import DOMPurify from 'dompurify';
import Storage from '@converse/skeletor/src/storage.js';
import log from '@converse/headless/log';
import { _converse, api } from '@converse/headless/core';
import { getOpenPromise } from '@converse/openpromise';

export function getDefaultStore () {
    if (_converse.config.get('trusted')) {
        const is_non_persistent = api.settings.get('persistent_store') === 'sessionStorage';
        return is_non_persistent ? 'session': 'persistent';
    } else {
        return 'session';
    }
}

function storeUsesIndexedDB (store) {
    return store === 'persistent' && api.settings.get('persistent_store') === 'IndexedDB';
}

export function createStore (id, store) {
    const name = store || getDefaultStore();
    const s = _converse.storage[name];
    if (typeof s === 'undefined') {
        throw new TypeError(`createStore: Could not find store for ${id}`);
    }
    return new Storage(id, s, storeUsesIndexedDB(store));
}

export function initStorage (model, id, type) {
    const store = type || getDefaultStore();
    model.browserStorage = _converse.createStore(id, store);
    if (storeUsesIndexedDB(store)) {
        const flush = () => model.browserStorage.flush();
        window.addEventListener(_converse.unloadevent, flush);
        model.on('destroy', () => window.removeEventListener(_converse.unloadevent, flush));
        model.listenTo(_converse, 'beforeLogout', flush);
    }
}

export function replacePromise (name) {
    const existing_promise = _converse.promises[name];
    if (!existing_promise) {
        throw new Error(`Tried to replace non-existing promise: ${name}`);
    }
    if (existing_promise.replace) {
        const promise = getOpenPromise();
        promise.replace = existing_promise.replace;
        _converse.promises[name] = promise;
    } else {
        log.debug(`Not replacing promise "${name}"`);
    }
}

const element = document.createElement('div');

export function decodeHTMLEntities (str) {
    if (str && typeof str === 'string') {
        element.innerHTML = DOMPurify.sanitize(str);
        str = element.textContent;
        element.textContent = '';
    }
    return str;
}