from __future__ import annotations

from textual.app import ComposeResult
from textual.binding import Binding
from textual.containers import Vertical
from textual.screen import Screen
from textual.widgets import Button, Footer, Header, Input, Label, Static


class LoginScreen(Screen):
    """Anmeldebildschirm – erscheint beim Start der TUI."""

    BINDINGS = [Binding("ctrl+c", "quit_app", "Beenden")]

    def compose(self) -> ComposeResult:
        yield Header(show_clock=True)
        with Vertical(id="login-container"):
            yield Static("Anmeldung", id="login-title")
            yield Label("Benutzername:")
            yield Input(placeholder="admin", id="username-input")
            yield Label("Passwort:")
            yield Input(placeholder="", password=True, id="password-input")
            yield Static("", id="login-error")
            yield Button("Anmelden", variant="primary", id="login-btn")
        yield Footer()

    def on_mount(self) -> None:
        self.query_one("#username-input", Input).focus()

    def on_input_submitted(self, event: Input.Submitted) -> None:
        if event.input.id == "username-input":
            self.query_one("#password-input", Input).focus()
        elif event.input.id == "password-input":
            self._do_login()

    def on_button_pressed(self, event: Button.Pressed) -> None:
        if event.button.id == "login-btn":
            self._do_login()

    def _do_login(self) -> None:
        import asyncio
        asyncio.create_task(self._login_async())

    async def _login_async(self) -> None:
        username = self.query_one("#username-input", Input).value.strip()
        password = self.query_one("#password-input", Input).value
        if not username or not password:
            self.query_one("#login-error", Static).update("Benutzername und Passwort eingeben.")
            return

        btn = self.query_one("#login-btn", Button)
        btn.disabled = True
        self.query_one("#login-error", Static).update("")

        try:
            ok = await self.app._api_client.login(username, password)  # type: ignore[attr-defined]
        except Exception:
            ok = False

        btn.disabled = False

        if ok:
            from tui.screens.main_screen import MainScreen
            self.app.switch_screen(MainScreen())
        else:
            self.query_one("#login-error", Static).update("Ungültige Zugangsdaten oder Server nicht erreichbar.")
            self.query_one("#password-input", Input).clear()
            self.query_one("#password-input", Input).focus()

    def action_quit_app(self) -> None:
        self.app.exit()