# ChannelStatus (P10 收尾) —— 频道负载查询（对齐 CServerStateChecker）。
#
#   var cs := preload("res://net/channel_status.gd").new()
#   add_child(cs)
#   cs.query(host, port, func(map): ...)   # map: { port:int -> status:int }
#
# 明文 TCP（无 libsodium）：连上任一频道端口 → 发 CG_STATE_CHECKER(0x000F,len 4) →
# 跳过其它包直到 GC_RESPOND_CHANNELSTATUS(0x0010) → 读 int32 count → count × {i16 port, u8 status}。
# status：0 关 / 1 正常 / 2 忙 / 3 满（Metin2 约定，非在线人数——那要改服务器）。
extends Node

const CG_STATE_CHECKER := 0x000F
const GC_RESPOND_CHANNELSTATUS := 0x0010

const STATUS_TEXT := {0: "关闭", 1: "正常", 2: "拥挤", 3: "爆满"}

signal done(status_by_port: Dictionary)

var _peer: StreamPeerTCP
var _cb: Callable
var _deadline := 0.0
var _sent := false

func query(host: String, port: int, callback: Callable = Callable(), timeout_s := 3.0) -> void:
	_cb = callback
	_peer = StreamPeerTCP.new()
	_sent = false
	_deadline = _now() + timeout_s
	if _peer.connect_to_host(host, port) != OK:
		_finish({})
		return
	set_process(true)

func text_for(status: int) -> String:
	return STATUS_TEXT.get(status, "?")

func _now() -> float:
	return Time.get_ticks_msec() / 1000.0

func _process(_dt: float) -> void:
	if _peer == null:
		return
	_peer.poll()
	var st := _peer.get_status()
	if st == StreamPeerTCP.STATUS_ERROR or _now() > _deadline:
		_finish({})
		return
	if st != StreamPeerTCP.STATUS_CONNECTED:
		return
	if not _sent:
		var req := PackedByteArray()
		req.resize(4)
		req.encode_u16(0, CG_STATE_CHECKER)
		req.encode_u16(2, 4)
		_peer.put_data(req)
		_sent = true
	# 攒够一个包就解析
	_try_parse()

func _try_parse() -> void:
	var avail := _peer.get_available_bytes()
	if avail < 4:
		return
	# 逐包扫，跳到 RESPOND_CHANNELSTATUS
	while _peer.get_available_bytes() >= 4:
		var head: Array = _peer.get_partial_data(4)
		if head[0] != OK:
			return
		var hb: PackedByteArray = head[1]
		var header := hb.decode_u16(0)
		var length := hb.decode_u16(2)
		if header == GC_RESPOND_CHANNELSTATUS:
			_read_body()
			return
		# 别的包：按 length 跳过剩余（已吃掉 4 字节头）
		var rest := maxi(0, length - 4)
		if rest > 0:
			if _peer.get_available_bytes() < rest:
				return   # 等更多数据（简化：不缓存半包，靠 timeout 兜底）
			_peer.get_data(rest)

func _read_body() -> void:
	# 已消费 4 字节头；接着 int32 count + count × {i16 port, u8 status}
	if _peer.get_available_bytes() < 4:
		return
	var cnt_r: Array = _peer.get_data(4)
	var count: int = (cnt_r[1] as PackedByteArray).decode_s32(0)
	var out := {}
	for i in count:
		if _peer.get_available_bytes() < 3:
			break
		var rec: PackedByteArray = _peer.get_data(3)[1]
		out[rec.decode_s16(0)] = rec.decode_u8(2)
	_finish(out)

func _finish(m: Dictionary) -> void:
	set_process(false)
	if _peer:
		_peer.disconnect_from_host()
		_peer = null
	done.emit(m)
	if _cb.is_valid():
		_cb.call(m)