Use sorcery for logins

This gives us more flexibility and allows us to use password authentication
later. Also we don't need to build the login functionality ourself.

app/assets/stylesheets/application.css.scss

@@ -37,4 +37,9 @@ $light: #fff;
 
 body {
   min-height: 100vh;
+}
+
+.button.google {
+  background: rgb(225, 98, 89);
+  color: white;
 }

app/controllers/oauths_controller.rb

@@ -0,0 +1,34 @@
+class OauthsController < ApplicationController
+
+  # Sends the user on a trip to the provider,
+  # and after authorizing there back to the callback url.
+  def oauth
+    login_at(params[:provider])
+  end
+
+  def callback
+    provider = params[:provider]
+    if @user = login_from(provider)
+      redirect_to root_path, :notice => "Logged in from #{provider.titleize}!"
+    else
+      begin
+        @user = create_from(provider)
+        if authentication = @user.authentications.find_by(provider: provider)
+          authentication.update({
+            access_token: @access_token.token,
+            refresh_token: @access_token.refresh_token,
+            expires_at: Time.at(@access_token.expires_at)
+          })
+        end
+
+        reset_session
+        auto_login(@user)
+        redirect_to root_path, :notice => "Logged in from #{provider.titleize}!"
+      rescue
+        Rails.logger.error("Failed to login from #{provider}")
+        redirect_to root_path, :alert => "Failed to login from #{provider.titleize}!"
+      end
+    end
+  end
+
+end

app/controllers/sessions_controller.rb

@@ -1,29 +1,7 @@
-require 'google/apis/oauth2_v2'
 class SessionsController < ApplicationController
 
   def new
     reset_session
-    redirect_to auth_client.authorization_uri.to_s
-  end
-
-  def auth
-    reset_session
-    if params[:error]
-      flash[:error] = 'Login failed'
-      redirect_to root_url
-    else
-      auth_client.code = params[:code]
-      auth_client.fetch_access_token!
-
-      @user, @authentication = User.find_by_oauth_info(auth_client)
-      if @user.persisted? && @authentication.persisted?
-        session[:user_id] = @user.id.to_s
-        redirect_to forms_url
-      else
-        flash[:error] = 'Login failed'
-        redirect_to root_url
-      end
-    end
   end
 
   def destroy
@@ -31,18 +9,4 @@ class SessionsController < ApplicationController
     redirect_to root_url
   end
 
-  private
-
-  def auth_client
-    @auth_client ||= CLIENT_SECRETS.to_authorization.tap do |c|
-      c.update!(
-        scope: 'https://www.googleapis.com/auth/userinfo.email https://www.googleapis.com/auth/userinfo.profile https://www.googleapis.com/auth/spreadsheets',
-        redirect_uri: auth_url,
-        additional_parameters: {
-          'access_type' => 'offline',         # offline access
-          'include_granted_scopes' => 'true'  # incremental auth
-        }
-      )
-    end
-  end
 end

app/models/authentication.rb

@@ -1,6 +1,8 @@
 class Authentication < ApplicationRecord
   belongs_to :user
 
+  scope :for, -> (provider) { where(provider: provider) }
+
   encrypts :access_token
   encrypts :refresh_token
 
@@ -9,6 +11,7 @@ class Authentication < ApplicationRecord
   end
 
   def google_authorization
+    return nil unless provider == 'google'
     @google_authorization ||= CLIENT_SECRETS.to_authorization.tap do |c|
       c.access_token = self.access_token
       c.refresh_token = self.refresh_token

app/models/user.rb

@@ -1,40 +1,18 @@
 class User < ApplicationRecord
+  authenticates_with_sorcery!
   has_many :authentications, dependent: :destroy
   has_many :forms, dependent: :destroy
 
-  def self.find_by_oauth_info(auth_client)
-    oauth = Google::Apis::Oauth2V2::Oauth2Service.new
-    oauth.authorization = auth_client
-    user_info = oauth.get_userinfo
-
-    if user = User.find_by(google_id: user_info.id)
-      authentication = user.authentications.last
-      authentication.access_token = auth_client.access_token if auth_client.access_token.present?
-      authentication.refresh_token = auth_client.refresh_token if auth_client.refresh_token.present?
-      authentication.expires_at = Time.at(auth_client.expires_at) if auth_client.expires_at.present?
-      authentication.save
-      return user, authentication
-    else
-      user = User.create(name: user_info.name, email: user_info.email, google_id: user_info.id)
-      authentication = user.authentications.create(
-        access_token: auth_client.access_token,
-        refresh_token: auth_client.refresh_token,
-        expires_at: Time.at(auth_client.expires_at)
-      )
-      return user, authentication
-    end
-  end
-
   def deactivate!(reason = nil)
     # currently we only use deactivate if we get an authentication exception appending data to a spreadsheet
     authentications.last&.update(expires_at: Time.current)
   end
 
   def active?
-    authentications.last.present? && !authentications.last.expired?
+    authentications.any? { |a| !a.expired? }
   end
 
   def google_authorization
-    authentications.last.google_authorization
+    authentications.for(:google).last.google_authorization
   end
 end

app/views/sessions/new.html.erb

@@ -0,0 +1,22 @@
+<div class="columns">
+  <div class="column">
+  </div>
+  <div class="column">
+    <div class="container has-text-centered">
+      <h1 class="title has-text-centered">
+        Login
+      </h1>
+      <div class="button google">
+        <svg viewBox="0 0 15 15" class="googleLogo" style="width: 14px; height: 14px; display: block; fill: currentcolor; flex-shrink: 0; backface-visibility: hidden; margin-right: 6px;"><path d="M 7.28571 6.4125L 7.28571 9L 11.3929 9C 11.2143 10.0875 10.1429 12.225 7.28571 12.225C 4.78571 12.225 2.78571 10.0875 2.78571 7.5C 2.78571 4.9125 4.82143 2.775 7.28571 2.775C 8.71429 2.775 9.64286 3.4125 10.1786 3.9375L 12.1429 1.9875C 10.8929 0.75 9.25 0 7.28571 0C 3.25 0 0 3.3375 0 7.5C 0 11.6625 3.25 15 7.28571 15C 11.5 15 14.25 11.9625 14.25 7.6875C 14.25 7.2 14.2143 6.825 14.1429 6.45L 7.28571 6.45L 7.28571 6.4125Z"></path></svg>
+        Login with Google
+      </div>
+      <hr>
+      <p>
+        As tinyforms builds on Google Sheets.<br>
+        Simply login with your Google account.
+      </p>
+    </div>
+  </div>
+  <div class="column">
+  </div>
+</div>