enigma-bbs/core/connect.js

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2014-10-17 02:21:06 +00:00
/* jslint node: true */
'use strict';
// ENiGMA½
const ansi = require('./ansi_term.js');
const Events = require('./events.js');
const { Errors } = require('./enig_error.js');
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// deps
const async = require('async');
exports.connectEntry = connectEntry;
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function ansiDiscoverHomePosition(client, cb) {
//
// We want to find the home position. ANSI-BBS and most terminals
// utilize 1,1 as home. However, some terminals such as ConnectBot
// think of home as 0,0. If this is the case, we need to offset
// our positioning to accommodate for such.
//
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const done = (err) => {
client.removeListener('cursor position report', cprListener);
clearTimeout(giveUpTimer);
return cb(err);
};
const cprListener = function(pos) {
const h = pos[0];
const w = pos[1];
//
// We expect either 0,0, or 1,1. Anything else will be filed as bad data
//
if(h > 1 || w > 1) {
client.log.warn( { height : h, width : w }, 'Ignoring ANSI home position CPR due to unexpected values');
return done(Errors.UnexpectedState('Home position CPR expected to be 0,0, or 1,1'));
}
if(0 === h & 0 === w) {
//
// Store a CPR offset in the client. All CPR's from this point on will offset by this amount
//
client.log.info('Setting CPR offset to 1');
client.cprOffset = 1;
}
return done(null);
};
client.once('cursor position report', cprListener);
const giveUpTimer = setTimeout( () => {
return done(Errors.General('Giving up on home position CPR'));
}, 3000); // 3s
client.term.write(`${ansi.goHome()}${ansi.queryPos()}`); // go home, query pos
}
function ansiAttemptDetectUTF8(client, cb) {
//
// Trick to attempt and detect UTF-8. While there is a lot more than
// just UTF-8 and CP437, many those are the main concerns, when it comes
// terminals that for example tell us they are "xterm" but still want CP437.
//
// Try to detect UTF-8 by discovering the cursor position, writing some
// multi-byte UTF-8, and checking the position again. If the term is really
// UTF-8, we should get a proper position, otherwise we'll be further out.
//
// We currently only do this if the term hasn't already been ID'd as a
// "*nix" terminal -- that is, xterm, etc.
//
if(!client.term.isNixTerm()) {
return cb(null);
}
let posStage = 1;
let initialPosition;
let giveUpTimer;
const giveUp = () => {
client.removeListener('cursor position report', cprListener);
clearTimeout(giveUpTimer);
return cb(null);
};
const ASCIIPortion = ' Character encoding detection ';
const cprListener = (pos) => {
switch(posStage) {
case 1 :
posStage = 2;
initialPosition = pos;
clearTimeout(giveUpTimer);
giveUpTimer = setTimeout( () => {
return giveUp();
}, 2000);
client.once('cursor position report', cprListener);
client.term.rawWrite(`\u9760${ASCIIPortion}\u9760`); // Unicode skulls on each side
client.term.rawWrite(ansi.queryPos());
break;
case 2 :
{
clearTimeout(giveUpTimer);
const len = pos[1] - initialPosition[1];
if(!isNaN(len) && len >= ASCIIPortion.length + 6) { // CP437 displays 3 chars each Unicode skull
client.log.info('Terminal identified as UTF-8 but does not appear to be. Overriding to "ansi".');
client.setTermType('ansi');
}
}
return cb(null);
}
};
giveUpTimer = setTimeout( () => {
return giveUp();
}, 2000);
client.once('cursor position report', cprListener);
client.term.rawWrite(ansi.goHome() + ansi.queryPos());
}
function ansiQueryTermSizeIfNeeded(client, cb) {
if(client.term.termHeight > 0 || client.term.termWidth > 0) {
return cb(null);
}
const done = function(err) {
client.removeListener('cursor position report', cprListener);
clearTimeout(giveUpTimer);
return cb(err);
};
const cprListener = function(pos) {
//
// If we've already found out, disregard
//
if(client.term.termHeight > 0 || client.term.termWidth > 0) {
return done(null);
}
const h = pos[0];
const w = pos[1];
//
// NetRunner for example gives us 1x1 here. Not really useful. Ignore
// values that seem obviously bad. Included in the set is the explicit
// 999x999 values we asked to move to.
//
if(h < 10 || h === 999 || w < 10 || w === 999) {
client.log.warn(
{ height : h, width : w },
'Ignoring ANSI CPR screen size query response due to non-sane values');
return done(Errors.Invalid('Term size <= 10 considered invalid'));
}
client.term.termHeight = h;
client.term.termWidth = w;
client.log.debug(
{
termWidth : client.term.termWidth,
termHeight : client.term.termHeight,
source : 'ANSI CPR'
},
'Window size updated'
);
return done(null);
};
client.once('cursor position report', cprListener);
// give up after 2s
const giveUpTimer = setTimeout( () => {
return done(Errors.General('No term size established by CPR within timeout'));
}, 2000);
// Start the process:
// 1 - Ask to goto 999,999 -- a very much "bottom right" (generally 80x25 for example
// is the real size)
// 2 - Query for screen size with bansi.txt style specialized Device Status Report (DSR)
// request. We expect a CPR of:
// a - Terms that support bansi.txt style: Screen size
// b - Terms that do not support bansi.txt style: Since we moved to the bottom right
// we should still be able to determine a screen size.
//
client.term.rawWrite(`${ansi.goto(999, 999)}${ansi.queryScreenSize()}`);
}
function prepareTerminal(term) {
term.rawWrite(`${ansi.normal()}${ansi.clearScreen()}`);
}
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function displayBanner(term) {
// note: intentional formatting:
term.pipeWrite(`
2016-08-27 03:28:29 +00:00
|06Connected to |02EN|10i|02GMA|10½ |06BBS version |12|VN
2019-01-06 04:17:18 +00:00
|06Copyright (c) 2014-2019 Bryan Ashby |14- |12http://l33t.codes/
2016-08-27 03:28:29 +00:00
|06Updates & source |14- |12https://github.com/NuSkooler/enigma-bbs/
|00`
);
}
function connectEntry(client, nextMenu) {
const term = client.term;
async.series(
[
function basicPrepWork(callback) {
term.rawWrite(ansi.queryDeviceAttributes(0));
return callback(null);
},
function discoverHomePosition(callback) {
ansiDiscoverHomePosition(client, () => {
// :TODO: If CPR for home fully fails, we should bail out on the connection with an error, e.g. ANSI support required
return callback(null); // we try to continue anyway
});
},
function queryTermSizeByNonStandardAnsi(callback) {
ansiQueryTermSizeIfNeeded(client, err => {
if(err) {
//
// Check again; We may have got via NAWS/similar before CPR completed.
//
if(0 === term.termHeight || 0 === term.termWidth) {
//
// We still don't have something good for term height/width.
// Default to DOS size 80x25.
//
// :TODO: Netrunner is currently hitting this and it feels wrong. Why is NAWS/ENV/CPR all failing???
client.log.warn( { reason : err.message }, 'Failed to negotiate term size; Defaulting to 80x25!');
term.termHeight = 25;
term.termWidth = 80;
}
}
return callback(null);
});
},
function checkUtf8IfNeeded(callback) {
return ansiAttemptDetectUTF8(client, callback);
}
],
() => {
prepareTerminal(term);
//
// Always show an ENiGMA½ banner
//
displayBanner(term);
// fire event
Events.emit(Events.getSystemEvents().TermDetected, { client : client } );
setTimeout( () => {
return client.menuStack.goto(nextMenu);
}, 500);
}
);
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}