/*
 * 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 { useContext, useEffect, useRef, useState } from 'react';
import List from '@mui/material/List';
import ListItemText from '@mui/material/ListItemText';
import { fromEvent } from 'file-selector';
import { useTranslation } from 'react-i18next';
import { ListItemButton } from '@mui/material';
import ListItemIcon from '@mui/material/ListItemIcon';
import { requestManager } from '@/lib/requests/RequestManager.ts';
import { makeToast } from '@/components/util/Toast';
import { ListItemLink } from '@/components/util/ListItemLink';
import { NavBarContext, useSetDefaultBackTo } from '@/components/context/NavbarContext';
import { BackupRestoreState, GetRestoreStatusQuery } from '@/lib/graphql/generated/graphql.ts';
import { Progress } from '@/components/util/Progress.tsx';

export function Backup() {
    const { t } = useTranslation();
    const { setTitle, setAction } = useContext(NavBarContext);
    useEffect(() => {
        setTitle(t('settings.backup.title'));
        setAction(null);
    }, [t]);

    useSetDefaultBackTo('settings');

    const [isRestoring, setIsRestoring] = useState<boolean | null>(null);
    const { data } = requestManager.useGetBackupRestoreStatus({
        skip: isRestoring !== null ? !isRestoring : false,
        pollInterval: 1000,
    });
    const prevRestoreStatusRef = useRef<GetRestoreStatusQuery['restoreStatus'] | null>(null);

    const restoreProgress = (() => {
        if (!isRestoring || !data) {
            return 0;
        }

        const progress = 100 * (data.restoreStatus.mangaProgress / data.restoreStatus.totalManga);
        return Number.isNaN(progress) ? 0 : progress;
    })();

    useEffect(() => {
        if (!data || isRestoring !== null) {
            return;
        }

        const isRestoreInProgress = data?.restoreStatus.state !== BackupRestoreState.Idle;
        setIsRestoring(isRestoreInProgress);
    }, [data?.restoreStatus.state]);

    useEffect(() => {
        if (!data) {
            return;
        }

        const isRestoreFinished =
            isRestoring &&
            data.restoreStatus.mangaProgress === data.restoreStatus.totalManga &&
            prevRestoreStatusRef.current?.state !== BackupRestoreState.Idle;
        if (isRestoreFinished) {
            setIsRestoring(false);
            makeToast(t('settings.backup.label.restored_backup'), 'success');
        }
        prevRestoreStatusRef.current = data.restoreStatus;
    }, [data?.restoreStatus.state]);

    const submitBackup = async (file: File) => {
        if (file.name.toLowerCase().match(/proto\.gz$|tachibk$/g)) {
            makeToast(t('settings.backup.label.restoring_backup'), 'info');

            try {
                await requestManager.restoreBackupFile(file).response;
                setIsRestoring(true);
            } catch (e) {
                makeToast(t('settings.backup.label.backup_restore_failed'), 'error');
            }
        } else if (file.name.toLowerCase().endsWith('json')) {
            makeToast(t('settings.backup.label.legacy_backup_unsupported'), 'error');
        } else {
            makeToast(t('global.error.label.invalid_file_type'), 'error');
        }
    };

    const dropHandler = async (e: Event) => {
        e.preventDefault();
        const files = await fromEvent(e);

        submitBackup(files[0] as File);
    };

    const dragOverHandler = (e: Event) => {
        e.preventDefault();
    };

    useEffect(() => {
        document.addEventListener('drop', dropHandler);
        document.addEventListener('dragover', dragOverHandler);

        const handleFileSelection = async (event: Event) => {
            const files = await fromEvent(event);
            submitBackup(files[0] as File);
        };

        const input = document.getElementById('backup-file');
        input?.addEventListener('change', handleFileSelection);

        return () => {
            document.removeEventListener('drop', dropHandler);
            document.removeEventListener('dragover', dragOverHandler);
            input?.removeEventListener('change', handleFileSelection);
        };
    }, []);

    return (
        <>
            <List sx={{ padding: 0 }}>
                <ListItemLink to={requestManager.getExportBackupUrl()} directLink>
                    <ListItemText
                        primary={t('settings.backup.label.create_backup')}
                        secondary={t('settings.backup.label.create_backup_info')}
                    />
                </ListItemLink>
                <ListItemButton
                    onClick={() => document.getElementById('backup-file')?.click()}
                    disabled={!!isRestoring}
                >
                    <ListItemText
                        primary={t('settings.backup.label.restore_backup')}
                        secondary={t('settings.backup.label.restore_backup_info')}
                    />
                    {isRestoring ? (
                        <ListItemIcon>
                            <Progress progress={restoreProgress} />
                        </ListItemIcon>
                    ) : null}
                </ListItemButton>
            </List>
            <input type="file" id="backup-file" style={{ display: 'none' }} />
        </>
    );
}