import { PureComponent } from 'react';
import Box from '@mui/material/Box';
import Button from '@mui/material/Button';
import Paper from '@mui/material/Paper';
import Typography from '@mui/material/Typography';
import GoogleIcon from '@mui/icons-material/Google';
import { enqueueSnackbar } from 'notistack';
import { notifyErrorMessage } from '../utils/notify';
import authAutomat, { bootstrapAuthMe } from '../automats/authAutomat';
import {
  abortGoogleSignIn,
  FEDCM_BLOCKED_MESSAGE,
  GoogleSignInBlockedError,
  GoogleSignInCancelledError,
  logError,
  requestGoogleIdToken,
} from '../auth/googleSignIn';

import quixposLogo from '../assets/quixpos-logo.png';
import {
  NAV_SURFACE,
} from '../colors';

class LoginPage extends PureComponent {
  constructor(props) {
    super(props);
    this.state = { ...authAutomat.state, busy: false };
    this.handleLogin = this.handleLogin.bind(this);
  }

  componentDidMount() {
    document.title = 'QuixPOS * Management Interface Login';
    this.unsubscribe = authAutomat.subscribe(this, ['status', 'googleClientId']);
  }

  componentWillUnmount() {
    this.unsubscribe?.();
  }

  async handleLogin() {
    const { googleClientId } = this.state;
    abortGoogleSignIn();
    try {
      const idToken = await requestGoogleIdToken(googleClientId, {
        onFedcmBlocked: () => {
          enqueueSnackbar(FEDCM_BLOCKED_MESSAGE, {
            variant: 'warning',
            autoHideDuration: 12000,
          });
        },
      });
      this.setState({ busy: true });
      await authAutomat.actions.loginWithGoogle(idToken);
      await bootstrapAuthMe();
      const params = new URLSearchParams(window.location.search);
      const returnTo = params.get('returnTo');
      if (returnTo) {
        window.location.replace(returnTo);
      }
    } catch (err) {
      if (err instanceof GoogleSignInCancelledError) return;
      logError('[login] Google sign-in failed', {
        message: err?.message,
        name: err?.name,
        code: err?.code,
        status: err?.status,
        cause: err?.cause,
        stack: err?.stack,
        clientId: googleClientId,
        origin: window.location.origin,
        href: window.location.href,
        dashHost: window.__dashHost
          ? {
            isDashNative: window.__dashHost.isDashNative,
            googleSignIn: window.__dashHost.googleSignIn,
          }
          : null,
        error: err,
      });
      if (err instanceof GoogleSignInBlockedError) {
        enqueueSnackbar(err.message, { variant: 'warning', autoHideDuration: 12000 });
        return;
      }
      const detail = [err?.message || String(err), err?.code, err?.status]
        .filter(Boolean)
        .join(' · ');
      notifyErrorMessage(`Login failed: ${detail}`);
    } finally {
      this.setState({ busy: false });
    }
  }

  render() {
    const { busy, status, googleClientId } = this.state;
    const loading = status === 'loading';
    const ready = Boolean(googleClientId);

    return (
      <Box
        sx={{
          display: 'flex',
          alignItems: 'center',
          justifyContent: 'center',
          minHeight: '100vh',
          bgcolor: 'background.default',
          p: 2,
        }}
      >
        <Paper
          elevation={3}
          sx={{
            display: 'flex',
            flexDirection: 'column',
            alignItems: 'center',
            gap: 2.5,
            px: 5,
            py: 5,
            maxWidth: 400,
            width: '100%',
            borderRadius: 3,
            textAlign: 'center',
          }}
        >
          <Box
            component="img"
            src={quixposLogo}
            alt="QuixPOS Logo"
            sx={{
              width: 96,
              height: 96,
              borderRadius: 3,
              display: 'block',
            }}
          />
          <Box>
            <Typography
              variant="h5"
              component="h1"
              sx={{ fontWeight: 700, color: NAV_SURFACE, letterSpacing: '-0.01em' }}
            >
              QuixPOS
            </Typography>
            <Typography
              variant="subtitle1"
              sx={{ color: 'text.secondary', fontWeight: 500, mt: 0.5 }}
            >
              Management Interface Login
            </Typography>
          </Box>
          <Button
            variant="contained"
            size="large"
            fullWidth
            startIcon={<GoogleIcon />}
            disabled={busy || loading || !ready}
            onClick={this.handleLogin}
            sx={{ mt: 1, py: 1.25, textTransform: 'none', fontWeight: 600 }}
          >
            {busy ? 'Anmeldung läuft…' : 'Mit Google anmelden'}
          </Button>
        </Paper>
      </Box>
    );
  }
}

export default LoginPage;