#!/bin/sh /etc/rc.common
#
# Copyright 2020 lwz322 <lwz322@qq.com>
# Licensed to the public under the MIT License.
#

START=99
USE_PROCD=1

NAME="frps"
CONFIG_FOLDER="/var/etc/$NAME"

_log() {
	local level="$1" ; shift
	local msg="$@"
	logger -p "daemon.$level" -t "$NAME" "$msg"

	echo "[$level] $msg" >&2
}

_info() {
	_log "info" $@
}

_err() {
	_log "err" $@
}

append_options() {
	local file="$1" ; shift
	local o v
	for o in "$@" ; do
		v="$(eval echo "\$$o")"
		if [ -n "$v" ] ; then
			# add brackets when ipv6 address
			if ( echo "$o" | grep -qE 'addr|ip' ) &&
				( echo "$v" | grep -q ':' ) ; then
				v="[$v]"
			fi

			echo "${o} = $v" >>"$file"
		fi
	done
}

append_setting() {
	local file="$1" ; shift
	local s="$1"
	if [ -n "$s" ] ; then
		echo "$s" >>"$file"
	fi
}

frps_scetion_validate() {
	uci_validate_section "$NAME" "frps" "$1" \
		'enabled:bool:0' \
		'client_file:file:/usr/bin/frps' \
		'run_user:string' \
		'enable_logging:bool:0' \
		'log_file:string:/var/log/frps.log' \
		'log_level:or("trace", "debug", "info", "warn", "error"):warn' \
		'log_max_days:uinteger:3' \
		'disable_log_color:or("true", "false")' \
		'max_pool_count:uinteger' \
		'max_ports_per_client:uinteger:0' \
		'subdomain_host:host' \
		'dashboard_addr:host' \
		'dashboard_port:port' \
		'dashboard_user:string' \
		'dashboard_pwd:string' \
	    'bind_port:port' \
		'token:string' \
		'tcp_mux:or("true", "false"):true' \
		'tls_only:or("true", "false"):false' \
		'bind_udp_port:port' \
		'kcp_bind_port:port' \
		'vhost_http_port:port' \
		'vhost_https_port:port'
}

client_file_validate() {
	local file="$1"

	test -f "$file" || return 1
	test -x "$file" || chmod 755 "$file"

	eval "$file" -h | grep -q "$NAME"
	return $?
}

add_rule_extra_option() {
	append_setting "$2" "$1"
}

create_config_file() {
	local config_file="$1"
	local tmp_file="$(mktemp /tmp/frps-XXXXXX)"

	echo "[common]" > "$tmp_file"
	
	append_options "$tmp_file" \
		"bind_port" "token" "tcp_mux" "tls_only" "bind_udp_port" "kcp_bind_port" "vhost_http_port" "vhost_https_port" 


	if [ "x$enable_logging" = "x1" ] ; then
		if [ -z "$log_file" ]; then
			log_file="/var/log/frps.log"
		fi

		append_options "$tmp_file" \
			"log_file" "log_level" "log_max_days" "disable_log_color"

		if [ -f "$log_file" ] ; then
			echo > "$log_file"
		else
			local log_folder="$(dirname "$log_file")"

			if [ ! -d "$log_folder" ] ; then
				mkdir -p "$log_folder"
			fi
		fi

		if [ -n "$run_user" ] && ( user_exists "$run_user" ) ; then
			chmod 644 "$log_file"
			chown "$run_user" "$log_file"
		else
			run_user=""
		fi
	fi

	append_options "$tmp_file" \
		"max_pool_count" "max_ports_per_client" "subdomain_host" "dashboard_addr" "dashboard_port" "dashboard_user" "dashboard_pwd"

	extra_setting=$(uci get frps.main.extra_setting 2>/dev/null)
	if [ -n "$extra_setting" ] ; then
		for o in $extra_setting ;do
			echo "$o" >> "$tmp_file"
		done
	fi

	sed '/^$/d' "$tmp_file" >"$config_file"

	if [ "$?" = "0" ] ; then
		rm -f "$tmp_file"
	fi
}

start_instance() {
	local section="$1"

	if ! frps_scetion_validate "$section" ; then
		_err "Config validate failed."
		return 1
	fi

	if [ "x$enabled" != "x1" ] ; then
		_info "Instance \"$section\" disabled."
		return 1
	fi

	if [ -z "$client_file" ] || ( ! client_file_validate "$client_file" ) ; then
		_err "Client file not valid."
		return 1
	fi

	test -d "$CONFIG_FOLDER" || mkdir -p "$CONFIG_FOLDER"

	local config_file="$CONFIG_FOLDER/frps.$section.ini"

	create_config_file "$config_file"

	if [ ! -f "$config_file" ] ; then
		_err "Could not create config file: \"$config_file\""
		return 1
	fi

	procd_open_instance "$NAME.$section"
	procd_set_param command "$client_file"
	procd_append_param command -c "$config_file"
	procd_set_param respawn
	procd_set_param file "$config_file"

	if [ -n "$run_user" ] ; then
		procd_set_param user "$run_user"
	fi

	procd_close_instance
}

service_triggers() {
	procd_add_reload_trigger "$NAME"
}

start_service() {
	config_load "$NAME"
	config_foreach start_instance "frps"
}