/**
* @description MeshCentral user messaging communication module
* @author Ylian Saint-Hilaire
* @copyright Intel Corporation 2022
* @license Apache-2.0
* @version v0.0.1
*/

/*xjslint node: true */
/*xjslint plusplus: true */
/*xjslint maxlen: 256 */
/*jshint node: true */
/*jshint strict: false */
/*jshint esversion: 6 */
"use strict";

/*
// For Telegram, add this in config.json
"messaging": {
    "telegram": {
        "apiid": 00000000,
        "apihash": "00000000000000000000000",
        "session": "aaaaaaaaaaaaaaaaaaaaaaa"
    }
}
*/

// Construct a SMS server object
module.exports.CreateServer = function (parent) {
    var obj = {};
    obj.parent = parent;
    obj.providers = 0; // 1 = Telegram, 2 = Signal
    obj.telegramClient = null;

    // Messaging client setup
    if (parent.config.messaging.telegram) {
        // Validate Telegram configuration values
        var telegramOK = true;
        if (typeof parent.config.messaging.telegram.apiid != 'number') { console.log('Invalid or missing Telegram apiid.'); telegramOK = false; }
        if (typeof parent.config.messaging.telegram.apihash != 'string') { console.log('Invalid or missing Telegram apihash.'); telegramOK = false; }
        if (typeof parent.config.messaging.telegram.session != 'string') { console.log('Invalid or missing Telegram session.'); telegramOK = false; }

        if (telegramOK) {
            // Setup Telegram
            async function setupTelegram() {
                const { TelegramClient } = require('telegram');
                const { StringSession } = require('telegram/sessions');
                const input = require('input');
                const stringSession = new StringSession(parent.config.messaging.telegram.session);
                const client = new TelegramClient(stringSession, parent.config.messaging.telegram.apiid, parent.config.messaging.telegram.apihash, { connectionRetries: 5 });
                await client.start({
                    phoneNumber: async function () { await input.text("Please enter your number: "); },
                    password: async function () { await input.text("Please enter your password: "); },
                    phoneCode: async function () { await input.text("Please enter the code you received: "); },
                    onError: function (err) { console.log('Telegram error', err); },
                });
                obj.telegramClient = client;
                obj.providers += 1; // Enable Telegram messaging
                console.log("MeshCentral Telegram client is connected.");
            }
            setupTelegram();
        }
    }

    // Send an user message
    obj.sendMessage = function(to, msg, func) {
        // Telegram
        if ((to.startsWith('telegram:')) && (obj.telegramClient != null)) {
            async function sendTelegramMessage(to, msg, func) {
                if (obj.telegramClient == null) return;
                parent.debug('email', 'Sending Telegram message to: ' + to.substring(9) + ': ' + msg);
                try { await obj.telegramClient.sendMessage(to.substring(9), { message: msg }); if (func != null) { func(true); } } catch (ex) { if (func != null) { func(false, ex); } }
            }
            sendTelegramMessage(to, msg, func);
        } else {
            // No providers found
            func(false, "No messaging providers found for this message.");
        }
    }

    // Get the correct SMS template
    function getTemplate(templateNumber, domain, lang) {
        parent.debug('email', 'Getting SMS template #' + templateNumber + ', lang: ' + lang);
        if (Array.isArray(lang)) { lang = lang[0]; } // TODO: For now, we only use the first language given.

        var r = {}, emailsPath = null;
        if ((domain != null) && (domain.webemailspath != null)) { emailsPath = domain.webemailspath; }
        else if (obj.parent.webEmailsOverridePath != null) { emailsPath = obj.parent.webEmailsOverridePath; }
        else if (obj.parent.webEmailsPath != null) { emailsPath = obj.parent.webEmailsPath; }
        if ((emailsPath == null) || (obj.parent.fs.existsSync(emailsPath) == false)) { return null }

        // Get the non-english email if needed
        var txtfile = null;
        if ((lang != null) && (lang != 'en')) {
            var translationsPath = obj.parent.path.join(emailsPath, 'translations');
            var translationsPathTxt = obj.parent.path.join(emailsPath, 'translations', 'sms-messages_' + lang + '.txt');
            if (obj.parent.fs.existsSync(translationsPath) && obj.parent.fs.existsSync(translationsPathTxt)) {
                txtfile = obj.parent.fs.readFileSync(translationsPathTxt).toString();
            }
        }

        // Get the english email
        if (txtfile == null) {
            var pathTxt = obj.parent.path.join(emailsPath, 'sms-messages.txt');
            if (obj.parent.fs.existsSync(pathTxt)) {
                txtfile = obj.parent.fs.readFileSync(pathTxt).toString();
            }
        }

        // No email templates
        if (txtfile == null) { return null; }

        // Decode the TXT file
        var lines = txtfile.split('\r\n').join('\n').split('\n')
        if (lines.length <= templateNumber) return null;

        return lines[templateNumber];
    }

    // Send messaging account verification
    obj.sendMessagingCheck = function (domain, to, verificationCode, language, func) {
        parent.debug('email', "Sending verification message to " + to);

        var sms = getTemplate(0, domain, language);
        if (sms == null) { parent.debug('email', "Error: Failed to get SMS template"); return; } // No SMS template found

        // Setup the template
        sms = sms.split('[[0]]').join(domain.title ? domain.title : 'MeshCentral');
        sms = sms.split('[[1]]').join(verificationCode);

        // Send the message
        obj.sendMessage(to, sms, func);
    };

    // Send 2FA verification
    obj.sendToken = function (domain, to, verificationCode, language, func) {
        parent.debug('email', "Sending login token message to " + to);

        var sms = getTemplate(1, domain, language);
        if (sms == null) { parent.debug('email', "Error: Failed to get SMS template"); return; } // No SMS template found

        // Setup the template
        sms = sms.split('[[0]]').join(domain.title ? domain.title : 'MeshCentral');
        sms = sms.split('[[1]]').join(verificationCode);

        // Send the message
        obj.sendMessage(to, sms, func);
    };

    return obj;
};