gcalendar@obindo.com

Written by Alex

Extract meetings and events from any email and save them to Google Calendar.

/**************************
Documentation Links/Description:
API References : https://developers.google.com/google-apps/calendar/v3/reference/
               : https://developers.google.com/google-apps/calendar/
Insert Event   : https://developers.google.com/google-apps/calendar/v3/reference/events/insert
Insert Sandbox : https://developers.google.com/google-apps/calendar/v3/reference/events/insert#try-it
OAuth2 Agent   : https://developers.google.com/accounts/docs/OAuth2UserAgent
Refresh Token  : https://developers.google.com/accounts/docs/OAuth2WebServer#refresh

Must obtain the API Key from creating a Server Key on the Google API Console 
      and inputting IP address 0.0.0.0/0 as the allowed IP address.
Make sure to activate the CalendarAPI on the Google API Console.
**************************/
 
var oauth2Credentials = {};

//#region PRIVATE set my oauth2 credentials

var requestUrl = 'https://accounts.google.com/o/oauth2/auth?';
var scopeUrl = 'https://www.googleapis.com/auth/calendar';
var tokenUrl = 'https://accounts.google.com/o/oauth2/token';
var apiRoot = 'https://www.googleapis.com/calendar/v3'; 
var calendarListRoot = 'https://www.googleapis.com/calendar/v3/users/me/calendarList?key=' + oauth2Credentials.apiKey;

var maxDescriptionLength= 7500;

oauth2.getAuthRedirectUrl= function() {
  
    var args= { scope: scopeUrl,
                state: tokens.getId(),
                response_type: 'code',
                client_id: oauth2Credentials.clientID,
                redirect_uri: oauth2.getCallbackUrl(true),
                access_type: 'offline',
                approval_prompt: 'auto'
              };
  
    //send off the request for a 'code'
    return requestUrl + util.getQueryArgsFromObject(args);
}

oauth2.onAuthResponse= function(q) {
    var qArgs= util.getObjectFromQueryArgs(q);

var args= { grant_type: 'authorization_code',
                client_id: oauth2Credentials.clientID,
                client_secret: oauth2Credentials.clientSecret,
                redirect_uri: oauth2.getCallbackUrl(true),
                code: qArgs.code 
              };  
  
    //requrest to exchange the code for an access token
    var response = post({url: tokenUrl, args: args});
    
    tokens.loadFromId(qArgs.state);
    tokens.accessToken= util.jsonify(response.text); 
}

oauth2.refreshAccessToken= function() {
    var rt= tokens.accessToken.refresh_token;
  
    var args= { grant_type: "refresh_token",
                refresh_token: rt,
                client_id: oauth2Credentials.clientID,
                client_secret: oauth2Credentials.clientSecret };
  
    var response= post({url: tokenUrl, args: args});

var newToken= util.jsonify(response.text);
    newToken.refresh_token = rt;
    tokens.accessToken = newToken;

}

function getAuthHeader() { 
  return { "Authorization": 'Bearer ' + tokens.accessToken.access_token }; 
}

function getCalendarId() {
  var response = get({url: calendarListRoot, header: getAuthHeader() });
  var calendars = util.jsonify(response.text).items;

for (var i = 0; i < calendars.length; i++)
    if (calendars[i].primary == true)
  	  return calendars[i].id;
  
  return null;
}

var oneHour= 1000 * 60 * 60;
var oneDay= oneHour * 24;

function getDateText(ms, includeTime) {
    var dt= new Date(ms);
  
    var s= dt.getUTCFullYear() + '-';
    s+= addLeading(dt.getUTCMonth() + 1) + '-';
    s+= addLeading(dt.getUTCDate());
  
    if (!includeTime)
       return s;

s+= 'T' + addLeading(dt.getUTCHours()) + ':';
    s+= addLeading(dt.getUTCMinutes()) + ':';
    s+= addLeading(dt.getUTCSeconds()) + '+00:00';
  return s;
  
  function addLeading(n) { return (n < 10) ? '0' + n : '' + n; }
}

function truncate(text, length) {
  if (text.length < length)
     return text;
  
