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
var app_menu: PanelContainer
var menu_exit_button: Button
var sound_toggle: CheckButton
var theme_button: Button
var theme_service
var current_screen_name := ""

func _ready() -> void:
	theme_service = get_node("/root/UIThemeService")
	Style.apply_app_theme(self)
	_build_ui()
	theme_service.theme_changed.connect(_on_theme_changed)
	resized.connect(_update_responsive_layout)
	_update_responsive_layout()
	show_screen("selection" if AuthState.is_logged_in else "login", "exam")


func _update_responsive_layout() -> void:
	if header_stats != null:
		header_stats.visible = size.x >= 900.0
	if app_menu != null:
		app_menu.custom_minimum_size.x = minf(340.0, maxf(280.0, size.x - 32.0))
		if app_menu.visible:
			app_menu.size = app_menu.custom_minimum_size
			app_menu.position = (get_viewport_rect().size - app_menu.size) * 0.5


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

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

	current_screen_name = screen_name
	screen.visible = true
	if header_panel != null:
		header_panel.visible = screen_name != "login" and screen_name != "player"
	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 = "RanaZe's Doctor Maker"
	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
	user_label.mouse_filter = Control.MOUSE_FILTER_STOP
	user_label.mouse_default_cursor_shape = Control.CURSOR_POINTING_HAND
	user_label.tooltip_text = "Open profile"
	user_label.gui_input.connect(_on_user_label_gui_input)
	header.add_child(user_label)

	theme_button = Button.new()
	theme_button.custom_minimum_size = Vector2(44, 44)
	theme_button.add_theme_font_size_override("font_size", 22)
	UISoundService.set_button_sound(theme_button, "toggle")
	theme_button.pressed.connect(theme_service.toggle_theme)
	header.add_child(theme_button)
	_refresh_theme_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 selector := preload("res://scripts/ui/study_selector.gd").new()
	selector.name = "StudySelector"
	selector.main = self
	screens_container.add_child(selector)
	screens["selection"] = selector

	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)
	QuestionBankService.ratings_changed.connect(_refresh_header_stats)
	AuthState.auth_changed.connect(_refresh_header_stats)
	_refresh_header_stats()
	_build_app_menu()


func _input(event: InputEvent) -> void:
	if not AuthState.is_logged_in or current_screen_name == "login":
		return
	if event.is_action_pressed("ui_cancel"):
		_toggle_app_menu()
		get_viewport().set_input_as_handled()


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


func _on_theme_changed(is_dark_mode: bool) -> void:
	Style.refresh_tree(self, not is_dark_mode)
	_refresh_theme_button()
	var player = screens.get("player")
	if player != null and player.has_method("refresh_theme_controls"):
		player.refresh_theme_controls()


func _refresh_theme_button() -> void:
	if theme_button == null:
		return
	theme_button.text = "☀" if theme_service.is_dark_mode() else "☾"
	theme_button.tooltip_text = "Switch to light mode" if theme_service.is_dark_mode() else "Switch to dark mode"
	Style.style_chip(theme_button, Style.CYAN)


func _logout() -> void:
	_close_app_menu()
	if BlockSessionService.block_started:
		BlockSessionService.finish_block()
	QuestionBankService.clear_questions()
	AuthState.clear_session()
	show_screen("login")


func _build_app_menu() -> void:
	app_menu = PanelContainer.new()
	app_menu.visible = false
	app_menu.top_level = true
	app_menu.mouse_filter = Control.MOUSE_FILTER_STOP
	app_menu.custom_minimum_size = Vector2(340, 230)
	app_menu.add_theme_stylebox_override("panel", Style.panel_box(Color("172337"), Style.CYAN))
	add_child(app_menu)

	var content := VBoxContainer.new()
	content.add_theme_constant_override("separation", 12)
	app_menu.add_child(content)

	var title := Label.new()
	title.text = "Paused"
	title.horizontal_alignment = HORIZONTAL_ALIGNMENT_CENTER
	Style.set_label(title, 28, Style.TEXT)
	content.add_child(title)

	var resume := Button.new()
	resume.text = "Resume"
	resume.custom_minimum_size = Vector2(0, 48)
	Style.style_primary_button(resume)
	UISoundService.set_button_sound(resume, "close")
	resume.pressed.connect(_close_app_menu)
	content.add_child(resume)

	sound_toggle = CheckButton.new()
	sound_toggle.text = "UI Sounds"
	sound_toggle.button_pressed = UISoundService.are_sounds_enabled()
	sound_toggle.custom_minimum_size = Vector2(0, 44)
	UISoundService.set_button_sound(sound_toggle, "none")
	sound_toggle.toggled.connect(UISoundService.set_sounds_enabled)
	content.add_child(sound_toggle)

	var profile := Button.new()
	profile.text = "Profile"
	profile.custom_minimum_size = Vector2(0, 48)
	Style.style_chip(profile, Style.CYAN)
	profile.pressed.connect(_open_profile_from_menu)
	content.add_child(profile)

	menu_exit_button = Button.new()
	menu_exit_button.text = "Exit Run"
	menu_exit_button.custom_minimum_size = Vector2(0, 48)
	UISoundService.set_button_sound(menu_exit_button, "back")
	menu_exit_button.pressed.connect(_exit_run)
	content.add_child(menu_exit_button)

	var logout := Button.new()
	logout.text = "Log Out"
	logout.custom_minimum_size = Vector2(0, 48)
	Style.style_chip(logout, Style.RED)
	UISoundService.set_button_sound(logout, "back")
	logout.pressed.connect(_logout)
	content.add_child(logout)


func _toggle_app_menu() -> void:
	if app_menu == null:
		return
	if app_menu.visible:
		UISoundService.play_sound("close")
		_close_app_menu()
	else:
		UISoundService.play_sound("open")
		app_menu.visible = true
		app_menu.size = app_menu.custom_minimum_size
		app_menu.position = (get_viewport_rect().size - app_menu.size) * 0.5
		menu_exit_button.visible = current_screen_name == "player" and BlockSessionService.block_started
		if menu_exit_button.visible:
			Style.style_chip(menu_exit_button, Style.AMBER)
			BlockSessionService.pause_current_question_timer()


func _close_app_menu() -> void:
	if app_menu != null:
		app_menu.visible = false
	BlockSessionService.resume_current_question_timer()


func _exit_run() -> void:
	_close_app_menu()
	if BlockSessionService.block_started:
		BlockSessionService.finish_block()
	show_screen("selection", "step3")


func _open_profile_from_menu() -> void:
	_close_app_menu()
	if BlockSessionService.block_started:
		BlockSessionService.finish_block()
	show_screen("profile")


func _on_user_label_gui_input(event: InputEvent) -> void:
	if not AuthState.is_logged_in:
		return
	var mouse_event := event as InputEventMouseButton
	if mouse_event == null or mouse_event.button_index != MOUSE_BUTTON_LEFT or not mouse_event.pressed:
		return
	_close_app_menu()
	if current_screen_name != "profile":
		show_screen("profile")