sage-fifty/bridge.js

Interact with Sage50 Accounts

var sageAccessQueue = require('./access-queue');
var Promise = require('bluebird');
var retry = require('bluebird-retry');
var child_process = require('child_process');
var path = require('path');
var _ = require('lodash');
var debug = require('debug')('sage-fifty:bridge');

var bridgeExe = path.resolve(__dirname, "./bin/sage50-bridge.exe");


module.exports = Promise.method(function Bridge(options, onprogress){

    function tryBridge() {

    	onprogress = onprogress || (function(){});

    	// queue will ensure we won't conflict with other apps on the same accdata/username
    	return sageAccessQueue(options.accdata, options.username)(function(){

    		debug("Spawning", bridgeExe, "with params", options);
    		var cp = child_process.spawn(bridgeExe, ["--pipe"], {stdio: 'pipe', windowsHide: true});

    		return new Promise(function(resolve, reject){

    			// provide program input
    			cp.stdin.write(JSON.stringify(options));
    			cp.stdin.end();

    			// store program output
    			var dataBuffer = "";

    			function parseJSONOut(js){
    				if (!js || !js.type) {
    					reject(Error("Invalid JSON response"));
    				}

    				switch (js.type) {
    					case 'progress':
    						debug("->progress", js.activity, js.current +"/"+ js.total);
    						onprogress(js.activity, js.current, js.total);
    						break;
    					case 'error':
    						debug("->error", js.message);
    						reject(Error(js.message));
    						break;
    					case 'data':
    						debug("->data");
    						resolve(js.data);
    						break;
    				}
    			}

    			function readOutput(){
    				var lines = dataBuffer.split("\x00");

    				while (lines.length) {
    					var line = lines.shift();
    					try {
    						parseJSONOut(JSON.parse(line));
    					} catch (x) {
    						if (lines.length > 0) {
    							// this line didn't parse and we have more queued up that need parsing?
    							reject(Error("Bridge data parse error"));
    						} else {
    							// if this was the last line, we can expect that it might be incomplete
    							dataBuffer = line;
    						}
    					}
    				}
    			}


    			cp.stdout.on('data', function(data){
    				dataBuffer += data;
    				readOutput();
    			});

    			var onerror = function(err){
    				reject(err);
    				removelisteners();
    			};

    			var onexit = function(code){
    				reject(Error("Premature exit: "+code));
    				removelisteners();
    			};

    			function removelisteners(){
    				cp.stdout.removeAllListeners();
    				cp.removeListener('error', onerror);
    				cp.removeListener('exit', onexit);
    			};

    			cp.on('error', onerror);
    			cp.on('exit', onexit);


    		});

    	});
    }

    return retry(tryBridge, {max_tries: 10, interval: 500, backoff: 1000, max_interval: 5000});

});