enigma-bbs/core/ansi_escape_parser.js

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

const miscUtil	= require('./misc_util.js');
const ansi		= require('./ansi_term.js');
const Log		= require('./logger.js').log;

//	deps
const events	= require('events');
const util		= require('util');
const _			= require('lodash');

exports.ANSIEscapeParser		= ANSIEscapeParser;

const CR = 0x0d;
const LF = 0x0a;

function ANSIEscapeParser(options) {
    var self = this;

    events.EventEmitter.call(this);

    this.column				= 1;
    this.row				= 1;
    this.scrollBack			= 0;
    this.graphicRendition	= {};

    this.parseState = {
        re	: /(?:\x1b\x5b)([?=;0-9]*?)([ABCDHJKfhlmnpsu])/g,	//	eslint-disable-line no-control-regex
    };

    options = miscUtil.valueWithDefault(options, {
        mciReplaceChar		: '',
        termHeight			: 25,
        termWidth			: 80,
        trailingLF			: 'default',	//	default|omit|no|yes, ...
    });

    this.mciReplaceChar		= miscUtil.valueWithDefault(options.mciReplaceChar, '');
    this.termHeight			= miscUtil.valueWithDefault(options.termHeight, 25);
    this.termWidth			= miscUtil.valueWithDefault(options.termWidth, 80);
    this.trailingLF			= miscUtil.valueWithDefault(options.trailingLF, 'default');

    self.moveCursor = function(cols, rows) {
        self.column	+= cols;
        self.row	+= rows;

        self.column	= Math.max(self.column, 1);
        self.column	= Math.min(self.column, self.termWidth);	//	can't move past term width
        self.row	= Math.max(self.row, 1);

        self.positionUpdated();
    };

    self.saveCursorPosition = function() {
        self.savedPosition = {
            row		: self.row,
            column	: self.column
        };
    };

    self.restoreCursorPosition = function() {
        self.row	= self.savedPosition.row;
        self.column	= self.savedPosition.column;
        delete self.savedPosition;

        self.positionUpdated();
        //		self.rowUpdated();
    };

    self.clearScreen = function() {
        //	:TODO: should be doing something with row/column?
        self.emit('clear screen');
    };

    /*
	self.rowUpdated = function() {
		self.emit('row update', self.row + self.scrollBack);
	};*/

    self.positionUpdated = function() {
        self.emit('position update', self.row, self.column);
    };

    function literal(text) {
        const len	= text.length;
        let pos		= 0;
        let start	= 0;
        let charCode;

        while(pos < len) {
            charCode = text.charCodeAt(pos) & 0xff;	//	8bit clean

            switch(charCode) {
                case CR :
                    self.emit('literal', text.slice(start, pos));
                    start = pos;

                    self.column = 1;

                    self.positionUpdated();
                    break;

                case LF :
                    self.emit('literal', text.slice(start, pos));
                    start = pos;

                    self.row += 1;

                    self.positionUpdated();
                    break;

                default :
                    if(self.column === self.termWidth) {
                        self.emit('literal', text.slice(start, pos + 1));
                        start = pos + 1;

                        self.column = 1;
                        self.row	+= 1;

                        self.positionUpdated();
                    } else {
                        self.column += 1;
                    }
                    break;
            }

            ++pos;
        }

        //
        //	Finalize this chunk
        //
        if(self.column > self.termWidth) {
            self.column = 1;
            self.row	+= 1;

            self.positionUpdated();
        }

        const rem = text.slice(start);
        if(rem) {
            self.emit('literal', rem);
        }
    }

    function parseMCI(buffer) {
        //	:TODO: move this to "constants" seciton @ top
        var mciRe = /%([A-Z]{2})([0-9]{1,2})?(?:\(([0-9A-Za-z,]+)\))*/g;
        var pos = 0;
        var match;
        var mciCode;
        var args;
        var id;

        do {
            pos		= mciRe.lastIndex;
            match	= mciRe.exec(buffer);

            if(null !== match) {
                if(match.index > pos) {
                    literal(buffer.slice(pos, match.index));
                }

                mciCode	= match[1];
                id		= match[2] || null;

                if(match[3]) {
                    args = match[3].split(',');
                } else {
                    args = [];
                }

