# (c) 2023-present Eroax
# (c) 2023-present Yagich
# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
class_name Util
## A class with commonly used methods.

static var _batches: Dictionary # Dictionary[StringName, BatchConnection]


## Connects the [param p_func] to [param p_signal] if that connection doesn't already exist.
static func safe_connect(p_signal: Signal, p_func: Callable) -> void:
	if is_instance_valid(p_signal.get_object()) and is_instance_valid(p_func.get_object()) and not p_signal.is_null() and p_func.is_valid() and not p_signal.is_connected(p_func):
		p_signal.connect(p_func)


## Disconnects the [param p_func] from [param p_signal] if that connection exists.
static func safe_disconnect(p_signal: Signal, p_func: Callable) -> void:
	if is_instance_valid(p_signal.get_object()) and is_instance_valid(p_func.get_object()) and not p_signal.is_null() and p_func.is_valid() and p_signal.is_connected(p_func):
		p_signal.disconnect(p_func)


## Returns a new [Util.BatchConnection] object.
static func batch_begin() -> BatchConnection:
	return BatchConnection.new()


## Adds the [param batch] object to storage, to be retrieved later with [param key].
static func push_batch(batch: BatchConnection, key: StringName) -> void:
	_batches[key] = batch


## Disconnects the signals in a batch connection stored at [param key]. See [method push_batch].
static func pop_batch(key: StringName) -> void:
	var b: BatchConnection = _batches.get(key, null)
	if not b:
		return
	
	b._pop()
	_batches.erase(key)


## Customized version of [method ProjectSettings.globalize_path] that handles
## a [code]$PWD[/code] template which points to the current working folder.
static func globalize_path(path: String) -> String:
	var pwd: String = ProjectSettings.globalize_path("res://").trim_suffix("/") if OS.has_feature("editor") else OS.get_executable_path().get_base_dir()
	return path.format({"$PWD": pwd})


## Use as the callback in [method Array.reduce] to find the greatest element.
static func array_max(accum, e):
	return max(accum, e)


## An object representing multiple connections.
##
## Useful when there's a need to connect multiple signals in one operation, to be disconnected later.
class BatchConnection:
	var _connections := {} # Dictionary[Signal, Array[Callable]]


	## Add a new connection from [param p_signal] to [param p_func]. Uses [method Util.safe_connect].
	func add(p_signal: Signal, p_func: Callable) -> void:
		var arr: Array = _connections.get(p_signal, [])
		arr.append(p_func)
		_connections[p_signal] = arr
		Util.safe_connect(p_signal, p_func)


	func _pop() -> void:
		for sig: Signal in _connections:
			for f in _connections[sig]:
				Util.safe_disconnect(sig, f)