import { PureComponent } from 'react';
import Autocomplete from '@mui/material/Autocomplete';
import Box from '@mui/material/Box';
import Button from '@mui/material/Button';
import AppDialog from '../AppDialog';
import DialogActions from '@mui/material/DialogActions';
import DialogContent from '@mui/material/DialogContent';
import DialogTitle from '@mui/material/DialogTitle';
import InputAdornment from '@mui/material/InputAdornment';
import MenuItem from '@mui/material/MenuItem';
import Stack from '@mui/material/Stack';
import TextInput from '../TextInput';
import Typography from '@mui/material/Typography';
import { companyTaxRateOptions } from '../../utils/articleDetail';
import { formatPriceAmount, parsePriceInput } from '../../utils/price';

function parseNumber(value, min = 0) {
  if (value === '' || value == null) return null;
  const num = Number(String(value).trim().replace(',', '.'));
  return Number.isFinite(num) && num >= min ? num : null;
}

export default class ArticleSupplierDialog extends PureComponent {
  constructor(props) {
    super(props);
    this.state = this.initState(props);
  }

  componentDidUpdate(prevProps) {
    if (this.props.open && !prevProps.open) {
      this.setState(this.initState(this.props));
    }
  }

  initState(props) {
    const item = props.item;
    const defaultTaxRate =
      props.company?.taxrate != null ? Number(props.company.taxrate) : 19;

    return {
      entityId: item?.entityId ? Number(item.entityId) : null,
      sku: item?.sku ?? '',
      pu: item?.pu != null ? String(item.pu) : '1',
      stock: item?.stock != null ? String(item.stock) : '',
      netPrice:
        item?.price?.net != null ? formatPriceAmount(item.price.net) : '',
      taxRate:
        item?.price?.taxRate != null
          ? Number(item.price.taxRate)
          : defaultTaxRate,
      submitting: false,
    };
  }

  handleSubmit = async (e) => {
    e.preventDefault();
    const { entityId, sku, pu, stock, netPrice, taxRate } = this.state;
    const isEdit = Boolean(this.props.item?.id);

    if (!isEdit && !entityId) return;

    const parsedPu = parseNumber(pu, 0.0001);
    if (parsedPu == null || parsedPu <= 0) {
      return;
    }

    const parsedStock = parseNumber(stock, 0);
    const parsedNet = netPrice !== '' ? parsePriceInput(netPrice) : null;

    this.setState({ submitting: true });
    try {
      await this.props.onSave({
        id: this.props.item?.id,
        entityId: isEdit ? this.props.item.entityId : entityId,
        sku: sku.trim() || null,
        pu: parsedPu,
        stock: parsedStock,
        netPrice: parsedNet,
        taxRate: parsedNet != null ? taxRate : undefined,
      });
    } finally {
      this.setState({ submitting: false });
    }
  };

  render() {
    const {
      open,
      onClose,
      suppliers = [],
      item,
      company,
      assignedEntityIds = [],
    } = this.props;
    const { entityId, sku, pu, stock, netPrice, taxRate, submitting } =
      this.state;
    const isEdit = Boolean(item?.id);

    const availableSuppliers = isEdit
      ? suppliers
      : suppliers.filter(
          (s) => !assignedEntityIds.includes(s.id) || s.id === entityId,
        );

    const selectedSupplier =
      suppliers.find((s) => s.id === entityId) ?? null;

    const taxOptions = companyTaxRateOptions(company, taxRate);

    const parsedPu = parseNumber(pu, 0.0001);
    const puValid = parsedPu != null && parsedPu > 0;

    return (
      <AppDialog open={open} onClose={onClose} maxWidth="sm" fullWidth>
        <form onSubmit={this.handleSubmit}>
          <DialogTitle sx={{ fontWeight: 600 }}>
            {isEdit ? 'Lieferant bearbeiten' : 'Lieferant zuweisen'}
          </DialogTitle>

          <DialogContent dividers>
            <Stack spacing={2.5}>
              {isEdit ? (
                <Box>
                  <Typography variant="caption" color="text.secondary" display="block">
                    Lieferant
                  </Typography>
                  <Typography variant="body1" sx={{ fontWeight: 600 }}>
                    {item.supplierName ?? `Lieferant #${item.entityId}`}
                  </Typography>
                </Box>
              ) : (
                <Autocomplete
                  options={availableSuppliers}
                  getOptionLabel={(opt) => opt.name ?? `Lieferant #${opt.id}`}
                  value={selectedSupplier}
                  onChange={(_e, val) => this.setState({ entityId: val ? val.id : null })}
                  renderInput={(params) => (
                    <TextInput
                      {...params}
                      label="Lieferant auswählen"
                      required
                      placeholder="Lieferant suchen…"
                    />
                  )}
                  isOptionEqualToValue={(opt, val) => opt.id === val.id}
                />
              )}

              <TextInput
                label="Lieferanten-Artikelnummer (SKU)"
                value={sku}
                onChange={(e) => this.setState({ sku: e.target.value })}
                placeholder="z. B. LF-09412"
                helperText="Wird beim Abgleich von Lieferscheinen / Wareneingängen genutzt"
              />

              <Stack direction={{ xs: 'column', sm: 'row' }} spacing={2}>
                <TextInput
                  label="Verpackungseinheit (VPE / PU)"
                  type="number"
                  required
                  error={!puValid}
                  helperText={!puValid ? 'Muss größer als 0 sein' : undefined}
                  slotProps={{ htmlInput: { step: 'any', min: 0.0001 } }}
                  value={pu}
                  onChange={(e) => this.setState({ pu: e.target.value })}
                  sx={{ flex: 1 }}
                />

                <TextInput
                  label="Bestand beim Lieferanten"
                  type="number"
                  slotProps={{ htmlInput: { step: 'any', min: 0 } }}
                  value={stock}
                  onChange={(e) => this.setState({ stock: e.target.value })}
                  sx={{ flex: 1 }}
                  helperText="Optional (in Stk / Mengeneinheit)"
                />
              </Stack>

              <Stack direction={{ xs: 'column', sm: 'row' }} spacing={2}>
                <TextInput
                  label="Einkaufspreis Netto"
                  value={netPrice}
                  onChange={(e) => this.setState({ netPrice: e.target.value })}
                  placeholder="0,00"
                  InputProps={{
                    endAdornment: (
                      <InputAdornment position="end">€</InputAdornment>
                    ),
                  }}
                  sx={{ flex: 1 }}
                  helperText="Optionaler Einkaufspreis (EK)"
                />

                <TextInput
                  select
                  label="MwSt.-Satz"
                  value={taxRate}
                  onChange={(e) =>
                    this.setState({ taxRate: Number(e.target.value) })
                  }
                  sx={{ width: { sm: 160 } }}
                  disabled={!netPrice}
                >
                  {taxOptions.map((rate) => (
                    <MenuItem key={rate} value={rate}>
                      {rate} %
                    </MenuItem>
                  ))}
                </TextInput>
              </Stack>
            </Stack>
          </DialogContent>

          <DialogActions sx={{ px: 3, py: 2 }}>
            <Button onClick={onClose} color="inherit" disabled={submitting}>
              Abbrechen
            </Button>
            <Button
              type="submit"
              variant="contained"
              disabled={submitting || (!isEdit && !entityId) || !puValid}
            >
              {isEdit ? 'Aktualisieren' : 'Hinzufügen'}
            </Button>
          </DialogActions>
        </form>
      </AppDialog>
    );
  }
}