/*
 * Copyright 2020-2022 Netsyms Technologies.
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */

/*
 * Matrix really, really, really needs better SDK docs.
 */

console.log("Starting up...");
import * as sdk from 'matrix-js-sdk';
import matrixcs from 'matrix-js-sdk';
import fs from 'fs';
import log4js from 'log4js';
import https from 'https';
import { fileURLToPath } from 'url';
import { dirname } from 'path';
import request from 'request';
import FileType from 'file-type';
import express from 'express';
import bodyParser from 'body-parser';
import fetch from 'node-fetch';

// Save script start time for ignoring older messages
var boottimestamp = Date.now();

var client;
var __dirname;
var __filename;
var initialsynccomplete = false;

// Init logging
var logger = log4js.getLogger();
logger.level = "debug";
logger.info("Log initialized.");
var settings = {};

/**
 * Load settings from config.json
 */
function loadSettingsFile() {
    __filename = fileURLToPath(import.meta.url);
            __dirname = dirname(__filename);
    let rawdata = fs.readFileSync(__dirname + '/config.json');
    settings = JSON.parse(rawdata);
    console.log(__dirname + "/config.json loaded.");
    logger.level = settings.loglevel;
}

loadSettingsFile();

// https://github.com/matrix-org/matrix-js-sdk/issues/2415#issuecomment-1188812401
matrixcs.request(request);

/**
 * From https://github.com/stevekinney/node-phone-formatter
 * @param {string} phoneNumber
 * @param {string} formatString
 * @returns {string}
 */
function formatPhoneNumber(phoneNumber, formatString) {
    phoneNumber = phoneNumber.replace(
            /^[\+\d{1,3}\-\s]*\(?([0-9]{3})\)?[-. ]?([0-9]{3})[-. ]?([0-9]{4})$/,
            "$1$2$3"
            );
    for (var i = 0, l = phoneNumber.length; i < l; i++) {
        formatString = formatString.replace("N", phoneNumber[i]);
    }
    return formatString;
}

function checkSMS() {
    logger.debug("Checking SMS");
    const options = {
        hostname: 'smsapi.voxtelesys.net',
        port: 443,
        path: '/api/v1/msgs/inbound?unread_only=true',
        method: 'GET',
        headers: {
            "Authorization": "Bearer " + settings.smsapikey
        }
    };
    const req = https.request(options, res => {
        res.on('data', d => {
            try {
                var json = JSON.parse(d);
                var messages = json.results;
                if (messages.length == 0) {
                    logger.debug("No new SMS messages.");
                }

                for (var i = 0; i < messages.length; i++) {
                    let msg = messages[i];
                    if (settings.smsonlyto.length > 0 && settings.smsonlyto.indexOf(msg.to) != -1) {
                        logger.info("Received SMS from " + msg.from + " for " + msg.to + ": " + msg.body);
                        createOrJoinSMSRoom(msg.from, msg.to, function (roomid) {
                            sendMatrix(roomid, msg.body, msg.media);
                        });
                    } else {
                        logger.info("Received SMS from " + msg.from + " for " + msg.to + ", ignoring based on smsonlyto list.");
                    }
                }
            } catch (ex) {
                logger.error(ex);
            }
        });
    });
    req.on('error', error => {
        logger.warn(error);
    });
    req.end();
}

/**
 * Connect to the server and get the room ID and stuff
 * @param {type} alias
 * @returns {undefined}
 */
async function getRoomIDFromAlias(alias) {
    var info = await client.getRoomIdForAlias(alias);
    if (typeof info.room_id != "undefined") {
        return info;
    }

    var response = await fetch(settings.homeserver + "/_matrix/client/v3/directory/room/" + encodeURIComponent(alias));
    if (response.status != 200) {
        throw new Error("Fetch returned invalid status code " + response.status);
    }
    var json = await response.json();
    return json;
}


