extends SceneTree
## Regression test for the Play -> Back navigation bug.
##
## The reported bug: after logging in and clicking Play, the user lands on
## world_list.tscn; clicking Back returns to main_menu.tscn, but the menu
## reset to a fully logged-out state (Play disabled, login form showing)
## even though ApiClient still held a valid token. main_menu.gd's _ready()
## used to unconditionally reset the UI on every scene load.
##
## This test drives the real navigation flow (change_scene_to_file) against
## a live backend:
##   1. Register a unique user so ApiClient holds a valid token.
##   2. Load main_menu.tscn and assert it restores the authenticated state.
##   3. Click Play -> world_list.tscn.
##   4. Click Back -> main_menu.tscn.
##   5. Assert the menu is STILL authenticated (Play enabled, welcome label
##      actually visible in the tree, login/register buttons hidden).
##
## Run with:
##     godot --headless --path . --script res://scripts/smoke_test_main_menu_back.gd
##
## Requires the backend to be running (default base URL
## `application/agp/api_base_url` -> http://127.0.0.1:8000).

const USERNAME := "backnav_%d"
const EMAIL := "backnav_%d@test.example.com"
const PASSWORD := "BackNav123!"
const DOB := "2000-01-01"

var passed := 0
var failed := 0


func _initialize() -> void:
	_run()


func _run() -> void:
	await process_frame

	var api := root.get_node("ApiClient")
	if api == null:
		printerr("FAIL: ApiClient autoload not found")
		quit(1)
		return

	# 1. Establish a real, valid session exactly the way a user would.
	randomize()
	var unique_id: int = int(Time.get_unix_time_from_system() * 1000) + randi() % 100000
	var username := USERNAME % unique_id
	var email := EMAIL % unique_id
	print("\n=== Setup: register ", username, " ===")
	var register_result: Dictionary = await api.register(username, email, PASSWORD, DOB)
	if not _check("register succeeds", register_result.ok):
		print("  detail: ", register_result.detail)
		_finish()
		return
	_check("ApiClient stores token after register", api.has_token())

	# 2. First visit to the main menu: should already show the authenticated
	#    state (no login form, Play enabled).
	change_scene_to_file("res://scenes/main_menu.tscn")
	# change_scene_to_file defers the actual swap -- a couple frames is
	# plenty for the scene object itself to exist (unlike the real
	# get_me() network round-trip afterward, which is what auth_state_ready
	# actually waits for below).
	for i in 5:
		await process_frame
		if current_scene is Control:
			break

	var menu: Control = current_scene
	if menu == null or not menu is Control:
		printerr("FAIL: main_menu.tscn did not become current_scene")
		_finish()
		return
	await menu.auth_state_ready
	_check("first main menu visit restores authenticated state", _is_authenticated(menu))

	# 3. Play -> world_list.tscn (real button press).
	var play_button: Button = menu.get_node("CenterContainer/VBoxContainer/PlayButton")
	play_button.pressed.emit()
	await _wait_for_scene_change(menu)

	var world_list_scene := current_scene
	if world_list_scene == null or world_list_scene == menu:
		printerr("FAIL: world_list.tscn did not become current_scene after Play")
		_finish()
		return

	# 4. Back -> main_menu.tscn (real button press).
	var back_button: Button = world_list_scene.get_node("VBoxContainer/HeaderHBox/BackButton")
	back_button.pressed.emit()
	await _wait_for_scene_change(world_list_scene)

	menu = current_scene
	if menu == null or not menu is Control:
		printerr("FAIL: main_menu.tscn did not become current_scene after Back")
		_finish()
		return

	# The new main_menu instance's own _ready() is *also* awaiting a real
	# get_me() call -- _wait_for_scene_change only confirms the scene
	# object exists, not that its authenticated-state fields have been
	# set yet. Wait for the real signal, not a guess.
	await menu.auth_state_ready

	# 5. THE regression assertion: still logged in after returning.
	_check("main menu stays authenticated after Play -> Back", _is_authenticated(menu))

	_finish()


func _is_authenticated(menu: Control) -> bool:
	var play_button: Button = menu.get_node("CenterContainer/VBoxContainer/PlayButton")
	var welcome_label: Label = menu.get_node("CenterContainer/VBoxContainer/AuthPanel/MarginContainer/AuthVBox/WelcomeLabel")
	var auth_buttons_row: HBoxContainer = menu.get_node("CenterContainer/VBoxContainer/AuthButtonsRow")
	var auth_panel: PanelContainer = menu.get_node("CenterContainer/VBoxContainer/AuthPanel")

	_check("Play enabled", not play_button.disabled)
	# WelcomeLabel lives inside AuthPanel, so `.visible` alone is a
	# false-positive: the label can have visible=true while its parent is
	# hidden and it renders as nothing. `is_visible_in_tree()` is the
	# check that proves the user can actually see the welcome message.
	_check("Welcome label visible in tree", welcome_label.is_visible_in_tree())
	_check("Auth buttons row hidden", not auth_buttons_row.visible)
	_check("Auth panel visible (it contains the welcome label)", auth_panel.visible)

	return (not play_button.disabled) \
		and welcome_label.is_visible_in_tree() \
		and not auth_buttons_row.visible \
		and auth_panel.visible


func _wait_for_scene_change(previous_scene: Node) -> void:
	for i in 20:
		await process_frame
		if current_scene != previous_scene and current_scene != null:
			return


func _check(description: String, condition: bool) -> bool:
	if condition:
		print("  PASS: ", description)
		passed += 1
	else:
		printerr("  FAIL: ", description)
		failed += 1
	return condition


func _finish() -> void:
	print("\n=== SMOKE RESULT: %d/%d passed ===" % [passed, passed + failed])
	quit(0 if failed == 0 else 1)