class_name OnlineManager
extends Node

signal connection_state_changed(state: String)
signal authenticated(user_id: String, username: String)
signal leaderboard_loaded(leaderboard_id: String, records: Array)
signal score_submitted(result: Dictionary)
signal matchmaking_state_changed(state: String)
signal match_found(match_data)
signal match_snapshot_received(snapshot: Dictionary)
signal match_event_received(event: Dictionary)
signal private_room_created(room_code: String)
signal friends_changed()
signal match_invite_received(invite: Dictionary)

const SERVER_KEY := "voidbastion-public-v1"
const PRODUCTION_HOST := "api.void-bastion.gergames.de"
const DEVELOPMENT_HOST := "192.168.178.20"
const DEFAULT_PORT := 7350
const OP_SNAPSHOT := 1
const OP_EVENT := 2
const OP_BUILD := 10
const OP_UPGRADE := 11
const OP_SELL := 12
const OP_START_WAVE := 13
const OP_READY := 14
const MAX_PENDING_SNAPSHOTS := 5

var client: NakamaClient
var session: NakamaSession
var socket: NakamaSocket
var connection_state := "offline"
var last_error := ""
var current_host := ""
var current_match = null
var matchmaker_ticket := ""
var private_room_code := ""
var lobby_ready := false
var intentional_disconnect := false
var reconnect_in_progress := false
var account_manager: AccountManager
var auto_connect_enabled := true
var snapshot_previous_ms := 0
var snapshot_report_ms := 0
var snapshot_count := 0
var snapshot_gap_max_ms := 0
var snapshot_bytes_max := 0
var snapshot_parse_max_us := 0
var snapshot_large_gap_count := 0
var snapshot_coalesced_count := 0
var pending_snapshot_payloads: Array[String] = []
var friends: Array[Dictionary] = []
var friend_statuses: Dictionary = {}
var presence_status := ""


func _ready() -> void:
	account_manager = get_parent().get_node_or_null("AccountManager") as AccountManager
	if _is_headless_or_editor():
		return
	call_deferred("connect_and_authenticate")


func _process(_delta: float) -> void:
	_flush_pending_snapshots()


func _flush_pending_snapshots() -> void:
	if pending_snapshot_payloads.is_empty():
		return
	var payloads := pending_snapshot_payloads.duplicate()
	pending_snapshot_payloads.clear()
	var latest: Dictionary = {}
	var recent_shots: Array = []
	for payload in payloads:
		var parse_start_us := Time.get_ticks_usec()
		var parsed = JSON.parse_string(payload)
		snapshot_parse_max_us = maxi(snapshot_parse_max_us, Time.get_ticks_usec() - parse_start_us)
		if not parsed is Dictionary:
			continue
		latest = parsed
		var shots = parsed.get("shots", [])
		if shots is Array:
			recent_shots.append_array(shots)
	if latest.is_empty():
		return
	if payloads.size() > 1:
		latest["shots"] = recent_shots
		snapshot_coalesced_count += payloads.size() - 1
	match_snapshot_received.emit(latest)


func _is_headless_or_editor() -> bool:
	return DisplayServer.get_name() == "headless" or Engine.is_editor_hint()


func connect_and_authenticate(force_production := false) -> bool:
	if connection_state in ["connecting", "online"]:
		return connection_state == "online"
	_set_connection_state("connecting")
	last_error = ""
	var production_ok := await _authenticate_on(PRODUCTION_HOST, 443, "https")
	if production_ok:
		await _after_authentication()
		return true
	if OS.is_debug_build() and not force_production:
		var development_ok := await _authenticate_on(DEVELOPMENT_HOST, DEFAULT_PORT, "http")
		if development_ok:
			await _after_authentication()
			return true
	_set_connection_state("offline")
	return false


