'use client';

import { useEffect, useState, useCallback } from 'react';
import { Tablette } from '@/types/tablette';

const EMPTY: Omit<Tablette, 'akt' | 'until' | 'warn'> = {
  tab: '',
  pday: 1,
  cnt: 0,
  at: '',
  rem: '',
  order: '',
};

type FormData = Omit<Tablette, 'akt' | 'until' | 'warn'>;

export default function TablettenTable() {
  const [rows, setRows] = useState<Tablette[]>([]);
  const [sortField, setSortField] = useState('until');
  const [sortDir, setSortDir] = useState<'asc' | 'desc'>('asc');
  const [modal, setModal] = useState<null | 'add' | 'edit' | 'del'>(null);
  const [selected, setSelected] = useState<Tablette | null>(null);
  const [form, setForm] = useState<FormData>({ ...EMPTY });
  const [loading, setLoading] = useState(false);
  const [error, setError] = useState('');

  const fetchData = useCallback(async () => {
    setLoading(true);
    try {
      const res = await fetch(`/api/data?sidx=${sortField}&sord=${sortDir}`);
      const json = await res.json();
      if (!res.ok) {
        setError(`Fehler beim Laden: ${json.error ?? res.status}`);
        return;
      }
      setRows(json.values || []);
    } catch {
      setError('Fehler beim Laden der Daten.');
    } finally {
      setLoading(false);
    }
  }, [sortField, sortDir]);

  useEffect(() => {
    fetchData();
  }, [fetchData]);

  function handleSort(field: string) {
    if (field === sortField) {
      setSortDir((d) => (d === 'asc' ? 'desc' : 'asc'));
    } else {
      setSortField(field);
      setSortDir('asc');
    }
  }

  function openAdd() {
    setForm({ ...EMPTY });
    setModal('add');
  }

  function openEdit(row: Tablette) {
    setSelected(row);
    setForm({ tab: row.tab, pday: row.pday, cnt: row.cnt, at: row.at, rem: row.rem, order: row.order });
    setModal('edit');
  }

  function openDel(row: Tablette) {
    setSelected(row);
    setModal('del');
  }

  async function handleSave() {
    const payload = { ...form, oper: modal === 'add' ? 'add' : 'edit' };
    await fetch('/api/data', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify(payload),
    });
    setModal(null);
    fetchData();
  }

  async function handleDelete() {
    if (!selected) return;
    await fetch('/api/data', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ oper: 'del', tab: selected.tab }),
    });
    setModal(null);
    fetchData();
  }

  const SortIndicator = ({ field }: { field: string }) =>
    sortField === field ? (sortDir === 'asc' ? ' ▲' : ' ▼') : '';

  const colHeader = (label: string, field: string) => (
    <th
      key={field}
      onClick={() => handleSort(field)}
      className="sortable-header"
    >
      {label}
      <SortIndicator field={field} />
    </th>
  );

  return (
    <div className="table-container">
      {error && <p className="error-msg">{error}</p>}
      <div className="toolbar">
        <button onClick={openAdd} className="btn btn-add">+ Hinzufügen</button>
        <button onClick={fetchData} className="btn btn-refresh">↻ Aktualisieren</button>
      </div>
      <table className="main-table">
        <thead>
          <tr>
            {colHeader('Tabletten', 'tab')}
            {colHeader('pro Tag', 'pday')}
            {colHeader('aktuell', 'akt')}
            {colHeader('reicht bis', 'until')}
            {colHeader('Anzahl…', 'cnt')}
            {colHeader('…am', 'at')}
            {colHeader('Bemerkungen', 'rem')}
            {colHeader('bestellt am', 'order')}
            <th>Aktion</th>
          </tr>
        </thead>
        <tbody>
          {loading && (
            <tr><td colSpan={9} style={{ textAlign: 'center' }}>Lade…</td></tr>
          )}
          {!loading && rows.map((row) => (
            <tr
              key={row.tab}
              className={
                row.warn ? 'row-warn' : row.rem === 'abgesetzt' ? 'row-abgesetzt' : ''
              }
            >
              <td className="col-tab">{row.tab}</td>
              <td className="col-pday">{row.pday}</td>
              <td className="cell-center">{row.akt}</td>
              <td className={`col-date ${row.warn ? 'cell-warn' : ''}`}>{row.until}</td>
              <td className="cell-center">{row.cnt}</td>
              <td className="col-date">{row.at}</td>
              <td>{row.rem}</td>
              <td className="col-date">{row.order}</td>
              <td className="cell-center action-cell">
                <button onClick={() => openEdit(row)} className="btn-icon" title="Bearbeiten">✏️</button>
                <button onClick={() => openDel(row)} className="btn-icon" title="Löschen">🗑️</button>
              </td>
            </tr>
          ))}
        </tbody>
      </table>

      {/* Add/Edit Modal */}
      {(modal === 'add' || modal === 'edit') && (
        <div className="modal-overlay" onClick={() => setModal(null)}>
          <div className="modal" onClick={(e) => e.stopPropagation()}>
            <h2>{modal === 'add' ? 'Neuer Eintrag' : 'Bearbeiten'}</h2>
            <label>Tabletten Name
              <input value={form.tab} onChange={(e) => setForm({ ...form, tab: e.target.value })}
                disabled={modal === 'edit'} />
            </label>
            <label>pro Tag
              <input type="number" step="0.25" value={form.pday}
                onChange={(e) => setForm({ ...form, pday: parseFloat(e.target.value) || 0 })} />
            </label>
            <label>Anzahl
              <input type="number" value={form.cnt}
                onChange={(e) => setForm({ ...form, cnt: parseInt(e.target.value, 10) || 0 })} />
            </label>
            <label>Kaufdatum (am)
              <input type="text" value={form.at} placeholder="YYYY-MM-DD"
                pattern="\d{4}-\d{2}-\d{2}"
                onChange={(e) => setForm({ ...form, at: e.target.value })} />
            </label>
            <label>Bemerkungen
              <input value={form.rem}
                onChange={(e) => setForm({ ...form, rem: e.target.value })} />
            </label>
            <label>Bestellt am
              <input type="text" value={form.order} placeholder="YYYY-MM-DD"
                pattern="\d{4}-\d{2}-\d{2}"
                onChange={(e) => setForm({ ...form, order: e.target.value })} />
            </label>
            <div className="modal-buttons">
              <button onClick={handleSave} className="btn btn-add">Speichern</button>
              <button onClick={() => setModal(null)} className="btn btn-refresh">Abbrechen</button>
            </div>
          </div>
        </div>
      )}

      {/* Delete Modal */}
      {modal === 'del' && selected && (
        <div className="modal-overlay" onClick={() => setModal(null)}>
          <div className="modal" onClick={(e) => e.stopPropagation()}>
            <h2>Eintrag löschen</h2>
            <p>Möchtest du <strong>{selected.tab}</strong> wirklich löschen?</p>
            <div className="modal-buttons">
              <button onClick={handleDelete} className="btn btn-delete">Löschen</button>
              <button onClick={() => setModal(null)} className="btn btn-refresh">Abbrechen</button>
            </div>
          </div>
        </div>
      )}
    </div>
  );
}