Persist password (#393)

* never hold the owner of the room on the waiting screen

* persist room passwords so we can always call create meeting, even if it's already running, to avoid any inconsistency or race condition when joining a meeting

* Fixed issues in migration, room attribute updates, random_password and tests

app/models/room.rb

@@ -51,19 +51,20 @@ class Room < ApplicationRecord
     create_options = {
       record: options[:meeting_recorded].to_s,
       logoutURL: options[:meeting_logout_url] || '',
-      moderatorPW: random_password(12),
-      attendeePW: random_password(12),
+      moderatorPW: moderator_pw,
+      attendeePW: attendee_pw,
       moderatorOnlyMessage: options[:moderator_message],
       muteOnStart: options[:mute_on_start] || false,
       "meta_#{META_LISTED}": false,
     }
 
-    # Update session info.
-    update_attributes(sessions: sessions + 1, last_session: DateTime.now)
-
     # Send the create request.
     begin
-      bbb.create_meeting(name, bbb_id, create_options)
+      meeting = bbb.create_meeting(name, bbb_id, create_options)
+      # Update session info.
+      unless meeting[:messageKey] == 'duplicateWarning'
+        update_attributes(sessions: sessions + 1, last_session: DateTime.now)
+      end
     rescue BigBlueButton::BigBlueButtonException => exc
       puts "BigBlueButton failed on create: #{exc.key}: #{exc.message}"
       raise exc
@@ -72,8 +73,8 @@ class Room < ApplicationRecord
 
   # Returns a URL to join a user into a meeting.
   def join_path(name, options = {}, uid = nil)
-    # Create the meeting if it isn't running.
-    start_session(options) unless running?
+    # Create the meeting, even if it's running
+    start_session(options)
 
     # Set meeting options.
     options[:meeting_logout_url] ||= nil
@@ -145,6 +146,8 @@ class Room < ApplicationRecord
   def setup
     self.uid = random_room_uid
     self.bbb_id = Digest::SHA1.hexdigest(Rails.application.secrets[:secret_key_base] + Time.now.to_i.to_s).to_s
+    self.moderator_pw = RandomPassword.generate(length: 12)
+    self.attendee_pw = RandomPassword.generate(length: 12)
   end
 
   # Deletes all recordings associated with the room.
@@ -163,10 +166,4 @@ class Room < ApplicationRecord
   def random_room_uid
     [owner.name_chunk, uid_chunk, uid_chunk].join('-').downcase
   end
-
-  # Generates a random password for a meeting.
-  def random_password(length)
-    charset = ("a".."z").to_a + ("A".."Z").to_a
-    ((0...length).map { charset[rand(charset.length)] }).join
-  end
 end