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 on the AuthButtonsRow directly set the panel's
## mode, so the user can switch between Login and Register at any time while
## the panel is open.
##
## On successful auth the token is stored via ApiClient, AuthButtonsRow hides,
## the welcome label shows the username, and the Play button becomes enabled.
## The auth form fields are hidden, leaving only the welcome message visible.
##
## When returning from another scene (e.g. world_list), _ready() checks whether
## ApiClient already holds a valid token. If so, it restores the authenticated
## UI state (Play enabled, welcome message visible) instead of forcing the user
## back to the login form.


## Emitted once _ready()'s session check (has_token() + the awaited
## get_me() call) has actually resolved, whichever way -- lets a test (or
## anything else) know the UI state is trustworthy now, rather than
## guessing from a frame count or from UI properties that are ambiguous
## mid-await (e.g. AuthButtonsRow.visible is true both before the check
## resolves AND in a genuine logged-out end state).
signal auth_state_ready

# ─── 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 _customize_button: Button
var _quit_button: Button

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


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


static func _build_label() -> String:
	var f := FileAccess.open("res://assets/build_info.json", FileAccess.READ)
	if f == null:
		return "dev"
	var d = JSON.parse_string(f.get_as_text())
	if d is Dictionary:
		return "%s %s" % [d.get("checkpoint", "?"), d.get("commit", "?")]
	return "dev"


func _ready() -> void:
	var v := Label.new()
	v.text = "build %s" % _build_label()
	v.add_theme_color_override("font_color", Color(1, 1, 1, 0.7))
	v.add_theme_color_override("font_outline_color", Color(0, 0, 0, 0.85))
	v.add_theme_constant_override("outline_size", 4)
	v.add_theme_font_size_override("font_size", 12)
	# Full-width strip pinned to the bottom, text right-aligned. A bare
	# BOTTOM_RIGHT preset + .position on a zero-size Label collapses the rect
	# and nothing renders -- which is why this never showed up.
	v.set_anchors_preset(Control.PRESET_BOTTOM_WIDE)
	v.horizontal_alignment = HORIZONTAL_ALIGNMENT_RIGHT
	v.vertical_alignment = VERTICAL_ALIGNMENT_BOTTOM
	v.offset_left = 8
	v.offset_right = -10
	v.offset_top = -28
	v.offset_bottom = -6
	v.mouse_filter = Control.MOUSE_FILTER_IGNORE
	add_child(v)

	# 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
	_customize_button = $CenterContainer/VBoxContainer/CustomizeButton
	_quit_button = $CenterContainer/VBoxContainer/QuitButton

	# Default to Play being gated. When a token exists, the async session
	# check below may take several frames (a real get_me() round-trip);
	# keeping the button disabled until validation succeeds prevents a fast
	# click from navigating to world_list with an expired/invalid token.
	_play_button.disabled = true
	_customize_button.disabled = true

	# Check whether a valid session already exists (e.g. user logged in,
	# navigated to world_list, then clicked Back). If so, restore the
	# authenticated UI state instead of forcing the login form again.
	if ApiClient.has_token():
		var me_result: Dictionary = await ApiClient.get_me()
		if me_result.ok and me_result.data is Dictionary:
			var username: String = str((me_result.data as Dictionary).get("username", ""))
			if username != "":
				_show_authenticated(username)
				await _prime_avatar()
				auth_state_ready.emit()
				return

	# Token missing or invalid — fall through to logged-out state.
	_reset_to_logged_out()
	auth_state_ready.emit()


## Restore the UI to the authenticated state (Play enabled, welcome message
## visible, auth buttons hidden). AuthPanel itself stays visible -- the
## welcome label lives inside it, so hiding the panel hides the label too
## even when the label's own `visible` is true (real bug, 2026-08-20: a
## review caught the panel being hidden here while the label claimed to be
## visible, which is a no-op UI-wise since Control.visible doesn't override
## an ancestor's hidden state).
func _show_authenticated(username: String) -> void:
	_auth_panel.visible = true
	_status_label.visible = false
	_welcome_label.text = "Welcome, %s!" % username
	_welcome_label.visible = true
	# Hide the same full set of form fields _on_auth_complete() hides right
	# after a fresh login/register -- this path (session restore on scene
	# reload, e.g. after Play -> Back) used to only hide EmailEdit/
	# Over18Check, leaving UsernameEdit/PasswordEdit/AuthButton/
	# AuthModeLabel visible on top of the welcome message. Real bug: Play
	# was enabled and the welcome label was correct, so it wasn't caught by
	# checks for those alone -- the login fields being back on screen is
	# what a user actually sees as "it's making me log in again."
	_username_edit.visible = false
	_password_edit.visible = false
	_email_edit.visible = false
	_dob_edit.visible = false
	_auth_button.visible = false
	_auth_mode_label.visible = false
	_play_button.disabled = false
	_customize_button.disabled = false
	_auth_buttons_row.visible = false
	print("Restored authenticated session for: ", username)


