#!/bin/sh

. /lib/functions.sh
. /usr/share/libubox/jshn.sh

STATE_CONFIG="onekeyap"
STATE_SECTION="main"
BACKUP_DIR="/etc/onekeyap"
NETWORK_BACKUP="${BACKUP_DIR}/network.backup"
DHCP_BACKUP="${BACKUP_DIR}/dhcp.backup"
RELOAD_LOG="/tmp/onekeyap-reload.log"

append_unique() {
	local var="$1"
	local item current

	shift
	eval "current=\${$var}"

	for item in "$@"; do
		[ -n "$item" ] || continue

		case " $current " in
			*" $item "*) ;;
			*) current="${current:+$current }$item" ;;
		esac
	done

	eval "$var=\$current"
}

ensure_state() {
	if ! uci -q get "${STATE_CONFIG}.${STATE_SECTION}" >/dev/null; then
		uci batch <<-EOF >/dev/null
			set ${STATE_CONFIG}.${STATE_SECTION}=settings
			set ${STATE_CONFIG}.${STATE_SECTION}.mode='router'
			set ${STATE_CONFIG}.${STATE_SECTION}.fallback_ip='10.0.0.1'
			set ${STATE_CONFIG}.${STATE_SECTION}.fallback_mask='255.255.255.0'
			set ${STATE_CONFIG}.${STATE_SECTION}.fallback_cidr='24'
EOF
		uci commit "${STATE_CONFIG}" >/dev/null
	fi
}

state_get() {
	uci -q get "${STATE_CONFIG}.${STATE_SECTION}.$1"
}

state_set() {
	uci set "${STATE_CONFIG}.${STATE_SECTION}.$1=$2"
}

state_set_list() {
	local option="$1"
	local item

	shift
	uci -q delete "${STATE_CONFIG}.${STATE_SECTION}.${option}"

	for item in "$@"; do
		[ -n "$item" ] || continue
		uci add_list "${STATE_CONFIG}.${STATE_SECTION}.${option}=${item}"
	done
}

reply_json() {
	local code="${1:-0}"
	local mode="${2}"
	local message="${3}"

	json_init
	json_add_int code "${code}"
	[ -n "${mode}" ] && json_add_string mode "${mode}"
	[ -n "${message}" ] && json_add_string message "${message}"
	json_dump
}

json_add_words() {
	local name="$1"
	local item

	shift
	json_add_array "${name}"
	for item in "$@"; do
		[ -n "${item}" ] || continue
		json_add_string "" "${item}"
	done
	json_close_array
}

collect_ipv4_addrs() {
	local dev="$1"

	[ -n "${dev}" ] || return 0

	ip -o -4 addr show dev "${dev}" 2>/dev/null | awk '{ print $4 }'
}

find_device_section_match=""

find_device_section_cb() {
	local section="$1"
	local target="$2"
	local name

	config_get name "${section}" name
	[ "${name}" = "${target}" ] && find_device_section_match="${section}"
}

find_device_section() {
	local target="$1"

	find_device_section_match=""
	config_load network
	config_foreach find_device_section_cb device "${target}"

	printf '%s\n' "${find_device_section_match}"
}

collect_interface_devices() {
	local iface="$1"
	local direct dev section ports type

	direct="$(uci -q get "network.${iface}.device")"
	[ -n "${direct}" ] || direct="$(uci -q get "network.${iface}.device")"
	[ -n "${direct}" ] || return 0

	for dev in ${direct}; do
		case "${dev}" in
			@*) continue ;;
		esac

		section="$(find_device_section "${dev}")"
		type="$(uci -q get "network.${section}.type")"

		if [ -n "${section}" ] && [ "${type}" = "bridge" ]; then
			ports="$(uci -q get "network.${section}.ports")"
			if [ -n "${ports}" ]; then
				printf '%s\n' "${ports}"
			else
				printf '%s\n' "${dev}"
			fi
		else
			printf '%s\n' "${dev}"
		fi
	done
}

zone_networks=""

find_zone_networks_cb() {
	local section="$1"
	local target="$2"
	local name network

	config_get name "${section}" name
	[ "${name}" = "${target}" ] || return 0

	config_get network "${section}" network
	zone_networks="${network}"
}

get_wan_networks() {
	local iface result=""

	zone_networks=""
	config_load firewall
	config_foreach find_zone_networks_cb zone "wan"

	if [ -n "${zone_networks}" ]; then
		for iface in ${zone_networks}; do
			uci -q get "network.${iface}" >/dev/null || continue
			append_unique result "${iface}"
		done
	fi

	if [ -z "${result}" ]; then
		for iface in wan wan6; do
			uci -q get "network.${iface}" >/dev/null || continue
			append_unique result "${iface}"
		done
	fi

	printf '%s\n' "${result}"
}

get_lan_ports() {
	local result="" item

	for item in $(collect_interface_devices lan); do
		append_unique result "${item}"
	done

