/*
 * Copyright (C) Contributors to the Suwayomi project
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at https://mozilla.org/MPL/2.0/.
 */

import { StringParam, useQueryParam } from 'use-query-params';
import { useMemo } from 'react';
import { LibraryOptions, LibrarySortMode, NullAndUndefined, TManga } from '@/typings.ts';
import { useLibraryOptionsContext } from '@/components/context/LibraryOptionsContext.tsx';
import { useMetadataServerSettings } from '@/lib/metadata/metadataServerSettings.ts';
import { Trackers } from '@/lib/data/Trackers.ts';

const triStateFilter = (
    triState: NullAndUndefined<boolean>,
    enabledFilter: () => boolean,
    disabledFilter: () => boolean,
): boolean => {
    switch (triState) {
        case true:
            return enabledFilter();
        case false:
            return disabledFilter();
        default:
            return true;
    }
};

const triStateFilterNumber = (triState: NullAndUndefined<boolean>, count?: number): boolean =>
    triStateFilter(
        triState,
        () => !!count && count >= 1,
        () => count === 0,
    );

const queryFilter = (query: NullAndUndefined<string>, { title }: TManga): boolean => {
    if (!query) return true;
    return title.toLowerCase().includes(query.toLowerCase());
};

const queryGenreFilter = (query: NullAndUndefined<string>, { genre }: TManga): boolean => {
    if (!query) return true;
    const queries = query.split(',').map((str) => str.toLowerCase().trim());
    return queries.every((element) => genre.map((el) => el.toLowerCase()).includes(element));
};

const trackerFilter = (trackFilters: LibraryOptions['tracker'], manga: TManga): boolean =>
    Object.entries(trackFilters)
        .map(([trackFilterId, trackFilterState]) => {
            const mangaTrackers = Trackers.getTrackers(manga.trackRecords.nodes);
            const isTrackerBound = mangaTrackers.some((tracker) => tracker.id === Number(trackFilterId));

            return triStateFilter(
                trackFilterState,
                () => isTrackerBound,
                () => !isTrackerBound,
            );
        })
        .every((matchesFilter) => matchesFilter);

const filterManga = (
    mangas: TManga[],
    query: NullAndUndefined<string>,
    unread: NullAndUndefined<boolean>,
    downloaded: NullAndUndefined<boolean>,
    bookmarked: NullAndUndefined<boolean>,
    tracker: LibraryOptions['tracker'],
    ignoreFilters: boolean,
): TManga[] =>
    mangas.filter((manga) => {
        const ignoreFiltersWhileSearching = ignoreFilters && query?.length;
        const matchesSearch = queryFilter(query, manga) || queryGenreFilter(query, manga);
        const matchesFilters =
            ignoreFiltersWhileSearching ||
            (triStateFilterNumber(downloaded, manga.downloadCount) &&
                triStateFilterNumber(unread, manga.unreadCount) &&
                triStateFilterNumber(bookmarked, manga.bookmarkCount) &&
                trackerFilter(tracker, manga));

        return matchesSearch && matchesFilters;
    });

const sortByNumber = (a: number | string = 0, b: number | string = 0) => Number(a) - Number(b);

const sortByString = (a: string, b: string): number => a.localeCompare(b);

const sortManga = (
    manga: TManga[],
    sort: NullAndUndefined<LibrarySortMode>,
    desc: NullAndUndefined<boolean>,
): TManga[] => {
    const result = [...manga];

    switch (sort) {
        case 'sortAlph':
            result.sort((a, b) => sortByString(a.title, b.title));
            break;
        case 'sortDateAdded':
            result.sort((a, b) => sortByNumber(a.inLibraryAt, b.inLibraryAt));
            break;
        case 'sortToRead':
            result.sort((a, b) => sortByNumber(a.unreadCount, b.unreadCount));
            break;
        case 'sortLastRead':
            result.sort((a, b) => sortByNumber(a.lastReadChapter?.lastReadAt, b.lastReadChapter?.lastReadAt));
            break;
        case 'sortLatestUploadedChapter':
            result.sort((a, b) =>
                sortByNumber(a.latestUploadedChapter?.uploadDate, b.latestUploadedChapter?.uploadDate),
            );
            break;
        case 'sortLatestFetchedChapter':
            result.sort((a, b) => sortByNumber(a.latestFetchedChapter?.fetchedAt, b.latestFetchedChapter?.fetchedAt));
            break;
        default:
            break;
    }

    if (desc) {
        result.reverse();
    }

    return result;
};

export const useGetVisibleLibraryMangas = (mangas: TManga[]) => {
    const [query] = useQueryParam('query', StringParam);
    const { options } = useLibraryOptionsContext();
    const { unread, downloaded, bookmarked, tracker } = options;
    const { settings } = useMetadataServerSettings();

    const filteredMangas = useMemo(
        () => filterManga(mangas, query, unread, downloaded, bookmarked, tracker, settings.ignoreFilters),
        [mangas, query, unread, downloaded, bookmarked, tracker, settings.ignoreFilters],
    );
    const sortedMangas = useMemo(
        () => sortManga(filteredMangas, options.sorts, options.sortDesc),
        [filteredMangas, options.sorts, options.sortDesc],
    );

    const isATrackFilterActive = Object.values(options.tracker).some((trackFilterState) => trackFilterState != null);
    const showFilteredOutMessage =
        (unread != null || downloaded != null || bookmarked != null || !!query || isATrackFilterActive) &&
        filteredMangas.length === 0 &&
        mangas.length > 0;

    return {
        visibleMangas: sortedMangas,
        showFilteredOutMessage,
    };
};