diff --git a/app/controllers/api_controller.rb b/app/controllers/api_controller.rb
new file mode 100644
index 0000000..75bb517
--- /dev/null
+++ b/app/controllers/api_controller.rb
@@ -0,0 +1,2 @@
+class ApiController < ActionController::Base
+end
\ No newline at end of file
diff --git a/app/controllers/api_v1/messages_controller.rb b/app/controllers/api_v1/messages_controller.rb
new file mode 100644
index 0000000..25f608e
--- /dev/null
+++ b/app/controllers/api_v1/messages_controller.rb
@@ -0,0 +1,9 @@
+class ApiV1::MessagesController < ApiController
+
+
+	# GET http://localhost:3000/api/v1/messages.json
+	def index
+		@messages = Message.all
+	end
+end
+
diff --git a/app/controllers/comments_controller.rb b/app/controllers/comments_controller.rb
index e9d6aaa..24f4236 100644
--- a/app/controllers/comments_controller.rb
+++ b/app/controllers/comments_controller.rb
@@ -14,9 +14,16 @@ def create
 
   def destroy
     @comment = current_user.comments.find( params[:id] )
-    @comment.destroy
-
-    redirect_to :back
+    if @comment.user != current_user
+      render :back, alert: "你不是作者，沒有權限！"
+    else
+      @comment.destroy
+    end
+
+    respond_to do |format|
+      # format.html { redirect_to message_path(@message) }
+      format.js 
+    end
   end
 
   protected
diff --git a/app/controllers/messages_controller.rb b/app/controllers/messages_controller.rb
index 96f65e5..3132a90 100644
--- a/app/controllers/messages_controller.rb
+++ b/app/controllers/messages_controller.rb
@@ -4,19 +4,19 @@ class MessagesController < ApplicationController
 
   def index
     # TODO: fix N+1 queries for user and comments
-    @messages = Message.order("id DESC").page( params[:page] )
+    @messages = Message.includes(:user, :comments).order("id DESC").page( params[:page] )
 
     if params[:status] == "pending"
       # TODO: @messages = @messages.pending
-      @messages = @messages.where( :status => "pending" )
+      @messages = @messages.pending
     elsif params[:status] == "completed"
       # TODO: @messages = @messages.completed
-      @messages = @messages.where( :status => "completed" )
+      @messages = @messages.completed
     end
 
     if params[:days]
       # TODO: @messages = @messages.within_days(params[:days].to_i)
-      @messages = @messages.where( ["created_at >= ?", Time.now - params[:days].to_i.days ] )
+      @messages = @messages.within_days(params[:days].to_i)
     end
   end
 
diff --git a/app/models/like.rb b/app/models/like.rb
new file mode 100644
index 0000000..88c087f
--- /dev/null
+++ b/app/models/like.rb
@@ -0,0 +1,4 @@
+class Like < ActiveRecord::Base
+	belongs_to :user
+	belongs_to :message
+end
diff --git a/app/models/message.rb b/app/models/message.rb
index e24a8b2..433209d 100644
--- a/app/models/message.rb
+++ b/app/models/message.rb
@@ -4,6 +4,16 @@ class Message < ActiveRecord::Base
 
   has_many :comments, :dependent => :destroy
 
+  has_many :likes, dependent: :destroy
+  has_many :liked_messages, through: :likes, source: :user
+
+  has_many :subscriptions, dependent: :destroy
+  has_many :sub_messages, through: :subscriptions, source: :user
+
+	scope :completed, -> { where( :status => "completed" ) }
+	scope :pending, -> { where( :status => "pending" ) }
+	scope :within_days, -> (date){ where( "created_at >= ?", Time.now - date.days ) }
+
   def last_comment_summary
     self.comments.last.try(:content).try(:truncate, 20)
   end
diff --git a/app/models/subscription.rb b/app/models/subscription.rb
new file mode 100644
index 0000000..1a521fd
--- /dev/null
+++ b/app/models/subscription.rb
@@ -0,0 +1,5 @@
+class Subscription < ActiveRecord::Base
+	belongs_to :user
+	belongs_to :message
+
+end
diff --git a/app/models/user.rb b/app/models/user.rb
index 6d01aa9..3bf6e0a 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -6,6 +6,12 @@ class User < ActiveRecord::Base
 
   has_many :messages
   has_many :comments
+  
+  has_many :likes, dependent: :destroy
+  has_many :liked_messages, through: :likes, source: :message
+
+  has_many :subscriptions, dependent: :destroy
+  has_many :sub_messages, through: :subscriptions, source: :message
 
   def display_name
     self.email.split("@").first
@@ -13,6 +19,7 @@ def display_name
 
   def posts_count
     # TODO: 請完成我
+    self.messages.count + self.comments.count
   end
 
   def words_count
diff --git a/app/views/api_v1/messages/_message.json.jbuilder b/app/views/api_v1/messages/_message.json.jbuilder
new file mode 100644
index 0000000..66c6354
--- /dev/null
+++ b/app/views/api_v1/messages/_message.json.jbuilder
@@ -0,0 +1 @@
+json.(message, :status, :category_name, :title, :content, :created_at)
diff --git a/app/views/api_v1/messages/index.json.jbuilder b/app/views/api_v1/messages/index.json.jbuilder
new file mode 100644
index 0000000..ec04e4a
--- /dev/null
+++ b/app/views/api_v1/messages/index.json.jbuilder
@@ -0,0 +1,7 @@
+json.array! @messages do |message|
+	json.(message, :id)
+
+	json.detalis do 
+		json.partial! message
+	end
+end
\ No newline at end of file
diff --git a/app/views/comments/destroy.js.erb b/app/views/comments/destroy.js.erb
new file mode 100644
index 0000000..347af22
--- /dev/null
+++ b/app/views/comments/destroy.js.erb
@@ -0,0 +1 @@
+$('#comment-<%= @comment.id %>').remove();
diff --git a/app/views/messages/show.html.erb b/app/views/messages/show.html.erb
index 41401f6..550ad0b 100644
--- a/app/views/messages/show.html.erb
+++ b/app/views/messages/show.html.erb
@@ -2,6 +2,20 @@
 
