start and use mdns discovery in client; fixes #177

6 files changed, 118 insertions, 35 deletions

diff --git a/client/menu/main.gd b/client/menu/main.gd
index 997653c9..5aa3fbaa 100644
--- a/client/menu/main.gd
+++ b/client/menu/main.gd
@@ -24,7 +24,7 @@ func _ready():
 	if OS.has_feature("web"):
 		quit_button.hide()
 	Sound.play_music("MainMenu")
-	ServerList.fetch_server_list()
+	ServerList.one_shot()
 
 func _menu_cover(state):
 	$side.visible = not state
diff --git a/client/menu/play.gd b/client/menu/play.gd
index b117d6a4..44cd3eb0 100644
--- a/client/menu/play.gd
+++ b/client/menu/play.gd
@@ -37,21 +37,23 @@ func _ready():
 	ServerList.update_loading.connect(update_server_list_loading)
 	update_server_list(ServerList.current_list)
 	update_server_list_loading(ServerList.loading)
-	
+
+	ServerList.start()
 	super()
 
-func update_server_list(json: Array):
+func update_server_list(lists: Array[Array]):
 	for c in server_list.get_children():
 		c.queue_free()
-	for i in json:
-		var b := Button.new()
-		b.text_overrun_behavior = TextServer.OVERRUN_TRIM_WORD_ELLIPSIS
-		b.text = "%s (%d players)" % [i.name, i.players_online]
-		# TODO: Implement fallback address correctly
-		if i.version[0] != Multiplayer.VERSION_MAJOR or i.version[1] > Multiplayer.VERSION_MINOR:
-			b.disabled = true
-		b.pressed.connect(connect_to.bind(i.address[0]))
-		server_list.add_child(b)
+	for l in lists:
+		for i in l:
+			var b := Button.new()
+			b.text_overrun_behavior = TextServer.OVERRUN_TRIM_WORD_ELLIPSIS
+			b.text = "%s (%d players)" % [i.name, i.players_online]
+			# TODO: Implement fallback address correctly
+			if i.version[0] != Multiplayer.VERSION_MAJOR or i.version[1] > Multiplayer.VERSION_MINOR:
+				b.disabled = true
+			b.pressed.connect(connect_to.bind(i.address[0]))
+			server_list.add_child(b)
 
 func update_server_list_loading(status: bool):
 	server_list_loading.visible = status
@@ -127,3 +129,7 @@ func _on_uri_text_changed(new_text):
 
 func _on_back_pressed():
 	exit()
+
+func _menu_exit():
+	ServerList.stop()
+	super()
diff --git a/client/project.godot b/client/project.godot
index d1e85f05..d931a1b0 100644
--- a/client/project.godot
+++ b/client/project.godot
@@ -24,7 +24,7 @@ Server="*res://server.gd"
 Sound="*res://audio/sound.tscn"
 DisableWrongJoypads="*res://disable_wrong_joypads.gd"
 InputManager="*res://menu/settings/input/input_manager.gd"
-ServerList="*res://server_list.tscn"
+ServerList="*res://server_list.gd"
 
 [display]
 
diff --git a/client/server_list.gd b/client/server_list.gd
index f509a34e..43cfc15c 100644
--- a/client/server_list.gd
+++ b/client/server_list.gd
@@ -1,5 +1,6 @@
 # Hurry Curry! - a game about cooking
 # Copyright 2024 tpart
+# Copyright 2024 nokoe
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU Affero General Public License as published by
@@ -18,24 +19,78 @@ extends Node
 signal update_loading(status: bool)
 signal update_server_list(list: Array)
 
-var current_list := []
+enum Registry {
+	MDNS = 0,
+	GLOBAL = 1,
+}
+
+const MDNS_URL: String = "http://127.0.0.1:27033/v1/list"
+const HEADERS: Array[String] = [
+		"Accept: application/json",
+		"User-Agent: Hurry Curry! %s" % Global.VERSION
+	]
+
+var current_list: Array[Array] = [[], []]
 var loading := false
+var mdns := HTTPRequest.new()
+var reg := HTTPRequest.new()
 