func _authenticate_on(host: String, port: int, scheme: String) -> bool:
	current_host = host
	client = Nakama.create_client(SERVER_KEY, host, port, scheme, 5, NakamaLogger.LOG_LEVEL.ERROR)
	var device_id := _device_id()
	var username = "pilot_%s" % device_id.md5_text().left(20)
	var result: NakamaSession = await client.authenticate_device_async(device_id, username, true)
	if result == null or result.is_exception():
		last_error = "Server %s nicht erreichbar" % host
		return false
	session = result
	if account_manager:
		await client.update_account_async(session, null, account_manager.display_name)
		account_manager.attach_online_identity(session.user_id, session.username)
	return true


func _after_authentication() -> void:
	await _record_activity()
	socket = Nakama.create_socket_from(client)
	_bind_socket_signals()
	var result = await socket.connect_async(session, true, 5)
	if result == null or result.is_exception():
		last_error = "Echtzeitverbindung konnte nicht aufgebaut werden"
		socket = null
		_set_connection_state("authenticated")
	else:
		intentional_disconnect = false
		_set_connection_state("online")
		var parent_game = get_parent()
		await set_presence_status("playing" if parent_game != null and parent_game.game_mode in ["playing", "paused", "victory", "game_over", "endless_offer", "endless_result"] else "menu")
	authenticated.emit(session.user_id, session.username)
	await flush_pending_scores()


func _record_activity() -> void:
	if not is_authenticated():
		return
	var payload := {
		"platform": OS.get_name().to_lower(),
		"version": str(ProjectSettings.get_setting("application/config/version", "development"))
	}
	await client.rpc_async(session, "record_activity", JSON.stringify(payload))


func _bind_socket_signals() -> void:
	socket.received_matchmaker_matched.connect(_on_matchmaker_matched)
	socket.received_match_state.connect(_on_match_state)
	socket.received_status_presence.connect(_on_status_presence)
	socket.received_notification.connect(_on_notification)
	socket.closed.connect(_on_socket_closed)


func disconnect_from_server() -> void:
	intentional_disconnect = true
	pending_snapshot_payloads.clear()
	if socket:
		socket.close()
	socket = null
	session = null
	current_match = null
	friends.clear()
	friend_statuses.clear()
	presence_status = ""
	matchmaker_ticket = ""
	private_room_code = ""
	lobby_ready = false
	_set_connection_state("offline")


func server_info() -> Dictionary:
	if not is_authenticated():
		return {}
	var result = await client.rpc_async(session, "server_info", "{}")
	return _parse_rpc_result(result)


func submit_run(record: Dictionary) -> bool:
	if not is_authenticated():
		return false
	var payload := record.duplicate(true)
	payload["client_version"] = str(ProjectSettings.get_setting("application/config/version", "development"))
	var result = await client.rpc_async(session, "submit_run", JSON.stringify(payload))
	var parsed := _parse_rpc_result(result)
	if parsed.is_empty() or not bool(parsed.get("accepted", false)):
		return false
	if account_manager:
		account_manager.mark_submission_complete(record)
	score_submitted.emit(parsed)
	return true


func flush_pending_scores() -> void:
	if not account_manager or not is_authenticated():
		return
	var queued: Array = account_manager.pending_submissions.duplicate(true)
	for record in queued:
		if record is Dictionary:
			await submit_run(record)


func update_display_name(value: String) -> Dictionary:
	if not account_manager:
		return {"accepted": false, "error": "Lokales Profil fehlt."}
	var validation_error := account_manager.validate_display_name(value)
	if not validation_error.is_empty():
		return {"accepted": false, "error": validation_error}
	var normalized := account_manager.normalize_display_name(value)
	if is_authenticated():
		var result = await client.rpc_async(session, "update_display_name", JSON.stringify({"display_name": normalized}))
		var parsed := _parse_rpc_result(result)
		if parsed.is_empty() or not bool(parsed.get("accepted", false)):
			return {"accepted": false, "error": str(parsed.get("error", "Der Name konnte online nicht gespeichert werden."))}
		normalized = str(parsed.get("display_name", normalized))
	account_manager.set_display_name(normalized)
	return {"accepted": true, "display_name": normalized, "online": is_authenticated()}


