class_name TopBar
extends Control
## The bar along the top of the main window, with the title, the Quiz and Statistics tabs
## and the buttons for things that are not part of a quiz.
##
## With a music folder picked, the buttons that need the server are turned off and the
## folder's name is shown.

## Shown on the buttons that need the server while a music folder is used.
const OFFLINE_TOOLTIP: String = "Not available with a music folder"

signal sync_pressed
signal settings_pressed
signal shortcuts_pressed
signal about_pressed
signal qr_pressed
## Emitted when a tab is chosen: [code]&"quiz"[/code] or [code]&"statistics"[/code].
signal tab_selected(tab: StringName)
## Emitted when "Version X is available" is clicked, with the newest version.
signal update_pressed(latest_version: String)

## Space between the message in the middle and the tabs and buttons around it.
const MIDDLE_GAP: float = 16.0

## The newest release the server knows of, once asked, or empty.
var latest_version: String = ""

@onready var sync_button: Button = %SyncButton
@onready var debug_label: Label = $DebugLabel
@onready var update_box: HBoxContainer = $UpdateBox
@onready var update_button: Button = %UpdateButton
@onready var offline_label: Label = $OfflineLabel
@onready var qr_button: Button = %QRButton
@onready var quiz_tab: Button = %QuizTab
@onready var statistics_tab: Button = %StatisticsTab


func _ready() -> void:
	# Debug builds use the local server, see Settings
	debug_label.visible = Settings.is_debug
	sync_button.pressed.connect(sync_pressed.emit)
	%SettingsButton.pressed.connect(settings_pressed.emit)
	%ShortcutsButton.pressed.connect(shortcuts_pressed.emit)
	%AboutButton.pressed.connect(about_pressed.emit)
	qr_button.pressed.connect(qr_pressed.emit)
	quiz_tab.pressed.connect(tab_selected.emit.bind(&"quiz"))
	statistics_tab.pressed.connect(tab_selected.emit.bind(&"statistics"))
	update_button.pressed.connect(func() -> void: update_pressed.emit(latest_version))
	# The buttons are as wide as the theme makes them, so the message fits between
	statistics_tab.item_rect_changed.connect(_fit_middle)
	sync_button.item_rect_changed.connect(_fit_middle)
	_fit_middle()
	update_offline_state()
	check_for_update()


## Turns the buttons that need the server off or on, after a music folder was picked or
## the server is used again.
func update_offline_state() -> void:
	var offline: bool = Settings.is_offline()
	for button: Button in [sync_button, qr_button, statistics_tab]:
		button.disabled = offline
		button.tooltip_text = OFFLINE_TOOLTIP if offline else ""
	offline_label.visible = offline
	if offline:
		offline_label.text = "Offline: " + Settings.music_folder.display_name()
		offline_label.tooltip_text = Settings.music_folder.path
		update_box.visible = false


## Asks the server for the newest MusicPlayer release and tells the user when it is newer
## than this one. Not asked while a music folder is used.
func check_for_update() -> void:
	if Settings.is_offline():
		update_box.visible = false
		return
	MusicServerClient.fetch_latest_client_version(show_latest_version)


## Shows that [param latest] is available when it is newer than this version, and hides
## the message otherwise.
func show_latest_version(latest: Variant) -> void:
	var newer: bool = latest is String && is_newer_version(latest, Settings.version) \
			&& !Settings.is_offline()
	update_box.visible = newer
	if newer:
		latest_version = latest
		update_button.text = "Version %s is available" % latest
		update_button.tooltip_text = "You have %s. Click to update." % Settings.version


# Fits "Version X is available" and the offline label between the tabs and the buttons
func _fit_middle() -> void:
	var left: float = statistics_tab.position.x + statistics_tab.size.x + MIDDLE_GAP
	var right: float = sync_button.global_position.x - global_position.x - MIDDLE_GAP
	for middle: Control in [update_box, offline_label]:
		middle.position.x = left
		middle.size.x = maxf(right - left, 0.0)


## Whether version [param latest] is newer than [param current], comparing numbers such as
## [code]1.10.0[/code] part by part. A leading "v" is ignored, and missing parts count as 0.
static func is_newer_version(latest: String, current: String) -> bool:
	var latest_parts: PackedStringArray = latest.strip_edges().trim_prefix("v").split(".")
	var current_parts: PackedStringArray = current.strip_edges().trim_prefix("v").split(".")
	for i: int in maxi(latest_parts.size(), current_parts.size()):
		var a: int = latest_parts[i].to_int() if i < latest_parts.size() else 0
		var b: int = current_parts[i].to_int() if i < current_parts.size() else 0
		if a != b:
			return a > b
	return false


## Shows [param tab] as the chosen tab, without emitting [signal tab_selected].
func select_tab(tab: StringName) -> void:
	quiz_tab.set_pressed_no_signal(tab == &"quiz")
	statistics_tab.set_pressed_no_signal(tab == &"statistics")