extends Control
## Main menu with login/register UI wired to the backend auth API.
##
## The AuthPanel is hidden by default. When the user clicks the LoginButton or
## RegisterButton (AuthButtonsRow, above the panel), the auth panel slides in.
## The Login and Register buttons in AuthButtonsRow also switch the panel's mode
## when clicked while the panel is already open, so the user can toggle between
## Login and Register modes at any time.

# ─── UI references ────────────────────────────────────────────────────────────

var _auth_buttons_row: HBoxContainer
var _login_button: Button
var _register_button: Button
var _auth_panel: PanelContainer
var _auth_mode_label: Label
var _username_edit: LineEdit
var _password_edit: LineEdit
var _email_edit: LineEdit
var _dob_edit: LineEdit
var _auth_button: Button
var _status_label: Label
var _welcome_label: Label
var _play_button: Button
var _quit_button: Button

var _is_register_mode: bool = false
var _is_authenticating: bool = false


# ─── Lifecycle ────────────────────────────────────────────────────────────────

func _ready() -> void:
	# Cache node references.
	_auth_buttons_row = $CenterContainer/VBoxContainer/AuthButtonsRow
	_login_button = $CenterContainer/VBoxContainer/AuthButtonsRow/LoginButton
	_register_button = $CenterContainer/VBoxContainer/AuthButtonsRow/RegisterButton
	_auth_panel = $CenterContainer/VBoxContainer/AuthPanel
	_auth_mode_label = $CenterContainer/VBoxContainer/AuthPanel/MarginContainer/AuthVBox/AuthModeLabel
	_username_edit = $CenterContainer/VBoxContainer/AuthPanel/MarginContainer/AuthVBox/UsernameEdit
	_password_edit = $CenterContainer/VBoxContainer/AuthPanel/MarginContainer/AuthVBox/PasswordEdit
	_email_edit = $CenterContainer/VBoxContainer/AuthPanel/MarginContainer/AuthVBox/EmailEdit
	_dob_edit = $CenterContainer/VBoxContainer/AuthPanel/MarginContainer/AuthVBox/DOBEdit
	_auth_button = $CenterContainer/VBoxContainer/AuthPanel/MarginContainer/AuthVBox/AuthButton
	_status_label = $CenterContainer/VBoxContainer/AuthPanel/MarginContainer/AuthVBox/AuthStatusLabel
	_welcome_label = $CenterContainer/VBoxContainer/AuthPanel/MarginContainer/AuthVBox/WelcomeLabel
	_play_button = $CenterContainer/VBoxContainer/PlayButton
	_quit_button = $CenterContainer/VBoxContainer/QuitButton

	# Initial state.
	_auth_panel.visible = false
	_status_label.visible = false
	_welcome_label.visible = false
	_email_edit.visible = false
	_dob_edit.visible = false
	_play_button.disabled = true  # Gate play behind successful auth.
	_update_auth_mode_ui()


# ─── Play / Quit ──────────────────────────────────────────────────────────────

func _on_play_button_pressed() -> void:
	if _play_button.disabled:
		return
	# Browse worlds is the first real screen past login -- actual gameplay
	# (joining a world) doesn't exist yet, browsing does.
	get_tree().change_scene_to_file("res://scenes/world_list.tscn")


func _on_quit_button_pressed() -> void:
	get_tree().quit()


# ─── Auth panel toggle ────────────────────────────────────────────────────────

func _on_login_button_pressed() -> void:
	"""Show the auth panel in login mode, called from AuthButtonsRow/LoginButton."""
	_auth_panel.visible = true
	_is_register_mode = false
	_update_auth_mode_ui()
	_clear_status()
	_username_edit.grab_focus()


func _on_register_button_pressed() -> void:
	"""Show the auth panel in register mode, called from AuthButtonsRow/RegisterButton."""
	_auth_panel.visible = true
	_is_register_mode = true
	_update_auth_mode_ui()
	_clear_status()
	_username_edit.grab_focus()


func _update_auth_mode_ui() -> void:
	"""Update labels and field visibility based on login vs register mode."""
	if _is_register_mode:
		_auth_mode_label.text = "Register"
		_auth_button.text = "Register"
		_email_edit.visible = true
		_dob_edit.visible = true
	else:
		_auth_mode_label.text = "Login"
		_auth_button.text = "Login"
		_email_edit.visible = false
		_dob_edit.visible = false


# ─── Auth submission ──────────────────────────────────────────────────────────

func _on_auth_button_pressed() -> void:
	"""Handle login or register button press."""
	if _is_authenticating:
		return

	# Validate inputs.
	var username := _username_edit.text.strip_edges()
	var password := _password_edit.text

	if username == "":
		_show_status("Username is required.")
		return
	if password == "":
		_show_status("Password is required.")
		return

	if _is_register_mode:
		var email := _email_edit.text.strip_edges()
		var dob := _dob_edit.text.strip_edges()

		if email == "":
			_show_status("Email is required.")
			return
		if dob == "":
			_show_status("Date of birth is required.")
			return
		# Basic YYYY-MM-DD format check.
		if not _is_valid_date(dob):
			_show_status("Date of birth must be in YYYY-MM-DD format.")
			return

		_auth_button.disabled = true
		_auth_button.text = "Registering..."
		_is_authenticating = true
		_clear_status()

		var result := await ApiClient.register(username, email, password, dob)
		_on_auth_complete(result)
	else:
		_auth_button.disabled = true
		_auth_button.text = "Logging in..."
		_is_authenticating = true
		_clear_status()

		var result := await ApiClient.login(username, password)
		_on_auth_complete(result)


func _on_auth_complete(result: Dictionary) -> void:
	"""Handle the result of a login or register call."""
	_auth_button.disabled = false
	_auth_button.text = "Register" if _is_register_mode else "Login"
	_is_authenticating = false

	if result.ok:
		# Success — show welcome, enable Play, hide the now-redundant
		# Login/Register entry points (the auth panel itself stays open,
		# showing the welcome message in place of the form).
		_welcome_label.text = "Welcome, %s!" % _username_edit.text.strip_edges()
		_welcome_label.visible = true
		_status_label.visible = false
		_play_button.disabled = false
		_auth_buttons_row.visible = false
		print("Auth successful. Token stored.")
	else:
		# Failure — show backend error detail.
		_show_status(result.detail)


# ─── Status helpers ───────────────────────────────────────────────────────────

func _show_status(message: String) -> void:
	_status_label.text = message
	_status_label.visible = true


func _clear_status() -> void:
	_status_label.text = ""
	_status_label.visible = false


# ─── Validation ───────────────────────────────────────────────────────────────

func _is_valid_date(date_str: String) -> bool:
	"""Check if a string looks like a valid YYYY-MM-DD date."""
	if date_str.length() != 10:
		return false
	var parts := date_str.split("-")
	if parts.size() != 3:
		return false
	var year := parts[0].to_int()
	var month := parts[1].to_int()
	var day := parts[2].to_int()
	if month < 1 or month > 12:
		return false
	if day < 1 or day > 31:
		return false
	# Rough month-day validation.
	var days_in_month := [0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
	if day > days_in_month[month]:
		return false
	return true