diff --git a/Gemfile b/Gemfile
index 3f1e6961..29aa7b86 100644
--- a/Gemfile
+++ b/Gemfile
@@ -39,6 +39,9 @@ gem 'simple_form'
 # Reduces boot times through caching; required in config/boot.rb
 gem 'bootsnap', '>= 1.1.0', require: false
 
+gem 'will_paginate', '~> 3.1.0'
+gem 'acts_as_votable'
+
 group :development, :test do
   # Call 'byebug' anywhere in the code to stop execution and get a debugger console
   gem 'byebug', platforms: [:mri, :mingw, :x64_mingw]
@@ -58,6 +61,10 @@ group :development do
   gem 'spring-watcher-listen', '~> 2.0.0'
 end
 
+group :test do
+  gem 'database_cleaner-active_record'
+end
+
 
 # Windows does not include zoneinfo files, so bundle the tzinfo-data gem
 gem 'tzinfo-data', platforms: [:mingw, :mswin, :x64_mingw, :jruby]
diff --git a/Gemfile.lock b/Gemfile.lock
index 16c3b7bc..20882829 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -42,6 +42,7 @@ GEM
       i18n (>= 0.7, < 2)
       minitest (~> 5.1)
       tzinfo (~> 1.1)
+    acts_as_votable (0.13.1)
     addressable (2.5.2)
       public_suffix (>= 2.0.2, < 4.0)
     arel (9.0.0)
@@ -68,6 +69,10 @@ GEM
     coffee-script-source (1.12.2)
     concurrent-ruby (1.0.5)
     crass (1.0.4)
+    database_cleaner-active_record (2.0.0)
+      activerecord (>= 5.a)
+      database_cleaner-core (~> 2.0.0)
+    database_cleaner-core (2.0.1)
     devise (4.4.3)
       bcrypt (~> 3.0)
       orm_adapter (~> 0.1)
@@ -220,6 +225,7 @@ GEM
     websocket-driver (0.7.0)
       websocket-extensions (>= 0.1.0)
     websocket-extensions (0.1.3)
+    will_paginate (3.1.8)
     xpath (3.0.0)
       nokogiri (~> 1.8)
 
@@ -227,10 +233,12 @@ PLATFORMS
   ruby
 
 DEPENDENCIES
+  acts_as_votable
   bootsnap (>= 1.1.0)
   byebug
   capybara
   coffee-rails (~> 4.2)
+  database_cleaner-active_record
   devise
   factory_bot_rails
   jbuilder (~> 2.5)
@@ -249,9 +257,10 @@ DEPENDENCIES
   tzinfo-data
   uglifier (>= 1.3.0)
   web-console (>= 3.3.0)
+  will_paginate (~> 3.1.0)
 
 RUBY VERSION
    ruby 2.4.4p296
 
 BUNDLED WITH
-   1.16.2
+   2.2.11
diff --git a/app/controllers/dogs_controller.rb b/app/controllers/dogs_controller.rb
index cb9eebc5..fb2c50b7 100644
--- a/app/controllers/dogs_controller.rb
+++ b/app/controllers/dogs_controller.rb
@@ -1,10 +1,16 @@
 class DogsController < ApplicationController
-  before_action :set_dog, only: [:show, :edit, :update, :destroy]
+  before_action :set_dog, only: [:show, :edit, :update, :destroy, :like]
 
   # GET /dogs
   # GET /dogs.json
   def index
-    @dogs = Dog.all
+    if params[:sort] == 'likes'
+      dogs = Dog.order(:cached_weighted_average => :desc)
+    else
+      dogs = Dog
+    end
+    @sorted = params[:sort] == 'likes'
+    @dogs = dogs.paginate(page: params[:page], per_page: 5)
   end
 
   # GET /dogs/1
@@ -14,17 +20,22 @@ def show
 
   # GET /dogs/new
   def new
+    redirect_to dogs_url, notice: 'Dog was successfully destroyed.' if current_user.nil?
     @dog = Dog.new
   end
 
   # GET /dogs/1/edit
   def edit
+    redirect_to(@dog, notice: 'You do not own this dog') if current_user.nil? || @dog.owner != current_user
   end
 
   # POST /dogs
   # POST /dogs.json
   def create
+    redirect_to(@dog, notice: 'You are not signed in.') if current_user.nil?
+
     @dog = Dog.new(dog_params)
+    @dog.user = current_user
 
     respond_to do |format|
       if @dog.save
@@ -42,6 +53,7 @@ def create
   # PATCH/PUT /dogs/1
   # PATCH/PUT /dogs/1.json
   def update
+    redirect_to(@dog, notice: 'You do not own this dog.') if current_user.nil? || @dog.owner != current_user
     respond_to do |format|
       if @dog.update(dog_params)
         @dog.images.attach(params[:dog][:image]) if params[:dog][:image].present?
@@ -58,6 +70,7 @@ def update
   # DELETE /dogs/1
   # DELETE /dogs/1.json
   def destroy
+    redirect_to(@dog, notice: 'You do not own this dog.') if current_user.nil? || @dog.owner != current_user
     @dog.destroy
     respond_to do |format|
       format.html { redirect_to dogs_url, notice: 'Dog was successfully destroyed.' }
@@ -65,6 +78,23 @@ def destroy
     end
   end
 
