extends VBoxContainer

const Style := preload("res://scripts/ui/ui_style.gd")
const AUTH_LOGIN_URL := "https://pauth.ranaze.com/api/Auth/login"
const AUTH_REGISTER_URL := "https://pauth.ranaze.com/api/Auth/register"

var main: Control
var auth_panel: PanelContainer
var login_tab: Button
var register_tab: Button
var login_fields: VBoxContainer
var register_fields: VBoxContainer
var username_input: LineEdit
var password_input: LineEdit
var registration_username_input: LineEdit
var registration_email_input: LineEdit
var registration_password_input: LineEdit
var registration_confirm_input: LineEdit
var login_button: Button
var register_button: Button
var error_label: Label
var success_label: Label
var login_request: HTTPRequest
var register_request: HTTPRequest
var auth_mode := "login"
var automatic_login_pending := false
var login_attempt_username := ""


func _ready() -> void:
	set_anchors_preset(Control.PRESET_FULL_RECT)
	add_theme_constant_override("separation", 18)

	var spacer_top := Control.new()
	spacer_top.size_flags_vertical = Control.SIZE_EXPAND_FILL
	add_child(spacer_top)

	var center := CenterContainer.new()
	center.size_flags_horizontal = Control.SIZE_EXPAND_FILL
	add_child(center)

	auth_panel = PanelContainer.new()
	auth_panel.custom_minimum_size = Vector2(540, 470)
	auth_panel.add_theme_stylebox_override("panel", Style.panel_box(Color("172337"), Style.CYAN))
	center.add_child(auth_panel)

	var content := VBoxContainer.new()
	content.add_theme_constant_override("separation", 14)
	auth_panel.add_child(content)

	var title := Label.new()
	title.text = "RanaZe's Doctor Maker"
	title.horizontal_alignment = HORIZONTAL_ALIGNMENT_CENTER
	Style.set_label(title, 34, Style.TEXT)
	content.add_child(title)

	var subtitle := Label.new()
	subtitle.text = "Sign in or create an account to start studying."
	subtitle.horizontal_alignment = HORIZONTAL_ALIGNMENT_CENTER
	subtitle.autowrap_mode = TextServer.AUTOWRAP_WORD_SMART
	Style.set_label(subtitle, 16, Style.MUTED)
	content.add_child(subtitle)

	var tabs := HBoxContainer.new()
	tabs.add_theme_constant_override("separation", 8)
	content.add_child(tabs)

	login_tab = Button.new()
	login_tab.text = "Log In"
	login_tab.custom_minimum_size = Vector2(0, 44)
	login_tab.size_flags_horizontal = Control.SIZE_EXPAND_FILL
	login_tab.pressed.connect(func(): _set_auth_mode("login"))
	tabs.add_child(login_tab)

	register_tab = Button.new()
	register_tab.text = "Create Account"
	register_tab.custom_minimum_size = Vector2(0, 44)
	register_tab.size_flags_horizontal = Control.SIZE_EXPAND_FILL
	register_tab.pressed.connect(func(): _set_auth_mode("register"))
	tabs.add_child(register_tab)

	login_fields = VBoxContainer.new()
	login_fields.add_theme_constant_override("separation", 10)
	content.add_child(login_fields)
	username_input = _add_text_field(login_fields, "Username", "enter username")
	username_input.text_submitted.connect(_on_login_input_submitted)
	password_input = _add_text_field(login_fields, "Password", "enter password", true)
	password_input.text_submitted.connect(_on_login_input_submitted)

	login_button = Button.new()
	login_button.text = "Log In"
	login_button.custom_minimum_size = Vector2(0, 50)
	Style.style_primary_button(login_button)
	login_button.pressed.connect(_on_login_pressed)
	login_fields.add_child(login_button)

	register_fields = VBoxContainer.new()
	register_fields.add_theme_constant_override("separation", 10)
	content.add_child(register_fields)
	registration_username_input = _add_text_field(register_fields, "Username", "3-24 letters, numbers, or underscores")
	registration_email_input = _add_text_field(register_fields, "Email", "name@example.com")
	registration_password_input = _add_text_field(register_fields, "Password", "at least 8 characters", true)
	registration_confirm_input = _add_text_field(register_fields, "Confirm password", "re-enter password", true)
	registration_confirm_input.text_submitted.connect(_on_register_input_submitted)

