var path = require('path');
var _ = require('underscore');
// We only need `fork()` to create new processes
var fork = require('child_process').fork;

var ProcessManager = function() {
  this.children = [];
  this.routes = [];
};

// Fork a module and add it to the children list
// @modulePath Path of the module relative to the root directory
ProcessManager.prototype.fork = function(modulePath) {
  var self = this;
  modulePath = require.resolve(path.join(process.env.PWD, modulePath));
  moduleName = path.basename(modulePath, '.js');
  var child = this.getChild(moduleName);
  if (!child) {
    child = fork(modulePath);
    // Add module metadata
    child.modulePath = modulePath;
    child.moduleName = moduleName;
    // Listen to messages from child
    child.on('message', function(data) {
      self.handleMessage(data, child);
    });
    this.children.push(child);
  }
  return child;
};

// Get child process from module name
ProcessManager.prototype.getChild = function(moduleName) {
  return _.findWhere(this.children, {moduleName: moduleName});
};

// Handle different types of messages
ProcessManager.prototype.handleMessage = function(data, child) {
  switch (data.event) {
    case 'register':
      this.registerRoute(data, child);
      break;
    default:
      this.forwardMessage(data, child);
      break;
  }
};

// Add route to map
ProcessManager.prototype.registerRoute = function(options, child) {
  var self = this;
  var emitter = this.getChild(options.emitterModule);
  options.listenerModule = child.moduleName;
  options.events.forEach(function(event) {
    var route = _.extend(_.omit(options, 'events'), {registeredEvent: event});
    // Avoid duplicate routes
    if (!_.findWhere(self.routes, route)) {
      self.routes.push(route);
      // Forward route information to outgoing emitter
      if (emitter && route.event === 'register') emitter.send(route);
    }
  });
};

// Forward message from a child process to another child process
ProcessManager.prototype.forwardMessage = function(data, emitterChild) {
  var self = this;
  var routes = _.where(this.routes, {emitterModule: emitterChild.moduleName, registeredEvent: data.event});
  routes.forEach(function(route) {
    var listeningChild = self.getChild(route.listenerModule);
    // When forwarding a 'pong' response, send 'ping' to the recipient to get
    // 'pong' back and complete the forward ping-pong cycle between two modules
    if (data.event === 'pong' && listeningChild.moduleName !== emitterChild.moduleName) data = 'ping';
    if (listeningChild) listeningChild.send(data);
  });
  // Emit same event in the parent process. This is used for within-process
  // communication in case we are running in a single process.
  emitterChild.emit(data.event, data);
};

module.exports = new ProcessManager();

@@ -379,21 +379,23 @@
 unction(
-modul
+relativ
 ePath) %7B
@@ -416,21 +416,23 @@
 this;%0A  
-modul
+absolut
 ePath = 
@@ -474,21 +474,23 @@
 nv.PWD, 
-modul
+relativ
 ePath));
@@ -519,21 +519,23 @@
 asename(
-modul
+absolut
 ePath, '
@@ -615,21 +615,23 @@
  = fork(
-modul
+absolut
 ePath);%0A
@@ -671,21 +671,23 @@
 ild.
-modul
+relativ
 ePath = 
 modu
@@ -682,21 +682,62 @@
 ePath = 
-modul
+relativePath;%0A    child.absolutePath = absolut
 ePath;%0A 
@@ -903,215 +903,828 @@
     
-this.children.push(child);%0A  %7D%0A  return child;%0A%7D;%0A%0A// Get child process from module name%0AProcessManager.prototype.getChild = function(moduleName) %7B%0A  return _.findWhere(this.children, %7BmoduleName: moduleName
+// Monitor child and re-spawn if necessary%0A    child.on('exit', function(code, signal) %7B%0A      self.removeChild(child.moduleName);%0A      self.fork(child.relativePath);%0A    %7D);%0A    child.on('error', function(err) %7B%0A      if (!child.connected) %7B%0A        self.removeChild(child.moduleName);%0A        self.fork(child.relativePath);%0A      %7D%0A    %7D);%0A    this.children.push(child);%0A  %7D%0A  return child;%0A%7D;%0A%0A// Get child process from module name%0AProcessManager.prototype.getChild = function(moduleName) %7B%0A  return _.findWhere(this.children, %7BmoduleName: moduleName%7D);%0A%7D;%0A%0A// Remove child process from process list%0AProcessManager.prototype.removeChild = function(moduleName) %7B%0A  var self = this;%0A  _.each(this.children, function(child, index) %7B%0A    if (child.moduleName === moduleName) %7B%0A      delete self.children%5Bindex%5D;%0A    %7D%0A  
 %7D);%0A

Monitor child processes and respawn as necessary.