extends CanvasLayer
## In-game system menu, opened with Escape.
##
## Exists because without it there is no way out of a session short of killing
## the process -- and "kill the process" is exactly the behaviour the escape
## channel is designed to discourage, so leaving it as the only exit would work
## against the rest of the design.

signal resumed
signal return_to_hub_requested
signal disconnect_requested

var _panel: VBoxContainer
var _hub_button: Button
var _open: bool = false


func _ready() -> void:
	layer = 20
	var root := Control.new()
	root.set_anchors_and_offsets_preset(Control.PRESET_FULL_RECT)
	add_child(root)

	# Dim the game behind the menu so it is obvious the world is still running.
	var scrim := ColorRect.new()
	scrim.color = Color(0.0, 0.0, 0.0, 0.55)
	scrim.set_anchors_and_offsets_preset(Control.PRESET_FULL_RECT)
	scrim.mouse_filter = Control.MOUSE_FILTER_STOP
	root.add_child(scrim)

	var center := CenterContainer.new()
	center.set_anchors_and_offsets_preset(Control.PRESET_FULL_RECT)
	root.add_child(center)

	_panel = VBoxContainer.new()
	_panel.custom_minimum_size = Vector2(320.0, 0.0)
	_panel.add_theme_constant_override("separation", 10)
	center.add_child(_panel)

	var title := Label.new()
	title.text = "PAUSED"
	title.add_theme_font_size_override("font_size", 26)
	_panel.add_child(title)

	var note := Label.new()
	note.text = "The world keeps running. You are not safe here."
	note.add_theme_font_size_override("font_size", 12)
	note.add_theme_color_override("font_color", Color(1.0, 0.7, 0.5))
	_panel.add_child(note)

	_hub_button = _button("Return to hub", func() -> void:
		return_to_hub_requested.emit()
		close())
	_button("Resume", func() -> void: close())
	_button("Disconnect to menu", func() -> void:
		disconnect_requested.emit()
		close())
	_button("Quit game", func() -> void: get_tree().quit())

	visible = false


func _button(text: String, on_press: Callable) -> Button:
	var b := Button.new()
	b.text = text
	b.pressed.connect(on_press)
	_panel.add_child(b)
	return b


func _unhandled_input(event: InputEvent) -> void:
	if event.is_action_pressed("system_menu"):
		toggle()
		get_viewport().set_input_as_handled()


func toggle() -> void:
	if _open:
		close()
	else:
		open()


func open() -> void:
	_open = true
	visible = true
	# Nothing is paused -- the server does not stop for one client's menu, so
	# neither does the view. Only the mouse is freed.
	Input.mouse_mode = Input.MOUSE_MODE_VISIBLE


func close() -> void:
	_open = false
	visible = false


func is_open() -> bool:
	return _open


## The hub button is meaningless when you are already in the hub.
func set_in_dungeon(in_dungeon: bool) -> void:
	_hub_button.disabled = not in_dungeon