utils.js

/*
** Utility Functions
*/
var config = require('./config.js');

/*
** General utilities
*/ 
var dec2binstr = exports.dec2binstr = function dec2binstr(str,padding) {
	//http://stackoverflow.com/questions/57803/how-to-convert-decimal-to-hex-in-javascript
    var bin = Number(str).toString(2);
    while(bin.length < padding) {
        bin = '0' + bin;
    }
    return bin;
};

var dec2hexstr = exports.dec2hexstr = function dec2hexstr(str) {
	//http://stackoverflow.com/questions/57803/how-to-convert-decimal-to-hex-in-javascript
    var hex = Number(str).toString(16);
    padding = 2;
    while(hex.length < padding) {
        hex = '0' + hex;
    }
    return hex;
};

var arrayToString = exports.arrayToString = function arrayToString(a) {
    var s = '';
    for(var i=0; i < a.length; i++) {
        s += a[i];
    }
    return s;
};

var byteArrayToHexString = exports.byteArrayToHexString = function byteArrayToHexString(ba) {
    var str = '';
    for(var i=0; i < ba.length; i++) {
        str += dec2hexstr(ba[i]);
    }
    return str;
};

var byteArrayToHexStringArray = exports.byteArrayToHexStringArray = function byteArrayToHexStringArray(ba) {
    var data = [];
    for(var i=0; i < ba.length; i++) {
        data.push(dec2hexstr(ba[i]));
    }
    return data;
};

var compareArray = exports.compareArray = function compareArray(arr1, arr2) {
    if(arr1.length != arr1.length) return false;
    for(i=0; i < arr1.length; i++) {
        if(arr1[i] != arr2[i]) return false;
    }
    return true;
};

var sleep = exports.sleep = function sleep(milliSeconds) {
    // use only in case of emergencies
    var startTime = new Date().getTime();
    while (new Date().getTime() < startTime + milliSeconds);
};



/*
** Insteon Utilities
*/
var getInsteonMessageLength = exports.getInsteonMessageLength = function getInsteonMessageLength(aByte) {
    // given insteon command code (second byte) return expected length of message
    var cmd = dec2hexstr(aByte);
    if(typeof(config.INSTEON_MESSAGES[cmd]) != 'undefined') {
        if(cmd == '62') return 9; // insteon standard or extended message - assume standard;
        return config.INSTEON_MESSAGES[cmd].len;
    }
    return -1; // not implemented
};

var getInsteonCommandType = exports.getInsteonCommandType = function getInsteonCommandType(aByte) {
    // given insteon command code (second byte) return associated type of message in plaintext
    var cmd = dec2hexstr(aByte);
    if(typeof(config.INSTEON_MESSAGES[cmd]) != 'undefined') return config.INSTEON_MESSAGES[cmd].type;
    return ''; // not implemented
};

var getMessageFlagsByHex = exports.getMessageFlagsByHex = function getMessageFlagsByHex(hex) {
    return getMessageFlags(parseInt(hex, 16));
};

var getMessageFlags = exports.getMessageFlags = function getMessageFlags(aByte) {
    // returns parsed message flag in json
    var binstr = dec2binstr(aByte, 8);
    var type = binstr.substring(0,3);
    switch(type) {
        case '000':
            type = 'Direct Message';
            break;
        case '001':
            type = 'ACK of Direct Message';
            break;
        case '010':
            type = 'ALL-Link Cleanup Message';
            break;
        case '011':
            type = 'ACK of ALL-Link Cleanup Message';
            break;
        case '100':
            type = 'Broadcast Message';
            break;
        case '101':
            type = 'NAK of Direct Message';
            break;
        case '110':
            type = 'ALL-Link Broadcast Message';
            break;
        case '111':
            type = 'NAK of ALL-Link Cleanup Message';
            break;
        default:
            throw 'getMessageFlags:: undefined message type '+type+'';
    }
    var extended = parseInt(binstr.substring(3,4), 2);
    var hops_left = parseInt(binstr.substring(4,6), 2);
    var max_hops = parseInt(binstr.substring(6),2);
    return {type: type, extended: extended, hops_left: hops_left, max_hops: max_hops};
};

var setMessageFlags = exports.setMessageFlags = function setMessageFlags(type, extended, hops_left, max_hops) {
    // returns binary string representation of provided message flags
    extended = typeof(extended) != 'undefined' ? extended : false;
    hops_left = typeof(hops_left) != 'undefined' ? hops_left : 1; // hops left should = max_hops
    max_hops = typeof(max_hops) != 'undefined' ? max_hops : 1;
    // TO DO -
    // broadcast & all-link broadcast messages max_hops should be 3 by default
    // direct and all-link cleanup max_hops should be 1 by default
    var binstr = '';
    switch(type) {
        case 'Broadcast Message':
            binstr = '100';
            break;
        case 'Direct Message':
            binstr = '000';
            break;
        case 'ACK of Direct Message':
            binstr = '001';
            break;
        case 'NAK of Direct Message':
            binstr = '101';
            break;
        case 'ALL-Link Broadcast Message':
            binstr = '110';
            break;
        case 'ALL-Link Cleanup Message':
            binstr = '010';
            break;
        case 'ACK of ALL-Link Cleanup Message':
            binstr = '011';
            break;
        case 'NAK of ALL-Link Cleanup Message':
            binstr = '111';
            break;
        default:
            throw('setMessageFlags::' + type + ' undefined message type');
    }
    if(extended) {
        binstr += '1';
    } else {
        binstr += '0';
    }
    binstr += dec2binstr(hops_left, 2);
    binstr += dec2binstr(max_hops, 2);
    return binstr;
};