  var s= text.substring(0, length);
  var i= s.lastIndexOf(' ');
  
  return (i > 0) ? s.substring(0,i) : s;
}

function getDescription(text) {
  var s= truncate(text, maxDescriptionLength);   
  var footer= '-- This Google Calendar event was created automatically by emailing googlecal@obindo.com. ';
  footer+= 'Learn more at http://obindo.com.';  
  
  return (s && s.length > 0) ? s + '\n\n' + footer : footer;
}

function sendConfirm(email, events, existingEvents, attendees, success) {
  var existingOnly= (existingEvents.length > 0 && events.length == 0);  
  var attendeesExist= (attendees.length > 0);
  var bWriteUrls= ((events.length + existingEvents.length) > 1);
  var subject= (existingOnly) ? 'Obindo found similar events already in your Google Calendar!' 
                              : 'Obindo created a Google Calendar event for you!';
  var sAttend= getAttendeeDisplay();
  
  var s= getHeader();    
  s+= getEventsDisplay((existingOnly) ? existingEvents : events);
  s+= getAttendeeFooter(existingOnly);
  
  if (!existingOnly && existingEvents.length > 0) {
     var plural= (existingEvents.length > 1);
     s+= '\n\nWe also found ' + ((plural) ? 'these events' : 'this event');
     s+= ' that already '+ ((plural) ? 'exist and look' : 'exists and looks') +' similar.';
     s+= ' In order to avoid possibly sending out multiple invitations';
     s+= ' for the same event, we didn\'t make any changes to ' + ((plural) ? 'them.' : 'it.');
     s+= getEventsDisplay(existingEvents);
     s+= getAttendeeFooter(true);
  }

s+= '\n\nThanks for using Obindo!'; 
  var emailArgs= { to: email, subject: subject, text: s, 
                   templateFields: { recipientName: message.from.name } };

if (message.appUrl) {
    emailArgs.templateFields.buttonText= 'View in Google Calendar';
    emailArgs.templateFields.buttonLink= message.appUrl;
  }

sendEmail(emailArgs);  
  
  function getHeader() {
    var s= '';
    
    if (!success) {
      s= 'Sorry we couldn\'t figure out exactly when you wanted this date set up for you, ';
      s+= ' but we created it and all you\'ll have to do is update the date if necessary.';
    } else if (existingOnly) {
      var plural= (existingEvents.length > 1);
      s+= 'We found ' + ((plural) ? 'these events' : 'this event');
      s+= ' that already '+ ((plural) ? 'exist and look' : 'exists and looks') +' similar.';
      s+= ' In order to avoid possibly sending out multiple invitations';
      s+= ' for the same event, we didn\'t make any changes to ' + ((plural) ? 'them.' : 'it.'); 
    } else {
       s= 'We created the following event' + ((events.length == 1) ? '' : 's') + ' for you:';
    }
    
    return s;
  }
  
  function getAttendeeDisplay() {
    if (!attendeesExist)
       return '';
    
    var s= '';
    
    for (var i=0; i < attendees.length; i++) {
       if (i > 0) s+= ', ';
       s+= (attendees[i].displayName) ? attendees[i].displayName : attendees[i].email;
    }
    
    return s;
  }
  
  function getAttendeeFooter(existing) {
    if (!attendeesExist)
       return '';
    if (!success)
       return '\n\nBecause we weren\'t certain of the date, invitations were not sent to the attendees.';
    if (existing)
       return '\n\nYour attendees were not sent any additional invitations.';
    
    return '\n\nYour attendees will be sent an invitation from Google Calendar.';
  }
  
  function getEventsDisplay(events) {
    var s= '';
    
    for (var i=0; i < events.length; i++) {
       var event= events[i];
    
       s+= '\n\nTitle: ' + event.summary;
       s+= '\nStart: ' + getFriendlyDate(event.start);
       s+= '\nEnd: ' + getFriendlyDate(event.end);
    
       if (sAttend.length > 0)
         s+= '\nAttendees: ' + sAttend;    
       if (bWriteUrls)
         s+= '\n' + event.htmlLink;
    }
    
    return s;
  }
}