remember me, password reset

app/models/user.rb

@@ -27,6 +27,8 @@ class User < ApplicationRecord
 
   # Invitation token expires after 14 days
   INVITATION_TOKEN_EXPIRY = 14.days
+  # Remember me token expires after 2 weeks
+  REMEMBER_TOKEN_EXPIRY = 2.weeks
 
   def invitation_expired?
     return false if invitation_sent_at.nil?
@@ -37,10 +39,43 @@ class User < ApplicationRecord
     invitation_token.present? && invitation_accepted_at.nil? && !invitation_expired?
   end
 
+  def invite_by(invitee)
+    self.invited_by = invitee if invitee && invited_by.nil?
+    self.invitation_token = SecureRandom.urlsafe_base64(32)
+    self.invitation_sent_at = Time.current
+  end
+
+  def invite_by!(invitee = nil)
+    invite_by(invitee)
+    save!
+  end
+
   def self.find_by_valid_invitation_token(token)
     where(invitation_token: token)
       .where(invitation_accepted_at: nil)
       .where("invitation_sent_at > ?", INVITATION_TOKEN_EXPIRY.ago)
       .first
   end
+
+  def remember_me
+    self.remember_token = SecureRandom.urlsafe_base64(32)
+    self.remember_created_at = Time.current
+    save(validate: false)
+    remember_token
+  end
+
+  def forget_me
+    update_columns(remember_token: nil, remember_created_at: nil)
+  end
+
+  def remember_token_expired?
+    return true if remember_created_at.nil?
+    remember_created_at < REMEMBER_TOKEN_EXPIRY.ago
+  end
+
+  def self.find_by_valid_remember_token(token)
+    user = find_by(remember_token: token)
+    return nil if user.nil? || user.remember_token_expired?
+    user
+  end
 end