/**
 * Join or create+join a room with alias #SMS_{tel}. If already joined, do nothing.
 * @param {string} tel
 * @param {string} ournumber the phone number Matrix messages will be sent from for this room
 * @param {function} callback function with the room ID as an argument.
 * @returns {undefined}
 */
async function createOrJoinSMSRoom(tel, ournumber, callback) {
    var roomName = "#SMS_" + tel + "_" + ournumber + ":" + settings.matrixdomain;
    logger.debug("Checking if room " + roomName + " exists.");
    try {
        var res = await getRoomIDFromAlias(roomName);
        logger.debug(JSON.stringify(res));
        logger.debug("Room " + roomName + " exists!");
        var inRoom = false;
        if (!res.error) {
            var rooms = (await client.getJoinedRooms()).joined_rooms;
            for (var i = 0; i < rooms.length; i++) {
                if (rooms[i] == res.room_id) {
                    inRoom = true;
                    break;
                }
            }
        }
        if (inRoom) {
            // we're already in the room, do nothing
            logger.debug("Room " + roomName + " already joined.");
            client.setRoomTag(res.room_id, "u.matrix-bridge-voxtelesys-sms", {tel: tel, ournumber: ournumber, order: 0.5});
            callback(res.room_id);
        } else {
            // not in the room, join it
            client.joinRoom(res.room_id).then((room) => {
                logger.debug("Room " + roomName + " joined.");
                client.setRoomTag(room.room_id, "u.matrix-bridge-voxtelesys-sms", {tel: tel, ournumber: ournumber, order: 0.5});
                callback(res.room_id);
            });
        }
        return;
    } catch (err) {
        // room doesn't exist, create it
        logger.debug(err);
        logger.debug("Room " + roomName + " does not exist. Creating it now.");
        var userPowerLevels = {};
        for (var i = 0; i < settings.inviteusers.length; i++) {
            userPowerLevels[settings.inviteusers[i]] = 50;
        }
        userPowerLevels[settings["matrixuser"]] = 100;
        try {
            var room = await client.createRoom({
                room_alias_name: "SMS_" + tel + "_" + ournumber,
                preset: "trusted_private_chat",
                visibility: "private",
                invite: settings.inviteusers,
                power_level_content_override: {
                    "events": {
                        "m.room.name": 50,
                        "m.room.power_levels": 50,
                        "m.room.canonical_alias": 100
                    },
                    "events_default": 0,
                    "invite": 50,
                    "kick": 50,
                    "notifications": {
                        "room": 50
                    },
                    "redact": 50,
                    "state_default": 50,
                    "users": userPowerLevels,
                    "users_default": 50
                },
                is_direct: true,
                name: formatPhoneNumber(tel, "(NNN) NNN-NNNN"),
                topic: "SMS conversation with " + formatPhoneNumber(tel, "(NNN) NNN-NNNN") + " (using " + formatPhoneNumber(ournumber, "(NNN) NNN-NNNN") + ")"
            });
            logger.debug("Room" + roomName + " created with ID " + room.room_id);
            // The first message or two we send doesn't go through unless we do this.
            // It just spits out "Error sending event M_FORBIDDEN: Unknown room" instead.
            createOrJoinSMSRoom(tel, ournumber, callback);
        } catch (errr) {
            logger.error("Could not create " + roomName + ".");
            logger.error(errr);
        }
    }
}

function getAndUploadFile(url, callback) {
    logger.info("Downloading MMS media " + url);
    // download
    request({url, encoding: null}, (err, resp, buffer) => {
        FileType.fromBuffer(buffer).then(function (mimeobj) {
            logger.debug(mimeobj);
            if (typeof mimeobj == "undefined") {
                logger.error("Undefined media mimetype, not uploading to Matrix.");
                return;
            }
            // upload
            logger.info("Uploading MMS media to Matrix " + url);
            client.uploadContent(buffer, {
                onlyContentUri: true,
                rawResponse: false,
                type: mimeobj.mime
            }).then((res) => {
                if (typeof callback == "function") {
                    callback(res, mimeobj.mime);
                    logger.info("Media URI: " + res);
                }
            }).catch((err) => {
                if (typeof callback == "function") {
                    callback(false);
                }
                if (err.data.error == "Unknown room") {
                    return;
                }
                logger.error(err);
            });
        });
    });
}

