import { Component } 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 FormControl from '@mui/material/FormControl';
import FormLabel from '@mui/material/FormLabel';
import InputAdornment from '@mui/material/InputAdornment';
import Stack from '@mui/material/Stack';
import TextInput from '../TextInput';
import ToggleButton from '@mui/material/ToggleButton';
import ToggleButtonGroup from '@mui/material/ToggleButtonGroup';
import { enqueueSnackbar } from 'notistack';
import BackendError from '../BackendError';
import SingleLineTextEdit from 'dashgui/SingleLineTextEdit';
import companyAutomat from '../../automats/companyAutomat';
import { ISO639_OPTIONS, parseTaxRate } from '../../utils/companyForm';
import { backendErrorFrom, isBackendFailure } from '../../utils/backendError';
import { notifyError } from '../../utils/notify';

export default class CompanySettingsPanel extends Component {
  constructor(props) {
    super(props);
    const current = companyAutomat.state.current;
    this.state = {
      isAdmin: current?.role === 'admin',
      status: current ? 'ready' : 'loading',
      busy: false,
      error: null,
      name: current?.name ?? '',
      iso639: current?.iso639 ?? 'de',
      taxrate: current?.taxrate != null ? String(current.taxrate) : '',
      reducedtaxrate: current?.reducedtaxrate != null ? String(current.reducedtaxrate) : '',
    };
    this.handleSubmit = this.handleSubmit.bind(this);
    this.handleRetry = this.handleRetry.bind(this);
    this.loadCompany = this.loadCompany.bind(this);
    this.syncFormFromCompany = this.syncFormFromCompany.bind(this);
  }

  componentDidMount() {
    this.unsub = companyAutomat.subscribe(this, (state) => {
      if (state.current && this.state.status === 'loading') {
        this.syncFormFromCompany(state.current);
      }
      return {
        isAdmin: state.current?.role === 'admin',
      };
    });
    if (companyAutomat.state.current) {
      this.syncFormFromCompany(companyAutomat.state.current);
    }
  }

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

  syncFormFromCompany(companyRow) {
    if (!companyRow) return;
    this._initial = {
      name: companyRow.name ?? '',
      iso639: companyRow.iso639 ?? 'de',
      taxrate: companyRow.taxrate != null ? String(companyRow.taxrate) : '',
      reducedtaxrate: companyRow.reducedtaxrate != null ? String(companyRow.reducedtaxrate) : '',
    };
    this.setState({
      name: this._initial.name,
      iso639: this._initial.iso639,
      taxrate: this._initial.taxrate,
      reducedtaxrate: this._initial.reducedtaxrate,
      status: 'ready',
    });
  }

  async loadCompany() {
    this.setState({ error: null });
    try {
      const companyRow = await companyAutomat.actions.load();
      this.syncFormFromCompany(companyRow);
    } catch (err) {
      notifyError(err);
      this.setState({ status: 'failed', error: backendErrorFrom(err) });
    }
  }

  handleRetry() {
    void this.loadCompany();
  }

  async handleSubmit(event) {
    event?.preventDefault?.();
    if (!this.state.isAdmin) return;
    const { name, iso639, taxrate, reducedtaxrate } = this.state;
    const parsedTaxrate = parseTaxRate(taxrate);
    const parsedReducedtaxrate = parseTaxRate(reducedtaxrate);
    const canSave =
      name.trim() !== '' &&
      ISO639_OPTIONS.includes(iso639) &&
      parsedTaxrate != null &&
      parsedReducedtaxrate != null;

    if (!canSave) {
      this.setState({ error: 'Bitte alle Pflichtfelder ausfüllen.' });
      return;
    }

    this.setState({ busy: true, error: null });
    try {
      await companyAutomat.actions.update({
        name: name.trim(),
        iso639,
        taxrate: parsedTaxrate,
        reducedtaxrate: parsedReducedtaxrate,
      });
      this._initial = {
        name: name.trim(),
        iso639,
        taxrate: String(parsedTaxrate),
        reducedtaxrate: String(parsedReducedtaxrate),
      };
      enqueueSnackbar('Unternehmen gespeichert.', { variant: 'success' });
    } catch (err) {
      this.setState({ error: backendErrorFrom(err) });
    } finally {
      this.setState({ busy: false });
    }
  }

  render() {
    const { isAdmin, status, busy, error, name, iso639, taxrate, reducedtaxrate } = this.state;

