Initial release of Discourse

app/models/invite.rb

@@ -0,0 +1,87 @@
+class Invite < ActiveRecord::Base
+  
+  belongs_to :user
+  belongs_to :topic
+  belongs_to :invited_by, class_name: User
+
+  has_many :topic_invites
+  has_many :topics, through: :topic_invites, source: :topic  
+  validates_presence_of :email
+  validates_presence_of :invited_by_id
+
+  acts_as_paranoid
+  
+
+  before_create do
+    self.invite_key ||= SecureRandom.hex
+  end
+
+  before_save do
+    self.email = self.email.downcase
+  end
+
+  validate :user_doesnt_already_exist
+  attr_accessor :email_already_exists
+  
+  def user_doesnt_already_exist
+    @email_already_exists = false
+    return if email.blank?
+    if User.where("lower(email) = ?", email.downcase).exists?  
+      @email_already_exists = true
+      errors.add(:email)
+    end
+  end
+
+  def redeemed?
+    redeemed_at.present?
+  end
+
+  def expired?
+    created_at < SiteSetting.invite_expiry_days.days.ago
+  end
+
+  def redeem
+    result = nil
+    Invite.transaction do
+      # Avoid a race condition
+      row_count = Invite.update_all('redeemed_at = CURRENT_TIMESTAMP', 
+                                    ['id = ? AND redeemed_at IS NULL AND created_at >= ?', self.id, SiteSetting.invite_expiry_days.days.ago])
+
+      if row_count == 1
+
+        # Create the user if we are redeeming the invite and the user doesn't exist
+        result = User.where(email: email).first
+        result = User.create_for_email(email, trust_level: SiteSetting.default_invitee_trust_level) if result.blank?
+        result.send_welcome_message = false
+        
+        # If there are topic invites for private topics
+        topics.private_messages.each do |t|
+          t.topic_allowed_users.create(user_id: result.id)
+        end
+
+        # Check for other invites by the same email. Don't redeem them, but approve their 
+        # topics.
+        Invite.where('invites.email = ? and invites.id != ?', self.email, self.id).includes(:topics).where('topics.archetype = ?', Archetype::private_message).each do |i|
+          i.topics.each do |t|
+            t.topic_allowed_users.create(user_id: result.id)
+          end
+        end
+
+        if Invite.update_all(['user_id = ?', result.id], ['email = ?', self.email]) == 1
+          result.send_welcome_message = true
+        end
+
+          # Notify the invitee
+          invited_by.notifications.create(notification_type: Notification.Types[:invitee_accepted], 
+                                          data: {display_username: result.username}.to_json)
+
+      else
+        # Otherwise return the existing user
+        result = User.where(email: email).first
+      end
+    end    
+
+    result
+  end
+
+end