/**
 * Send a message to a Matrix room.
 * @param {string} room the room to post the message in.
 * @param {string} body message content.
 * @param {array} media Array of media URLs to download via HTTP(s) and send to Matrix.
 * @returns {undefined}
 */
async function sendMatrix(room, body, media) {
    var roomid = room;
    if (room.startsWith("#")) {
        try {
            roomid = (await getRoomIDFromAlias()).room_id;
            logger.info("Translated alias " + room + " to room ID " + roomid);
        } catch (err) {
            logger.error(err);
        }
    }
    if (Array.isArray(media)) {
        for (var i = 0; i < media.length; i++) {
            getAndUploadFile(media[i], async function (uri, mimetype) {
                if (mimetype == "image/jpg" || mimetype == "image/jpeg" || mimetype == "image/png" || mimetype == "image/gif") {
                    var content = {
                        body: "Image",
                        msgtype: "m.image",
                        url: uri,
                        info: {
                            mimetype: mimetype
                        }
                    };
                } else {
                    var content = {
                        body: "File",
                        msgtype: "m.file",
                        url: uri,
                        info: {
                            mimetype: mimetype
                        }
                    };
                }

                try {
                    await client.sendEvent(roomid, "m.room.message", content, "");
                    return true;
                } catch (err) {
                    if (err.data.error == "Unknown room") {
                        return;
                    }
                    logger.error(err);
                }
            });
        }
    }

    if (body != "") {
        var content = {
            body: body,
            msgtype: "m.text"
        };
        try {
            await client.sendEvent(roomid, "m.room.message", content, "");
            return true;
        } catch (err) {
            if (err.data.error == "Unknown room") {
                return false;
            }
            logger.error(err);
        }
    } else {
        return true;
    }
}

function sendMatrixNotice(roomid, body, callback) {
    var content = {
        body: body,
        msgtype: "m.notice"
    };
    client.sendEvent(roomid, "m.room.message", content, "").then((res) => {
        if (typeof callback == "function") {
            callback(true);
        }
    }).catch((err) => {
        if (typeof callback == "function") {
            callback(false);
        }
        if (err.data.error == "Unknown room") {
            return;
        }
        logger.error(err);
    });
}

/**
 * Send a SMS to a phone number.
 * @param {string} number
 * @param {string} body message content.
 * @param {function|undefined} callback passes true when successful, false on failure.
 * @returns {undefined}
 */
function sendSMS(number, from, body, callback) {
    if (settings.googleverifiedsms) {
        // Use Google Verified SMS to add business branding to SMS message
    }
    logger.info("Sending SMS to " + number + " from " + from);
    var data = {
        to: [number],
        from: from,
        body: body
    };
    const jsondata = JSON.stringify(data);
    const options = {
        hostname: 'smsapi.voxtelesys.net',
        port: 443,
        path: '/api/v1/sms',
        method: 'POST',
        headers: {
            "Authorization": "Bearer " + settings.smsapikey,
            "Content-Type": "application/json",
            "Accept": "application/json"
        }
    }

    const req = https.request(options, res => {
        res.on('data', d => {
            logger.debug(d.toString('utf8'));
        });
    });
    req.on('error', error => {
        logger.error(error);
        callback(false);
    });
    req.write(jsondata);
    req.end();
    if (typeof callback == "function") {
        callback(true);
    }
}

/**
 * Send a SMS to a phone number.
 * @param {string} number
 * @param {string} body message content.
 * @param {function|undefined} callback passes true when successful, false on failure.
 * @returns {undefined}
 */
function sendMMS(number, from, mediauri, mimetype, callback) {
    logger.info("Sending MMS to " + number + " from " + from);
    var urichunks = mediauri.split("/"); // should result in something like [ "mxc:", "", "matrix.org", "mediaidhere90473473" ]
    if (urichunks.length < 4) {
        logger.error("Invalid media uri");
        if (typeof callback == "function") {
            callback(false);
        }
        return;
    }
    var httpmediaurl = settings.mediaurlpath;

    httpmediaurl = httpmediaurl.replace("{{server-name}}", urichunks[2]);
    httpmediaurl = httpmediaurl.replace("{{media-id}}", urichunks[3]);

    var body = "";
    var media = [httpmediaurl];

    switch (mimetype) {
        case "image/jpeg":
        case "image/png":
        case "image/gif":
        case "image/bmp":
            // These are likely to work, so don't include the URL
            body = "";
            break;
        default:
            // Send link to content too
            body = httpmediaurl;
            //media = [];
    }

