enigma-bbs/core/client_term.js

/* jslint node: true */
'use strict';

//  ENiGMA½
const Log = require('./logger.js').log;
const renegadeToAnsi = require('./color_codes.js').renegadeToAnsi;
const Config = require('./config.js').get;
const iconv = require('iconv-lite');
const assert = require('assert');
const _ = require('lodash');

exports.ClientTerminal = ClientTerminal;

function ClientTerminal(output) {
    this.output = output;

    let outputEncoding = 'cp437';
    assert(iconv.encodingExists(outputEncoding));

    //  convert line feeds such as \n -> \r\n
    this.convertLF = true;

    this.syncTermFontsEnabled = false;

    //
    //  Some terminal we handle specially
    //  They can also be found in this.env{}
    //
    let termType = 'unknown';
    let termHeight = 0;
    let termWidth = 0;
    let termClient = 'unknown';

    this.currentSyncFont = 'not_set';

    //  Raw values set by e.g. telnet NAWS, ENVIRONMENT, etc.
    this.env = {};

    Object.defineProperty(this, 'outputEncoding', {
        get: function () {
            return outputEncoding;
        },
        set: function (enc) {
            if (iconv.encodingExists(enc)) {
                Log.info(
                    { encoding: enc, currentEncoding: outputEncoding },
                    `Output encoding changed to ${enc}`
                );
                outputEncoding = enc;
            } else {
                Log.warn({ encoding: enc }, 'Unknown encoding');
            }
        },
    });

    Object.defineProperty(this, 'termType', {
        get: function () {
            return termType;
        },
        set: function (ttype) {
            termType = ttype.toLowerCase();

            if (this.isNixTerm()) {
                this.outputEncoding = 'utf8';
            } else {
                this.outputEncoding = 'cp437';
            }

            //  :TODO: according to this: http://mud-dev.wikidot.com/article:telnet-client-identification
            //  Windows telnet will send "VTNT". If so, set termClient='windows'
            //  there are some others on the page as well

            Log.debug(
                { encoding: this.outputEncoding },
                'Set output encoding due to terminal type change'
            );
        },
    });

    Object.defineProperty(this, 'termWidth', {
        get: function () {
            return termWidth;
        },
        set: function (width) {
            if (width > 0) {
                termWidth = width;
            }
        },
    });

    Object.defineProperty(this, 'termHeight', {
        get: function () {
            return termHeight;
        },
        set: function (height) {
            if (height > 0) {
                termHeight = height;
            }
        },
    });

    Object.defineProperty(this, 'termClient', {
        get: function () {
            return termClient;
        },
        set: function (tc) {
            termClient = tc;

            Log.debug({ termClient: this.termClient }, 'Set known terminal client');
        },
    });
}

ClientTerminal.prototype.disconnect = function () {
    this.output = null;
};

ClientTerminal.prototype.isNixTerm = function () {
    //
    //  Standard *nix type terminals
    //
    if (this.termType.startsWith('xterm')) {
        return true;
    }

    const utf8TermList = Config().term.utf8TermList;
    return utf8TermList.includes(this.termType);
};

ClientTerminal.prototype.isANSI = function () {
    //
    //  ANSI terminals should be encoded to CP437
    //
    //  Some terminal types provided by Mercyful Fate / Enthral:
    //      ANSI-BBS
    //      PC-ANSI
    //      QANSI
    //      SCOANSI
    //      VT100
    //      QNX
    //
    //  Reports from various terminals
    //
    //  NetRunner v2.00beta 20
    //      * This version adds 256 colors and reports as "ansi-256color"
    //
    //  syncterm:
    //      * SyncTERM
    //
    //  xterm:
    //      * PuTTY
    //
    //  ansi-bbs:
    //      * fTelnet
    //
    //  pcansi:
    //      * ZOC
    //
    //  screen:
    //      * ConnectBot (Android)
    //
    //  linux:
    //      * JuiceSSH (note: TERM=linux also)
    //
    const cp437TermList = Config().term.cp437TermList;
    return cp437TermList.includes(this.termType);
};

//  :TODO: probably need to update these to convert IAC (0xff) -> IACIAC (escape it)

ClientTerminal.prototype.write = function (s, convertLineFeeds, cb) {
    this.rawWrite(this.encode(s, convertLineFeeds), cb);
};

ClientTerminal.prototype.rawWrite = function (s, cb) {
    if (this.output && this.output.writable) {
        this.output.write(s, err => {
            if (cb) {
                return cb(err);
            }

            if (err) {
                Log.warn({ error: err.message }, 'Failed writing to socket');
            }
        });
    }
};

ClientTerminal.prototype.pipeWrite = function (s, cb) {
    this.write(renegadeToAnsi(s, this), null, cb); //  null = use default for |convertLineFeeds|
};

ClientTerminal.prototype.encode = function (s, convertLineFeeds) {
    convertLineFeeds = _.isBoolean(convertLineFeeds) ? convertLineFeeds : this.convertLF;

    if (convertLineFeeds && _.isString(s)) {
        s = s.replace(/\n/g, '\r\n');
    }
    return iconv.encode(s, this.outputEncoding);
};