+  # GET /dogs/1/like
+  # GET /dogs/1/like.json
+  def like
+    redirect_to(@dog, notice: 'You own this dog.') if current_user.nil? || @dog.owner == current_user
+
+    if current_user.voted_for? @dog
+      @dog.unliked_by current_user
+    else
+      @dog.liked_by current_user
+    end
+
+    respond_to do |format|
+      format.html { redirect_to @dog }
+      format.json { render :show, status: :ok, location: @dog }
+    end
+  end
+
   private
     # Use callbacks to share common setup or constraints between actions.
     def set_dog
@@ -73,6 +103,6 @@ def set_dog
 
     # Never trust parameters from the scary internet, only allow the white list through.
     def dog_params
-      params.require(:dog).permit(:name, :description, :images)
+      params.require(:dog).permit(:name, :description, images: [])
     end
 end
diff --git a/app/models/dog.rb b/app/models/dog.rb
index eb40bf6e..7f700256 100644
--- a/app/models/dog.rb
+++ b/app/models/dog.rb
@@ -1,3 +1,13 @@
 class Dog < ApplicationRecord
   has_many_attached :images
+  belongs_to :user
+
+  alias_method :owner, :user
+
+  validates :name, presence: true
+  validates :owner, presence: true
+  validates :description, presence: true
+  validates :images, presence: true
+
+  acts_as_votable
 end
diff --git a/app/models/user.rb b/app/models/user.rb
index b2091f9a..8b379908 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -3,4 +3,8 @@ class User < ApplicationRecord
   # :confirmable, :lockable, :timeoutable and :omniauthable
   devise :database_authenticatable, :registerable,
          :recoverable, :rememberable, :trackable, :validatable
+
+  has_many :dogs
+
+  acts_as_voter
 end
diff --git a/app/views/dogs/_form.html.erb b/app/views/dogs/_form.html.erb
index 6dfc7dc9..54915388 100644
--- a/app/views/dogs/_form.html.erb
+++ b/app/views/dogs/_form.html.erb
@@ -1,10 +1,10 @@
 <%= simple_form_for @dog do |f| %>
   <%= f.input :name %>
   <%= f.input :description, as: :text %>
-  <%= f.input :image, as: :file %>
+  <%= f.input :images, as: :file, input_html: { multiple: true } %>
 
-  <% if @dog.images.any? %>
-    <%= image_tag @dog.images.first %>
+  <% @dog.images.each do |image| %>
+    <%= image_tag image %>
   <% end %>
 
   <%= f.button :submit %>
diff --git a/app/views/dogs/_thumbnail.html.erb b/app/views/dogs/_thumbnail.html.erb
index 4d6bb441..23aae5e9 100644
--- a/app/views/dogs/_thumbnail.html.erb
+++ b/app/views/dogs/_thumbnail.html.erb
@@ -4,3 +4,6 @@
     <%= image_tag url_for(dog.images.first), class: "dog-photo", alt: "Photo of #{dog.name}" %>
   </article>
 </a>
+<% if dog_counter % 2 == 1 %>
+  <%= image_tag 'ad.jpg', class: "ad", alt: "A very cool ad." %>
+<% end %>
diff --git a/app/views/dogs/index.html.erb b/app/views/dogs/index.html.erb
index 91ea5603..aa08f33d 100644
--- a/app/views/dogs/index.html.erb
+++ b/app/views/dogs/index.html.erb
@@ -1 +1,8 @@
+<% if @sorted %>
+  <%= link_to "Unsort", root_path, title: "sort by likes", id: 'sort' %>
+<% else %>
+  <%= link_to "Sort by Likes", root_path + '?sort=likes', title: "unsort by likes", id: 'sort' %>
+<% end %>
+<%= will_paginate @dogs %>
 <%= render partial: 'thumbnail', collection: @dogs, as: :dog %>
+<%= will_paginate @dogs %>
diff --git a/app/views/dogs/show.html.erb b/app/views/dogs/show.html.erb
index 562324d2..2dea1231 100644
--- a/app/views/dogs/show.html.erb
+++ b/app/views/dogs/show.html.erb
@@ -1,5 +1,14 @@
 <section>
-  <h2><%= @dog.name %></h2>
+  <h2>
+    <%= @dog.name %>
+    <% unless current_user.nil? || @dog.owner == current_user %>
+      <% if current_user&.voted_for?(@dog) %>
+        <%= link_to "❤️", like_dog_path(@dog), title: "click to unlike", id: 'like_dog_link' %>
+      <% else %>
+        <%= link_to "🤍", like_dog_path(@dog), title: "click to like", id: 'unlike_dog_link' %>
+      <% end %>
+    <% end %>
+  </h2>
 
