Add direct-connect multiplayer foundation

network/endpoint_parser.gd

@@ -0,0 +1,69 @@
+class_name EndpointParser
+extends RefCounted
+
+const DEFAULT_PORT: int = 7777
+
+
+static func parse(value: String, default_port: int = DEFAULT_PORT) -> ConnectionEndpoint:
+	var result := ConnectionEndpoint.new()
+	result.original_display = value.strip_edges()
+	result.port = default_port
+	if default_port < 1 or default_port > 65535:
+		result.error_message = "The configured default port is invalid."
+		return result
+	var input: String = result.original_display
+	if input.is_empty():
+		result.error_message = "Enter a hostname or IP address."
+		return result
+
+	var host: String = ""
+	var port_text: String = ""
+	if input.begins_with("["):
+		var closing: int = input.find("]")
+		if closing < 0:
+			result.error_message = "The IPv6 address is missing a closing bracket."
+			return result
+		host = input.substr(1, closing - 1).strip_edges()
+		var suffix: String = input.substr(closing + 1).strip_edges()
+		if not suffix.is_empty():
+			if not suffix.begins_with(":") or suffix.length() == 1:
+				result.error_message = "Use [IPv6]:port for an IPv6 port."
+				return result
+			port_text = suffix.substr(1).strip_edges()
+	elif input.contains("[") or input.contains("]"):
+		result.error_message = "IPv6 brackets are malformed."
+		return result
+	else:
+		var colon_count: int = input.count(":")
+		if colon_count == 1:
+			var separator: int = input.rfind(":")
+			host = input.substr(0, separator).strip_edges()
+			port_text = input.substr(separator + 1).strip_edges()
+		else:
+			# Zero colons is a hostname/IPv4 host. More than one is a raw
+			# IPv6 host; an explicit port for it must use brackets.
+			host = input.strip_edges()
+
+	if host.is_empty():
+		result.error_message = "The hostname or IP address is empty."
+		return result
+	if host.contains(" ") or host.contains("\t") or host.contains("\n"):
+		result.error_message = "The hostname or IP address contains whitespace."
+		return result
+	if not port_text.is_empty():
+		if not port_text.is_valid_int():
+			result.error_message = "The port must be a number from 1 to 65535."
+			return result
+		result.port = int(port_text)
+		if result.port < 1 or result.port > 65535:
+			result.error_message = "The port must be from 1 to 65535."
+			return result
+
+	result.host = host.to_lower()
+	var is_ipv6: bool = result.host.contains(":")
+	result.normalized_display = (
+		"[%s]:%d" % [result.host, result.port]
+		if is_ipv6
+		else "%s:%d" % [result.host, result.port]
+	)
+	return result