from kivy.uix.screenmanager import Screen
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.label import Label
from kivy.metrics import dp
from kivy.logger import Logger
from kivy.app import App
from kivy.clock import Clock

from ui_utils import _popup_info
import numberpad 
from kivy.uix.anchorlayout import AnchorLayout
from kivy.core.window import Window

MAX_LOGIN_FAILS = 3   # nebo treba 5



class LoginUserScreen(Screen):
    def __init__(self, controller, on_success, **kwargs):
        super().__init__(**kwargs)
        self.fail_count = 0
        self.controller = controller
        self.on_success = on_success
        root = BoxLayout(orientation="vertical")
        self.lbl_info = Label(
            text="Zadej PIN číšníka",
            size_hint_y=None,
            height=40,
        )
        self.lbl_error = Label(
            text="",
            color=(1, 0, 0, 1),
            size_hint_y=None,
            height=30,
        )
        root.add_widget(self.lbl_info)
        root.add_widget(self.lbl_error)
        self.center_layout = AnchorLayout(anchor_x="center", anchor_y="center")
        root.add_widget(self.center_layout)
        self.pad = None
        self._keyboard_bound = False
        self.add_widget(root)

    def _on_key_down(self, window, key, scancode, codepoint, modifiers):
        if self.manager and self.manager.current != self.name:
            return False
        if self.pad:
            if key == 27:
                self.pad._cancel()
                return True   # 🔥 zabráni zatvoreniu appky
            if key in range(48, 58):  # top row
                self.pad._press(chr(key))
                return True
            elif key in range(256, 266):  # numpad
                self.pad._press(str(key - 256))
                return True
            elif chr(key)=='*' or key == 268:
                self.pad._press("*")
                return True
            elif chr(key)=='.' or key == 266:
                self.pad._press(".")
                return True
            elif key > 300:
                print("pass")
                pass
                return True
            elif codepoint and (codepoint.isalpha() or codepoint.isdigit()):
                self.pad._press(codepoint)
                return True
            elif key == 8:
                self.pad._press('⌫')
                return True
            elif key in (13, 40, 10, 271):  # Enter / Numpad Enter
                self.pad._accept()
                return True
            else:
                return False
        else:
            return False

    def on_enter(self):
        self._bind_keyboard()
        self.lbl_error.text = ""
        if self.pad:
            self.center_layout.remove_widget(self.pad)
        self.pad = numberpad.NumberPad(
            mode="code",
            max_len=10,
            on_accept=self._accept,
            on_cancel=self._cancel,
        )
        self.pad.size_hint = (None, None)
        self.pad.size = (dp(300), dp(400))
        self.center_layout.add_widget(self.pad)

    def on_leave(self):
        self._unbind_keyboard()
        if self.pad:
            self.center_layout.remove_widget(self.pad)
            self.pad = None

    def _bind_keyboard(self):
        if self._keyboard_bound:
            return
        Window.unbind(on_key_down=self._on_key_down)
        Window.bind(on_key_down=self._on_key_down)
        self._keyboard_bound = True

    def _unbind_keyboard(self):
        Window.unbind(on_key_down=self._on_key_down)
        self._keyboard_bound = False

    def _accept(self, pin: str):
        try:
            self.controller.login_user(pin)
            # úspěch → reset čítače
            self.fail_count = 0
            Logger.info("LOGIN USER OK")
            self.on_success()
        except Exception as e:
            self.fail_count += 1
            Logger.warning(
                f"LOGIN FAILED ({self.fail_count}): {type(e).__name__}: {e}"
            )
            self.pad.clear()
            # příliš mnoho pokusů → konec aplikace
            if self.fail_count >= MAX_LOGIN_FAILS:
                Logger.error("MAX LOGIN FAILS REACHED")
                _popup_info("Chyba", "Příliš mnoho chybných pokusů.\nAplikace bude ukončena.")
                Clock.schedule_once(lambda *_: App.get_running_app().stop(), 2)

    def _cancel(self):
        # v POS obvykle znamená ukončení aplikace
        Logger.info("LOGIN CANCEL")
        App.get_running_app().stop()