ep_email_notifications/update.js

// Main job is to check pads periodically for activity and notify owners when someone begins editing and when someone finishes.
 var  db = require('../../src/node/db/DB').db,
     API = require('../../src/node/db/API.js'),
   async = require('../../src/node_modules/async'),
   check = require('validator').check,
   email = require('emailjs'),
settings = require('../../src/node/utils/Settings');

// Settings -- EDIT THESE IN settings.json not here..
var pluginSettings = settings.ep_email_notifications;
var checkFrequency = pluginSettings.checkFrequency || 60000; // 10 seconds
var staleTime = pluginSettings.staleTime || 300000; // 5 minutes
var fromName = pluginSettings.fromName || "Etherpad";
var fromEmail = pluginSettings.fromEmail || "pad@etherpad.org";
var urlToPads = pluginSettings.urlToPads || "http://beta.etherpad.org/p/";
var emailServer = pluginSettings.emailServer || {host:"127.0.0.1"};

// A timer object we maintain to control how we send emails
var timers = {};

// Connect to the email server -- This might not be the ideal place to connect but it stops us having lots of connections 
var server  = email.server.connect(emailServer);

exports.padUpdate = function (hook_name, _pad) {
  var pad = _pad.pad;
  var padId = pad.id;
  exports.sendUpdates(padId);

  // does an interval not exist for this pad?
  if(!timers[padId]){
    console.debug("Someone started editing "+padId);
    exports.notifyBegin(padId);
    console.debug("Created an interval time check for "+padId);
    // if not then create one and write it to the timers object
    timers[padId] = exports.createInterval(padId, checkFrequency); 
  }else{ // an interval already exists so don't create

  }
};

exports.notifyBegin = function(padId){
  console.debug("Getting pad email stuff for "+padId);
  db.get("emailSubscription:" + padId, function(err, recipients){ // get everyone we need to email
    if(recipients){
      async.forEach(Object.keys(recipients), function(recipient, cb){
        // Is this recipient already on the pad?
        exports.isUserEditingPad(padId, recipients[recipient].authorId, function(err,userIsOnPad){ // is the user already on the pad?
          if(!userIsOnPad){ 
            console.debug("Emailing "+recipient +" about a new begin update");
            server.send({
              text:    "Your pad at "+urlToPads+padId +" is being edited, we're just emailing you let you know :)\n\n -- This plugin is in alpha state, can you help fund it's development? https://github.com/johnmclear/ep_email_notifications", 
              from:    fromName+ "<"+fromEmail+">", 
              to:      recipient,
              subject: "Someone started editing "+padId
            }, function(err, message) { console.log(err || message); });
          }
          else{
            console.debug("Didn't send an email because user is already on the pad");
          }
        });
        cb(); // finish each user
      },
      function(err){
        // do some error handling..
      });
    }
  });
}

exports.notifyEnd = function(padId){
  // get the modified contents...
  var changesToPad = "Functionality does not exist";

  db.get("emailSubscription:" + padId, function(err, recipients){ // get everyone we need to email
    if(recipients){
      async.forEach(Object.keys(recipients), function(recipient, cb){
        // Is this recipient already on the pad?
        exports.isUserEditingPad(padId, recipients[recipient].authorId, function(err,userIsOnPad){ // is the user already on the$
          if(!userIsOnPad){
            console.debug("Emailing "+recipient +" about a pad finished being updated");
            server.send({
              text:    "Your pad at "+urlToPads+padId +" has finished being edited, we're just emailing you let you know :) \n\n  The changes look like this: \n" + changesToPad,
              from:    fromName+ "<"+fromEmail+">",
              to:      recipient,
              subject: "Someone finished editing "+padId
            }, function(err, message) { console.log(err || message); });
          }
          else{
            console.debug("Didn't send an email because user is already on the pad");
          }
        });
        cb(); // finish each user
      },
      function(err){
        // do some error handling..
      });
    }
  });
}

exports.sendUpdates = function(padId){
  // check to see if we can delete this interval
  API.getLastEdited(padId, function(callback, message){
    // we delete an interval if a pad hasn't been edited in X seconds.
    var currTS = new Date().getTime();
    if(currTS - message.lastEdited > staleTime){
      exports.notifyEnd(padId);
      console.warn("Interval went stale so deleting it from object and timer");
      var interval = timers[padId];
      clearInterval(timers[padId]); // remove the interval timer
      delete timers[padId]; // remove the entry from the padId
    }else{
      console.debug("email timeout not stale so not deleting");
    }
  });
  // The status of the users relationship with the pad -- IE if it's subscribed to this pad / if it's already on the pad
  // This comes frmo the database
  var userStatus = {}; // I'm not even sure we use this value..  I put it here when drunk or something
}


// Is the user editing the pad?
exports.isUserEditingPad = function(padId, user, cb){
  API.padUsers(padId, function(callback, padUsers){ // get the current users editing the pad
    var userIsEditing = false;
    console.debug("Current Pad Users:"+padUsers);
    // for each user on the pad right now
    async.forEach(padUsers.padUsers,
      function(userOnPad, callback){
        if(userOnPad.id == user){
          console.debug("User is on the pad so don't send any notification");
          userIsEditing = true; // If the user is editing the pad then return true
        }else{
          userIsEditing = false; // If the user isnt on this pad then that'd be okay to contact em
        }
        callback(userIsEditing);

      },
      function(err){
        cb(null, userIsEditing);
      });
   });
};

// Creates an interval process to check to send Updates based on checkFrequency and it returns an ID
exports.createInterval = function(padId){
  return setInterval(function(){
    exports.sendUpdates(padId), checkFrequency
  });
}