	printf '%s\n' "${result}"
}

get_wan_ports() {
	local iface result="" item

	for iface in $(get_wan_networks); do
		for item in $(collect_interface_devices "${iface}"); do
			append_unique result "${item}"
		done
	done

	printf '%s\n' "${result}"
}

ensure_lan_bridge() {
	local current_lan_device bridge_section final_device port

	current_lan_device="$(uci -q get network.lan.device)"
	final_device="${current_lan_device}"

	if [ -n "${current_lan_device}" ]; then
		bridge_section="$(find_device_section "${current_lan_device}")"
	fi

	if [ -n "${bridge_section}" ] && [ "$(uci -q get "network.${bridge_section}.type")" = "bridge" ]; then
		final_device="${current_lan_device}"
	else
		final_device="br-lan"
		bridge_section="$(find_device_section "${final_device}")"
		[ -n "${bridge_section}" ] || bridge_section="$(uci add network device)"
	fi

	uci set "network.${bridge_section}=device"
	uci set "network.${bridge_section}.name=${final_device}"
	uci set "network.${bridge_section}.type=bridge"
	uci -q delete "network.${bridge_section}.ports"

	for port in "$@"; do
		[ -n "${port}" ] || continue
		uci add_list "network.${bridge_section}.ports=${port}"
	done

	uci set "network.lan.device=${final_device}"
	uci -q delete network.lan.device
	uci -q delete network.lan.type

	printf '%s\n' "${final_device}"
}

schedule_reload() {
	local target_mode="$1"

	(
		sleep 1
		/etc/init.d/network restart
		/etc/init.d/dnsmasq restart
		/etc/init.d/odhcpd restart
		/etc/init.d/firewall restart
		[ "${target_mode}" = "ap" ] && /usr/libexec/onekeyap refresh-fallback
	) >"${RELOAD_LOG}" 2>&1 &
}

get_lan_runtime_device() {
	local json dev

	json="$(ubus call network.interface.lan status 2>/dev/null)"
	if [ -n "${json}" ]; then
		json_load "${json}"
		json_get_var dev l3_device
		[ -n "${dev}" ] || json_get_var dev device
		json_cleanup
	fi

	[ -n "${dev}" ] || dev="$(uci -q get network.lan.device)"
	[ -n "${dev}" ] || dev="$(state_get ap_lan_device)"

	printf '%s\n' "${dev}"
}

refresh_fallback() {
	local mode dev fallback_ip fallback_cidr

	ensure_state
	mode="$(state_get mode)"
	[ "${mode}" = "ap" ] || exit 0

	dev="$(get_lan_runtime_device)"
	fallback_ip="$(state_get fallback_ip)"
	fallback_cidr="$(state_get fallback_cidr)"

	[ -n "${dev}" ] || exit 0
	[ -n "${fallback_ip}" ] || exit 0
	[ -n "${fallback_cidr}" ] || fallback_cidr="24"

	ip -o -4 addr show dev "${dev}" 2>/dev/null | grep -q " ${fallback_ip}/${fallback_cidr} " && exit 0
	ip addr add "${fallback_ip}/${fallback_cidr}" dev "${dev}" 2>/dev/null
}

remove_current_fallback() {
	local dev fallback_ip fallback_cidr

	dev="$(get_lan_runtime_device)"
	fallback_ip="$(state_get fallback_ip)"
	fallback_cidr="$(state_get fallback_cidr)"

	[ -n "${dev}" ] || return 0
	[ -n "${fallback_ip}" ] || return 0
	[ -n "${fallback_cidr}" ] || fallback_cidr="24"

	ip addr del "${fallback_ip}/${fallback_cidr}" dev "${dev}" 2>/dev/null
}

status() {
	local mode button_text fallback_ip fallback_cidr
	local current_lan_ports current_lan_ipv4
	local saved_lan_ports saved_wan_ports
	local lan_runtime_dev item current_lan_ports_words="" current_lan_ipv4_words=""

	ensure_state

	mode="$(state_get mode)"
	[ -n "${mode}" ] || mode="router"

	if [ "${mode}" = "ap" ]; then
		button_text="开启路由器模式"
	else
		button_text="开启 AP 模式"
	fi

	fallback_ip="$(state_get fallback_ip)"
	fallback_cidr="$(state_get fallback_cidr)"
	[ -n "${fallback_ip}" ] || fallback_ip="10.0.0.1"
	[ -n "${fallback_cidr}" ] || fallback_cidr="24"

	current_lan_ports="$(get_lan_ports)"
	saved_lan_ports="$(state_get last_lan_ports)"
	saved_wan_ports="$(state_get last_wan_ports)"
	lan_runtime_dev="$(get_lan_runtime_device)"

	for item in ${current_lan_ports}; do
		append_unique current_lan_ports_words "${item}"
	done