func delete_online_account() -> Dictionary:
	if not is_authenticated():
		return {"accepted": false, "error": "Für die Kontolöschung ist eine Serververbindung erforderlich."}
	var result = await client.rpc_async(session, "delete_account", "{}")
	var parsed := _parse_rpc_result(result)
	if parsed.is_empty() or not bool(parsed.get("accepted", false)):
		return {"accepted": false, "error": str(parsed.get("error", "Das Online-Konto konnte nicht gelöscht werden."))}
	disconnect_from_server()
	if account_manager:
		account_manager.reset_after_account_deletion()
	return {"accepted": true}


func redeem_unlock_code(code: String) -> Dictionary:
	if not is_authenticated():
		return {"accepted": false, "error": "offline"}
	var result = await client.rpc_async(session, "redeem_unlock_code", JSON.stringify({"code": code}))
	var parsed := _parse_rpc_result(result)
	if parsed.is_empty():
		return {"accepted": false, "error": "invalid"}
	return parsed


func get_promo_unlocks() -> Dictionary:
	if not is_authenticated():
		return {}
	var result = await client.rpc_async(session, "get_promo_unlocks", "{}")
	var parsed := _parse_rpc_result(result)
	return parsed if bool(parsed.get("accepted", false)) else {}


func set_presence_status(value: String) -> void:
	if not is_online() or value == presence_status:
		return
	var safe_value := "playing" if value == "playing" else "menu"
	var result = await socket.update_status_async(safe_value)
	if result != null and not result.is_exception():
		presence_status = safe_value


func refresh_friends() -> bool:
	if not is_authenticated():
		return false
	var result = await client.list_friends_async(session, null, 100)
	if result == null or result.is_exception():
		return false
	var rows: Array[Dictionary] = []
	var follow_ids := PackedStringArray()
	for item in result.friends:
		if item.user == null:
			continue
		var user_id: String = item.user.id
		var state: int = item.state
		rows.append({"id": user_id, "username": item.user.username,
			"name": item.user.display_name if not item.user.display_name.is_empty() else item.user.username,
			"state": state, "online": item.user.online})
		if state == 0:
			follow_ids.append(user_id)
	friends = rows
	friend_statuses.clear()
	if is_online() and not follow_ids.is_empty():
		var statuses = await socket.follow_users_async(follow_ids, PackedStringArray())
		if statuses != null and not statuses.is_exception():
			for presence in statuses.presences:
				friend_statuses[presence.user_id] = presence.status
	friends_changed.emit()
	return true


func add_friend_by_username(username: String) -> bool:
	var normalized := username.strip_edges()
	if not is_authenticated() or normalized.is_empty() or normalized == session.username:
		return false
	var result = await client.add_friends_async(session, null, PackedStringArray([normalized]))
	if result == null or result.is_exception():
		return false
	await refresh_friends()
	return true


func accept_friend(user_id: String) -> bool:
	if not is_authenticated() or user_id.is_empty():
		return false
	var result = await client.add_friends_async(session, PackedStringArray([user_id]))
	if result == null or result.is_exception():
		return false
	await refresh_friends()
	return true


func remove_friend(user_id: String) -> bool:
	if not is_authenticated() or user_id.is_empty():
		return false
	var result = await client.delete_friends_async(session, PackedStringArray([user_id]))
	if result == null or result.is_exception():
		return false
	friend_statuses.erase(user_id)
	await refresh_friends()
	return true


func invite_friend(user_id: String, room_code: String) -> bool:
	if not is_authenticated() or user_id.is_empty() or room_code.length() != 6:
		return false
	var result = await client.rpc_async(session, "invite_friend", JSON.stringify({"friend_id": user_id, "room_code": room_code}))
	return bool(_parse_rpc_result(result).get("accepted", false))


func _on_status_presence(event) -> void:
	for presence in event.joins:
		friend_statuses[presence.user_id] = presence.status
	for presence in event.leaves:
		friend_statuses.erase(presence.user_id)
	friends_changed.emit()


func _on_notification(notification) -> void:
	if notification.code in [-2, -3]:
		refresh_friends()
		return
	if notification.code != 101:
		return
	var content = JSON.parse_string(notification.content)
	if not content is Dictionary:
		return
	var code := String(content.get("room_code", ""))
	if code.length() != 6:
		return
	match_invite_received.emit({"room_code": code, "from": String(content.get("from", "Mitspieler"))})


