import { useState, useEffect, useCallback } from 'react';
import { useNavigate } from 'react-router-dom';
import { useAuth } from '../context/AuthContext';
import { 
  fetchFormexMaterials, 
  fetchFormexCollections, 
  deleteFormexMaterial 
} from '../api/client';
import MaterialModal from '../components/MaterialModal';
import styles from './Materials.module.css';

export default function Materials() {
  const { isAdmin } = useAuth();
  const navigate = useNavigate();
  
  // Data state
  const [materials, setMaterials] = useState([]);
  const [collections, setCollections] = useState([]);
  const [pagination, setPagination] = useState({ page: 1, limit: 25, total: 0, totalPages: 0 });
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState('');

  // Filter state
  const [search, setSearch] = useState('');
  const [collection, setCollection] = useState('');
  const [searchInput, setSearchInput] = useState('');

  // Modal state
  const [modalOpen, setModalOpen] = useState(false);
  const [editingMaterial, setEditingMaterial] = useState(null);

  // Delete confirmation
  const [deletingId, setDeletingId] = useState(null);

  const loadMaterials = useCallback(async (page = 1) => {
    setLoading(true);
    setError('');
    try {
      const result = await fetchFormexMaterials({ search, collection, page, limit: 25 });
      setMaterials(result.materials);
      setPagination(result.pagination);
    } catch (err) {
      setError(err.message);
    } finally {
      setLoading(false);
    }
  }, [search, collection]);

  useEffect(() => {
    if (!isAdmin) {
      navigate('/login?next=/materiaux', { replace: true });
      return;
    }
    // Load collections for filter dropdown
    fetchFormexCollections()
      .then(setCollections)
      .catch(() => {});
    // Load materials
    loadMaterials(1);
  }, [isAdmin, navigate, loadMaterials]);

  const handleSearch = (e) => {
    e.preventDefault();
    setSearch(searchInput);
  };

  const handleCollectionChange = (e) => {
    setCollection(e.target.value);
  };

  // Reload when filters change
  useEffect(() => {
    loadMaterials(1);
  }, [search, collection, loadMaterials]);

  const handlePageChange = (newPage) => {
    loadMaterials(newPage);
  };

  const handleCreate = () => {
    setEditingMaterial(null);
    setModalOpen(true);
  };

  const handleEdit = (material) => {
    setEditingMaterial(material);
    setModalOpen(true);
  };

  const handleModalClose = () => {
    setModalOpen(false);
    setEditingMaterial(null);
  };

  const handleModalSave = () => {
    setModalOpen(false);
    setEditingMaterial(null);
    loadMaterials(pagination.page);
  };

  const handleDeleteClick = (id) => {
    setDeletingId(id);
  };

  const handleDeleteConfirm = async () => {
    if (!deletingId) return;
    try {
      await deleteFormexMaterial(deletingId);
      setDeletingId(null);
      loadMaterials(pagination.page);
    } catch (err) {
      setError(err.message);
      setDeletingId(null);
    }
  };

  const handleDeleteCancel = () => {
    setDeletingId(null);
  };

  if (!isAdmin) return null;

  return (
    <div className={styles.page}>
      <div className={styles.header}>
        <h1>Matériaux Formex</h1>
        <button type="button" onClick={handleCreate} className={styles.createBtn}>
          + Nouveau matériau
        </button>
      </div>

      {/* Filters */}
      <div className={styles.filters}>
        <form onSubmit={handleSearch} className={styles.searchForm}>
          <input
            type="text"
            placeholder="Rechercher par nom ou code…"
            value={searchInput}
            onChange={(e) => setSearchInput(e.target.value)}
            className={styles.searchInput}
          />
          <button type="submit" className={styles.searchBtn}>Rechercher</button>
        </form>
        <select 
          value={collection} 
          onChange={handleCollectionChange}
          className={styles.collectionSelect}
        >
          <option value="">Toutes les collections</option>
          {collections.map((c) => (
            <option key={c} value={c}>{c}</option>
          ))}
        </select>
      </div>

      {error && <p className={styles.error}>{error}</p>}

      {loading ? (
        <p className={styles.muted}>Chargement…</p>
      ) : (
        <>
          <div className={styles.tableWrap}>
            <table className={styles.table}>
              <thead>
                <tr>
                  <th>Code</th>
                  <th>Nom</th>
                  <th>Collection</th>
                  <th>Dimensions (mm)</th>
                  <th>Actions</th>
                </tr>
              </thead>
              <tbody>
                {materials.length === 0 ? (
                  <tr>
                    <td colSpan={5} className={styles.empty}>
                      Aucun matériau trouvé.
                    </td>
                  </tr>
                ) : (
                  materials.map((m) => (
                    <tr key={m.id}>
                      <td className={styles.code}>{m.formex_code}</td>
                      <td>{m.name}</td>
                      <td>{m.collection}</td>
                      <td>
                        {m.width_mm && m.height_mm && m.thickness_mm
                          ? `${m.width_mm} × ${m.height_mm} × ${m.thickness_mm}`
                          : '—'}
                      </td>
                      <td className={styles.actions}>
                        <button 
                          type="button" 
                          onClick={() => handleEdit(m)}
                          className={styles.editBtn}
                        >
                          Modifier
                        </button>
                        <button 
                          type="button" 
                          onClick={() => handleDeleteClick(m.id)}
                          className={styles.deleteBtn}
                        >
                          Supprimer
                        </button>
                      </td>
                    </tr>
                  ))
                )}
              </tbody>
            </table>
          </div>

          {/* Pagination */}
          {pagination.totalPages > 1 && (
            <div className={styles.pagination}>
              <button
                type="button"
                onClick={() => handlePageChange(pagination.page - 1)}
                disabled={pagination.page <= 1}
                className={styles.pageBtn}
              >
                Précédent
              </button>
              <span className={styles.pageInfo}>
                Page {pagination.page} sur {pagination.totalPages} ({pagination.total} résultats)
              </span>
              <button
                type="button"
                onClick={() => handlePageChange(pagination.page + 1)}
                disabled={pagination.page >= pagination.totalPages}
                className={styles.pageBtn}
              >
                Suivant
              </button>
            </div>
          )}
        </>
      )}

      {/* Delete confirmation dialog */}
      {deletingId && (
        <div className={styles.overlay}>
          <div className={styles.dialog}>
            <p>Voulez-vous vraiment supprimer ce matériau ?</p>
            <div className={styles.dialogActions}>
              <button type="button" onClick={handleDeleteCancel} className={styles.cancelBtn}>
                Annuler
              </button>
              <button type="button" onClick={handleDeleteConfirm} className={styles.confirmDeleteBtn}>
                Supprimer
              </button>
            </div>
          </div>
        </div>
      )}

      {/* Create/Edit Modal */}
      {modalOpen && (
        <MaterialModal
          material={editingMaterial}
          collections={collections}
          onClose={handleModalClose}
          onSave={handleModalSave}
        />
      )}
    </div>
  );
}