import { useState, useEffect, useRef, useCallback } from 'react';
import api from './lib/api.js';
import { 
  IconPlus, 
  IconSearch, 
  IconEdit, 
  IconTrash, 
  IconCheck, 
  IconX, 
  IconDatabase,
  IconRefresh,
  IconArrowsExchange,
  IconDownload,
  IconUpload,
  IconAlertTriangle
} from '@/lib/icons';
import { ConfirmDialog } from '@/components/shared/feedback'

const API_URL = '/api';

function DataManager({ entityName, entityKey, placeholder }) {
  const [items, setItems] = useState([]);
  const [newItem, setNewItem] = useState({ domain: '', type: 'SharkFIN' });
  const [error, setError] = useState('');
  const [success, setSuccess] = useState('');
  const [searchTerm, setSearchTerm] = useState('');
  const [editingDomain, setEditingDomain] = useState(null);
  const [editingValue, setEditingValue] = useState('');
  const [bulkFrom, setBulkFrom] = useState('SharkFIN');
  const [bulkTo, setBulkTo] = useState('SharkAM');
  const [loading, setLoading] = useState(false);
  const [showDeleteModal, setShowDeleteModal] = useState(false);
  const [itemToDelete, setItemToDelete] = useState(null);
  const [currentPage, setCurrentPage] = useState(1);
  const [sortField, setSortField] = useState('domain');
  const [sortOrder, setSortOrder] = useState('asc');
  const [filterType, setFilterType] = useState('');
  const editInputRef = useRef(null);
  const pageSize = 10;
  const [confirmState, setConfirmState] = useState({ open: false, text: '', onConfirm: null });

  const fetchItems = useCallback(async () => {
    setLoading(true);
    try {
      const response = await api.get(`/${entityKey}`);
      setItems(response.data);
      setError('');
    } catch (error) {
      console.error(`Error fetching ${entityKey}:`, error);
      setError(`Не удалось загрузить ${entityName}. Проверьте, запущен ли бэкенд.`);
    } finally {
      setLoading(false);
    }
  }, [entityKey, entityName]);

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

  const handleAddItem = () => {
    if (newItem.domain.trim() === '') {
      setError(`Имя ${entityName} не может быть пустым.`);
      return;
    }
    setError('');
    setItems([...items, newItem]);
    setNewItem({ domain: '', type: 'SharkFIN' });
  };

  const handleEdit = (item) => {
    setEditingDomain(item.domain);
    setEditingValue(item.type);
  };

  const handleSaveEdit = (domainName) => {
    const updatedItems = items.map(i =>
      i.domain === domainName ? { ...i, type: editingValue } : i
    );
    setItems(updatedItems);
    setEditingDomain(null);
  };

  const handleCancelEdit = () => {
    setEditingDomain(null);
  };

  const handleDeleteItem = (domainNameToDelete) => {
    setItems(items.filter(i => i.domain !== domainNameToDelete));
  };

  const confirmDelete = (item) => {
    setItemToDelete(item);
    setShowDeleteModal(true);
  };

  const executeDelete = () => {
    if (itemToDelete) {
      handleDeleteItem(itemToDelete.domain);
      setShowDeleteModal(false);
      setItemToDelete(null);
    }
  };

  const handleSaveChanges = async () => {
    setLoading(true);
    try {
      await api.post(`/${entityKey}`, { domains: items });
      setSuccess('Изменения успешно сохранены!');
      setTimeout(() => setSuccess(''), 3000);
    } catch (error) {
      console.error('Error saving changes:', error);
      setError('Не удалось сохранить изменения.');
    } finally {
      setLoading(false);
    }
  };

  const handleBulkUpdate = () => {
    if (!bulkFrom || !bulkTo) {
      setError('Оба поля для массового обновления должны быть заполнены.');
      return;
    }
    setConfirmState({
      open: true,
      text: `Вы уверены, что хотите заменить все шлюзы "${bulkFrom}" на "${bulkTo}"? Это действие необратимо.`,
      onConfirm: () => {
        const updatedItems = items.map(i => i.type === bulkFrom ? { ...i, type: bulkTo } : i);
        setItems(updatedItems);
        setSuccess(`Шлюзы "${bulkFrom}" были успешно заменены на "${bulkTo}". Не забудьте сохранить изменения.`);
        setConfirmState({ open: false, text: '', onConfirm: null });
      },
    });
  };