## Reset the UI to the logged-out state (Play disabled, auth panel hidden,
## login/register buttons visible).
func _reset_to_logged_out() -> void:
	_auth_panel.visible = false
	_status_label.visible = false
	_welcome_label.visible = false
	_email_edit.visible = false
	_dob_edit.visible = false
	_dob_edit.text = ""
	_play_button.disabled = true  # Gate play behind successful auth.
	_customize_button.disabled = true
	_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_customize_button_pressed() -> void:
	if _customize_button.disabled:
		return
	get_tree().change_scene_to_file("res://scenes/avatar_customization.tscn")


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


## Loose client-side check -- YYYY-MM-DD, a real calendar date, not in the
## future. The backend does the authoritative age computation.
func _is_valid_dob(dob: String) -> bool:
	var m := RegEx.new()
	m.compile("^\\d{4}-\\d{2}-\\d{2}$")
	if m.search(dob) == null:
		return false
	var parts := dob.split("-")
	var d := {"year": int(parts[0]), "month": int(parts[1]), "day": int(parts[2]), "hour": 0, "minute": 0, "second": 0}
	var unix := Time.get_unix_time_from_datetime_dict(d)
	return unix > 0 and unix < Time.get_unix_time_from_system()


# ─── 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()

		if email == "":
			_show_status("Email is required.")
			return
		var dob := _dob_edit.text.strip_edges()
		if not _is_valid_dob(dob):
			_show_status("Enter your date of birth as YYYY-MM-DD.")
			return

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

		var result := await ApiClient.register(username, email, password, dob)
		await _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)
		await _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:
		# Update the UI to the authenticated state first, synchronously, so
		# the player sees "Welcome" + an enabled Play immediately -- then
		# prime the avatar (a catalog load + a loadout fetch) in the
		# background. A slow or failing prime must never gate getting in.
		_username_edit.visible = false
		_password_edit.visible = false
		_email_edit.visible = false
		_dob_edit.visible = false
		_auth_button.visible = false
		_auth_mode_label.visible = false
		_status_label.visible = false
		_welcome_label.text = "Welcome, %s!" % _username_edit.text.strip_edges()
		_welcome_label.visible = true
		_play_button.disabled = false
		_customize_button.disabled = false
		_auth_buttons_row.visible = false
		print("Auth successful. Token stored.")
		await _prime_avatar()
	else:
		# Failure — show backend error detail.
		_show_status(result.detail)


# ─── Avatar priming ───────────────────────────────────────────────────────────

## After a successful auth, load the asset catalog and the player's saved
## loadout so the in-world player renders as their avatar. Best-effort: a
## failure here just means the player falls back to the default capsule, it
## never blocks getting into the game.
func _prime_avatar() -> void:
	if not Engine.has_singleton("AvatarSystem") and get_node_or_null("/root/AvatarSystem") == null:
		return
	var avatars = get_node_or_null("/root/AvatarSystem")
	if avatars == null:
		return
	if not await avatars.ensure_catalog():
		push_warning("main_menu: avatar catalog failed to load; using fallback look")
		return
	var res: Dictionary = await ApiClient.get_avatar_loadout()
	if res.ok and res.data is Dictionary and (res.data as Dictionary).has("data"):
		avatars.set_loadout_from_dict((res.data as Dictionary)["data"])
	else:
		# No saved loadout reachable -- fall back to the catalog's first base body.
		var bases: Array = avatars.get_assets_for_slot("base_body")
		if bases.size() > 0:
			avatars.set_loadout_from_dict({"base_body": bases[0], "slots": {}})


# ─── 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