	register_button = Button.new()
	register_button.text = "Create Account"
	register_button.custom_minimum_size = Vector2(0, 50)
	Style.style_primary_button(register_button)
	register_button.pressed.connect(_on_register_pressed)
	register_fields.add_child(register_button)

	success_label = Label.new()
	success_label.horizontal_alignment = HORIZONTAL_ALIGNMENT_CENTER
	success_label.autowrap_mode = TextServer.AUTOWRAP_WORD_SMART
	Style.set_label(success_label, 15, Style.LIME)
	content.add_child(success_label)

	error_label = Label.new()
	error_label.horizontal_alignment = HORIZONTAL_ALIGNMENT_CENTER
	error_label.autowrap_mode = TextServer.AUTOWRAP_WORD_SMART
	Style.set_label(error_label, 15, Style.RED)
	content.add_child(error_label)

	var spacer_bottom := Control.new()
	spacer_bottom.size_flags_vertical = Control.SIZE_EXPAND_FILL
	add_child(spacer_bottom)

	login_request = HTTPRequest.new()
	login_request.name = "LoginRequest"
	login_request.request_completed.connect(_on_login_request_completed)
	add_child(login_request)

	register_request = HTTPRequest.new()
	register_request.name = "RegisterRequest"
	register_request.request_completed.connect(_on_register_request_completed)
	add_child(register_request)
	_set_auth_mode("login")


func on_show(_payload: Variant = null) -> void:
	_set_busy(false)
	_set_auth_mode("login")
	_clear_messages()
	username_input.grab_focus()


func _add_text_field(parent: VBoxContainer, field_name: String, placeholder: String, secret: bool = false) -> LineEdit:
	var label := Label.new()
	label.text = field_name
	Style.set_label(label, 15, Style.CYAN)
	parent.add_child(label)

	var input := LineEdit.new()
	input.placeholder_text = placeholder
	input.secret = secret
	input.custom_minimum_size = Vector2(0, 42)
	parent.add_child(input)
	return input


func _set_auth_mode(next_mode: String) -> void:
	auth_mode = next_mode
	if login_fields == null:
		return
	login_fields.visible = auth_mode == "login"
	register_fields.visible = auth_mode == "register"
	auth_panel.custom_minimum_size.y = 470 if auth_mode == "login" else 650
	if auth_mode == "login":
		Style.style_primary_button(login_tab)
		Style.style_chip(register_tab, Style.CYAN)
		username_input.grab_focus()
	else:
		Style.style_chip(login_tab, Style.CYAN)
		Style.style_primary_button(register_tab)
		registration_username_input.grab_focus()
	_clear_messages()


func _on_login_pressed() -> void:
	_send_login(username_input.text.strip_edges(), password_input.text, false)


func _send_login(username: String, password: String, is_automatic: bool) -> void:
	if username.is_empty() or password.is_empty():
		_show_error("Username and password required.")
		return

	automatic_login_pending = is_automatic
	login_attempt_username = username
	_set_busy(true)
	login_button.text = "Signing in..."
	_clear_messages()
	if is_automatic:
		success_label.text = "Account created. Signing you in..."
	var payload := {"username": username, "password": password}
	var headers := PackedStringArray(["Content-Type: application/json"])
	var request_error := login_request.request(AUTH_LOGIN_URL, headers, HTTPClient.METHOD_POST, JSON.stringify(payload))
	if request_error != OK:
		_set_busy(false)
		login_button.text = "Log In"
		_show_error("Failed to send login request.")


func _on_login_request_completed(result: int, response_code: int, _headers: PackedStringArray, body: PackedByteArray) -> void:
	_set_busy(false)
	login_button.text = "Log In"

	if result != HTTPRequest.RESULT_SUCCESS or response_code < 200 or response_code >= 300:
		if automatic_login_pending:
			_set_auth_mode("login")
			username_input.text = login_attempt_username
			password_input.text = ""
			_show_error("Account created, but automatic login failed. Please log in with your new account.")
		else:
			_show_error("Login failed. Check your credentials and try again.")
		automatic_login_pending = false
		return

	var response: Variant = JSON.parse_string(body.get_string_from_utf8())
	if typeof(response) != TYPE_DICTIONARY:
		_show_error("Login response was not valid JSON.")
		return

	var token := String(response.get("accessToken", ""))
	var response_username := String(response.get("username", login_attempt_username))
	if token.is_empty():
		_show_error("Login response did not include an access token.")
		return