func load_leaderboard(map_index: int, difficulty_index: int, endless: bool, limit := 20) -> Array:
	if not is_authenticated():
		return []
	var leaderboard_id := make_leaderboard_id(map_index, difficulty_index, "endless" if endless else "mission")
	var result = await client.list_leaderboard_records_async(session, leaderboard_id, null, null, clampi(limit, 1, 100))
	if result == null or result.is_exception():
		return []
	var owner_ids := PackedStringArray()
	for record in result.records:
		if not record.owner_id.is_empty() and not owner_ids.has(record.owner_id):
			owner_ids.append(record.owner_id)
	var current_names := {}
	if not owner_ids.is_empty():
		var users_result = await client.get_users_async(session, owner_ids)
		if users_result != null and not users_result.is_exception():
			for user in users_result.users:
				if not user.display_name.is_empty():
					current_names[user.id] = user.display_name
	var rows: Array = []
	for record in result.records:
		rows.append({
			"rank": int(record.rank),
			"username": str(current_names.get(record.owner_id, record.username)),
			"score": int(record.score),
			"wave": int(record.subscore),
			"owner_id": record.owner_id,
			"map": map_index,
			"difficulty": difficulty_index,
			"mode": "endless" if endless else "mission"
		})
	leaderboard_loaded.emit(leaderboard_id, rows)
	return rows


func begin_matchmaking(mode := "quick", difficulty := 1) -> bool:
	intentional_disconnect = false
	if not is_online() or socket == null:
		matchmaking_state_changed.emit("offline")
		return false
	if not matchmaker_ticket.is_empty():
		return true
	var string_properties := {"game": "void_bastion", "mode": mode}
	var numeric_properties := {"difficulty": float(difficulty)}
	var query := "+properties.game:void_bastion +properties.mode:%s +properties.difficulty:%d" % [mode, difficulty]
	var ticket = await socket.add_matchmaker_async(query, 2, 2, string_properties, numeric_properties)
	if ticket == null or ticket.is_exception():
		matchmaking_state_changed.emit("error")
		return false
	matchmaker_ticket = ticket.ticket
	matchmaking_state_changed.emit("searching")
	return true


func cancel_matchmaking() -> void:
	intentional_disconnect = true
	pending_snapshot_payloads.clear()
	if socket and not matchmaker_ticket.is_empty():
		await socket.remove_matchmaker_async(matchmaker_ticket)
	matchmaker_ticket = ""
	if current_match != null and not private_room_code.is_empty():
		await socket.leave_match_async(current_match.match_id)
		current_match = null
	private_room_code = ""
	matchmaking_state_changed.emit("idle")


func create_private_room(difficulty := 1) -> bool:
	intentional_disconnect = false
	pending_snapshot_payloads.clear()
	if not is_online() or socket == null:
		matchmaking_state_changed.emit("offline")
		return false
	matchmaking_state_changed.emit("creating_room")
	var result = await client.rpc_async(session, "create_private_room", JSON.stringify({"difficulty": clampi(difficulty, 0, 2)}))
	var data := _parse_rpc_result(result)
	var match_id := String(data.get("match_id", ""))
	private_room_code = String(data.get("room_code", ""))
	if match_id.is_empty() or private_room_code.length() != 6:
		private_room_code = ""
		matchmaking_state_changed.emit("error")
		return false
	current_match = await socket.join_match_async(match_id)
	if current_match == null or current_match.is_exception():
		current_match = null
		private_room_code = ""
		matchmaking_state_changed.emit("error")
		return false
	private_room_created.emit(private_room_code)
	matchmaking_state_changed.emit("hosting")
	lobby_ready = false
	await set_lobby_ready(false)
	return true


