import React, { useState, useEffect } from 'react';
import { useNavigate } from 'react-router-dom';
import { useDispatch, useSelector } from 'react-redux';
import { showNotification } from '../../store/notification.slice';
import {
    fetchKnowledgeBases,
    searchKnowledgeBases,
    createKnowledgeBase,
} from '../../store/knowledgeBase/knowledgeBase.thunks';
import { resetSearchState } from '../../store/knowledgeBase/knowledgeBase.slice';
import SvgIcon from '../../components/SvgIcon';

// 导入拆分的组件
import SearchBar from './components/SearchBar';
import Pagination from './components/Pagination';
import CreateKnowledgeBaseModal from './components/CreateKnowledgeBaseModal';
import KnowledgeBaseList from './components/KnowledgeBaseList';

export default function KnowledgeBase() {
    const dispatch = useDispatch();
    const navigate = useNavigate();
    const [showCreateModal, setShowCreateModal] = useState(false);
    const [showAccessRequestModal, setShowAccessRequestModal] = useState(false);
    const [formErrors, setFormErrors] = useState({});
    const [accessRequestErrors, setAccessRequestErrors] = useState({});
    const [accessRequestData, setAccessRequestData] = useState({
        id: '',
        title: '',
        accessType: '只读访问',
        duration: '一周',
        projectInfo: '',
        reason: '',
    });
    const [newKnowledgeBase, setNewKnowledgeBase] = useState({
        name: '',
        desc: '',
    });

    // Search state
    const [searchKeyword, setSearchKeyword] = useState('');
    const [isSearching, setIsSearching] = useState(false);

    // Pagination state
    const [pagination, setPagination] = useState({
        page: 1,
        page_size: 10,
    });

    // Get knowledge bases from Redux store
    const { items: knowledgeBases, total, status, error } = useSelector((state) => state.knowledgeBase.list);
    const {
        items: searchResults,
        total: searchTotal,
        status: searchStatus,
        error: searchError,
        keyword: storeKeyword,
    } = useSelector((state) => state.knowledgeBase.search);
    const { status: operationStatus, error: operationError } = useSelector((state) => state.knowledgeBase.operations);

    // Determine which data to display based on search state
    const displayData = isSearching ? searchResults : knowledgeBases;
    const displayTotal = isSearching ? searchTotal : total;
    const displayStatus = isSearching ? searchStatus : status;
    const displayError = isSearching ? searchError : error;

    // Fetch knowledge bases when component mounts or pagination changes
    useEffect(() => {
        if (!isSearching) {
            dispatch(fetchKnowledgeBases(pagination));
        } else if (searchKeyword.trim()) {
            dispatch(
                searchKnowledgeBases({
                    keyword: searchKeyword,
                    page: pagination.page,
                    page_size: pagination.page_size,
                })
            );
        }
    }, [dispatch, pagination.page, pagination.page_size, isSearching, searchKeyword]);

    // Handle search input change
    const handleSearchInputChange = (e) => {
        setSearchKeyword(e.target.value);
    };

    // Handle search submit
    const handleSearch = (e) => {
        e.preventDefault();

        if (searchKeyword.trim()) {
            setIsSearching(true);
            setPagination((prev) => ({ ...prev, page: 1 })); // Reset to first page
            dispatch(
                searchKnowledgeBases({
                    keyword: searchKeyword,
                    page: 1,
                    page_size: pagination.page_size,
                })
            );
        } else {
            // If search is empty, reset to normal list view
            handleClearSearch();
        }
    };

    // Handle clear search
    const handleClearSearch = () => {
        setSearchKeyword('');
        setIsSearching(false);
        setPagination((prev) => ({ ...prev, page: 1 })); // Reset to first page
        dispatch(resetSearchState());
    };

    // Show loading state while fetching data
    const isLoading = displayStatus === 'loading';

    // Show error notification if fetch fails
    useEffect(() => {
        if (displayStatus === 'failed' && displayError) {
            dispatch(
                showNotification({
                    message: `获取知识库列表失败: ${displayError.message || displayError}`,
                    type: 'danger',
                })
            );
        }
    }, [displayStatus, displayError, dispatch]);

    // Show notification for operation status
    useEffect(() => {
        if (operationStatus === 'succeeded') {
            dispatch(
                showNotification({
                    message: '操作成功',
                    type: 'success',
                })
            );
            // Refresh the list after successful operation
            if (isSearching && searchKeyword.trim()) {
                dispatch(
                    searchKnowledgeBases({
                        keyword: searchKeyword,
                        page: pagination.page,
                        page_size: pagination.page_size,
                    })
                );
            } else {
                dispatch(fetchKnowledgeBases(pagination));
            }
        } else if (operationStatus === 'failed' && operationError) {
            dispatch(
                showNotification({
                    message: `操作失败: ${operationError.message || operationError}`,
                    type: 'danger',
                })
            );
        }
    }, [operationStatus, operationError, dispatch, pagination, isSearching, searchKeyword]);

