class_name DeckHolder
## @experimental
## A static class holding references to all decks opened in the current session.

## List of decks opened this session.
#static var decks: Array[Deck]
static var decks: Dictionary # Dictionary[String -> id, (Deck|Dictionary[String -> instance_id, Deck])]


## Returns a new empty deck and assigns a new random ID to it.
static func add_empty_deck() -> Deck:
	var deck := Deck.new()
	var uuid := UUID.v4()
	decks[uuid] = deck
	deck.id = uuid
	return deck


## Opens a deck from the [param path].
static func open_deck_from_file(path: String) -> Deck:
	var f := FileAccess.open(path, FileAccess.READ)
	if f.get_error() != OK:
		return null

	var deck := open_deck_from_dict(JSON.parse_string(f.get_as_text()), path)
	return deck


static func open_deck_from_dict(data: Dictionary, path := "") -> Deck:
	var deck := Deck.from_dict(data, path)
	decks[deck.id] = deck
	return deck


static func add_group_from_dict(data: Dictionary, deck_id: String, instance_id: String) -> Deck:
	var group := Deck.from_dict(data)
	group.instance_id = instance_id
	group.is_group = true
	group.group_input_node = data.deck.group_input_node
	group.group_output_node = data.deck.group_output_node
	var instances: Dictionary = decks.get(deck_id, {})
	instances[instance_id] = group
	decks[deck_id] = instances
	connect_group_signals(group)
	return group


static func make_new_group_instance(group_id: String) -> Deck:
	var group := get_deck(group_id)
	var data := group.to_dict()
	return add_group_from_dict(data, group_id, UUID.v4())


static func add_empty_group() -> Deck:
	var group := Deck.new()
	group.is_group = true
	group.id = UUID.v4()
	group.instance_id = UUID.v4()
	decks[group.id] = {group.instance_id: group}
	connect_group_signals(group)
	return group


static func connect_group_signals(group: Deck) -> void:
	group.node_added_to_group.connect(DeckHolder._on_node_added_to_group)
	group.node_removed_from_group.connect(DeckHolder._on_node_removed_from_group)
	group.nodes_connected_in_group.connect(DeckHolder._on_nodes_connected_in_group)
	group.nodes_disconnected_in_group.connect(DeckHolder._on_nodes_disconnected_in_group)
	group.node_port_value_updated.connect(DeckHolder._on_node_port_value_updated)
	group.node_renamed.connect(DeckHolder._on_node_renamed)
	group.node_moved.connect(DeckHolder._on_node_moved)


static func get_deck(id: String) -> Deck:
	if !decks.has(id):
		return null

	if !(decks[id] is Dictionary):
		return decks[id]
	else:
		return (decks[id] as Dictionary).values()[0]


static func get_group_instance(group_id: String, instance_id: String) -> Deck:
	if !decks.has(group_id):
		return null

	if decks[group_id] is Dictionary:
		return (decks[group_id] as Dictionary).get(instance_id)
	else:
		return null


static func close_group_instance(group_id: String, instance_id: String) -> void:
	# this is kinda dumb, but to close groups that may be dangling
	# when all instances are closed, we have to get that list
	# *before* we close the instance
	var dangling_groups := get_deck(group_id).get_referenced_groups()
	
	var group_instances: Dictionary = decks.get(group_id, {}) as Dictionary
	group_instances.erase(instance_id)
	if group_instances.is_empty():
		for group in dangling_groups:
			close_all_group_instances(group)
		decks.erase(group_id)


static func close_all_group_instances(group_id: String) -> void:
	if decks.get(group_id) is Dictionary:
		decks.erase(group_id)


## Unloads a deck. Returns a list of groups that are closed as a result of
## closing this deck.
static func close_deck(deck_id: String) -> Array:
	if decks.get(deck_id) is Deck:
		var deck: Deck = decks[deck_id] as Deck
		var groups := deck.get_referenced_groups()
		for group in groups:
			close_all_group_instances(group)
		decks.erase(deck_id)
		return groups
	
	return []


static func send_event(event_name: StringName, event_data: Dictionary = {}) -> void:
	for deck_id: String in decks:
		if decks[deck_id] is Deck:
			(decks[deck_id] as Deck).send_event(event_name, event_data)
		else:
			for deck_instance_id: String in decks[deck_id]:
				(decks[deck_id][deck_instance_id] as Deck).send_event(event_name, event_data)


#region group signal callbacks
static func _on_node_added_to_group(node: DeckNode, assign_id: String, assign_to_self: bool, deck: Deck) -> void:
	var group_id := deck.id
	for instance_id: String in decks[group_id]:
		if instance_id == deck.instance_id:
			continue

		var instance: Deck = get_group_instance(group_id, instance_id)
		instance.emit_group_signals = false
		var node_duplicate := DeckNode.from_dict(node.to_dict())
		instance.add_node_inst(node_duplicate, assign_id, assign_to_self)
		instance.emit_group_signals = true


static func _on_node_removed_from_group(node_id: String, remove_connections: bool, deck: Deck) -> void:
	var group_id := deck.id
	for instance_id: String in decks[group_id]:
		if instance_id == deck.instance_id:
			continue

		var instance: Deck = get_group_instance(group_id, instance_id)
		instance.emit_group_signals = false
		instance.remove_node(node_id, remove_connections)
		instance.emit_group_signals = true


static func _on_nodes_connected_in_group(from_node_id: String, to_node_id: String, from_output_port: int, to_input_port: int, deck: Deck) -> void:
	var group_id := deck.id
	for instance_id: String in decks[group_id]:
		if instance_id == deck.instance_id:
			continue

		var instance: Deck = get_group_instance(group_id, instance_id)
		instance.emit_group_signals = false
		instance.connect_nodes(from_node_id, to_node_id, from_output_port, to_input_port)
		instance.emit_group_signals = true


static func _on_nodes_disconnected_in_group(from_node_id: String, to_node_id: String, from_output_port: int, to_input_port: int, deck: Deck) -> void:
	var group_id := deck.id
	for instance_id: String in decks[group_id]:
		if instance_id == deck.instance_id:
			continue

		var instance: Deck = get_group_instance(group_id, instance_id)
		instance.emit_group_signals = false
		instance.disconnect_nodes(from_node_id, to_node_id, from_output_port, to_input_port)
		instance.emit_group_signals = true


static func _on_node_port_value_updated(node_id: String, port_idx: int, new_value: Variant, deck: Deck) -> void:
	var group_id := deck.id
	for instance_id: String in decks[group_id]:
		if instance_id == deck.instance_id:
			continue

		var instance: Deck = get_group_instance(group_id, instance_id)
		instance.emit_group_signals = false
		instance.get_node(node_id).get_all_ports()[port_idx].set_value_no_signal(new_value)
		instance.emit_group_signals = true


static func _on_node_renamed(node_id: String, new_name: String, deck: Deck) -> void:
	var group_id := deck.id
	for instance_id: String in decks[group_id]:
		if instance_id == deck.instance_id:
			continue

		var instance: Deck = get_group_instance(group_id, instance_id)
		instance.emit_group_signals = false
		instance.get_node(node_id).name = new_name
		instance.emit_group_signals = true


static func _on_node_moved(node_id: String, new_position: Dictionary, deck: Deck) -> void:
	var group_id := deck.id
	for instance_id: String in decks[group_id]:
		if instance_id == deck.instance_id:
			continue

		var instance: Deck = get_group_instance(group_id, instance_id)
		instance.emit_group_signals = false
		instance.get_node(node_id).position = new_position.duplicate()
		instance.emit_group_signals = true

#endregion