   <% @dog.images.each do |image| %>
     <%= image_tag url_for(image), alt: "Photo of #{@dog.name}" %>
@@ -7,7 +16,9 @@
 
   <p><%= @dog.description %></p>
 
-  <%= link_to "Edit #{@dog.name}'s Profile", edit_dog_path %>
-  <br>
-  <%= link_to "Delete #{@dog.name}'s Profile", dog_path, method: :delete, data: { confirm: 'Are you sure?' } %>
+  <% if current_user && @dog.owner == current_user %>
+    <%= link_to "Edit #{@dog.name}'s Profile", edit_dog_path %>
+    <br>
+    <%= link_to "Delete #{@dog.name}'s Profile", dog_path, method: :delete, data: { confirm: 'Are you sure?' } %>
+  <% end %>
 </section>
diff --git a/config/routes.rb b/config/routes.rb
index 06b01adc..5efc9991 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -1,6 +1,10 @@
 Rails.application.routes.draw do
   # For details on the DSL available within this file, see http://guides.rubyonrails.org/routing.html
   devise_for :users
-  resources :dogs
+  resources :dogs do
+    member do
+      get "like"
+    end
+  end
   root to: "dogs#index"
 end
diff --git a/db/migrate/20210219021259_add_owner_to_dogs.rb b/db/migrate/20210219021259_add_owner_to_dogs.rb
new file mode 100644
index 00000000..9727c3c2
--- /dev/null
+++ b/db/migrate/20210219021259_add_owner_to_dogs.rb
@@ -0,0 +1,5 @@
+class AddOwnerToDogs < ActiveRecord::Migration[5.2]
+  def change
+    add_reference :dogs, :user, index: true, foreign_key: true
+  end
+end
diff --git a/db/migrate/20210219042627_acts_as_votable_migration.rb b/db/migrate/20210219042627_acts_as_votable_migration.rb
new file mode 100644
index 00000000..2516d700
--- /dev/null
+++ b/db/migrate/20210219042627_acts_as_votable_migration.rb
@@ -0,0 +1,22 @@
+class ActsAsVotableMigration < ActiveRecord::Migration[4.2]
+  def self.up
+    create_table :votes do |t|
+
+      t.references :votable, :polymorphic => true
+      t.references :voter, :polymorphic => true
+
+      t.boolean :vote_flag
+      t.string :vote_scope
+      t.integer :vote_weight
+
+      t.timestamps
+    end
+
+    add_index :votes, [:voter_id, :voter_type, :vote_scope]
+    add_index :votes, [:votable_id, :votable_type, :vote_scope]
+  end
+
+  def self.down
+    drop_table :votes
+  end
+end
diff --git a/db/migrate/20210220172412_add_cached_votes_to_dogs.rb b/db/migrate/20210220172412_add_cached_votes_to_dogs.rb
new file mode 100644
index 00000000..d6cae834
--- /dev/null
+++ b/db/migrate/20210220172412_add_cached_votes_to_dogs.rb
@@ -0,0 +1,16 @@
+class AddCachedVotesToDogs < ActiveRecord::Migration[5.2]
+  def change
+    change_table :dogs do |t|
+      t.integer :cached_votes_total, default: 0
+      t.integer :cached_votes_score, default: 0
+      t.integer :cached_votes_up, default: 0
+      t.integer :cached_votes_down, default: 0
+      t.integer :cached_weighted_score, default: 0
+      t.integer :cached_weighted_total, default: 0
+      t.float :cached_weighted_average, default: 0.0
+    end
+
+    # Uncomment this line to force caching of existing votes
+    Dog.find_each(&:update_cached_votes)
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 462bd430..542af6a9 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2018_06_07_114248) do
+ActiveRecord::Schema.define(version: 2021_02_20_172412) do
 
   create_table "active_storage_attachments", force: :cascade do |t|
     t.string "name", null: false
@@ -40,6 +40,15 @@
     t.text "description"
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
+    t.integer "user_id"
+    t.integer "cached_votes_total", default: 0
+    t.integer "cached_votes_score", default: 0
+    t.integer "cached_votes_up", default: 0
+    t.integer "cached_votes_down", default: 0
+    t.integer "cached_weighted_score", default: 0
+    t.integer "cached_weighted_total", default: 0
+    t.float "cached_weighted_average", default: 0.0
+    t.index ["user_id"], name: "index_dogs_on_user_id"
   end
 
   create_table "users", force: :cascade do |t|
@@ -60,4 +69,18 @@
     t.index ["reset_password_token"], name: "index_users_on_reset_password_token", unique: true
   end
 