    // Handle pagination change
    const handlePageChange = (newPage) => {
        setPagination((prev) => ({
            ...prev,
            page: newPage,
        }));
    };

    // Handle page size change
    const handlePageSizeChange = (newPageSize) => {
        setPagination({
            page: 1, // Reset to first page when changing page size
            page_size: newPageSize,
        });
    };

    const handleInputChange = (e) => {
        const { name, value } = e.target;
        setNewKnowledgeBase((prev) => ({
            ...prev,
            [name]: value,
        }));

        // Clear error when user types
        if (formErrors[name]) {
            setFormErrors((prev) => ({
                ...prev,
                [name]: '',
            }));
        }
    };

    const handleAccessRequestInputChange = (e) => {
        const { name, value } = e.target;
        setAccessRequestData((prev) => ({
            ...prev,
            [name]: value,
        }));

        // Clear error when user types
        if (accessRequestErrors[name]) {
            setAccessRequestErrors((prev) => ({
                ...prev,
                [name]: '',
            }));
        }
    };

    const validateCreateForm = () => {
        const errors = {};

        if (!newKnowledgeBase.name.trim()) {
            errors.name = '请输入知识库名称';
        }

        if (!newKnowledgeBase.desc.trim()) {
            errors.desc = '请输入知识库描述';
        }

        setFormErrors(errors);
        return Object.keys(errors).length === 0;
    };

    const validateAccessRequestForm = () => {
        const errors = {};

        if (!accessRequestData.projectInfo.trim()) {
            errors.projectInfo = '请输入项目信息';
        }

        if (!accessRequestData.reason.trim()) {
            errors.reason = '请输入申请原因';
        }

        setAccessRequestErrors(errors);
        return Object.keys(errors).length === 0;
    };

    const handleCreateKnowledgeBase = () => {
        // Validate form
        if (!validateCreateForm()) {
            return;
        }

        // Dispatch create knowledge base action
        dispatch(
            createKnowledgeBase({
                name: newKnowledgeBase.name,
                desc: newKnowledgeBase.desc,
                type: 'private', // Default type
            })
        );

        // Reset form and close modal
        setNewKnowledgeBase({ name: '', desc: '' });
        setFormErrors({});
        setShowCreateModal(false);
    };

    // Handle card click to navigate to knowledge base detail
    const handleCardClick = (id) => {
        navigate(`/knowledge-base/${id}/datasets`);
    };

    const handleRequestAccess = (id, title) => {
        setAccessRequestData((prev) => ({
            ...prev,
            id,
            title,
        }));
        setAccessRequestErrors({});
        setShowAccessRequestModal(true);
    };

    const handleSubmitAccessRequest = () => {
        // Validate form
        if (!validateAccessRequestForm()) {
            return;
        }

        // Here you would typically call an API to submit the access request
        dispatch(
            showNotification({
                message: '权限申请已提交',
                type: 'success',
            })
        );

        // Reset form and close modal
        setAccessRequestData((prev) => ({
            ...prev,
            projectInfo: '',
            reason: '',
        }));
        setAccessRequestErrors({});
        setShowAccessRequestModal(false);
    };

    // Calculate total pages
    const totalPages = Math.ceil(displayTotal / pagination.page_size);

    return (
        <div className='knowledge-base container mt-4'>
            <div className='d-flex justify-content-between align-items-center mb-3'>
                <SearchBar
                    searchKeyword={searchKeyword}
                    isSearching={isSearching}
                    onSearchChange={handleSearchInputChange}
                    onSearch={handleSearch}
                    onClearSearch={handleClearSearch}
                />
                <button
                    className='btn btn-dark d-flex align-items-center gap-1'
                    onClick={() => setShowCreateModal(true)}
                >
                    <SvgIcon className={'plus'} />
                    新建知识库
                </button>
            </div>

            {isSearching && (
                <div className='alert alert-info'>
                    搜索结果: "{storeKeyword}" - 找到 {displayTotal} 个知识库
                </div>
            )}

            {isLoading ? (
                <div className='d-flex justify-content-center my-5'>
                    <div className='spinner-border' role='status'>
                        <span className='visually-hidden'>加载中...</span>
                    </div>
                </div>
            ) : (
                <>
                    <KnowledgeBaseList
                        knowledgeBases={displayData}
                        isSearching={isSearching}
                        onCardClick={handleCardClick}
                        onRequestAccess={handleRequestAccess}
                    />

