import { useState, useEffect, useRef, useCallback } from 'react';
import { useNavigate } from 'react-router-dom';
import axios from 'axios';
import Header from './Header';
import './css/BoardList.css';

const KBBoardsList = () => {
    const navigate = useNavigate();
    const debounceRef = useRef(null);
    const [error, setError] = useState('');
    const [loading, setLoading] = useState(false);
    const [showCreateModal, setShowCreateModal] = useState(false);
    const [timer, setTimer] = useState(400)

    const [sort_method, setSortMethod] = useState('title');
    const [reverse, setReverse] = useState(false);
    const [search_text, setSearchText] = useState('');
    const [page, setPage] = useState(1);
    const [limit, setLimit] = useState(5);

    const [title, setTitle] = useState('');
    const [description, setDescription] = useState('');
    const [items, setItems] = useState([]);
    const [totalItems, setTotalItems] = useState(null);


    


    function ListItem({ item }) {
        if (!item) return null;
        const openBoard = () => { navigate('/kanban-board/' + item.id); };
        return (
            <li>
                <button onClick={openBoard}>
                    <div className="sort-row">
                        <h3>{item.title}</h3>
                        <p><strong>Владелец:</strong> {item.owner_display_name}</p>
                    </div>
                    <div className="sort-row">
                        <p><strong>Описание:</strong> {item.description ? item.description : 'Отсутствует'}</p>
                    </div>
                </button>
            </li>
        );
    };

    const Pagination = () => {
        const totalPages = Math.ceil(totalItems / limit);
        if (totalPages <= 1) return null;
        const pages = [];
        for (let i = 1; i <= totalPages; i++) {
            pages.push(i);
        }
        return (
            <div className="pagination">
            {pages.map((pageNum) => (
                <button
                    key={pageNum}
                    onClick={() => setPage(pageNum)}
                    className={page === pageNum ? 'active' : ''}
                    disabled={loading}
                > {pageNum} </button>
            ))}
            </div>
        );
    };


    
    const loadBoardList = useCallback(async () => {
        clearTimeout(debounceRef.current);
        debounceRef.current = setTimeout(async () => {
            try {
                const newList = { sort_method, reverse, search_text, page, limit };
                const response = await axios.post('/api/boards/list', newList, {withCredentials: true });
                if (Array.isArray(response.data.boards)) {
                    setItems(response.data.boards);
                    setTotalItems(response.data.count || response.data.boards.length);
                } else {
                    setItems([]);
                    setTotalItems(0)
                    if (response.data?.detail === 'Доски отсутствуют.') {
                        console.log('Доски отсутствуют');
                    }
                }
            } catch (err) {
                if (err.response?.data?.message === 'Token Error' || err.response?.data?.message === 'Invalid Token') {
                    setError('Вы не авторизованы');
                    setTimeout(() => {
                        navigate('/login');
                    }, 1000);
                } else {
                    setError('Ошибка загрузки досок');
                    console.log(err);
                    setItems([]);
                }
            }
            setTimer(400)
        }, timer); 
    }, [sort_method, reverse, search_text, page, limit, timer, setItems, setTotalItems, setError, navigate]);

    useEffect(() => { 
        loadBoardList();
    }, [page, loadBoardList]);

    const setFilter = (method) => () => {
        const newMethod = method;
        const newReverse = sort_method === method ? !reverse : false;

        setSortMethod(newMethod);
        setReverse(newReverse);
        setTimer(100);
    };
    
    const createBoard = async (e) => {
        e.preventDefault();
        try {
            setLoading(true)
            const newBoard = { title, description };
            await axios.post('/api/boards/create', newBoard);
			setShowCreateModal(false);
            await loadBoardList();
        } catch (err) {
            setError('Ошибка');
        } finally {
            setLoading(false);
            
        }
    };
	
    const openCreateModal = () => { setShowCreateModal(true) };
    const closeCreateModal = () => { setShowCreateModal(false); setDescription(''); setTitle('') };
    
    return (
        <>
        	<Header />
			<div className="profile-page">
        		{
                    error && <div className="error">{error}</div>
            	}
				<div className="kan-ban-list-sort">
      				<h3>Сортировка по:</h3>
                    <div className="nav-sort">
                    	<button onClick={setFilter('title')}>
							Названию
                        </button>
						<button onClick={setFilter('owner')}>
							Создателю
                        </button>
						<button onClick={setFilter('update_time')}>
							Дате обновления
                        </button>
                    </div>
					<input
						type="text"
						placeholder="Поиск по названию..."
                        value={search_text}
                        onChange={(e) => setSearchText(e.target.value)}
                    />
   	 			</div>
				<div className="kan-ban-list">
                    <div className="inf">
      					<h3>Доступные канбан доски:</h3> 
						<button onClick={openCreateModal}>Создать канбан-доску</button>
					</div>
                    {items.length > 0 ? (
                        <ul>
                            {items.map((item) => (
                                <ListItem key={item.id} item={item} />
                            ))}
                        </ul>
                    ) : (
                      	<p>Нет данных</p>
                    )}
   	 			</div>
                <Pagination />
    		</div>
			{showCreateModal && (
        		<div className="confirm-modal">
          			<div className="modal-content">
            			<p><strong>Придумайте название и описание канбан доски</strong></p>
                		<form onSubmit={createBoard}>
                            <div>
                              	<label>Название:</label>
                              	<input
                                    type="text"
                                    value={title}
                                    onChange={(e) => setTitle(e.target.value)}
                                    required
                              	/>
                            </div>
                            <div>
                              	<label>Описание:</label>
                              	<input
                                    type="text"
                                    value={description}
                                    onChange={(e) => setDescription(e.target.value)}
                              	/>
                            </div>
							<div className="modal-buttons">
          	  					<button type="submit" disabled={loading}>{loading ? 'Создание...' : 'Создать'}</button>
              					<button onClick={closeCreateModal}>Отменить</button>
            				</div>
                        </form>
          			</div>
        		</div>
            )}
        </>
	);
}

export default KBBoardsList;