+  create_table "votes", force: :cascade do |t|
+    t.string "votable_type"
+    t.integer "votable_id"
+    t.string "voter_type"
+    t.integer "voter_id"
+    t.boolean "vote_flag"
+    t.string "vote_scope"
+    t.integer "vote_weight"
+    t.datetime "created_at"
+    t.datetime "updated_at"
+    t.index ["votable_id", "votable_type", "vote_scope"], name: "index_votes_on_votable_id_and_votable_type_and_vote_scope"
+    t.index ["voter_id", "voter_type", "vote_scope"], name: "index_votes_on_voter_id_and_voter_type_and_vote_scope"
+  end
+
 end
diff --git a/spec/factories/dogs.rb b/spec/factories/dogs.rb
index 406874f5..79c86317 100644
--- a/spec/factories/dogs.rb
+++ b/spec/factories/dogs.rb
@@ -1,5 +1,7 @@
 FactoryBot.define do
   factory :dog do
+    association :user
+    description { 'the goodest dog' }
     sequence :name do |n|
       "Good Pup #{n}"
     end
diff --git a/spec/factories/user.rb b/spec/factories/user.rb
new file mode 100644
index 00000000..dce0043a
--- /dev/null
+++ b/spec/factories/user.rb
@@ -0,0 +1,8 @@
+FactoryBot.define do
+  factory :user do
+    sequence :email do |n|
+      "email#{n}@example.com"
+    end
+    password { '123456' }
+  end
+end
diff --git a/spec/features/dog_resource_spec.rb b/spec/features/dog_resource_spec.rb
index d9337477..8f428779 100644
--- a/spec/features/dog_resource_spec.rb
+++ b/spec/features/dog_resource_spec.rb
@@ -1,6 +1,10 @@
 require 'rails_helper'
+require_relative '../support/devise'
 
 describe 'Dog resource', type: :feature do
+  let!(:spec_user) { User.first || FactoryBot.create(:user) }
+  before { login_as spec_user }
+
   it 'can create a profile' do
     visit new_dog_path
     fill_in 'Name', with: 'Speck'
@@ -11,7 +15,7 @@
   end
 
   it 'can edit a dog profile' do
-    dog = create(:dog)
+    dog = create(:dog, user: spec_user)
     visit edit_dog_path(dog)
     fill_in 'Name', with: 'Speck'
     click_button 'Update Dog'
@@ -19,7 +23,7 @@
   end
 
   it 'can delete a dog profile' do
-    dog = create(:dog)
+    dog = create(:dog, user: spec_user)
     visit dog_path(dog)
     click_link "Delete #{dog.name}'s Profile"
     expect(Dog.count).to eq(0)
diff --git a/spec/rails_helper.rb b/spec/rails_helper.rb
index 4e322aeb..3642aba5 100644
--- a/spec/rails_helper.rb
+++ b/spec/rails_helper.rb
@@ -56,4 +56,23 @@
   config.filter_rails_from_backtrace!
   # arbitrary gems may also be filtered via:
   # config.filter_gems_from_backtrace("gem name")
+  config.expect_with :rspec do |c|
+    c.syntax = :expect
+  end
+
+  config.include Devise::Test::ControllerHelpers, :type => :controller
+
+  config.include Warden::Test::Helpers
+
+  config.before(:suite) do
+    DatabaseCleaner.strategy = :transaction
+    DatabaseCleaner.clean_with(:truncation)
+  end
+
+  config.around(:each) do |example|
+    DatabaseCleaner.cleaning do
+      example.run
+    end
+  end
+
 end
diff --git a/spec/support/controller_macros.rb b/spec/support/controller_macros.rb
new file mode 100644
index 00000000..e0da1ab8
--- /dev/null
+++ b/spec/support/controller_macros.rb
@@ -0,0 +1,9 @@
+module ControllerMacros
+  def login_user
+    before(:each) do
+      @request.env["devise.mapping"] = Devise.mappings[:user]
+      user = FactoryBot.create(:user)
+      sign_in user
+    end
+  end
+end
diff --git a/spec/support/devise.rb b/spec/support/devise.rb
new file mode 100644
index 00000000..888c28b3
--- /dev/null
+++ b/spec/support/devise.rb
@@ -0,0 +1,9 @@
+require_relative './controller_macros' # or require_relative './controller_macros' if write in `spec/support/devise.rb`
+
+RSpec.configure do |config|
+  # For Devise > 4.1.1
+  config.include Devise::Test::ControllerHelpers, :type => :controller
+  # Use the following instead if you are on Devise <= 4.1.1
+  # config.include Devise::TestHelpers, :type => :controller
+  config.extend ControllerMacros, :type => :controller
+end