                    {/* Pagination */}
                    {totalPages > 1 && (
                        <Pagination
                            currentPage={pagination.page}
                            totalPages={totalPages}
                            pageSize={pagination.page_size}
                            onPageChange={handlePageChange}
                            onPageSizeChange={handlePageSizeChange}
                        />
                    )}
                </>
            )}

            {/* 新建知识库弹窗 */}
            <CreateKnowledgeBaseModal
                show={showCreateModal}
                formData={newKnowledgeBase}
                formErrors={formErrors}
                isSubmitting={operationStatus === 'loading'}
                onClose={() => setShowCreateModal(false)}
                onChange={handleInputChange}
                onSubmit={handleCreateKnowledgeBase}
            />

            {/* 申请权限弹窗 */}
            {showAccessRequestModal && (
                <div
                    className='modal-backdrop'
                    style={{
                        position: 'fixed',
                        top: 0,
                        left: 0,
                        right: 0,
                        bottom: 0,
                        backgroundColor: 'rgba(0, 0, 0, 0.5)',
                        display: 'flex',
                        alignItems: 'center',
                        justifyContent: 'center',
                        zIndex: 1050,
                    }}
                >
                    <div
                        className='modal-content bg-white rounded shadow'
                        style={{
                            width: '500px',
                            maxWidth: '90%',
                            padding: '20px',
                        }}
                    >
                        <div className='modal-header d-flex justify-content-between align-items-center mb-3'>
                            <h5 className='modal-title m-0'>申请访问权限</h5>
                            <button
                                type='button'
                                className='btn-close'
                                onClick={() => setShowAccessRequestModal(false)}
                                aria-label='Close'
                            ></button>
                        </div>
                        <div className='modal-body'>
                            <div className='mb-3'>
                                <label className='form-label'>知识库名称</label>
                                <input type='text' className='form-control' value={accessRequestData.title} readOnly />
                            </div>
                            <div className='mb-3'>
                                <label className='form-label'>权限类型</label>
                                <select
                                    className='form-select'
                                    name='accessType'
                                    value={accessRequestData.accessType}
                                    onChange={handleAccessRequestInputChange}
                                >
                                    <option value='只读访问'>只读访问</option>
                                    <option value='编辑权限'>编辑权限</option>
                                </select>
                            </div>
                            <div className='mb-3'>
                                <label className='form-label'>访问时长</label>
                                <select
                                    className='form-select'
                                    name='duration'
                                    value={accessRequestData.duration}
                                    onChange={handleAccessRequestInputChange}
                                >
                                    <option value='一周'>一周</option>
                                    <option value='一个月'>一个月</option>
                                    <option value='三个月'>三个月</option>
                                    <option value='六个月'>六个月</option>
                                    <option value='永久'>永久</option>
                                </select>
                            </div>
                            <div className='mb-3'>
                                <label htmlFor='projectInfo' className='form-label'>
                                    项目信息 <span className='text-danger'>*</span>
                                </label>
                                <input
                                    type='text'
                                    className={`form-control ${accessRequestErrors.projectInfo ? 'is-invalid' : ''}`}
                                    id='projectInfo'
                                    name='projectInfo'
                                    value={accessRequestData.projectInfo}
                                    onChange={handleAccessRequestInputChange}
                                    placeholder='请输入项目信息'
                                />
                                {accessRequestErrors.projectInfo && (
                                    <div className='invalid-feedback'>{accessRequestErrors.projectInfo}</div>
                                )}
                            </div>
                            <div className='mb-3'>
                                <label htmlFor='reason' className='form-label'>
                                    申请原因 <span className='text-danger'>*</span>
                                </label>
                                <textarea
                                    className={`form-control ${accessRequestErrors.reason ? 'is-invalid' : ''}`}
                                    id='reason'
                                    name='reason'
                                    rows='3'
                                    value={accessRequestData.reason}
                                    onChange={handleAccessRequestInputChange}
                                    placeholder='请输入申请原因'
                                ></textarea>
                                {accessRequestErrors.reason && (
                                    <div className='invalid-feedback'>{accessRequestErrors.reason}</div>
                                )}
                            </div>
                        </div>
                        <div className='modal-footer'>
                            <button
                                type='button'
                                className='btn btn-secondary'
                                onClick={() => setShowAccessRequestModal(false)}
                            >
                                取消
                            </button>
                            <button type='button' className='btn btn-primary' onClick={handleSubmitAccessRequest}>
                                提交申请
                            </button>
                        </div>
                    </div>
                </div>
            )}
        </div>
    );
}