	AuthState.set_session(
		response_username,
		token,
		String(response.get("refreshToken", "")),
		String(response.get("role", "")),
		String(response.get("exp", ""))
	)
	QuestionBankService.load_questions_from_api()
	password_input.text = ""
	registration_password_input.text = ""
	registration_confirm_input.text = ""
	automatic_login_pending = false
	main.show_screen("selection", "exam")


func _on_register_pressed() -> void:
	var username := registration_username_input.text.strip_edges()
	var email := registration_email_input.text.strip_edges()
	var password := registration_password_input.text
	var confirmation := registration_confirm_input.text
	var validation_error := _validate_registration(username, email, password, confirmation)
	if validation_error != "":
		_show_error(validation_error)
		return

	_set_busy(true)
	register_button.text = "Creating account..."
	_clear_messages()
	var payload := {"username": username, "email": email, "password": password}
	var headers := PackedStringArray(["Content-Type: application/json"])
	var request_error := register_request.request(AUTH_REGISTER_URL, headers, HTTPClient.METHOD_POST, JSON.stringify(payload))
	if request_error != OK:
		_set_busy(false)
		register_button.text = "Create Account"
		_show_error("Failed to send account creation request.")


func _on_register_request_completed(result: int, response_code: int, _headers: PackedStringArray, body: PackedByteArray) -> void:
	_set_busy(false)
	register_button.text = "Create Account"
	if result != HTTPRequest.RESULT_SUCCESS:
		_clear_registration_passwords()
		_show_error("Network error. Please try again.")
		return
	if response_code < 200 or response_code >= 300:
		_clear_registration_passwords()
		var server_message := _response_message(body)
		_show_error(server_message if server_message != "" else "Account creation failed.")
		return

	var username := registration_username_input.text.strip_edges()
	var password := registration_password_input.text
	username_input.text = username
	_send_login(username, password, true)


func _validate_registration(username: String, email: String, password: String, confirmation: String) -> String:
	var username_pattern := RegEx.new()
	username_pattern.compile("^[A-Za-z0-9_]{3,24}$")
	if username_pattern.search(username) == null:
		registration_username_input.grab_focus()
		return "Username must be 3-24 characters using only letters, numbers, or underscores."
	var email_pattern := RegEx.new()
	email_pattern.compile("^[^@\\s]+@[^@\\s]+\\.[^@\\s]+$")
	if email_pattern.search(email) == null:
		registration_email_input.grab_focus()
		return "Enter a valid email address."
	if password.length() < 8:
		registration_password_input.grab_focus()
		return "Password must be at least 8 characters."
	if password != confirmation:
		registration_confirm_input.grab_focus()
		return "Passwords do not match."
	return ""


func _set_busy(is_busy: bool) -> void:
	if login_button == null:
		return
	login_button.disabled = is_busy
	register_button.disabled = is_busy
	login_tab.disabled = is_busy
	register_tab.disabled = is_busy
	username_input.editable = not is_busy
	password_input.editable = not is_busy
	registration_username_input.editable = not is_busy
	registration_email_input.editable = not is_busy
	registration_password_input.editable = not is_busy
	registration_confirm_input.editable = not is_busy


func _clear_registration_passwords() -> void:
	registration_password_input.text = ""
	registration_confirm_input.text = ""


func _response_message(body: PackedByteArray) -> String:
	var raw := body.get_string_from_utf8().strip_edges()
	var parsed: Variant = JSON.parse_string(raw)
	return String(parsed) if typeof(parsed) == TYPE_STRING else raw


func _on_login_input_submitted(_new_text: String) -> void:
	_on_login_pressed()


func _on_register_input_submitted(_new_text: String) -> void:
	_on_register_pressed()


func _clear_messages() -> void:
	error_label.text = ""
	success_label.text = ""


func _show_error(message: String) -> void:
	success_label.text = ""
	error_label.text = message