    var data = {
        to: [number],
        from: from,
        body: body,
        media: media
    };
    const jsondata = JSON.stringify(data);
    const options = {
        hostname: 'smsapi.voxtelesys.net',
        port: 443,
        path: '/api/v1/sms',
        method: 'POST',
        headers: {
            "Authorization": "Bearer " + settings.smsapikey,
            "Content-Type": "application/json",
            "Accept": "application/json"
        }
    }

    const req = https.request(options, res => {
        res.on('data', d => {
            logger.debug(d.toString('utf8'));
        });
    });
    req.on('error', error => {
        logger.error(error);
        if (typeof callback == "function") {
            callback(false);
        }
    });
    req.write(jsondata);
    req.end();
    if (typeof callback == "function") {
        callback(true);
    }
}

function handleHTTPRequest(req, res) {
    try {
        logger.info("Got HTTP request: " + req.url);
        if (req.url == "/webhook") {
            try {
                var msg = req.body;

                if (msg.type == "mo") {
                    if (settings.smsonlyto.length > 0 && settings.smsonlyto.indexOf(msg.to) != -1) {
                        logger.info("Received SMS from " + msg.from + " for " + msg.to + ": " + msg.body);
                        createOrJoinSMSRoom(msg.from, msg.to, function (roomid) {
                            logger.info("Sending to room " + roomid);
                            sendMatrix(roomid, msg.body, msg.media);
                        });
                        res.sendStatus(204);
                        res.end();
                    } else {
                        logger.info("Received SMS from " + msg.from + " for " + msg.to + ", ignoring based on smsonlyto list.");
                        res.sendStatus(403);
                        res.end();
                    }
                } else {
                    res.sendStatus(403);
                    res.end();
                }
            } catch (ex) {
                logger.error("Decoding webhook body: " + ex);
                logger.error(req.body);
                res.sendStatus(500);
                res.end();
            }
        } else {
            try {
                res.sendStatus(404);
                res.end();
            } catch (err) {
                logger.error(err);
            }
        }
    } catch (exx) {
        logger.error(exx);
    }
}

// Access token empty
if (settings.matrixaccesstoken == false) {
    logger.error("Matrix access token not set.");
    if (settings.matrixuser == false || settings.matrixpass == false) {
        logger.error("Config values for matrixuser and/or matrixpass are not valid.");
        process.exit(1);
    }
    logger.error("Attempting to fetch access token for you...");
    try {
        request({
            method: "POST",
            uri: settings.homeserver + "/_matrix/client/v3/login",
            json: {
                type: "m.login.password",
                user: settings.matrixuser,
                password: settings.matrixpass
            }
        }, function (error, resp, body) {
            if (!error && resp.statusCode == 200) {
                if (body.access_token) {
                    logger.error("Got access token for you. Writing it to " + __dirname + "/config.json now.");
                    settings.matrixaccesstoken = body.access_token;
                    fs.writeFileSync(__dirname + '/config.json', JSON.stringify(settings, null, 4));
                    logger.error("Exiting. Please restart me to load new config file.");
                    process.exit();
                }
            } else {
                logger.error("Couldn't get access token. Get it yourself: curl -XPOST -d '{\"type\":\"m.login.password\", \"user\":\"" + settings.matrixuser + "\", \"password\":\"password here\"}' \"https://matrix.netsyms.net/_matrix/client/v3/login\"");
            }
        });
    } catch (ex) {
        logger.error("Couldn't get access token. Get it yourself: curl -XPOST -d '{\"type\":\"m.login.password\", \"user\":\"" + settings.matrixuser + "\", \"password\":\"password here\"}' \"https://matrix.netsyms.net/_matrix/client/v3/login\"");
    }
} else {
    client = sdk.createClient({baseUrl: settings.homeserver, userId: settings.matrixuser, accessToken: settings.matrixaccesstoken});
    var httpserver = express();
    var jsonParser = bodyParser.json();
    client.startClient({initialSyncLimit: 10});
    logger.info("Plugged into the matrix.");