  // Сортировка
  const sortedItems = [...items].sort((a, b) => {
    let valA = a[sortField] || '';
    let valB = b[sortField] || '';
    if (typeof valA === 'string') valA = valA.toLowerCase();
    if (typeof valB === 'string') valB = valB.toLowerCase();
    if (valA < valB) return sortOrder === 'asc' ? -1 : 1;
    if (valA > valB) return sortOrder === 'asc' ? 1 : -1;
    return 0;
  });

  // Фильтрация по шлюзу
  const filteredByType = filterType
    ? sortedItems.filter(i => i.type === filterType)
    : sortedItems;

  // Поиск
  const filteredItems = filteredByType.filter(i =>
    i.domain.toLowerCase().includes(searchTerm.toLowerCase())
  );

  // Пагинация
  const totalPages = Math.ceil(filteredItems.length / pageSize);
  const paginatedItems = filteredItems.slice((currentPage - 1) * pageSize, currentPage * pageSize);

  // Для фильтра - список всех уникальных шлюзов
  const allTypes = Array.from(new Set(items.map(i => i.type)));

  // Сортировка по клику
  const handleSort = (field) => {
    if (sortField === field) {
      setSortOrder(sortOrder === 'asc' ? 'desc' : 'asc');
    } else {
      setSortField(field);
      setSortOrder('asc');
    }
  };

  // Улучшенный инлайн-редакт
  useEffect(() => {
    if (editingDomain && editInputRef.current) {
      editInputRef.current.focus();
    }
  }, [editingDomain]);

  const handleEditKeyDown = (e, domainName) => {
    if (e.key === 'Enter') handleSaveEdit(domainName);
    if (e.key === 'Escape') handleCancelEdit();
  };

  return (
    <>
      {error && (
        <div className="alert alert-danger alert-dismissible" role="alert">
          <div className="d-flex">
            <div>
              <IconX className="icon alert-icon" />
            </div>
            <div>
              {error}
            </div>
          </div>
          <button type="button" className="btn-close" onClick={() => setError('')}></button>
        </div>
      )}
      
      {success && (
        <div className="alert alert-success alert-dismissible" role="alert">
          <div className="d-flex">
            <div>
              <IconCheck className="icon alert-icon" />
            </div>
            <div>
              {success}
            </div>
          </div>
          <button type="button" className="btn-close" onClick={() => setSuccess('')}></button>
        </div>
      )}

      <div className="row g-2 g-lg-3">
        <div className="col-12 col-lg-4">
          {/* Add New Item Card */}
          <div className="card card-md">
            <div className="card-header">
              <h3 className="card-title">
                <IconPlus className="icon me-2" />
                Добавить новый {entityName}
              </h3>
            </div>
            <div className="card-body">
              <form onSubmit={(e) => { e.preventDefault(); handleAddItem(); }}>
                <div className="mb-3">
                  <label className="form-label">Имя {entityName}</label>
                  <input
                    type="text"
                    className="form-control"
                    placeholder={placeholder}
                    value={newItem.domain}
                    onChange={(e) => setNewItem({ ...newItem, domain: e.target.value })}
                  />
                </div>
                <div className="mb-3">
                  <label className="form-label">Шлюз</label>
                  <input
                    type="text"
                    className="form-control"
                    value={newItem.type}
                    onChange={(e) => setNewItem({ ...newItem, type: e.target.value })}
                  />
                </div>
                <div className="form-footer">
                  <button type="submit" className="btn btn-primary w-100">
                    <IconPlus className="icon me-2" />
                    Добавить
                  </button>
                </div>
              </form>
            </div>
          </div>

          {/* Bulk Update Card */}
          <div className="card card-md">
            <div className="card-header">
              <h3 className="card-title">
                <IconArrowsExchange className="icon me-2" />
                Массовое обновление
              </h3>
            </div>
            <div className="card-body">
              <div className="mb-3">
                <label className="form-label">Заменить с</label>
                <input
                  type="text"
                  className="form-control"
                  value={bulkFrom}
                  onChange={(e) => setBulkFrom(e.target.value)}
                />
              </div>
              <div className="mb-3">
                <label className="form-label">Заменить на</label>
                <input
                  type="text"
                  className="form-control"
                  value={bulkTo}
                  onChange={(e) => setBulkTo(e.target.value)}
                />
              </div>
              <div className="form-footer">
                <button 
                  type="button" 
                  className="btn btn-warning w-100"
                  onClick={handleBulkUpdate}
                >
                  <IconArrowsExchange className="icon me-2" />
                  Обновить все
                </button>
              </div>
            </div>
          </div>

