class_name RegisterScreen
extends CanvasLayer

## RegisterScreen - Account creation form for online play

signal registration_successful(message: String)
signal login_requested
signal back_pressed

const WINDOW_SIZE := Vector2(400, 600)

# Validation constants
const USERNAME_MIN_LENGTH = 3
const USERNAME_MAX_LENGTH = 32
const PASSWORD_MIN_LENGTH = 8

# UI Components
var background: PanelContainer
var main_vbox: VBoxContainer
var title_label: Label
var email_input: LineEdit
var username_input: LineEdit
var password_input: LineEdit
var confirm_password_input: LineEdit
var register_button: Button
var login_link: Button
var back_button: Button
var error_label: Label
var success_label: Label

# State
var _is_loading: bool = false


func _ready() -> void:
	layer = 100
	_create_ui()


func _create_ui() -> void:
	# Background panel
	background = PanelContainer.new()
	add_child(background)
	background.position = Vector2.ZERO
	background.size = WINDOW_SIZE
	background.add_theme_stylebox_override("panel", _create_panel_style())

	# Main layout with margin
	var margin = MarginContainer.new()
	background.add_child(margin)
	margin.set_anchors_and_offsets_preset(Control.PRESET_FULL_RECT)
	margin.add_theme_constant_override("margin_left", 40)
	margin.add_theme_constant_override("margin_right", 40)
	margin.add_theme_constant_override("margin_top", 25)
	margin.add_theme_constant_override("margin_bottom", 25)

	main_vbox = VBoxContainer.new()
	margin.add_child(main_vbox)
	main_vbox.add_theme_constant_override("separation", 10)

	# Title
	_create_title()

	# Registration form
	_create_form()

	# Messages
	_create_message_labels()

	# Spacer
	var spacer = Control.new()
	spacer.size_flags_vertical = Control.SIZE_EXPAND_FILL
	main_vbox.add_child(spacer)

	# Links
	_create_links()

	# Back button
	_create_back_button()


func _create_title() -> void:
	title_label = Label.new()
	title_label.text = "CREATE ACCOUNT"
	title_label.horizontal_alignment = HORIZONTAL_ALIGNMENT_CENTER
	title_label.add_theme_font_size_override("font_size", 28)
	title_label.add_theme_color_override("font_color", Color(1.0, 0.95, 0.8))
	main_vbox.add_child(title_label)

	# Separator
	var separator = HSeparator.new()
	separator.add_theme_stylebox_override("separator", _create_separator_style())
	main_vbox.add_child(separator)

	# Small spacer
	var spacer = Control.new()
	spacer.custom_minimum_size.y = 10
	main_vbox.add_child(spacer)


func _create_form() -> void:
	# Email field
	var email_label = Label.new()
	email_label.text = "Email"
	email_label.add_theme_font_size_override("font_size", 15)
	email_label.add_theme_color_override("font_color", Color(0.9, 0.85, 0.7))
	main_vbox.add_child(email_label)

	email_input = LineEdit.new()
	email_input.placeholder_text = "Enter your email"
	email_input.custom_minimum_size = Vector2(0, 38)
	_style_input(email_input)
	main_vbox.add_child(email_input)

	# Username field
	var username_label = Label.new()
	username_label.text = "Username"
	username_label.add_theme_font_size_override("font_size", 15)
	username_label.add_theme_color_override("font_color", Color(0.9, 0.85, 0.7))
	main_vbox.add_child(username_label)

	username_input = LineEdit.new()
	username_input.placeholder_text = "3-32 characters"
	username_input.custom_minimum_size = Vector2(0, 38)
	username_input.max_length = USERNAME_MAX_LENGTH
	_style_input(username_input)
	main_vbox.add_child(username_input)

	# Password field
	var password_label = Label.new()
	password_label.text = "Password"
	password_label.add_theme_font_size_override("font_size", 15)
	password_label.add_theme_color_override("font_color", Color(0.9, 0.85, 0.7))
	main_vbox.add_child(password_label)

	password_input = LineEdit.new()
	password_input.placeholder_text = "At least 8 characters"
	password_input.secret = true
	password_input.custom_minimum_size = Vector2(0, 38)
	_style_input(password_input)
	main_vbox.add_child(password_input)