                //	if MCI codes are changing, save off the current color
                var fullMciCode = mciCode + (id || '');
                if(self.lastMciCode !== fullMciCode) {

                    self.lastMciCode = fullMciCode;

                    self.graphicRenditionForErase = _.clone(self.graphicRendition);
                }


                self.emit('mci', {
                    mci		: mciCode,
                    id		: id ? parseInt(id, 10) : null,
                    args	: args,
                    SGR		: ansi.getSGRFromGraphicRendition(self.graphicRendition, true)
                });

                if(self.mciReplaceChar.length > 0) {
                    const sgrCtrl = ansi.getSGRFromGraphicRendition(self.graphicRenditionForErase);

                    self.emit('control', sgrCtrl, 'm', sgrCtrl.slice(2).split(/[;m]/).slice(0, 3));

                    literal(new Array(match[0].length + 1).join(self.mciReplaceChar));
                } else {
                    literal(match[0]);
                }
            }

        } while(0 !== mciRe.lastIndex);

        if(pos < buffer.length) {
            literal(buffer.slice(pos));
        }
    }

    self.reset = function(input) {
        self.parseState = {
            //	ignore anything past EOF marker, if any
            buffer	: input.split(String.fromCharCode(0x1a), 1)[0],
            re		: /(?:\x1b\x5b)([?=;0-9]*?)([ABCDHJKfhlmnpsu])/g,	//	eslint-disable-line no-control-regex
            stop	: false,
        };
    };

    self.stop = function()  {
        self.parseState.stop = true;
    };

    self.parse = function(input) {
        if(input) {
            self.reset(input);
        }

        //	:TODO: ensure this conforms to ANSI-BBS / CTerm / bansi.txt for movement/etc.
        var pos;
        var match;
        var opCode;
        var args;
        var re		= self.parseState.re;
        var buffer	= self.parseState.buffer;

        self.parseState.stop = false;

        do {
            if(self.parseState.stop) {
                return;
            }

            pos		= re.lastIndex;
            match	= re.exec(buffer);

            if(null !== match) {
                if(match.index > pos) {
                    parseMCI(buffer.slice(pos, match.index));
                }

                opCode	= match[2];
                args	= match[1].split(';').map(v => parseInt(v, 10));	//	convert to array of ints

                escape(opCode, args);

                //self.emit('chunk', match[0]);
                self.emit('control', match[0], opCode, args);
            }
        } while(0 !== re.lastIndex);

        if(pos < buffer.length) {
            var lastBit = buffer.slice(pos);

            //	:TODO: check for various ending LF's, not just DOS \r\n
            if('\r\n' === lastBit.slice(-2).toString()) {
                switch(self.trailingLF) {
                    case 'default' :
                        //
                        //	Default is to *not* omit the trailing LF
                        //	if we're going to end on termHeight
                        //
                        if(this.termHeight === self.row) {
                            lastBit = lastBit.slice(0, -2);
                        }
                        break;

                    case 'omit' :
                    case 'no' :
                    case false :
                        lastBit = lastBit.slice(0, -2);
                        break;
                }
            }

            parseMCI(lastBit);
        }

        self.emit('complete');
    };

    /*
	self.parse = function(buffer, savedRe) {
		//	:TODO: ensure this conforms to ANSI-BBS / CTerm / bansi.txt for movement/etc.
		//	:TODO: move this to "constants" section @ top
		var re	= /(?:\x1b\x5b)([\?=;0-9]*?)([ABCDHJKfhlmnpsu])/g;
		var pos = 0;
		var match;
		var opCode;
		var args;

		//	ignore anything past EOF marker, if any
		buffer = buffer.split(String.fromCharCode(0x1a), 1)[0];

		do {
			pos		= re.lastIndex;
			match	= re.exec(buffer);

			if(null !== match) {
				if(match.index > pos) {
					parseMCI(buffer.slice(pos, match.index));
				}

				opCode	= match[2];
				args	= getArgArray(match[1].split(';'));

				escape(opCode, args);

				self.emit('chunk', match[0]);
			}



		} while(0 !== re.lastIndex);

		if(pos < buffer.length) {
			parseMCI(buffer.slice(pos));
		}

		self.emit('complete');
	};
	*/

    function escape(opCode, args) {
        let arg;

        switch(opCode) {
            //	cursor up
            case 'A' :
                //arg = args[0] || 1;
                arg = isNaN(args[0]) ? 1 : args[0];
                self.moveCursor(0, -arg);
                break;

                //	cursor down
            case 'B' :
                //arg = args[0] || 1;
                arg = isNaN(args[0]) ? 1 : args[0];
                self.moveCursor(0, arg);
                break;

                //	cursor forward/right
            case 'C' :
                //arg = args[0] || 1;
                arg = isNaN(args[0]) ? 1 : args[0];
                self.moveCursor(arg, 0);
                break;