          {/* Actions Card */}
          <div className="card card-md">
            <div className="card-header">
              <h3 className="card-title">
                <IconDatabase className="icon me-2" />
                Действия
              </h3>
            </div>
            <div className="card-body">
              <div className="d-grid gap-2">
                <button 
                  className="btn btn-primary"
                  onClick={handleSaveChanges}
                  disabled={loading}
                >
                  {loading ? (
                    <>
                      <span className="spinner-border spinner-border-sm me-2" role="status"></span>
                      Сохранение...
                    </>
                  ) : (
                    <>
                      <IconDatabase className="icon me-2" />
                      Сохранить в S3
                    </>
                  )}
                </button>
                <button 
                  className="btn btn-outline-secondary"
                  onClick={fetchItems}
                  disabled={loading}
                >
                  <IconRefresh className="icon me-2" />
                  Обновить
                </button>
              </div>
            </div>
          </div>
        </div>

        <div className="col-12 col-lg-8">
          <div className="card">
            <div className="card-header d-flex flex-column flex-md-row justify-content-between align-items-stretch align-items-md-center gap-2">
              <h3 className="card-title mb-0">Список {entityName === 'домен' ? 'доменов' : entityName}</h3>
              <div className="d-flex flex-wrap gap-2 flex-grow-1 flex-md-grow-0">
                {/* Фильтр по шлюзу */}
                <select className="form-select w-auto" value={filterType} onChange={e => { setFilterType(e.target.value); setCurrentPage(1); }}>
                  <option value="">Все шлюзы</option>
                  {allTypes.map(type => (
                    <option key={type} value={type}>{type}</option>
                  ))}
                </select>
                {/* Поиск */}
                <div className="input-icon flex-grow-1">
                  <span className="input-icon-addon">
                    <IconSearch size={18} />
                  </span>
                  <input
                    type="text"
                    className="form-control"
                    placeholder={`Поиск ${entityName}...`}
                    value={searchTerm}
                    onChange={e => { setSearchTerm(e.target.value); setCurrentPage(1); }}
                  />
                </div>
              </div>
            </div>
            <div className="table-responsive">
              <table className="table card-table table-vcenter table-nowrap mb-0">
                <thead>
                  <tr>
                    <th className="cursor-pointer" onClick={() => handleSort('domain')}>
                      Домен
                      {sortField === 'domain' && (
                        <span className="ms-1">
                          {sortOrder === 'asc' ? '▲' : '▼'}
                        </span>
                      )}
                    </th>
                    <th className="cursor-pointer" onClick={() => handleSort('type')}>
                      Шлюз
                      {sortField === 'type' && (
                        <span className="ms-1">
                          {sortOrder === 'asc' ? '▲' : '▼'}
                        </span>
                      )}
                    </th>
                    <th className="text-end"> </th>
                  </tr>
                </thead>
                <tbody>
                  {paginatedItems.map((item) => (
                    <tr key={item.domain} className={editingDomain === item.domain ? 'table-info' : ''}>
                      <td>{item.domain}</td>
                      <td><span className="badge bg-blue-lt text-blue">{item.type}</span></td>
                      <td className="text-end">
                        {editingDomain === item.domain ? (
                          <>
                            <input
                              type="text"
                              className="form-control d-inline-block w-auto me-2"
                              value={editingValue}
                              ref={editInputRef}
                              onChange={e => setEditingValue(e.target.value)}
                              onKeyDown={e => handleEditKeyDown(e, item.domain)}
                              style={{maxWidth: 120}}
                            />
                            <button className="btn btn-success btn-icon btn-sm me-1" onClick={() => handleSaveEdit(item.domain)}><IconCheck size={16} /></button>
                            <button className="btn btn-secondary btn-icon btn-sm" onClick={handleCancelEdit}><IconX size={16} /></button>
                          </>
                        ) : (
                          <>
                            <button className="btn btn-outline-primary btn-icon btn-sm me-1" onClick={() => handleEdit(item)}><IconEdit size={16} /></button>
                            <button className="btn btn-outline-danger btn-icon btn-sm" onClick={() => confirmDelete(item)}><IconTrash size={16} /></button>
                          </>
                        )}
                      </td>
                    </tr>
                  ))}
                </tbody>
              </table>
            </div>
            {/* Пагинация */}
            {totalPages > 1 && (
              <div className="card-footer d-flex align-items-center justify-content-between">
                <div className="text-muted">
                  Показано {((currentPage - 1) * pageSize) + 1} - {Math.min(currentPage * pageSize, filteredItems.length)} из {filteredItems.length}
                </div>
                <ul className="pagination m-0">
                  <li className={`page-item${currentPage === 1 ? ' disabled' : ''}`}>
                    <button className="page-link" onClick={() => setCurrentPage(1)} disabled={currentPage === 1}>Первая</button>
                  </li>
                  <li className={`page-item${currentPage === 1 ? ' disabled' : ''}`}>
                    <button className="page-link" onClick={() => setCurrentPage(currentPage - 1)} disabled={currentPage === 1}>Назад</button>
                  </li>
                  {(() => {
                    const pages = [];
                    let start = Math.max(1, currentPage - 2);
                    let end = Math.min(totalPages, currentPage + 2);
                    if (currentPage <= 3) end = Math.min(totalPages, 5);
                    if (currentPage >= totalPages - 2) start = Math.max(1, totalPages - 4);
                    if (start > 1) pages.push('start-ellipsis');
                    for (let p = start; p <= end; p++) pages.push(p);
                    if (end < totalPages) pages.push('end-ellipsis');
                    return pages.map((p) => (
                      p === 'start-ellipsis' || p === 'end-ellipsis' ? (
                        <li key={p} className="page-item disabled"><span className="page-link">…</span></li>
                      ) : (
                        <li key={p} className={`page-item${currentPage === p ? ' active' : ''}`}>
                          <button className="page-link" onClick={() => setCurrentPage(p)}>{p}</button>
                        </li>
                      )
                    ));
                  })()}
                  <li className={`page-item${currentPage === totalPages ? ' disabled' : ''}`}>
                    <button className="page-link" onClick={() => setCurrentPage(currentPage + 1)} disabled={currentPage === totalPages}>Вперед</button>
                  </li>
                  <li className={`page-item${currentPage === totalPages ? ' disabled' : ''}`}>
                    <button className="page-link" onClick={() => setCurrentPage(totalPages)} disabled={currentPage === totalPages}>Последняя</button>
                  </li>
                </ul>
              </div>
            )}
          </div>
        </div>
      </div>