	# Confirm password field
	var confirm_label = Label.new()
	confirm_label.text = "Confirm Password"
	confirm_label.add_theme_font_size_override("font_size", 15)
	confirm_label.add_theme_color_override("font_color", Color(0.9, 0.85, 0.7))
	main_vbox.add_child(confirm_label)

	confirm_password_input = LineEdit.new()
	confirm_password_input.placeholder_text = "Re-enter your password"
	confirm_password_input.secret = true
	confirm_password_input.custom_minimum_size = Vector2(0, 38)
	_style_input(confirm_password_input)
	confirm_password_input.text_submitted.connect(_on_input_submitted)
	main_vbox.add_child(confirm_password_input)

	# Register button
	var button_spacer = Control.new()
	button_spacer.custom_minimum_size.y = 10
	main_vbox.add_child(button_spacer)

	register_button = Button.new()
	register_button.text = "Create Account"
	register_button.custom_minimum_size = Vector2(0, 45)
	_style_button(register_button, true)
	register_button.pressed.connect(_on_register_pressed)
	main_vbox.add_child(register_button)


func _create_message_labels() -> void:
	# Error label
	error_label = Label.new()
	error_label.text = ""
	error_label.horizontal_alignment = HORIZONTAL_ALIGNMENT_CENTER
	error_label.add_theme_font_size_override("font_size", 13)
	error_label.add_theme_color_override("font_color", Color(1.0, 0.4, 0.4))
	error_label.autowrap_mode = TextServer.AUTOWRAP_WORD
	error_label.visible = false
	main_vbox.add_child(error_label)

	# Success label
	success_label = Label.new()
	success_label.text = ""
	success_label.horizontal_alignment = HORIZONTAL_ALIGNMENT_CENTER
	success_label.add_theme_font_size_override("font_size", 13)
	success_label.add_theme_color_override("font_color", Color(0.4, 1.0, 0.5))
	success_label.autowrap_mode = TextServer.AUTOWRAP_WORD
	success_label.visible = false
	main_vbox.add_child(success_label)


func _create_links() -> void:
	# Login link
	login_link = Button.new()
	login_link.text = "Already have an account? Login"
	login_link.flat = true
	login_link.add_theme_font_size_override("font_size", 14)
	login_link.add_theme_color_override("font_color", Color(0.6, 0.7, 1.0))
	login_link.add_theme_color_override("font_hover_color", Color(0.8, 0.85, 1.0))
	login_link.pressed.connect(_on_login_pressed)
	main_vbox.add_child(login_link)


func _create_back_button() -> void:
	var button_container = HBoxContainer.new()
	button_container.alignment = BoxContainer.ALIGNMENT_CENTER
	main_vbox.add_child(button_container)

	back_button = Button.new()
	back_button.text = "Back"
	back_button.custom_minimum_size = Vector2(100, 38)
	_style_button(back_button, false)
	back_button.pressed.connect(_on_back_pressed)
	button_container.add_child(back_button)


# ======= STYLING =======

func _create_panel_style() -> StyleBoxFlat:
	var style = StyleBoxFlat.new()
	style.bg_color = Color(0.08, 0.08, 0.12, 1.0)
	style.set_border_width_all(0)
	style.set_corner_radius_all(0)
	return style


func _create_separator_style() -> StyleBoxFlat:
	var style = StyleBoxFlat.new()
	style.bg_color = Color(0.5, 0.4, 0.2, 0.5)
	style.content_margin_top = 1
	return style


func _style_input(input: LineEdit) -> void:
	var style = StyleBoxFlat.new()
	style.bg_color = Color(0.12, 0.12, 0.16)
	style.border_color = Color(0.4, 0.35, 0.25)
	style.set_border_width_all(1)
	style.set_corner_radius_all(4)
	style.content_margin_left = 12
	style.content_margin_right = 12
	style.content_margin_top = 6
	style.content_margin_bottom = 6

	input.add_theme_stylebox_override("normal", style)

	var focus_style = style.duplicate()
	focus_style.border_color = Color(0.7, 0.6, 0.3)
	input.add_theme_stylebox_override("focus", focus_style)

	input.add_theme_color_override("font_color", Color(0.95, 0.9, 0.8))
	input.add_theme_color_override("font_placeholder_color", Color(0.5, 0.5, 0.55))
	input.add_theme_font_size_override("font_size", 15)


func _style_button(button: Button, is_primary: bool) -> void:
	var style = StyleBoxFlat.new()
	if is_primary:
		style.bg_color = Color(0.3, 0.25, 0.15)
		style.border_color = Color(0.6, 0.5, 0.3)
	else:
		style.bg_color = Color(0.15, 0.15, 0.2)
		style.border_color = Color(0.4, 0.35, 0.25)
	style.set_border_width_all(2)
	style.set_corner_radius_all(6)
	style.content_margin_left = 20
	style.content_margin_right = 20
	style.content_margin_top = 8
	style.content_margin_bottom = 8

