import {useRef, useState} from 'react';
import {useTranslation} from 'react-i18next';
import {toast} from 'sonner';
import {saveBacklogEntry, toBacklogRequest} from '../utils/backlog.js';

/**
 * Returns `{save, pending, busy}`. `save(field, value)` sends that one field (PATCH .../backlog; 0 or NONE clear it),
 * shows the saved or error toast and calls `onSaved(entry)` with the whole saved entry. One request at a time: a call
 * while one runs does nothing. Resolves to true when saved.
 *
 * `pending` is `{field, value}` while saving, else null. Show `pending.value` for that field meanwhile: a failed save
 * then falls back to the saved value by itself.
 */
export default function useSaveBacklogField(appid, {onSaved} = {}) {
    const {t} = useTranslation();
    const [pending, setPending] = useState(null);
    const running = useRef(false);

    const save = async (field, value) => {
        if (running.current) return false;
        running.current = true;
        setPending({field, value});
        try {
            const response = await saveBacklogEntry(appid, {[field]: toBacklogRequest({[field]: value})[field]});
            if (response.status === 401) return false;
            if (!response.ok) {
                toast.error(t('BACKLOG.SAVE_FAILED'));
                return false;
            }
            const entry = await response.json();
            onSaved?.(entry);
            toast.success(t('BACKLOG.SAVED'));
            return true;
        } catch (err) {
            console.error('backlog save error:', err);
            toast.error(t('INFO.ERROR.NETWORK_FAILURE'));
            return false;
        } finally {
            running.current = false;
            setPending(null);
        }
    };

    return {save, pending, busy: pending !== null};
}