/********************************************************************************
 * Copyright (c) 2026 Contributors to the Eclipse Foundation
 *
 * See the NOTICE file(s) distributed with this work for additional
 * information regarding copyright ownership.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License 2.0 which is available at
 * https://www.eclipse.org/legal/epl-2.0
 *
 * SPDX-License-Identifier: EPL-2.0
 ********************************************************************************/

import { useMemo, useCallback } from 'react';
import { useScanContext } from '../../context/scan-admin';

/**
 * Hook for managing pagination state and actions.
 * Provides page navigation, total pages calculation, and loading state.
 */
export const usePagination = () => {
    const { state, actions, derived } = useScanContext();

    const goToPage = useCallback((page: number) => {
        if (page >= 0 && page < derived.totalPages) {
            actions.setPage(page);
        }
    }, [actions, derived.totalPages]);

    const goToNextPage = useCallback(() => {
        if (state.currentPage < derived.totalPages - 1) {
            actions.setPage(state.currentPage + 1);
        }
    }, [state.currentPage, derived.totalPages, actions]);

    const goToPreviousPage = useCallback(() => {
        if (state.currentPage > 0) {
            actions.setPage(state.currentPage - 1);
        }
    }, [state.currentPage, actions]);

    const goToFirstPage = useCallback(() => {
        actions.setPage(0);
    }, [actions]);

    const goToLastPage = useCallback(() => {
        if (derived.totalPages > 0) {
            actions.setPage(derived.totalPages - 1);
        }
    }, [derived.totalPages, actions]);

    // Determine if we're in a loading state based on selected tab
    const isLoading = state.selectedTab >= 3 ? state.isLoadingFiles : state.isLoadingScans;

    // Get total items based on selected tab
    const totalItems = state.selectedTab >= 3 ? state.totalFiles : state.totalScans;

    return useMemo(() => ({
        currentPage: state.currentPage,
        pageSize: state.pageSize,
        totalPages: derived.totalPages,
        totalItems,
        isLoading,
        goToPage,
        goToNextPage,
        goToPreviousPage,
        goToFirstPage,
        goToLastPage,
        hasNextPage: state.currentPage < derived.totalPages - 1,
        hasPreviousPage: state.currentPage > 0,
        isFirstPage: state.currentPage === 0,
        isLastPage: state.currentPage >= derived.totalPages - 1,
        // Range info (1-indexed for display)
        startItem: totalItems > 0 ? state.currentPage * state.pageSize + 1 : 0,
        endItem: Math.min((state.currentPage + 1) * state.pageSize, totalItems),
    }), [
        state.currentPage,
        state.pageSize,
        derived.totalPages,
        totalItems,
        isLoading,
        goToPage,
        goToNextPage,
        goToPreviousPage,
        goToFirstPage,
        goToLastPage,
    ]);
};

export type UsePaginationReturn = ReturnType<typeof usePagination>;