extends Control

const Style := preload("res://scripts/ui/ui_style.gd")

var screens := {}
var header_stats: Label
var header_panel: PanelContainer
var user_label: Label

func _ready() -> void:
	Style.apply_app_theme(self)
	_build_ui()
	show_screen("menu" if AuthState.is_logged_in else "login")


func show_screen(screen_name: String, payload: Variant = null) -> void:
	for child in $Root/Screens.get_children():
		child.visible = false

	var screen = screens.get(screen_name)
	if screen == null:
		return

	screen.visible = true
	if header_panel != null:
		header_panel.visible = screen_name != "login"
	if screen.has_method("on_show"):
		screen.on_show(payload)


func _build_ui() -> void:
	var background := ColorRect.new()
	background.color = Style.BACKGROUND
	background.set_anchors_preset(Control.PRESET_FULL_RECT)
	add_child(background)

	var root := VBoxContainer.new()
	root.name = "Root"
	root.set_anchors_preset(Control.PRESET_FULL_RECT)
	root.add_theme_constant_override("separation", 0)
	add_child(root)

	header_panel = PanelContainer.new()
	header_panel.name = "Header"
	header_panel.add_theme_stylebox_override("panel", Style.panel_box(Style.SURFACE_DARK, Color("263752")))
	root.add_child(header_panel)

	var header := HBoxContainer.new()
	header.custom_minimum_size = Vector2(0, 78)
	header.add_theme_constant_override("separation", 14)
	header_panel.add_child(header)

	var title := Label.new()
	title.text = "STEP 3 Arcade"
	Style.set_label(title, 31, Style.TEXT)
	title.size_flags_horizontal = Control.SIZE_EXPAND_FILL
	header.add_child(title)

	header_stats = Label.new()
	header_stats.name = "HeaderStats"
	Style.set_label(header_stats, 15, Style.MUTED)
	header_stats.size_flags_horizontal = Control.SIZE_EXPAND_FILL
	header_stats.horizontal_alignment = HORIZONTAL_ALIGNMENT_RIGHT
	header.add_child(header_stats)

	user_label = Label.new()
	Style.set_label(user_label, 15, Style.CYAN)
	user_label.horizontal_alignment = HORIZONTAL_ALIGNMENT_RIGHT
	header.add_child(user_label)

	var profile_button := Button.new()
	profile_button.text = "Profile"
	profile_button.pressed.connect(func(): show_screen("profile"))
	header.add_child(profile_button)

	var map_button := Button.new()
	map_button.text = "Study Map"
	map_button.pressed.connect(func(): show_screen("map"))
	header.add_child(map_button)

	var logout_button := Button.new()
	logout_button.text = "Log Out"
	logout_button.pressed.connect(_logout)
	header.add_child(logout_button)

	var screens_container := MarginContainer.new()
	screens_container.name = "Screens"
	screens_container.size_flags_vertical = Control.SIZE_EXPAND_FILL
	screens_container.add_theme_constant_override("margin_left", 24)
	screens_container.add_theme_constant_override("margin_right", 24)
	screens_container.add_theme_constant_override("margin_top", 18)
	screens_container.add_theme_constant_override("margin_bottom", 22)
	root.add_child(screens_container)

	var menu := preload("res://scripts/ui/main_menu.gd").new()
	menu.name = "MainMenu"
	menu.main = self
	screens_container.add_child(menu)
	screens["menu"] = menu

	var login := preload("res://scripts/ui/login_screen.gd").new()
	login.name = "LoginScreen"
	login.main = self
	screens_container.add_child(login)
	screens["login"] = login

	var map := preload("res://scripts/ui/study_map.gd").new()
	map.name = "StudyMap"
	map.main = self
	screens_container.add_child(map)
	screens["map"] = map

	var setup := preload("res://scripts/ui/block_setup.gd").new()
	setup.name = "BlockSetup"
	setup.main = self
	screens_container.add_child(setup)
	screens["setup"] = setup

	var player := preload("res://scripts/ui/question_player.gd").new()
	player.name = "QuestionPlayer"
	player.main = self
	screens_container.add_child(player)
	screens["player"] = player

	var review := preload("res://scripts/ui/review_results.gd").new()
	review.name = "ReviewResults"
	review.main = self
	screens_container.add_child(review)
	screens["review"] = review

	var profile := preload("res://scripts/ui/progress_profile.gd").new()
	profile.name = "ProgressProfile"
	profile.main = self
	screens_container.add_child(profile)
	screens["profile"] = profile

	ProfileService.profile_changed.connect(_refresh_header_stats)
	AuthState.auth_changed.connect(_refresh_header_stats)
	_refresh_header_stats()


func _refresh_header_stats() -> void:
	if header_stats == null:
		return
	var profile := ProfileService.get_profile()
	header_stats.text = "LV %d  |  %d XP  |  Streak %d" % [
		profile.get("level", 1),
		profile.get("xp", 0),
		profile.get("current_streak", 0)
	]
	if user_label != null:
		user_label.text = AuthState.username if AuthState.is_logged_in else ""


func _logout() -> void:
	AuthState.clear_session()
	show_screen("login")