" "\033[31m\033[1m" "error" "\e[0m")"
		;;
	esac

	echo -e "[$(date '+%H:%M:%S.%3N')] [${level}]" "${messages[@]}" >&2
}

function print-if-executable() {
	local file="${1}"

	if [ -x "${file}" ]; then
		echo "${file}"
		return 0
	fi

	return 1
}

function find-program() {
	local name="${1}" script_dir="${2}" project_dir="${3:-}"

	# If the calling script is installed to /usr, the program should be right next to it
	if print-if-executable "${script_dir}/${name}"; then
		return 0
	fi

	# Otherwise the script might be called from the cloned git repository
	if [ -n "${project_dir}" ] && [ -f "${project_dir}/meson_options.txt" ]; then
		local -r file="$(find "${project_dir}" -type f -executable -name "${name}" | head -n1)"

		if print-if-executable "${file}"; then
			spdlog info "Located ${name} at ./$(realpath --relative-to="${PWD}" "${file}")"
			return 0
		fi
	fi

	# Fall back to looking in PATH
	if print-if-executable "$(command -v "${name}" || true)"; then
		spdlog warn "Located ${name} using PATH"
		spdlog warn "This script is designed to not use PATH, something might be wrong"
		return 0
	fi

	return 1
}

function run-iptsd-foreach() {
	local -r script_dir="$(dirname "$(realpath "${BASH_SOURCE[0]}")")"
	local -r project_dir="$(realpath "${script_dir}/../..")"

	local device_index=""
	local device_type="any"
	local xargs_procs="1"
	local tmux_socket=""
	local show_help=""

	while getopts ":t:i:pmh" args; do
		case "${args}" in
		i)
			device_index="${OPTARG}"
			;;
		t)
			device_type="${OPTARG}"
			;;
		p)
			xargs_procs="0"
			;;
		m)
			xargs_procs="0"
			tmux_socket="$(mktemp -u)"
			;;
		*)
			show_help="1"
			;;
		esac
	done

	shift $((OPTIND - 1))

	if (("$#" == 0)); then
		show_help="1"
	fi

	if [ -n "${show_help}" ]; then
		echo "Usage: iptsd-foreach [OPTIONS] -- COMMAND"
		echo "Run commands on all IPTS devices"
		echo ""
		echo "The string that is passed as COMMAND is executed in a bash shell."
		echo "Every occurence of {} will be replaced with the selected device."
		echo ""
		echo "Options:"
		echo "  -h                                   Print this help message and exit"
		echo "  -t  TEXT:{any,touchscreen,touchpad}  Selects all devices with the given type"
		echo "  -i  INTEGER                          Selects a single device by its index"
		echo "  -p                                   Run all commands in parallel"
		echo "  -m                                   Like -p, but runs every instance in seperate tmux windows"

		return 0
	fi

	if [ -n "${tmux_socket}" ] && [ ! -x "$(command -v tmux)" ]; then
		spdlog error "tmux is not installed"
		return 1
	fi

	local -r check_device="$(find-program "iptsd-check-device" "${script_dir}" "${project_dir}")"

	if [ -z "${check_device}" ]; then
		spdlog error "Could not locate iptsd-check-device"
		return 1
	fi

	local devices=()

	while read -rd $'\n' device; do
		if [ ! -r "${device}" ]; then
			spdlog warn "Can't read from ${device}, is the program running as root?"
			continue
		fi

		if ! "${check_device}" --quiet --type="${device_type}" "${device}"; then
			continue
		fi

		devices+=("${device}")
	done <<<"$(find /dev -maxdepth 1 | grep -E "hidraw[0-9]+" | sort)"

	# If no devices were found, exit
	if (("${#devices[@]}" == 0)); then
		spdlog info "No devices found"
		return 0
	fi

	if [ -n "${device_index}" ]; then
		if (("${#devices[@]}" <= "${device_index}")) || (("${device_index}" < 0)); then
			spdlog error "Device index is out of range"
			return 1
		fi

		devices=("${devices[${device_index}]}")
	fi

	# Ignore the tmux option if there is only one device
	if (("${#devices[@]}" == 1)); then
		tmux_socket=""
	fi

	local xargs_cmd=("bash" "-c" "$*")

	if [ -n "${tmux_socket}" ]; then
		xargs_cmd=("tmux" "-S" "${tmux_socket}" "new-window" "-n" "{}" "${xargs_cmd[@]}")
		tmux -S "${tmux_socket}" new-session -d -n iptsd
	fi

	# Save existing traps
	local -r saved_traps="$(trap)"

	# Ignore SIGINT and SIGTERM, these have to be handled by xargs / iptsd
	trap -- "" SIGINT
	trap -- "" SIGTERM

	# Run the supplied commands on all devices
	echo -n "${devices[@]}" | xargs -d ' ' -P "${xargs_procs}" -i "${xargs_cmd[@]}"

	# Restore SIGINT and SIGTERM to their defaults
	trap -- - SIGINT
	trap -- - SIGTERM

	# Restore previous traps
	eval "${saved_traps}"

	if [ -n "${tmux_socket}" ]; then
		tmux -S "${tmux_socket}" kill-window -t 0
		tmux -S "${tmux_socket}" attach
	fi

	return 0
}

if [ "${BASH_SOURCE[0]}" = "${0}" ]; then
	run-iptsd-foreach "$@"
fi