Done

.gitignore

@@ -1,3 +1,5 @@
 *.sqlite3
 *.log
-tmp/Gemfile.lock
+tmp/Gemfile.lock
+FACEBOOK_KEY=
+FACEBOOK_SECRET=

Gemfile

@@ -12,7 +12,9 @@ gem 'uglifier', '>= 1.3.0'
 gem 'coffee-rails', '~> 4.1.0'
 # See https://github.com/rails/execjs#readme for more supported runtimes
 # gem 'therubyracer', platforms: :ruby
-
+gem 'omniauth'
+gem 'omniauth-facebook'
+gem 'dotenv-rails'
 gem 'thin'
 
 # Use jquery as the JavaScript library

Gemfile.lock

@@ -52,18 +52,26 @@ GEM
     concurrent-ruby (1.1.5)
     crass (1.0.5)
     daemons (1.3.1)
+    dotenv (2.7.5)
+    dotenv-rails (2.7.5)
+      dotenv (= 2.7.5)
+      railties (>= 3.2, < 6.1)
     erubis (2.7.0)
     eventmachine (1.2.7)
     execjs (2.7.0)
+    faraday (1.0.1)
+      multipart-post (>= 1.2, < 3)
     ffi (1.11.1)
     globalid (0.4.2)
       activesupport (>= 4.2.0)
+    hashie (4.1.0)
     i18n (1.6.0)
       concurrent-ruby (~> 1.0)
     jquery-rails (4.3.5)
       rails-dom-testing (>= 1, < 3)
       railties (>= 4.2.0)
       thor (>= 0.14, < 2.0)
+    jwt (2.2.1)
     loofah (2.3.1)
       crass (~> 1.0.2)
       nokogiri (>= 1.5.9)
@@ -73,9 +81,26 @@ GEM
     mini_mime (1.0.2)
     mini_portile2 (2.4.0)
     minitest (5.11.3)
+    multi_json (1.14.1)
+    multi_xml (0.6.0)
+    multipart-post (2.1.1)
     nio4r (2.4.0)
     nokogiri (1.10.5)
       mini_portile2 (~> 2.4.0)
+    oauth2 (1.4.4)
+      faraday (>= 0.8, < 2.0)
+      jwt (>= 1.0, < 3.0)
+      multi_json (~> 1.3)
+      multi_xml (~> 0.5)
+      rack (>= 1.2, < 3)
+    omniauth (1.9.1)
+      hashie (>= 3.4.6)
+      rack (>= 1.6.2, < 3)
+    omniauth-facebook (6.0.0)
+      omniauth-oauth2 (~> 1.2)
+    omniauth-oauth2 (1.6.0)
+      oauth2 (~> 1.1)
+      omniauth (~> 1.9)
     pry (0.12.2)
       coderay (~> 1.1.0)
       method_source (~> 0.9.0)
@@ -153,7 +178,10 @@ PLATFORMS
 DEPENDENCIES
   byebug
   coffee-rails (~> 4.1.0)
+  dotenv-rails
   jquery-rails
+  omniauth
+  omniauth-facebook
   pry
   rails (~> 5.0)
   sass-rails (~> 5.0)

app/assets/javascripts/sessions.coffee

@@ -0,0 +1,3 @@
+# Place all the behaviors and hooks related to the matching controller here.
+# All this logic will automatically be available in application.js.
+# You can use CoffeeScript in this file: http://coffeescript.org/

app/assets/stylesheets/sessions.scss

@@ -0,0 +1,3 @@
+// Place all the styles related to the sessions controller here.
+// They will automatically be included in application.css.
+// You can use Sass (SCSS) here: http://sass-lang.com/

app/controllers/sessions_controller.rb

@@ -0,0 +1,19 @@
+class SessionsController < ApplicationController
+  def create
+    @user = User.find_or_create_by(uid: auth['uid']) do |u|
+      u.name = auth['info']['name']
+      u.email = auth['info']['email']
+      u.image = auth['info']['image']
+    end
+
+    session[:user_id] = @user.id
+
+    render 'welcome/home'
+  end
+
+  private
+
+  def auth
+    request.env['omniauth.auth']
+  end
+end

app/helpers/sessions_helper.rb

@@ -0,0 +1,2 @@
+module SessionsHelper
+end

app/models/application_record.rb

@@ -0,0 +1,3 @@
+class ApplicationRecord < ActiveRecord::Base
+  self.abstract_class = true
+end

app/models/user.rb

@@ -0,0 +1,2 @@
+class User < ApplicationRecord
+end

app/views/welcome/home.html.erb

@@ -1 +1,9 @@
 <%# Add the Facebook login link here %>
+<% if session[:user_id] %>
+  <h1><%= @user.name %></h1>
+  <h2>Email: <%= @user.email %></h2>
+  <h2>Facebook UID: <%= @user.uid %></h2>
+  <img src="<%= @user.image %>">
+<% else %>
+  <%= link_to('Log in with Facebook!', '/auth/facebook') %>
+<% end %>

config/initializers/omniauth.rb

@@ -0,0 +1,3 @@
+Rails.application.config.middleware.use OmniAuth::Builder do
+  provider :facebook, ENV['FACEBOOK_KEY'], ENV['FACEBOOK_SECRET']
+end

config/routes.rb

@@ -1,5 +1,6 @@
 Rails.application.routes.draw do
   root 'welcome#home'
+  get '/auth/facebook/callback' => 'sessions#create'
 
   # The priority is based upon order of creation: first created -> highest priority.
   # See how all your routes lay out with "rake routes".

db/migrate/20200415195454_create_users.rb

@@ -0,0 +1,11 @@
+class CreateUsers < ActiveRecord::Migration[5.0]
+  def change
+    create_table :users do |t|
+      t.string :name
+      t.string :email
+      t.string :image
+      t.string :uid
+      t.timestamps
+    end
+  end
+end

db/schema.rb

@@ -1,4 +1,3 @@
-# encoding: UTF-8
 # This file is auto-generated from the current state of the database. Instead
 # of editing this file, please use the migrations feature of Active Record to
 # incrementally modify your database, and then regenerate this schema definition.
@@ -11,6 +10,15 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 0) do
+ActiveRecord::Schema.define(version: 20200415195454) do
+
+  create_table "users", force: :cascade do |t|
+    t.string   "name"
+    t.string   "email"
+    t.string   "image"
+    t.string   "uid"
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+  end
 
 end

test/controllers/sessions_controller_test.rb

@@ -0,0 +1,7 @@
+require 'test_helper'
+
+class SessionsControllerTest < ActionDispatch::IntegrationTest
+  # test "the truth" do
+  #   assert true
+  # end
+end

test/fixtures/users.yml

@@ -0,0 +1,13 @@
+# Read about fixtures at http://api.rubyonrails.org/classes/ActiveRecord/FixtureSet.html
+
+one:
+  name,: MyString
+  email,: MyString
+  image,: MyString
+  uid: MyString
+
+two:
+  name,: MyString
+  email,: MyString
+  image,: MyString
+  uid: MyString

test/models/user_test.rb

@@ -0,0 +1,7 @@
+require 'test_helper'
+
+class UserTest < ActiveSupport::TestCase
+  # test "the truth" do
+  #   assert true
+  # end
+end