var getInsteonTimer = exports.getInsteonTimer = function getInsteonTimer(extended, ack, max_hops) {
    // INSTEON Full Message Cycle Times (Dev Guide, Chapter 6, rounded up)
    var times = [];
    times[0] = [], times[1] = [], times[0][0] = [], times[0][1] = [], times[1][0] = [], times[1][1] = [];
    // standard
    times[0][0][0] = 50;
    times[0][0][1] = 100;
    times[0][0][2] = 150;
    times[0][0][3] = 200;
    times[0][1][0] = 100;
    times[0][1][1] = 200;
    times[0][1][2] = 300;
    times[0][1][3] = 400;
    // extended
    times[1][0][0] = 109;
    times[1][0][1] = 217;
    times[1][0][2] = 325;
    times[1][0][3] = 434;
    times[1][1][0] = 159;
    times[1][1][1] = 317;
    times[1][1][2] = 475;
    times[1][1][3] = 634;
    if(config.active_timers == undefined) config.active_timers = 0;
    if(times[extended][ack][max_hops] != undefined) {
        return times[extended][ack][max_hops] + 240*2 + Math.min(1400*config.active_timers, 2800);
        // heuristic: 240ms request to PLM, time on network above, 240ms response from PLM, plus add 1.4s allowance for each item in the queue due to higher likelihood of buffer overruns and reconnects (trial-and-error).
    }
    return 240*2 + 634;  // no time found, default max
};

var getPlmTimer = exports.getPlmTimer = function getPlmTimer(cmd) {
    var type = getInsteonCommandType(cmd);
    switch(type) {
        case 'Reset the IM':
            return '5000';
            break;
        default:
            return config.INSTEON_PLM_TRANS_TIME_LIMIT;
    }
};

/*
** insteonJS: 'jsonify' an insteon message into various parts
*/
var insteonJS = exports.insteonJS = function insteonJS(byteArray) {
    var data = new Object;
    data['dec'] = byteArray;
    data['hex'] = byteArrayToHexStringArray(byteArray);

    data['cmd'] = byteArray[1];
    data['type'] = getInsteonCommandType(data.cmd);

    switch(data['type']) {
        case 'Button Event Report':
            data['button_event'] = data['hex'][2];
            break;
        case 'Get IM Info':
            data['device_id'] = data['hex'].slice(2,5);
            data['device_cat'] = data['hex'][5];
            data['device_subcat'] = data['hex'][6];
            data['device_firmware'] = data['hex'][7];
            data['ack_nak'] = data['hex'][8];
            break;
        case 'INSTEON Standard Message Received':
            data['from'] = data['hex'].slice(2,5);
            data['to']  = data['hex'].slice(5,8);
            data['message_flags'] = data['hex'][8];
            data['command1'] = data['hex'][9];
            data['command2'] = data['hex'][10];
            data['message_flags_details'] = getMessageFlags(data['dec'][8]);
            break;
        case 'Send INSTEON Standard or Extended Message':
            data['to'] = data['hex'].slice(2,5);
            data['message_flags'] = data['hex'][5];
            data['command1'] = data['hex'][6];
            data['command2'] = data['hex'][7];
            if(data['hex'].length == 9) { // standard
                data['ack_nak'] = data['hex'][8];
            } else if(data['hex'].length == 23) { // extended
                data['user_data'] = data['hex'].slice(8,22);
                data['ack_nak'] = data['hex'][22];
            } else {
                throw('insteonjs: standard or extended messages is invalid');
            }
            break;
        case 'Get IM Configuration':
            data['config_flags'] = data['hex'][2];
            data['ack_nak'] = data['hex'][5];
            break;
        case 'Set IM Configuration':
            data['config_flags'] = data['hex'][2];
            data['ack_nak'] = data['hex'][3];
            break;
        case 'Get First ALL-Link Record':
            data['ack_nak'] = data['hex'][2];
            break;
        case 'Get Next ALL-Link Record':
            data['ack_nak'] = data['hex'][2];
            break;
        case 'Start ALL-Linking':
            data['link_code'] = data['hex'][2];
            data['all_link_group'] = data['hex'][3];
            data['ack_nak'] = data['hex'][4];
            break;
        case 'Cancel ALL-Linking':
            data['ack_nak'] = data['hex'][2];
            break;
        case 'ALL-Link Record Response':
            data['record_flags'] = data['hex'][2];
            data['link_group'] = data['hex'][3];
            data['deviceid'] = data['hex'].slice(4,7);
            data['data1'] = data['hex'][7];
            data['data2'] = data['hex'][8];
            data['data3'] = data['hex'][9];
            break;
        case 'Send ALL-Link Command':
            data['all_link_group'] = data['hex'][2];
            data['all_link_command'] = data['hex'][3];
            data['broadcast_cmd2'] = data['hex'][4];
            break;
        case 'ALL-Linking Completed':
            data['link_code'] = data['hex'][2];
            data['link_group'] = data['hex'][3];
            data['device_id'] = data['hex'].slice(4,7);
            data['device_cat'] = data['hex'][7];
            data['device_subcat'] = data['hex'][8];
            data['device_firmware'] = data['hex'][9];
            break;
        case 'Reset the IM':
            data['ack_nak'] = data['hex'][2];
            break;
        default:
            data['error'] = 'Unrecognized command or command not implemented';
            if(byteArray[0] == config.INSTEON_PLM_NAK) data['error'] = 'PLM NAK received (buffer overrun)';
            break;
    }
    return data;
};