func join_private_room(room_code: String) -> bool:
	intentional_disconnect = false
	pending_snapshot_payloads.clear()
	if not is_online() or socket == null:
		matchmaking_state_changed.emit("offline")
		return false
	private_room_code = room_code.to_upper().strip_edges()
	matchmaking_state_changed.emit("joining_room")
	var result = await client.rpc_async(session, "join_private_room", JSON.stringify({"room_code": private_room_code}))
	var data := _parse_rpc_result(result)
	var match_id := String(data.get("match_id", ""))
	if not bool(data.get("found", false)) or match_id.is_empty():
		private_room_code = ""
		matchmaking_state_changed.emit("room_not_found")
		return false
	current_match = await socket.join_match_async(match_id)
	if current_match == null or current_match.is_exception():
		current_match = null
		private_room_code = ""
		matchmaking_state_changed.emit("room_not_found")
		return false
	matchmaking_state_changed.emit("matched")
	lobby_ready = false
	await set_lobby_ready(false)
	return true


func _on_matchmaker_matched(matched) -> void:
	intentional_disconnect = false
	pending_snapshot_payloads.clear()
	matchmaker_ticket = ""
	current_match = await socket.join_matched_async(matched)
	if current_match == null or current_match.is_exception():
		matchmaking_state_changed.emit("error")
		return
	matchmaking_state_changed.emit("matched")
	match_found.emit(current_match)
	lobby_ready = false
	await set_lobby_ready(false)


func set_lobby_ready(value: bool) -> bool:
	lobby_ready = value
	var player_name := account_manager.display_name if account_manager else session.username
	return await send_match_command(OP_READY, {"ready": value, "name": player_name})


func send_match_command(op_code: int, payload: Dictionary) -> bool:
	if not is_online() or current_match == null:
		return false
	var result = await socket.send_match_state_async(current_match.match_id, op_code, JSON.stringify(payload))
	return result != null and not result.is_exception()


func request_tower_build(tower_type: int, position: Vector2) -> bool:
	return await send_match_command(OP_BUILD, {"tower_type": tower_type, "x": position.x, "y": position.y})


func request_tower_upgrade(tower_id: int) -> bool:
	return await send_match_command(OP_UPGRADE, {"tower_id": tower_id})


func request_tower_sell(tower_id: int) -> bool:
	return await send_match_command(OP_SELL, {"tower_id": tower_id})


func request_wave_start() -> bool:
	return await send_match_command(OP_START_WAVE, {})


func leave_current_match() -> void:
	pending_snapshot_payloads.clear()
	if socket and current_match != null:
		await socket.leave_match_async(current_match.match_id)
	current_match = null
	private_room_code = ""
	lobby_ready = false


func _on_match_state(data) -> void:
	if current_match == null or data.match_id != current_match.match_id:
		return
	if data.op_code == OP_SNAPSHOT:
		var now_ms := Time.get_ticks_msec()
		if snapshot_previous_ms > 0:
			var gap_ms := now_ms - snapshot_previous_ms
			snapshot_gap_max_ms = maxi(snapshot_gap_max_ms, gap_ms)
			if gap_ms > 500:
				snapshot_large_gap_count += 1
		snapshot_previous_ms = now_ms
		snapshot_count += 1
		snapshot_bytes_max = maxi(snapshot_bytes_max, String(data.data).to_utf8_buffer().size())
		pending_snapshot_payloads.append(String(data.data))
		if pending_snapshot_payloads.size() > MAX_PENDING_SNAPSHOTS:
			pending_snapshot_payloads.pop_front()
			snapshot_coalesced_count += 1
		if snapshot_report_ms == 0:
			snapshot_report_ms = now_ms
		elif now_ms - snapshot_report_ms >= 10000:
			print("ONLINE DIAG snapshots=%d coalesced=%d max_gap_ms=%d gaps_over_500ms=%d max_bytes=%d max_parse_us=%d" % [snapshot_count, snapshot_coalesced_count, snapshot_gap_max_ms, snapshot_large_gap_count, snapshot_bytes_max, snapshot_parse_max_us])
			snapshot_report_ms = now_ms
			snapshot_count = 0
			snapshot_coalesced_count = 0
			snapshot_gap_max_ms = 0
			snapshot_large_gap_count = 0
			snapshot_bytes_max = 0
			snapshot_parse_max_us = 0
	elif data.op_code == OP_EVENT:
		var parsed = JSON.parse_string(data.data)
		if parsed is Dictionary:
			match_event_received.emit(parsed)


