import React from 'react';
import {act, renderHook} from '@testing-library/react';
import {render, screen} from '../test-utils';
import {usePages, useDriveTemperature, useDriveHealth} from './customHooks';
import {QueryContext, StatusContext} from '../contexts/contexts';
import {Paginator} from '../components/Common';

// Build a wrapper that provides a controlled QueryContext so usePages can read
// `o` and `l` from searchParams without a real router.
const makeWrapper = (initialParams = {}) => {
    const params = new URLSearchParams(initialParams);
    const Wrapper = ({children}) => {
        const [searchParams, setSearchParams] = React.useState(params);

        const updateQuery = (newParams) => {
            const next = new URLSearchParams(searchParams.toString());
            Object.entries(newParams).forEach(([k, v]) => {
                if (v === null || v === undefined) {
                    next.delete(k);
                } else {
                    next.set(k, String(v));
                }
            });
            setSearchParams(next);
        };

        return (
            <QueryContext.Provider value={{searchParams, updateQuery, getLocationStr: () => '/'}}>
                {children}
            </QueryContext.Provider>
        );
    };
    return Wrapper;
};

// Mock Media so Paginator renders both mobile + tablet variants synchronously.
jest.mock('../contexts/contexts', () => {
    const actual = jest.requireActual('../contexts/contexts');
    return {
        ...actual,
        Media: ({children}) => <>{children}</>,
    };
});

describe('usePages.setTotal -> totalPages', () => {
    // These cases describe the contract: how many pages should the Paginator
    // render given a total result count and a per-page limit?
    const cases = [
        // [total, limit, expectedPages, label]
        [0, 24, 1, 'no results -> 1 page'],
        [1, 24, 1, 'fewer than one page'],
        [23, 24, 1, 'just under one page'],
        [24, 24, 1, 'exactly one page (BUG: reports 2)'],
        [25, 24, 2, 'one full page plus one'],
        [47, 24, 2, 'just under two pages'],
        [48, 24, 2, 'exactly two pages (BUG: reports 3)'],
        [49, 24, 3, 'just over two pages'],
        [72, 24, 3, 'exactly three pages (BUG: reports 4)'],
        [100, 24, 5, 'partial last page'],
        [144, 24, 6, 'exactly six pages (BUG: reports 7)'],
    ];

    test.each(cases)('total=%i limit=%i -> %i pages (%s)', (total, limit, expected) => {
        const wrapper = makeWrapper({l: String(limit)});
        const {result} = renderHook(() => usePages(limit), {wrapper});

        act(() => {
            result.current.setTotal(total);
        });

        expect(result.current.totalPages).toBe(expected);
    });

    test('the last reported page yields an offset within total (no empty trailing page)', () => {
        // This is the user-visible symptom: clicking the last page link should
        // produce an offset that the API can still satisfy.  When totalPages is
        // off-by-one, the last page maps to offset === total (or > total) and
        // the API returns zero rows.
        const total = 48;
        const limit = 24;
        const wrapper = makeWrapper({l: String(limit)});
        const {result} = renderHook(() => usePages(limit), {wrapper});

        act(() => {
            result.current.setTotal(total);
        });

        act(() => {
            result.current.setPage(result.current.totalPages);
        });

        // setPage stores (page - 1) * limit as `o` in the query.
        const lastOffset = (result.current.totalPages - 1) * limit;
        expect(lastOffset).toBeLessThan(total);
    });
});

describe('useDriveTemperature', () => {
    const makeStatusWrapper = (status) => ({children}) => (
        <StatusContext.Provider value={{status}}>
            {children}
        </StatusContext.Provider>
    );

    test('selects the hottest drive and reads thresholds from the payload', () => {
        const status = {
            smart_stats: {
                drives: [
                    {device: 'sda', temperature: 51},
                    {device: 'sdb', temperature: 60},
                ],
                high_temperature: 55,
                critical_temperature: 65,
            },
        };
        const {result} = renderHook(() => useDriveTemperature(),
            {wrapper: makeStatusWrapper(status)});
        expect(result.current.device).toBe('sdb');
        expect(result.current.temperature).toBe(60);
        expect(result.current.highTemperature).toBe(55);
        expect(result.current.criticalTemperature).toBe(65);
    });

    test('ignores drives without a numeric temperature', () => {
        const status = {
            smart_stats: {
                drives: [
                    {device: 'sda', temperature: null},
                    {device: 'sdb', temperature: 48},
                ],
                high_temperature: 55,
                critical_temperature: 65,
            },
        };
        const {result} = renderHook(() => useDriveTemperature(),
            {wrapper: makeStatusWrapper(status)});
        expect(result.current.device).toBe('sdb');
        expect(result.current.temperature).toBe(48);
    });

    test('defaults to no warning and default thresholds when smart_stats is absent', () => {
        const {result} = renderHook(() => useDriveTemperature(),
            {wrapper: makeStatusWrapper({})});
        expect(result.current.device).toBeNull();
        expect(result.current.temperature).toBe(0);
        expect(result.current.highTemperature).toBe(55);
        expect(result.current.criticalTemperature).toBe(65);
    });