                //	cursor back/left
            case 'D' :
                //arg = args[0] || 1;
                arg = isNaN(args[0]) ? 1 : args[0];
                self.moveCursor(-arg, 0);
                break;

            case 'f' :	//	horiz & vertical
            case 'H' :	//	cursor position
                //self.row	= args[0] || 1;
                //self.column	= args[1] || 1;
                self.row	= isNaN(args[0]) ? 1 : args[0];
                self.column	= isNaN(args[1]) ? 1 : args[1];
                //self.rowUpdated();
                self.positionUpdated();
                break;

                //	save position
            case 's' :
                self.saveCursorPosition();
                break;

                //	restore position
            case 'u' :
                self.restoreCursorPosition();
                break;

                //	set graphic rendition
            case 'm' :
                self.graphicRendition.reset = false;

                for(let i = 0, len = args.length; i < len; ++i) {
                    arg = args[i];

                    if(ANSIEscapeParser.foregroundColors[arg]) {
                        self.graphicRendition.fg = arg;
                    } else if(ANSIEscapeParser.backgroundColors[arg]) {
                        self.graphicRendition.bg = arg;
                    } else if(ANSIEscapeParser.styles[arg]) {
                        switch(arg) {
                            case 0 :
                                //	clear out everything
                                delete self.graphicRendition.intensity;
                                delete self.graphicRendition.underline;
                                delete self.graphicRendition.blink;
                                delete self.graphicRendition.negative;
                                delete self.graphicRendition.invisible;

                                delete self.graphicRendition.fg;
                                delete self.graphicRendition.bg;

                                self.graphicRendition.reset = true;
                                //self.graphicRendition.fg = 39;
                                //self.graphicRendition.bg = 49;
                                break;

                            case 1 :
                            case 2 :
                            case 22 :
                                self.graphicRendition.intensity = arg;
                                break;

                            case 4 :
                            case 24 :
                                self.graphicRendition.underline = arg;
                                break;

                            case 5 :
                            case 6 :
                            case 25 :
                                self.graphicRendition.blink = arg;
                                break;

                            case 7 :
                            case 27 :
                                self.graphicRendition.negative = arg;
                                break;

                            case 8 :
                            case 28 :
                                self.graphicRendition.invisible = arg;
                                break;

                            default :
                                Log.trace( { attribute : arg }, 'Unknown attribute while parsing ANSI');
                                break;
                        }
                    }
                }

                self.emit('sgr update', self.graphicRendition);
                break;	//	m

                //	:TODO: s, u, K

                //	erase display/screen
            case 'J' :
                //	:TODO: Handle other 'J' types!
                if(2 === args[0]) {
                    self.clearScreen();
                }
                break;
        }
    }
}

util.inherits(ANSIEscapeParser, events.EventEmitter);

ANSIEscapeParser.foregroundColors = {
    30	: 'black',
    31	: 'red',
    32	: 'green',
    33	: 'yellow',
    34	: 'blue',
    35	: 'magenta',
    36	: 'cyan',
    37	: 'white',
    39	: 'default',	//	same as white for most implementations

    90	: 'grey'
};
Object.freeze(ANSIEscapeParser.foregroundColors);

ANSIEscapeParser.backgroundColors = {
    40	: 'black',
    41	: 'red',
    42	: 'green',
    43	: 'yellow',
    44	: 'blue',
    45	: 'magenta',
    46	: 'cyan',
    47	: 'white',
    49	: 'default',	//	same as black for most implementations
};
Object.freeze(ANSIEscapeParser.backgroundColors);

//	:TODO: ensure these names all align with that of ansi_term.js
//
//	See the following specs:
//	* http://www.ansi-bbs.org/ansi-bbs-core-server.html
//	* http://www.vt100.net/docs/vt510-rm/SGR
//	* https://github.com/protomouse/synchronet/blob/master/src/conio/cterm.txt
//
//	Note that these are intentionally not in order such that they
//	can be grouped by concept here in code.
//
ANSIEscapeParser.styles = {
    0		: 'default',			//	Everything disabled

    1		: 'intensityBright',	//	aka bold
    2		: 'intensityDim',
    22		: 'intensityNormal',

    4		: 'underlineOn',		//	Not supported by most BBS-like terminals
    24		: 'underlineOff',		//	Not supported by most BBS-like terminals

    5		: 'blinkSlow',			//	blinkSlow & blinkFast are generally treated the same
    6		: 'blinkFast',			//	blinkSlow & blinkFast are generally treated the same
    25		: 'blinkOff',

    7		: 'negativeImageOn',	//	Generally not supported or treated as "reverse FG & BG"
    27		: 'negativeImageOff',	//	Generally not supported or treated as "reverse FG & BG"

    8		: 'invisibleOn',		//	FG set to BG
    28		: 'invisibleOff',		//	Not supported by most BBS-like terminals
};
Object.freeze(ANSIEscapeParser.styles);