func _on_socket_closed() -> void:
	print("ONLINE DIAG websocket_closed reconnect=%s" % str(not intentional_disconnect and current_match != null))
	pending_snapshot_payloads.clear()
	presence_status = ""
	friend_statuses.clear()
	friends_changed.emit()
	snapshot_previous_ms = 0
	var reconnect_match_id := ""
	if not intentional_disconnect and current_match != null:
		reconnect_match_id = String(current_match.match_id)
	current_match = null
	if connection_state != "offline":
		_set_connection_state("authenticated")
	if not reconnect_match_id.is_empty() and not reconnect_in_progress:
		reconnect_in_progress = true
		matchmaking_state_changed.emit("reconnecting")
		_recover_match.call_deferred(reconnect_match_id)
	elif not intentional_disconnect and reconnect_match_id.is_empty() and not reconnect_in_progress and is_authenticated():
		reconnect_in_progress = true
		_recover_presence.call_deferred()


func _recover_presence() -> void:
	for attempt in 5:
		await get_tree().create_timer(1.5 + attempt).timeout
		if intentional_disconnect or not is_authenticated():
			break
		socket = Nakama.create_socket_from(client)
		_bind_socket_signals()
		var connected = await socket.connect_async(session, true, 5)
		if connected == null or connected.is_exception():
			continue
		reconnect_in_progress = false
		_set_connection_state("online")
		var parent_game = get_parent()
		await set_presence_status("playing" if parent_game != null and parent_game.game_mode in ["playing", "paused", "victory", "game_over", "endless_offer", "endless_result"] else "menu")
		await refresh_friends()
		return
	reconnect_in_progress = false


func _recover_match(match_id: String) -> void:
	for attempt in 5:
		await get_tree().create_timer(1.5 + attempt).timeout
		if intentional_disconnect or not is_authenticated():
			break
		socket = Nakama.create_socket_from(client)
		_bind_socket_signals()
		var connected = await socket.connect_async(session, true, 5)
		if connected == null or connected.is_exception():
			continue
		var rejoined = await socket.join_match_async(match_id)
		if rejoined != null and not rejoined.is_exception():
			print("ONLINE DIAG websocket_reconnected attempt=%d" % (attempt + 1))
			current_match = rejoined
			intentional_disconnect = false
			reconnect_in_progress = false
			_set_connection_state("online")
			var parent_game = get_parent()
			await set_presence_status("playing" if parent_game != null and parent_game.game_mode in ["playing", "paused", "victory", "game_over"] else "menu")
			matchmaking_state_changed.emit("reconnected")
			return
	reconnect_in_progress = false
	print("ONLINE DIAG websocket_reconnect_failed")
	matchmaking_state_changed.emit("connection_lost")


func _device_id() -> String:
	if account_manager and not account_manager.player_id.is_empty():
		return account_manager.player_id
	var fallback := "voidbastion_%s" % Crypto.new().generate_random_bytes(16).hex_encode()
	return fallback


func is_authenticated() -> bool:
	return session != null and session.is_valid() and not session.expired


func is_online() -> bool:
	return is_authenticated() and socket != null and socket.is_connected_to_host()


func make_leaderboard_id(map_index: int, difficulty_index: int, mode: String) -> String:
	var safe_mode := mode if mode in ["mission", "endless", "coop_ai", "coop_online"] else "mission"
	return "%s_map%d_difficulty%d" % [safe_mode, clampi(map_index, 0, 6), clampi(difficulty_index, 0, 2)]


func _parse_rpc_result(result) -> Dictionary:
	if result == null or result.is_exception():
		return {}
	var parsed = JSON.parse_string(result.payload)
	return parsed if parsed is Dictionary else {}


func _set_connection_state(value: String) -> void:
	if connection_state == value:
		return
	connection_state = value
	connection_state_changed.emit(connection_state)