      {/* Delete Confirmation Modal */}
      {showDeleteModal && (
        <div className="modal modal-blur fade show" style={{display: 'block'}} tabIndex="-1">
          <div className="modal-dialog modal-sm modal-dialog-centered" role="document">
            <div className="modal-content">
              <button 
                type="button" 
                className="btn-close" 
                onClick={() => setShowDeleteModal(false)}
              ></button>
              <div className="modal-status bg-danger"></div>
              <div className="modal-body text-center py-4">
                <IconTrash className="icon mb-2 text-danger icon-lg" />
                <h3>Удалить {entityName}?</h3>
                <div className="text-muted">
                  Вы уверены, что хотите удалить "{itemToDelete?.domain}"? Это действие необратимо.
                </div>
              </div>
              <div className="modal-footer">
                <div className="w-100">
                  <div className="row">
                    <div className="col">
                      <button 
                        className="btn w-100" 
                        onClick={() => setShowDeleteModal(false)}
                      >
                        Отмена
                      </button>
                    </div>
                    <div className="col">
                      <button 
                        className="btn btn-danger w-100" 
                        onClick={executeDelete}
                      >
                        Удалить
                      </button>
                    </div>
                  </div>
                </div>
              </div>
            </div>
          </div>
        </div>
      )}

      <ConfirmDialog
        open={confirmState.open}
        title="Подтверждение"
        message={confirmState.text}
        onCancel={() => setConfirmState({ open: false, text: '', onConfirm: null })}
        onConfirm={() => confirmState.onConfirm?.()}
      />
    </>
  );
}

export default DataManager;