extends Node
## HUD visibility group manager (D-170).
##
## Nodes register into hierarchical groups. Groups control show/hide as a unit.
##
## Hierarchy:
##   "gameplay"          — stance, minimap, health, prompts, cursor, inventory
##   "implant/map"       — star map
##   "implant/wiki"      — GTTR reader
##   "implant/journal"   — knowledge journal
##   "implant/travel"    — travel planner
##   "implant/station"   — station profile
##   "implant/cargo"     — cargo manifest
##   "modal"             — settings, bug report, loading (independent layer)
##   "debug"             — debug overlay, gauntlet HUD (independent layer)
##
## Rules:
##   - "gameplay" and any "implant/*" are mutually exclusive.
##     Opening an implant app hides gameplay.
##   - "implant/*" apps are mutually exclusive with each other.
##     Opening implant/map hides implant/wiki.
##   - "modal" and "debug" are independent — overlay on anything.
##
## Usage:
##   HudGroups.register(self, "gameplay")
##   HudGroups.register(self, "implant/map")
##   HudGroups.open_app("implant/map")    # hides gameplay + other implant apps
##   HudGroups.close_app()                # returns to gameplay
##   HudGroups.toggle_app("implant/map")  # open if closed, close if open

var _groups: Dictionary = {}  # group_name -> Array[Control]
var _active_app: String = ""  # currently open implant/* app ("" = none)


func register(node: Control, group: String) -> void:
	if not _groups.has(group):
		_groups[group] = []
	if node not in _groups[group]:
		_groups[group].append(node)
	# Apply current visibility
	if group == "gameplay":
		node.visible = _active_app.is_empty()
	elif group.begins_with("implant/"):
		node.visible = (group == _active_app)


func unregister(node: Control, group: String) -> void:
	if _groups.has(group):
		_groups[group].erase(node)


## Open an implant app. Hides gameplay and any other implant app.
func open_app(app: String) -> void:
	if not app.begins_with("implant/"):
		push_warning("HudGroups.open_app: expected implant/* group, got: " + app)
		return

	# Hide previous app if different
	if not _active_app.is_empty() and _active_app != app:
		_set_group_visible(_active_app, false)

	_active_app = app
	_set_group_visible("gameplay", false)
	_set_group_visible(app, true)


## Close the current implant app. Returns to gameplay.
func close_app() -> void:
	if not _active_app.is_empty():
		_set_group_visible(_active_app, false)
	_active_app = ""
	_set_group_visible("gameplay", true)


## Toggle an implant app. If it's open, close it. If another is open, switch.
func toggle_app(app: String) -> void:
	if _active_app == app:
		close_app()
	else:
		open_app(app)


## Check if a specific app is currently open.
func is_app_active(app: String) -> bool:
	return _active_app == app


## Check if any implant app is open.
func is_implant_active() -> bool:
	return not _active_app.is_empty()


## Get the currently active app name, or "" if none.
func get_active_app() -> String:
	return _active_app


## Show/hide an independent group (modal, debug). Does not affect gameplay/implant.
func show_group(group: String, vis: bool = true) -> void:
	_set_group_visible(group, vis)


func _set_group_visible(group: String, vis: bool) -> void:
	if not _groups.has(group):
		return
	for node: Control in _groups[group]:
		if is_instance_valid(node):
			node.visible = vis