	button.add_theme_stylebox_override("normal", style)

	var hover_style = style.duplicate()
	if is_primary:
		hover_style.bg_color = Color(0.4, 0.35, 0.2)
		hover_style.border_color = Color(0.8, 0.7, 0.4)
	else:
		hover_style.bg_color = Color(0.2, 0.2, 0.25)
		hover_style.border_color = Color(0.5, 0.45, 0.35)
	button.add_theme_stylebox_override("hover", hover_style)

	var pressed_style = style.duplicate()
	pressed_style.bg_color = Color(0.1, 0.1, 0.12)
	button.add_theme_stylebox_override("pressed", pressed_style)

	var disabled_style = style.duplicate()
	disabled_style.bg_color = Color(0.1, 0.1, 0.12)
	disabled_style.border_color = Color(0.25, 0.25, 0.3)
	button.add_theme_stylebox_override("disabled", disabled_style)

	button.add_theme_color_override("font_color", Color(0.9, 0.85, 0.7))
	button.add_theme_color_override("font_hover_color", Color(1.0, 0.95, 0.8))
	button.add_theme_color_override("font_pressed_color", Color(0.7, 0.65, 0.55))
	button.add_theme_color_override("font_disabled_color", Color(0.45, 0.42, 0.38))
	button.add_theme_font_size_override("font_size", 16)


# ======= EVENT HANDLERS =======

func _on_input_submitted(_text: String) -> void:
	_on_register_pressed()


func _on_register_pressed() -> void:
	if _is_loading:
		return

	var email = email_input.text.strip_edges()
	var username = username_input.text.strip_edges()
	var password = password_input.text
	var confirm_password = confirm_password_input.text

	# Validate inputs
	var validation_error = _validate_inputs(email, username, password, confirm_password)
	if validation_error != "":
		_show_error(validation_error)
		return

	# Start registration
	_set_loading(true)
	_hide_messages()

	var result = await NetworkManager.register(email, password, username)

	_set_loading(false)

	if result.success:
		_show_success(result.message)
		registration_successful.emit(result.message)
	else:
		_show_error(result.message)


func _on_login_pressed() -> void:
	login_requested.emit()


func _on_back_pressed() -> void:
	back_pressed.emit()


# ======= VALIDATION =======

func _validate_inputs(email: String, username: String, password: String, confirm_password: String) -> String:
	# Email validation
	if email.is_empty():
		return "Please enter your email"

	if not _is_valid_email(email):
		return "Please enter a valid email address"

	# Username validation
	if username.is_empty():
		return "Please enter a username"

	if username.length() < USERNAME_MIN_LENGTH:
		return "Username must be at least %d characters" % USERNAME_MIN_LENGTH

	if username.length() > USERNAME_MAX_LENGTH:
		return "Username must be at most %d characters" % USERNAME_MAX_LENGTH

	if not _is_valid_username(username):
		return "Username can only contain letters, numbers, underscores, and hyphens"

	# Password validation
	if password.is_empty():
		return "Please enter a password"

	if password.length() < PASSWORD_MIN_LENGTH:
		return "Password must be at least %d characters" % PASSWORD_MIN_LENGTH

	# Confirm password
	if confirm_password != password:
		return "Passwords do not match"

	return ""


func _is_valid_email(email: String) -> bool:
	var regex = RegEx.new()
	regex.compile("^[^\\s@]+@[^\\s@]+\\.[^\\s@]+$")
	return regex.search(email) != null


func _is_valid_username(username: String) -> bool:
	var regex = RegEx.new()
	regex.compile("^[a-zA-Z0-9_-]+$")
	return regex.search(username) != null


# ======= HELPERS =======

func _show_error(message: String) -> void:
	error_label.text = message
	error_label.visible = true
	success_label.visible = false


func _show_success(message: String) -> void:
	success_label.text = message
	success_label.visible = true
	error_label.visible = false


func _hide_messages() -> void:
	error_label.visible = false
	success_label.visible = false


func _set_loading(loading: bool) -> void:
	_is_loading = loading
	register_button.disabled = loading
	register_button.text = "Creating Account..." if loading else "Create Account"
	email_input.editable = not loading
	username_input.editable = not loading
	password_input.editable = not loading
	confirm_password_input.editable = not loading


func clear_form() -> void:
	email_input.text = ""
	username_input.text = ""
	password_input.text = ""
	confirm_password_input.text = ""
	_hide_messages()
	_set_loading(false)


func focus_email() -> void:
	email_input.grab_focus()