    test('returns no drive when none report a temperature', () => {
        const status = {
            smart_stats: {
                drives: [{device: 'sda', temperature: null}],
                high_temperature: 55,
                critical_temperature: 65,
            },
        };
        const {result} = renderHook(() => useDriveTemperature(),
            {wrapper: makeStatusWrapper(status)});
        expect(result.current.device).toBeNull();
        expect(result.current.temperature).toBe(0);
    });
});

describe('useDriveHealth', () => {
    const makeStatusWrapper = (status) => ({children}) => (
        <StatusContext.Provider value={{status}}>
            {children}
        </StatusContext.Provider>
    );

    test('flags drives whose SMART assessment is FAIL', () => {
        const status = {
            smart_stats: {
                drives: [
                    {device: 'sda', assessment: 'PASS'},
                    {device: 'sdb', assessment: 'FAIL'},
                ],
            },
        };
        const {result} = renderHook(() => useDriveHealth(),
            {wrapper: makeStatusWrapper(status)});
        expect(result.current.failing).toBe(true);
        expect(result.current.failingDevices).toEqual(['sdb']);
    });

    test('reports every failing drive', () => {
        const status = {
            smart_stats: {
                drives: [
                    {device: 'sda', assessment: 'FAIL'},
                    {device: 'sdb', assessment: 'FAIL'},
                ],
            },
        };
        const {result} = renderHook(() => useDriveHealth(),
            {wrapper: makeStatusWrapper(status)});
        expect(result.current.failingDevices).toEqual(['sda', 'sdb']);
    });

    test('does not warn when all drives PASS', () => {
        const status = {
            smart_stats: {drives: [{device: 'sda', assessment: 'PASS'}]},
        };
        const {result} = renderHook(() => useDriveHealth(),
            {wrapper: makeStatusWrapper(status)});
        expect(result.current.failing).toBe(false);
        expect(result.current.failingDevices).toEqual([]);
    });

    test('ignores drives with an unknown (null) assessment', () => {
        const status = {
            smart_stats: {drives: [{device: 'sda', assessment: null}]},
        };
        const {result} = renderHook(() => useDriveHealth(),
            {wrapper: makeStatusWrapper(status)});
        expect(result.current.failing).toBe(false);
    });

    test('does not warn when smart_stats is absent', () => {
        const {result} = renderHook(() => useDriveHealth(),
            {wrapper: makeStatusWrapper({})});
        expect(result.current.failing).toBe(false);
        expect(result.current.failingDevices).toEqual([]);
    });

    test('surfaces WARN drives separately from FAIL', () => {
        const status = {
            smart_stats: {
                drives: [
                    {device: 'sda', health: 'PASS', assessment: 'PASS'},
                    {device: 'sdb', health: 'WARN', assessment: 'PASS'},
                    {device: 'sdc', health: 'FAIL', assessment: 'FAIL'},
                ],
            },
        };
        const {result} = renderHook(() => useDriveHealth(),
            {wrapper: makeStatusWrapper(status)});
        expect(result.current.failingDevices).toEqual(['sdc']);
        expect(result.current.warning).toBe(true);
        expect(result.current.warningDevices).toEqual(['sdb']);
    });

    test('prefers derived health over raw assessment', () => {
        // A drive self-assessing PASS but with pending sectors is WARN.
        const status = {
            smart_stats: {drives: [{device: 'sda', health: 'WARN', assessment: 'PASS'}]},
        };
        const {result} = renderHook(() => useDriveHealth(),
            {wrapper: makeStatusWrapper(status)});
        expect(result.current.failing).toBe(false);
        expect(result.current.warningDevices).toEqual(['sda']);
    });

    test('falls back to assessment when health is absent', () => {
        const status = {
            smart_stats: {drives: [{device: 'sda', assessment: 'FAIL'}]},
        };
        const {result} = renderHook(() => useDriveHealth(),
            {wrapper: makeStatusWrapper(status)});
        expect(result.current.failingDevices).toEqual(['sda']);
    });
});

describe('Paginator rendering', () => {
    test('renders exactly totalPages numbered page links (no phantom trailing link)', () => {
        // 48 results at 24 per page -> 2 pages.  If totalPages is 3, the pagination
        // will render an extra "3" link that fetches an empty page.
        render(
            <Paginator activePage={1} totalPages={2} onPageChange={() => {}}/>
        );

        // Page numbers render as <a> elements carrying the page text.
        // Tablet + mobile variants both render here because Media is mocked to
        // pass children through, so each numeric page appears at least once.
        expect(screen.queryAllByText('1').length).toBeGreaterThan(0);
        expect(screen.queryAllByText('2').length).toBeGreaterThan(0);
        expect(screen.queryByText('3')).toBeNull();
    });
});