hytek.js

var fs = require('fs'),
    utils = require('./hytekutils.js');

var Hytek = function() {
    console.log('!');
    this.includeAlias = true;
    this.tags = JSON.parse(fs.readFileSync('tags.json').toString());
}

function newline(buffer) {
    return buffer[131] === 0x0a ? 2 : 1;
}

Hytek.prototype.parseSync = function(file) {
    var o = [],
        buf = fs.readFileSync(file),
        str = buf.toString('ascii'),
        line = 130 + newline(buf),//determine if file uses 0D or 0D0A newline character, only one is interpretted by node when converted to string from buffer
        lines = str.length / line;
    console.log('( ' + str.length + ' / ' + line + ') = ' + lines);
    for (i = 0; i < lines; i++) {
        var start = i * line;
        var l = this.parseLine(str.slice(start, start + line), this.tags);
        o[i] = l;
        console.log(l);
        console.log('###');
    }
    return o;
}

Hytek.prototype.parse = function(file, callback){
    fs.readFile(file, function(err, buf){
        if(err)
            return callback(err, null);
        var str = buf.toString('ascii'),
            line = 130 + newline(buf),
            lines = str.length / line,
            o = new Array();
        for (i = 0; i < lines; i++) {
            var start = i * line;
            var l = this.parseLine(str.slice(start, start + line), tags);
            o[i] = l;
            console.log(l);
            console.log('###');
        }
        callback(null, o);
    });
}

Hytek.prototype.parseLine = function (str, tags) {
    str = str.slice(0, 130);
    var id = str.slice(0, 2).toString('ascii');
    var tag = tags[id];
    if (tag == undefined)
        return new Error('Tag not found: ' + id);
    var o = {};
    o.tagId = id;
    for (var intervalProperty in tag) {
        if (!tag.hasOwnProperty(intervalProperty) || (intervalProperty.toString() == 'alias' && this.includeAlias == false))
            continue;
        if (intervalProperty.toString() == 'alias') {
            o[intervalProperty] = tag[intervalProperty];
            continue;
        }
        var interval = tag[intervalProperty];
        if (!interval instanceof Array || interval.length != 2) {
            return new Error('Invalid interval: ' + interval);
            continue;
        }
        var data = str.slice(interval[0], interval[1] + 1).trim(); //assuming inclusive interval
        o[intervalProperty] = data;
    }
    o.checksum = str.slice(str.length - 2, str.length);
    return o;
}

function matchTag(jsonArray, tag) {
    for(var o in jsonArray) {
        if(o.tagId === tag)
            return o;
    }
}

function format(jsonArray, format){
    var o = {};
    for(var p in format) {
        var spec = format[p];
        for (var t in spec) {
            var tag = spec[t];
            var matchedTag = matchTag[jsonArray, tag];
            //o[p] = 

        }
    }
}

module.exports = new Hytek();
//exports.parseSync = parseSync;
//exports.parse = parse;