import {apiFetch} from './api.js';
import {storage} from './storage.js';

export const LANGUAGES = ['en', 'de'];

const LANGUAGE_STORAGE_KEY = 'tbp_language';
export const REQUEST_TIMEOUT_MS = 10000;

export const readCachedLanguage = () => {
    const stored = storage.get(LANGUAGE_STORAGE_KEY);
    return LANGUAGES.includes(stored) ? stored : null;
};

export const cacheLanguage = (language) => storage.set(LANGUAGE_STORAGE_KEY, language);

export const ME_URL = () => `${import.meta.env.VITE_API_URL}/api/users/me`;

/**
 * GET /api/users/me on Auth. The caller handles the response status.
 */
export const fetchMe = () => apiFetch(ME_URL(), {
    signal: AbortSignal.timeout(REQUEST_TIMEOUT_MS),
});

let queue = Promise.resolve();

/**
 * PUT /api/users/settings on Auth with `changes`. That endpoint replaces all four fields, so each save first loads
 * the saved ones; saves run one after another, from every page. The caller handles the response status.
 */
export const saveSettings = (changes) => {
    const save = async () => {
        const me = await fetchMe();
        if (!me.ok) return me;
        const data = await me.json();
        return apiFetch(`${import.meta.env.VITE_API_URL}/api/users/settings`, {
            method: 'PUT',
            headers: {'Content-Type': 'application/json'},
            body: JSON.stringify({
                useDarkTheme: !!data.settings?.useDarkTheme,
                language: data.settings?.language ?? '',
                displayName: data.displayName ?? null,
                publicProfile: !!data.settings?.publicProfile,
                ...changes,
            }),
            // A hung request must not hold back the next saves.
            signal: AbortSignal.timeout(REQUEST_TIMEOUT_MS),
        });
    };
    const result = queue.then(save, save);
    queue = result.catch(() => {});
    return result;
};

/** PUT on Auth, 204: show (or hide) the user by name in owner lists. The caller handles the response status. */
export const saveOwnerLists = (enabled) =>
    apiFetch(`${import.meta.env.VITE_API_URL}/api/users/settings/owner-lists`, {
        method: 'PUT',
        headers: {'Content-Type': 'application/json'},
        body: JSON.stringify({enabled}),
        signal: AbortSignal.timeout(REQUEST_TIMEOUT_MS),
    });

/** PUT on Auth, 204: the welcome page was seen. The caller handles the response status. */
export const markWelcomeSeen = () =>
    apiFetch(`${import.meta.env.VITE_API_URL}/api/users/settings/welcome-seen`, {
        method: 'PUT',
        signal: AbortSignal.timeout(REQUEST_TIMEOUT_MS),
    });