    client.once("sync", function (state, prevState, res) {
        logger.debug("Initial sync complete (" + state + ")");
        initialsynccomplete = true;
        httpserver.post("*", jsonParser, (req, res) => {
            handleHTTPRequest(req, res);
        });
        httpserver.get("*", (req, res) => {
            handleHTTPRequest(req, res);
        });
        httpserver.listen(settings.listenport, () => {
            logger.info("HTTP server listening on port " + settings.listenport);
        });
        logger.info("Up and running.");
        if (settings.smsinterval > 0) {
            setInterval(checkSMS, settings.smsinterval * 1000);
            checkSMS();
        }
    });
    client.on("Room.timeline", function (event, room) {
        try {
            if (!initialsynccomplete) {
                return; // ignore anything while we were offline
            }
            if (event.getType() !== "m.room.message") {
                return; // only use messages
            }
            if (client.getUserId() == event.getSender()) {
                return; // skip own messages to prevent loop
            }
            if (event.getTs() < (Date.now() - 1000 * 60 * 60 * 8)) {
                // Ignore old events (8 hrs), they're probably duplicates or something.
                logger.warn("Ignoring stale Matrix room event [" + event.getId() + "]: older than 8 hours");
                return;
            }
            if (event.getTs() < boottimestamp) {
                logger.warn("Ignoring stale Matrix room event [" + event.getId() + "]: event predates start of this program");
                return;
            }
            if (event.getContent() == null || typeof event.getContent().body == "undefined" || event.getContent().body == null) {
                // Apparently this can happen?
                return;
            }
            logger.debug("Got room message (event ID " + event.getId() + ")");

            if (event.getContent().body.toLowerCase().startsWith("!sms")) {
                // capture command to start room for new number
                const matches = event.getContent().body.match(/([1-9]?[0-9]{10})/g);
                if (matches == null) {
                    return;
                }
                if (matches.length == 1 || matches.length == 2) {
                    var tel = matches[0];
                    var ournumber = settings.smsfrom;
                    if (tel.length == 10) {
                        // make it the full number
                        tel = "1" + tel;
                    }
                    if (matches.length == 2) {
                        ournumber = matches[1];
                        if (ournumber.length == 10) {
                            // make it the full number
                            ournumber = "1" + ournumber;
                        }
                    }
                    logger.info("Got request to start new SMS conversation with " + tel + " using " + ournumber + " from " + event.getSender() + ".");
                    sendMatrixNotice(event.getRoomId(), "Starting conversation with " + tel);
                    createOrJoinSMSRoom(tel, ournumber, function (roomid) {
                        //client.setRoomTag(roomid, "u.matrix-bridge-voxtelesys-sms", {tel: tel, ournumber: ournumber});
                    });
                }
                return;
            } else if (event.getContent().body.toLowerCase().replace(/\s/g, "").startsWith("!sms")) {
                sendMatrixNotice(event.getRoomId(), "Malformed command detected, ignoring.");
                sendMatrixNotice(event.getRoomId(), "Hint: there aren't supposed to be any spaces before or in the \"!sms\" part.");
                return;
            }

            if (event.getContent().body.toLowerCase().startsWith("!fixusers")) {
                sendMatrixNotice(event.getRoomId(), "Inviting missing users across all SMS chats. You may need to run this command several times, there's a server limit to how many invites can be sent at once.");

                client.getJoinedRooms().then(function (rooms) {
                    var roomlist = rooms.joined_rooms;
                    for (var i = 0; i < roomlist.length; i++) {
                        (function (roomid) {
                            client.getJoinedRoomMembers(roomid).then(function (joined) {
                                var members = Object.keys(joined.joined);
                                for (var j = 0; j < settings.inviteusers.length; j++) {
                                    if (members.indexOf(settings.inviteusers[j]) == -1) {
                                        logger.info("Inviting missing user " + settings.inviteusers[j] + " to room " + roomid);
                                        client.invite(roomid, settings.inviteusers[j]);
                                    }
                                }
                            });
                        })(roomlist[i]);
                    }
                });


                return;
            } else if (event.getContent().body.toLowerCase().replace(/\s/g, "").startsWith("!fixusers")) {
                sendMatrixNotice(event.getRoomId(), "Malformed command detected, ignoring.");
                return;
            }

