import { PureComponent, createRef } from 'react';
import Alert from '@mui/material/Alert';
import Box from '@mui/material/Box';
import Button from '@mui/material/Button';
import CircularProgress from '@mui/material/CircularProgress';
import List from '@mui/material/List';
import Typography from '@mui/material/Typography';
import Sortable from 'sortablejs';
import { enqueueSnackbar } from 'notistack';
import BackendError from '../../components/BackendError';
import SingleLineTextEdit from 'dashgui/SingleLineTextEdit';
import { PanelTile, PanelTileGrid } from 'dashgui/panels';
import withNavigate from '../../components/withNavigate';
import { backendErrorFrom } from '../../utils/backendError';
import { notifyError } from '../../utils/notify';
import { setLastArticleSku } from '../../automats';
import warehouseAutomat from '../../automats/warehouseAutomat';
import { ArtikelLager } from '../../components/warehouse';
import { GREEN_PANEL } from '../../colors';

function getInitialParams(props) {
  const searchParams =
    typeof window !== 'undefined' ? new URLSearchParams(window.location.search) : null;
  const prefill =
    props.location?.state?.name ??
    props.location?.state?.newName ??
    searchParams?.get('name') ??
    searchParams?.get('newName') ??
    '';
  const returnTo =
    props.location?.state?.returnTo ??
    searchParams?.get('returnTo') ??
    null;
  return { prefill: prefill.trim(), returnTo };
}

class ArtikelLagerSearchField extends PureComponent {
  constructor(props) {
    super(props);
    const initial = warehouseAutomat.state.filter || props.prefill || '';
    this.state = {
      input: initial,
      submitting: false,
    };
    if (props.prefill && !warehouseAutomat.state.filter) {
      warehouseAutomat.actions.filter(props.prefill);
    }
    this.handleSubmit = this.handleSubmit.bind(this);
  }

  componentDidMount() {
    this.unsub = warehouseAutomat.subscribe(this, (state) => ({
      input: state.filter,
    }));
  }

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

  onInputChange(input) {
    this.setState({ input });
    warehouseAutomat.actions.filter(input);
  }

  async handleSubmit() {
    const name = this.state.input.trim();
    if (!name || this.state.submitting) return;

    this.setState({ submitting: true });
    try {
      const row = await warehouseAutomat.actions.create({ name });
      enqueueSnackbar(`Lager „${row.name || name}“ angelegt.`, { variant: 'success' });
      this.setState({ input: '', submitting: false });
      warehouseAutomat.actions.filter('');
      if (this.props.returnTo && this.props.navigate) {
        this.props.navigate(this.props.returnTo);
      }
    } catch (err) {
      this.setState({ submitting: false });
      notifyError(err);
    }
  }

  render() {
    const { inputRef, returnTo, navigate } = this.props;
    const { input, submitting } = this.state;
    const canSubmit = Boolean(input.trim()) && !submitting;

    return (
      <PanelTileGrid>
        <Box
          ref={inputRef}
          sx={{
            gridColumn: {
              xs: '1 / -1',
              sm: 'span 2',
              md: 'span 2',
            },
            display: 'flex',
            flexDirection: 'column',
            gap: 1,
            pb: 2,
          }}
        >
          {returnTo ? (
            <Alert
              severity="info"
              sx={{ py: 0.5, alignItems: 'center' }}
              action={
                <Button
                  color="inherit"
                  size="small"
                  onClick={() => navigate?.(returnTo)}
                >
                  Zurück
                </Button>
              }
            >
              {input
                ? `Lagername „${input}“ übernommen.`
                : 'Neues Lager anlegen.'}
            </Alert>
          ) : null}

          <Box sx={{ display: 'flex', alignItems: 'center', gap: 1 }}>
            <SingleLineTextEdit
              sx={{ flex: 1 }}
              size="small"
              search
              clear
              value={input}
              disabled={submitting}
              onChange={(next) => this.onInputChange(next)}
              onKeyDown={(event) => {
                if (event.key === 'Enter') {
                  event.preventDefault();
                  void this.handleSubmit();
                }
              }}
            />
            <Button
              variant="contained"
              disabled={!canSubmit}
              onClick={() => void this.handleSubmit()}
            >
              Hinzufügen
            </Button>
          </Box>
        </Box>
      </PanelTileGrid>
    );
  }
}

