import { Component } from 'react';
import AddIcon from '@mui/icons-material/Add';
import DeleteOutlineOutlinedIcon from '@mui/icons-material/DeleteOutlineOutlined';
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 IconButton from '@mui/material/IconButton';
import InputAdornment from '@mui/material/InputAdornment';
import TextInput from '../TextInput';
import Typography from '@mui/material/Typography';
import { formatPriceAmount, parsePriceInput } from '../../utils/price';

function emptyTier() {
  return { minmultiplier: '', gross: '' };
}

function parseMultiplier(value) {
  if (value === '' || value == null) return null;
  const n = Number(String(value).trim());
  return Number.isInteger(n) && n >= 2 ? n : null;
}

function tiersValid(tiers) {
  const seen = new Set();
  for (const tier of tiers) {
    const mult = parseMultiplier(tier.minmultiplier);
    const gross = parsePriceInput(tier.gross);
    if (mult == null || gross == null) return false;
    if (seen.has(mult)) return false;
    seen.add(mult);
  }
  return true;
}

class ArticlePriceTiersDialog extends Component {
  constructor(props) {
    super(props);
    this.state = { tiers: [] };
  }

  componentDidUpdate(prevProps) {
    if (this.props.open && !prevProps.open) {
      const tiers = this.props.tiers?.length
        ? this.props.tiers.map((row) => ({
            minmultiplier: String(row.minmultiplier),
            gross: row.gross,
          }))
        : [];
      this.setState({ tiers });
    }
  }

  handleChange = (index, field, value) => {
    this.setState((state) => {
      const tiers = state.tiers.map((row, i) =>
        i === index ? { ...row, [field]: value } : row,
      );
      return { tiers };
    });
  };

  handleAdd = () => {
    this.setState((state) => ({ tiers: [...state.tiers, emptyTier()] }));
  };

  handleRemove = (index) => {
    this.setState((state) => ({
      tiers: state.tiers.filter((_, i) => i !== index),
    }));
  };

  handleApply = () => {
    const { tiers } = this.state;
    if (!tiersValid(tiers)) return;
    this.props.onApply(
      tiers.map((row) => ({
        minmultiplier: parseMultiplier(row.minmultiplier),
        gross: formatPriceAmount(parsePriceInput(row.gross)),
      })),
    );
    this.props.onClose();
  };

  render() {
    const { open, onClose } = this.props;
    const { tiers } = this.state;
    const canApply = tiersValid(tiers);

    return (
      <AppDialog open={open} onClose={onClose} maxWidth="sm" fullWidth>
        <DialogTitle>Staffelpreise</DialogTitle>
        <DialogContent dividers>
          {tiers.length === 0 ? (
            <Typography color="text.secondary" sx={{ py: 1 }}>
              Keine Staffeln. Basispreis bleibt der Einzelpreis (×1).
            </Typography>
          ) : null}
          <Box sx={{ display: 'flex', flexDirection: 'column', gap: 1.5 }}>
            {tiers.map((tier, index) => {
              const mult = parseMultiplier(tier.minmultiplier);
              const gross = parsePriceInput(tier.gross);
              return (
                <Box
                  key={index}
                  sx={{
                    display: 'flex',
                    gap: 1,
                    alignItems: 'flex-start',
                  }}
                >
                  <TextInput
                    label="Ab Menge"
                    value={tier.minmultiplier}
                    onChange={(event) =>
                      this.handleChange(index, 'minmultiplier', event.target.value)
                    }
                    error={tier.minmultiplier !== '' && mult == null}
                    slotProps={{
                      htmlInput: { inputMode: 'numeric' },
                    }}
                    sx={{ width: 120 }}
                  />
                  <TextInput
                    label="Brutto"
                    value={tier.gross}
                    onChange={(event) =>
                      this.handleChange(index, 'gross', event.target.value)
                    }
                    fullWidth
                    error={tier.gross !== '' && gross == null}
                    slotProps={{
                      input: {
                        startAdornment: (
                          <InputAdornment position="start">€</InputAdornment>
                        ),
                      },
                      htmlInput: { inputMode: 'decimal' },
                    }}
                  />
                  <IconButton
                    type="button"
                    aria-label="Staffel entfernen"
                    onClick={() => this.handleRemove(index)}
                    sx={{ mt: 0.5 }}
                  >
                    <DeleteOutlineOutlinedIcon />
                  </IconButton>
                </Box>
              );
            })}
          </Box>
          <Button
            type="button"
            startIcon={<AddIcon />}
            onClick={this.handleAdd}
            sx={{ mt: 2 }}
          >
            Staffel hinzufügen
          </Button>
        </DialogContent>
        <DialogActions sx={{ px: 3, py: 2 }}>
          <Button type="button" onClick={onClose}>
            Abbrechen
          </Button>
          <Button
            type="button"
            variant="contained"
            onClick={this.handleApply}
            disabled={!canApply}
          >
            Übernehmen
          </Button>
        </DialogActions>
      </AppDialog>
    );
  }
}

export default ArticlePriceTiersDialog;