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

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

    const parsedTaxrate = parseTaxRate(taxrate);
    const parsedReducedtaxrate = parseTaxRate(reducedtaxrate);
    const isDirty =
      Boolean(this._initial) &&
      (name.trim() !== this._initial.name.trim() ||
        iso639 !== this._initial.iso639 ||
        taxrate.trim() !== this._initial.taxrate.trim() ||
        reducedtaxrate.trim() !== this._initial.reducedtaxrate.trim());
    const canSave =
      isAdmin &&
      isDirty &&
      name.trim() !== '' &&
      ISO639_OPTIONS.includes(iso639) &&
      parsedTaxrate != null &&
      parsedReducedtaxrate != null;

    return (
      <Box
        component="form"
        onSubmit={this.handleSubmit}
        noValidate
        sx={{ maxWidth: 540, mx: 'auto', py: 2 }}
      >
        {error ? (
          isBackendFailure(error) ? (
            <BackendError error={error} sx={{ mb: 2 }} />
          ) : (
            <Alert severity="error" sx={{ mb: 2 }}>
              {typeof error === 'string' ? error : error.message}
            </Alert>
          )
        ) : null}

        <Stack spacing={2.5}>
          <SingleLineTextEdit
            required
            size="small"
            label="Name"
            value={name}
            disabled={!isAdmin || busy}
            onChange={(nextName) => this.setState({ name: nextName })}
            autoComplete="off"
            autoFocus
          />

          <FormControl required>
            <FormLabel sx={{ mb: 0.5 }}>Sprache</FormLabel>
            <ToggleButtonGroup
              exclusive
              required
              size="small"
              value={iso639}
              disabled={!isAdmin || busy}
              onChange={(_event, value) => {
                if (value) this.setState({ iso639: value });
              }}
            >
              <ToggleButton value="de">Deutsch</ToggleButton>
              <ToggleButton value="en">English</ToggleButton>
            </ToggleButtonGroup>
          </FormControl>

          <Stack direction="row" spacing={2}>
            <TextInput
              fullWidth
              required
              size="small"
              type="number"
              label="Normalsatz"
              value={taxrate}
              disabled={!isAdmin || busy}
              onChange={(e) => this.setState({ taxrate: e.target.value })}
              error={taxrate !== '' && parsedTaxrate == null}
              slotProps={{
                input: {
                  endAdornment: <InputAdornment position="end">%</InputAdornment>,
                },
                htmlInput: { min: 0, max: 100, step: 0.01, required: true },
              }}
            />
            <TextInput
              fullWidth
              required
              size="small"
              type="number"
              label="Ermäßigter Satz"
              value={reducedtaxrate}
              disabled={!isAdmin || busy}
              onChange={(e) => this.setState({ reducedtaxrate: e.target.value })}
              error={reducedtaxrate !== '' && parsedReducedtaxrate == null}
              slotProps={{
                input: {
                  endAdornment: <InputAdornment position="end">%</InputAdornment>,
                },
                htmlInput: { min: 0, max: 100, step: 0.01, required: true },
              }}
            />
          </Stack>

          <Box sx={{ display: 'flex', justifyContent: 'flex-end', pt: 1 }}>
            <Button
              type="submit"
              variant="contained"
              color={canSave ? 'success' : 'inherit'}
              disabled={!isAdmin || busy || !canSave}
              startIcon={busy ? <CircularProgress size={16} color="inherit" /> : null}
              sx={
                canSave
                  ? { bgcolor: 'success.main', color: '#fff', '&:hover': { bgcolor: 'success.dark' } }
                  : undefined
              }
            >
              Speichern
            </Button>
          </Box>
        </Stack>
      </Box>
    );
  }
}