	for item in $(collect_ipv4_addrs "${lan_runtime_dev}"); do
		append_unique current_lan_ipv4_words "${item}"
	done

	json_init
	json_add_int code 0
	json_add_string mode "${mode}"
	json_add_string button_text "${button_text}"
	json_add_string fallback_ip "${fallback_ip}/${fallback_cidr}"
	json_add_words current_lan_ports ${current_lan_ports_words}
	json_add_words current_lan_ipv4 ${current_lan_ipv4_words}
	json_add_words saved_lan_ports ${saved_lan_ports}
	json_add_words saved_wan_ports ${saved_wan_ports}
	json_dump
}

enable_ap() {
	local mode lan_ports wan_ports all_ports="" lan_device iface item

	ensure_state
	mode="$(state_get mode)"

	if [ "${mode}" = "ap" ]; then
		reply_json 0 "ap" "当前已经是 AP 模式。"
		return 0
	fi

	mkdir -p "${BACKUP_DIR}" || {
		reply_json 1 "router" "无法创建备份目录。"
		return 0
	}

	cp /etc/config/network "${NETWORK_BACKUP}" || {
		reply_json 1 "router" "备份 network 配置失败。"
		return 0
	}

	cp /etc/config/dhcp "${DHCP_BACKUP}" || {
		reply_json 1 "router" "备份 dhcp 配置失败。"
		return 0
	}

	lan_ports="$(get_lan_ports)"
	wan_ports="$(get_wan_ports)"

	for item in ${lan_ports} ${wan_ports}; do
		append_unique all_ports "${item}"
	done

	if [ -z "${all_ports}" ]; then
		reply_json 1 "router" "未检测到可并入 LAN 的接口。"
		return 0
	fi

	lan_device="$(ensure_lan_bridge ${all_ports})"

	uci set network.lan.proto='dhcp'
	uci -q delete network.lan.ipaddr
	uci -q delete network.lan.netmask
	uci -q delete network.lan.gateway
	uci -q delete network.lan.broadcast
	uci -q delete network.lan.ip6assign
	uci -q delete network.lan.ip6hint
	uci -q delete network.lan.ip6ifaceid
	uci -q delete network.lan.ip6class

	for iface in $(get_wan_networks); do
		uci -q get "network.${iface}" >/dev/null || continue
		uci set "network.${iface}.proto=none"
		uci set "network.${iface}.auto=0"
		uci -q delete "network.${iface}.device"
		uci -q delete "network.${iface}.device"
	done

	if ! uci -q get dhcp.lan >/dev/null; then
		uci set dhcp.lan=dhcp
		uci set dhcp.lan.interface='lan'
	fi

	uci set dhcp.lan.ignore='1'
	uci set dhcp.lan.dhcpv4='disabled'
	uci set dhcp.lan.dhcpv6='disabled'
	uci set dhcp.lan.ra='disabled'
	uci set dhcp.lan.ndp='disabled'

	state_set mode 'ap'
	state_set ap_lan_device "${lan_device}"
	state_set_list last_lan_ports ${lan_ports}
	state_set_list last_wan_ports ${wan_ports}
	state_set_list last_wan_networks $(get_wan_networks)

	uci commit network >/dev/null
	uci commit dhcp >/dev/null
	uci commit "${STATE_CONFIG}" >/dev/null

	schedule_reload ap

	reply_json 0 "ap" "AP 模式切换请求已提交，WAN 口会并入 LAN，并保留 10.0.0.1/24 作为保底地址。"
}

enable_router() {
	local mode

	ensure_state
	mode="$(state_get mode)"

	if [ "${mode}" != "ap" ]; then
		reply_json 0 "router" "当前已经是路由器模式。"
		return 0
	fi

	if [ ! -f "${NETWORK_BACKUP}" ] || [ ! -f "${DHCP_BACKUP}" ]; then
		reply_json 1 "ap" "未找到原始配置备份，无法恢复路由器模式。"
		return 0
	fi

	remove_current_fallback

	cp "${NETWORK_BACKUP}" /etc/config/network || {
		reply_json 1 "ap" "恢复 network 配置失败。"
		return 0
	}

	cp "${DHCP_BACKUP}" /etc/config/dhcp || {
		reply_json 1 "ap" "恢复 dhcp 配置失败。"
		return 0
	}

	state_set mode 'router'
	uci commit "${STATE_CONFIG}" >/dev/null

	schedule_reload router

	reply_json 0 "router" "路由器模式恢复请求已提交，原始 WAN/LAN 配置会被还原。"
}

case "$1" in
	status)
		status
	;;
	enable-ap)
		enable_ap
	;;
	enable-router)
		enable_router
	;;
	refresh-fallback)
		refresh_fallback
	;;
	*)
		reply_json 1 "" "用法: $0 {status|enable-ap|enable-router|refresh-fallback}"
	;;
esac