/*
 * This file contains some module-wide constants and utility functions
 * that do not really fit elsewhere.
 */

import { module_settings } from "./settings.mjs";

export const module_id = "the-mills-messages";

// User flag to point to the ID of the journal to store message history to
export const history_flag = "history-journal";

/**
 * This is a copy of Foundry's internal formatting used by
 * localize.format(), so that we can be consistent.
 * @param {String} str The string whose "{named_args}" will be formatted
 * @param {Object} data An object with named_args members, whose data is replaced
 * @returns {String} The formatted string
 */
export function str_format(str, data) {
    const fmt = /{[^}]+}/g;
    str = str.replace(fmt, k => {
        return data[k.slice(1, -1)];
    });
    return str;
}

/**
 * Create the journal entry for the history of the specified user,
 * update the user's history flag and return the entry for further
 * manipulation if needed.
 * @param {User} user The user object that we are creating the history for
 * @return {Promise<JournalEntry>} The JournalEntry that was created.
 */
export async function create_history_journal(user) {
    // Use the settings' title for the journal, or revert to the default one if it is empty.
    let format_name = {name: user.character ? user.character.name : user.name};
    let formated_journal_title = str_format(game.settings.get(module_id, module_settings.HistoryJournalTitle), format_name)
    let title = formated_journal_title.length > 0 ?
        formated_journal_title :
        game.i18n.format("MM.UI.HistoryJournalTitle", format_name)

    return JournalEntry.create({
        name: title,
        ownership: {
            default: CONST.DOCUMENT_OWNERSHIP_LEVELS.NONE,
            [user.id]: CONST.DOCUMENT_OWNERSHIP_LEVELS.OBSERVER // Make the history private and unmodifiable
        },
    }).then(journal => {
        return user.setFlag(module_id, history_flag, journal.id).then(() => journal);
    });
}

/**
 * Go through all the user's histories to build a list of existing senders,
 * so that they can be displayed or re-used.
 * The final list is sorted and does not contain duplicates, as one sender
 * can send messages to multiple players at once.
 * @returns {String[]} A sorted array of the sender names, if any
 */
export function get_existing_senders() {
    /** @type {String[]} */
    let senders = []
    for (let user of game.users.players) {
        /** @type {JournalEntry} */
        let history = game.journal.get(user.getFlag(module_id, history_flag))
        if (!history) {
            continue;
        }
        for (let page of history.pages) {
            if (!senders.includes(page.name)) {
                senders.push(page.name);
            }
        }
    }
    return senders.sort();
}