-@onready var req: HTTPRequest = $HTTPRequest
+var thread: Thread
+var pid: int
+
+var mdns_timer := Timer.new()
+var reg_timer := Timer.new()
+# after 30 minutes we stop fetching results to reduce server load
+var timeout := Timer.new()
+
+func _ready() -> void:
+	add_child(mdns)
+	add_child(reg)
+	mdns_timer.wait_time = 5.
+	mdns_timer.one_shot = false
+	mdns_timer.timeout.connect(fetch_server_list.bind(Registry.MDNS))
+	add_child(mdns_timer)
+	reg_timer.wait_time = 60.
+	reg_timer.one_shot = false
+	reg_timer.timeout.connect(fetch_server_list.bind(Registry.GLOBAL))
+	add_child(reg_timer)
+	timeout.wait_time = 60. * 30.
+	timeout.timeout.connect(func():
+		stop()
+	)
+	add_child(timeout)
+	mdns.request_completed.connect(_on_request_completed.bind(Registry.MDNS))
+	reg.request_completed.connect(_on_request_completed.bind(Registry.GLOBAL))
+	if Global.get_setting("online.use_discovery"):
+		thread = Thread.new()
+		thread.start(func():
+			# SAFETY: reading/writing arrays/dictionaries is allowed as long as
+			# the size is not changed.
+			# cf.: https://docs.godotengine.org/en/4.3/tutorials/performance/thread_safe_apis.html#gdscript-arrays-dictionaries
+			var res = OS.create_process(get_discovery_path(), [], true)
+			# SAFETY: since this is not read until the thread stops, this should
+			# probably be safe without synchronisation :)
+			pid = res
+		)
+
+static func get_discovery_path() -> String:
+	var path: String = Global.get_setting("online.discovery_binary")
+	if path != "":
+		return path
+	else:
+		return "hurrycurry-discovery"
+
+func fetch_server_list(registry: Registry) -> void:
+	match registry:
+		Registry.MDNS:
+			mdns.request(MDNS_URL, HEADERS)
+		Registry.GLOBAL:
+			reg.request(Global.get_setting("online.registry_url") + "/v1/list", HEADERS)
 
-func fetch_server_list():
-	if loading:
-		push_warning("Server list is already loading")
-		return
 	loading = true
 	update_loading.emit(true)
-	req.request_completed.connect(_on_request_completed)
-	req.request("https://hurrycurry-registry.metamuffin.org/v1/list", [
-		"Accept: application/json",
-		"User-Agent: Hurry Curry! %s" % Global.VERSION
-	])
 
-func _on_request_completed(result: int, _response_code: int, _headers: PackedStringArray, body: PackedByteArray):
+func _on_request_completed(result: int, _response_code: int, _headers: PackedStringArray, body: PackedByteArray, registry: Registry):
 	loading = false
 	update_loading.emit(false)
 	if result != 0:
@@ -45,5 +100,28 @@ func _on_request_completed(result: int, _response_code: int, _headers: PackedStr
 	if json == null:
 		push_error("Server list response invalid")
 		return
-	current_list = json
-	update_server_list.emit(json)
+	current_list[registry] = json
+	update_server_list.emit(current_list)
+
+func start() -> void:
+	timeout.stop()
+	timeout.start()
+	if Global.get_setting("online.use_discovery"):
+		mdns_timer.start()
+		fetch_server_list(Registry.MDNS)
+	if Global.get_setting("online.use_registry"):
+		reg_timer.start()
+		fetch_server_list(Registry.GLOBAL)
+
+func stop() -> void:
+	timeout.stop()
+	mdns_timer.stop()
+	reg_timer.stop()
+
+func one_shot() -> void:
+	start()
+	stop()
+
+func _exit_tree():
+	if thread != null: thread.wait_to_finish()
+	if pid != null: OS.kill(pid)
diff --git a/client/server_list.tscn b/client/server_list.tscn
deleted file mode 100644
index f43da77f..00000000
--- a/client/server_list.tscn
+++ /dev/null
@@ -1,8 +0,0 @@
-[gd_scene load_steps=2 format=3 uid="uid://3p61jpqt7acp"]
-
-[ext_resource type="Script" path="res://server_list.gd" id="1_a8xqo"]
-
-[node name="ServerList" type="Node"]
-script = ExtResource("1_a8xqo")
-
-[node name="HTTPRequest" type="HTTPRequest" parent="."]
diff --git a/client/settings.gd b/client/settings.gd
index 667ffa41..eddc5207 100644
--- a/client/settings.gd
+++ b/client/settings.gd
@@ -70,6 +70,13 @@ static func get_root():
 			ToggleSetting.new("upnp", false),
 			ToggleSetting.new("mdns", false),
 			ToggleSetting.new("register", false),
+		]),
+		SettingsCategory.new("online", [
+			# TODO: make this opt-in
+			ToggleSetting.new("use_registry", true),
+			TextSetting.new("registry_url", "https://hurrycurry-registry.metamuffin.org/"),
+			ToggleSetting.new("use_discovery", true),
+			TextSetting.new("discovery_binary", ""),
 		])
 	])