            if (event.getContent().body.toLowerCase().replace(/\s/g, "").startsWith("!")) {
                sendMatrixNotice(event.getRoomId(), "I'm sorry, but my programming forbids me from sending text messages that start with `!`.");
                return;
            }

            var matches = room.name.match(/SMS_([1-9][0-9]+)(?:_([1-9][0-9]+))?/g);
            if (matches == null || (matches.length != 1 && matches.length != 2)) {
                client.getRoomTags(event.getRoomId()).then((response) => {
                    console.log(response);
                    if (typeof response.tags["u.matrix-bridge-voxtelesys-sms"] != "undefined") {
                        var tel = response.tags["u.matrix-bridge-voxtelesys-sms"].tel;
                        var from = response.tags["u.matrix-bridge-voxtelesys-sms"].ournumber;
                        logger.info("Got message for " + tel + " from " + event.getSender() + ", relaying to " + from + ".");
                        switch (event.getContent().msgtype) {
                            case "m.image":
                            case "m.file":
                            case "m.video":
                                sendMMS(
                                        tel,
                                        from,
                                        event.getContent().url,
                                        event.getContent().info.mimetype,
                                        function () {
                                            client.sendReadReceipt(event, "m.read");
                                        });
                                break;
                            case "m.text":
                            default:
                                sendSMS(
                                        tel,
                                        from,
                                        event.getContent().body,
                                        function () {
                                            client.sendReadReceipt(event, "m.read");
                                        });
                                break;
                        }
                    } else if (typeof response.tags["com.netsyms.matrix-bridge-voxtelesys.sms"] != "undefined") {
                        var tel = response.tags["com.netsyms.matrix-bridge-voxtelesys.sms"].tel;
                        var from = response.tags["com.netsyms.matrix-bridge-voxtelesys.sms"].ournumber;
                        client.setRoomTag(event.getRoomId(), "u.matrix-bridge-voxtelesys-sms", {tel: tel, ournumber: from, order: 0.5});
                        logger.info("Got message for " + tel + " from " + event.getSender() + ", relaying to " + from + ".");
                        switch (event.getContent().msgtype) {
                            case "m.image":
                            case "m.file":
                            case "m.video":
                                sendMMS(
                                        tel,
                                        from,
                                        event.getContent().url,
                                        event.getContent().info.mimetype,
                                        function () {
                                            client.sendReadReceipt(event, "m.read");
                                        });
                                break;
                            case "m.text":
                            default:
                                sendSMS(
                                        tel,
                                        from,
                                        event.getContent().body,
                                        function () {
                                            client.sendReadReceipt(event, "m.read");
                                        });
                                break;
                        }
                    } else {
                        console.log(response.tags);
                        sendMatrixNotice(room.roomId, "Error: couldn't determine correct number to send SMS from.");
                    }
                });
            } else {
                if (matches.length == 1) {
                    var tel = matches[0];
                    logger.info("Got message for " + tel + " from " + event.getSender() + ", relaying.");
                    switch (event.getContent().msgtype) {
                        case "m.image":
                        case "m.file":
                        case "m.video":
                            sendMMS(tel, settings.smsfrom, event.getContent().url,
                                    event.getContent().info.mimetype,
                                    function () {
                                        client.sendReadReceipt(event, "m.read");
                                    });
                            break;
                        case "m.text":
                        default:
                            sendSMS(tel, settings.smsfrom, event.getContent().body, function () {
                                client.sendReadReceipt(event, "m.read");
                            });
                            break;
                    }
                } else if (matches.length == 2) {
                    var tel = matches[0];
                    var from = matches[1];
                    logger.info("Got message for " + tel + " from " + event.getSender() + ", relaying to " + from + ".");
                    switch (event.getContent().msgtype) {
                        case "m.image":
                        case "m.file":
                        case "m.video":
                            sendMMS(tel, from, event.getContent().url,
                                    event.getContent().info.mimetype,
                                    function () {
                                        client.sendReadReceipt(event, "m.read");
                                    });
                            break;
                        case "m.text":
                        default:
                            sendSMS(tel, settings.smsfrom, event.getContent().body, function () {
                                client.sendReadReceipt(event, "m.read");
                            });
                            break;
                    }
                }
            }
        } catch (ex) {
            logger.error("Error handling incoming event: " + ex);
        }
    });
}