class ArtikelLagerPage extends PureComponent {
  constructor(props) {
    super(props);
    const initialWarehouses =
      warehouseAutomat.state.filteredWarehouses ?? warehouseAutomat.state.warehouses ?? [];
    this.state = {
      status: warehouseAutomat.state.status === 'ready' ? 'ready' : 'loading',
      error: warehouseAutomat.state.error ? backendErrorFrom(warehouseAutomat.state.error) : null,
      warehouses: initialWarehouses,
      filter: warehouseAutomat.state.filter ?? '',
    };
    this.searchRef = createRef();
    this.listRef = createRef();
    this._sortable = null;
    this._cancelled = false;
    this.handleRetry = this.handleRetry.bind(this);
    this._initSortable = this._initSortable.bind(this);
    this._destroySortable = this._destroySortable.bind(this);
  }

  componentDidMount() {
    setLastArticleSku(null);
    this._cancelled = false;

    this.unsub = warehouseAutomat.subscribe(this, (state) => {
      if (this._cancelled) return;
      return {
        warehouses: state.filteredWarehouses,
        filter: state.filter,
        status: state.status,
        error: state.error ? backendErrorFrom(state.error) : null,
      };
    });

    if (warehouseAutomat.state.status !== 'ready') {
      void warehouseAutomat.actions.load().catch((err) => notifyError(err));
    } else {
      this._initSortable();
    }
  }

  componentDidUpdate(prevProps, prevState) {
    if (
      prevState.status !== this.state.status ||
      prevState.warehouses !== this.state.warehouses ||
      prevState.filter !== this.state.filter
    ) {
      if (this.state.status === 'ready') {
        this._initSortable();
      }
    }
  }

  componentWillUnmount() {
    this._cancelled = true;
    this.unsub?.();
    this._destroySortable();
  }

  _initSortable() {
    this._destroySortable();
    const el = this.listRef.current;
    if (!el) return;

    const isFiltered = Boolean(this.state.filter?.trim());

    this._sortable = Sortable.create(el, {
      handle: '.drag-handle',
      animation: 150,
      ghostClass: 'sortable-ghost',
      chosenClass: 'sortable-chosen',
      disabled: isFiltered,
      onEnd: (evt) => {
        const { oldIndex, newIndex } = evt;
        if (oldIndex === newIndex) return;

        this.setState(
          (prev) => {
            const next = [...prev.warehouses];
            const [moved] = next.splice(oldIndex, 1);
            next.splice(newIndex, 0, moved);
            return { warehouses: next };
          },
          () => {
            const ids = this.state.warehouses.map((w) => w.id);
            void this._persistOrder(ids);
          }
        );
      },
    });
  }

  _destroySortable() {
    this._sortable?.destroy();
    this._sortable = null;
  }

  async _persistOrder(warehouseIds) {
    try {
      await warehouseAutomat.actions.reorder(warehouseIds);
    } catch (err) {
      if (this._cancelled) return;
      notifyError(err);
      void warehouseAutomat.actions.reload();
    }
  }

  handleRetry() {
    void warehouseAutomat.actions.load().catch((err) => notifyError(err));
  }

  render() {
    const { status, error, warehouses } = this.state;
    const { prefill, returnTo } = getInitialParams(this.props);

    if (status === 'loading' || status === 'idle') {
      return (
        <Box sx={{ display: 'flex', justifyContent: 'center', py: 6 }}>
          <CircularProgress />
        </Box>
      );
    }

    if (status === 'failed') {
      return <BackendError error={error} onRetry={this.handleRetry} />;
    }

    return (
      <>
        <ArtikelLagerSearchField
          inputRef={this.searchRef}
          prefill={prefill}
          returnTo={returnTo}
          navigate={this.props.navigate}
        />
        <PanelTileGrid>
          <PanelTile wide={2} minHeight={0} color={GREEN_PANEL}>
            <List dense disablePadding ref={this.listRef} sx={{ width: '100%' }}>
              {warehouses.length === 0 ? (
                <Typography variant="body2" color="text.secondary" sx={{ py: 1 }}>
                  Noch keine Lager angelegt.
                </Typography>
              ) : (
                warehouses.map((wh) => (
                  <ArtikelLager
                    key={wh.id}
                    warehouse={wh}
                  />
                ))
              )}
            </List>
          </PanelTile>
        </PanelTileGrid>
      </>
    );
  }
}

export { ArtikelLager, ArtikelLagerSearchField };
export default withNavigate(ArtikelLagerPage);