Fix users sign in

Email should be optional. Some social networks do not provide an email address.

Issue: #171

app/models/user.rb

@@ -24,10 +24,9 @@ class User < ApplicationRecord
 
   phony_normalize :phone, as: :normalized_phone, default_country_code: "RU"
 
-  validates :phone, presence: true, if: :sms_reminders?
-  validates :email, presence: true, uniqueness: { case_sensitive: false }
+  validates :phone, presence: true, phony_plausible: { country_code: "RU" }, if: :sms_reminders?
+  validates :email, uniqueness: { allow_blank: true, case_sensitive: false }
   validates :role, presence: true
-  validates_plausible_phone :phone, country_code: "RU"
 
   before_save :nullify_empty_email
   before_save :downcase_email
@@ -45,26 +44,24 @@ class User < ApplicationRecord
   scope :developers, -> { joins(:groups).where("groups.kind = 1") }
 
   def self.from_omniauth!(auth)
-    social = SocialAccount.includes(:user).find_or_initialize_by(uid: auth.uid, provider: auth.provider)
+    auth_info = auth.info
+    user = User.find_or_initialize_by(email: auth_info.email)
+
+    if user.new_record?
+      user.email = auth_info.email
+      user.name = auth_info.name
+      user.first_name = auth_info.first_name
+      user.last_name = auth_info.last_name
+      user.remote_avatar_url = avatar_from_auth(auth)
+    end
 
+    social = SocialAccount.includes(:user).find_or_initialize_by(uid: auth.uid, provider: auth.provider)
     if social.new_record?
       social.link = SocialAccount.link_for(auth)
-      social.save
+      user.social_accounts << social
     end
 
-    auth_info = auth.info
-    user = User.find_by(email: auth_info.email)
-
-    unless user.present?
-      user = social.build_user do |user|
-        user.email = auth_info.email
-        user.name = auth_info.name
-        user.first_name = auth_info.first_name
-        user.last_name = auth_info.last_name
-        user.remote_avatar_url = avatar_from_auth(auth)
-      end
-      user.save
-    end
+    user.save
     user
   end