 <%= simple_format @message.content %>
 
+<h3>Who likes this message</h3>
+<ul>
+  <% @message.liked_messages.each do |user| %>
+    <li><%= user.email if user %></li>
+  <% end %>
+</ul>
+
+<h3>Who subscribes this message</h3>
+<ul>
+  <% @message.sub_messages.each do |user| %>
+    <li><%= user.email if user %></li>
+  <% end %>
+</ul>
+
 <h2>Comments list</h2>
 
 <%= form_for [@message, @comment] do |f| %>
@@ -18,14 +32,17 @@
 <% end %>
 
 <% @message.comments.each do |comment| %>
+  
+  <div id="comment-<%= comment.id %>">
+    <p ><%= simple_format comment.content %> at <%= comment.created_at.to_s(:short) %> by <%= comment.user.display_name %>
 
-  <p><%= simple_format comment.content %> at <%= comment.created_at.to_s(:short) %> by <%= comment.user.display_name %>
-
-    <% if comment.user == current_user %>
-      <%# TODO: 修改成 AJAX 版本的刪除 %>
-      <%= link_to "Delete", message_comment_path(@message, comment), :method => :delete, :data => { :confirm => "Are u sure?"} %>
-    <% end %>
-  </p>
+      <% if comment.user == current_user %>
+        <%# TODO: 修改成 AJAX 版本的刪除 %>
+        <%= link_to "Delete", message_comment_path(@message, comment), :method => :delete, remote: true, :data => { :confirm => "Are u sure?"} %>
+      <% end %>
+    </p>
+  </div>
 
 <% end %>
 
+
diff --git a/config/routes.rb b/config/routes.rb
index 74d4dbf..c4abdd9 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -5,6 +5,11 @@
     resources :comments
   end
 
+  scope :path => '/api/v1/', :module => "api_v1", :as => 'v1', :defaults => { :format => :json } do
+  
+    resources :messages
+  end
+
   # The priority is based upon order of creation: first created -> highest priority.
   # See how all your routes lay out with "rake routes".
 
diff --git a/db/migrate/20161007150958_create_subscriptions.rb b/db/migrate/20161007150958_create_subscriptions.rb
new file mode 100644
index 0000000..5006646
--- /dev/null
+++ b/db/migrate/20161007150958_create_subscriptions.rb
@@ -0,0 +1,12 @@
+class CreateSubscriptions < ActiveRecord::Migration
+  def change
+    create_table :subscriptions do |t|
+    	t.integer :user_id
+    	t.integer :message_id
+    	t.index :user_id
+    	t.index :message_id
+
+      t.timestamps null: false
+    end
+  end
+end
diff --git a/db/migrate/20161007151005_create_likes.rb b/db/migrate/20161007151005_create_likes.rb
new file mode 100644
index 0000000..cf5906a
--- /dev/null
+++ b/db/migrate/20161007151005_create_likes.rb
@@ -0,0 +1,12 @@
+class CreateLikes < ActiveRecord::Migration
+  def change
+    create_table :likes do |t|
+    	t.integer :user_id
+    	t.integer :message_id
+    	t.index :user_id
+    	t.index :message_id
+
+      t.timestamps null: false
+    end
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index ef7b5c0..4a827eb 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20150728165437) do
+ActiveRecord::Schema.define(version: 20161007151005) do
 
   create_table "comments", force: :cascade do |t|
     t.text     "content"
@@ -23,6 +23,16 @@
 
   add_index "comments", ["message_id"], name: "index_comments_on_message_id"
 
+  create_table "likes", force: :cascade do |t|
+    t.integer  "user_id"
+    t.integer  "message_id"
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+  end
+
+  add_index "likes", ["message_id"], name: "index_likes_on_message_id"
+  add_index "likes", ["user_id"], name: "index_likes_on_user_id"
+
   create_table "messages", force: :cascade do |t|
     t.string   "title"
     t.text     "content"
@@ -36,6 +46,16 @@
   add_index "messages", ["status"], name: "index_messages_on_status"
   add_index "messages", ["user_id"], name: "index_messages_on_user_id"
 
+  create_table "subscriptions", force: :cascade do |t|
+    t.integer  "user_id"
+    t.integer  "message_id"
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+  end
+
+  add_index "subscriptions", ["message_id"], name: "index_subscriptions_on_message_id"
+  add_index "subscriptions", ["user_id"], name: "index_subscriptions_on_user_id"
+
   create_table "users", force: :cascade do |t|
     t.string   "email",                  default: "", null: false
     t.string   "encrypted_password",     default: "", null: false
diff --git a/lib/tasks/dev.rake b/lib/tasks/dev.rake
index 4673e72..58d7af6 100644
--- a/lib/tasks/dev.rake
+++ b/lib/tasks/dev.rake
@@ -17,6 +17,9 @@ namespace :dev do
                            :content => Faker::Lorem.paragraph,
                            :user => users.sample,
                            :created_at => Time.now - rand(30).days )
+      m.liked_messages << users.sample(2)
+      m.sub_messages << users.sample(2)
+
       5.times do
         m.comments.create!( :content => Faker::Lorem.paragraph,
                             :user => users.sample )
diff --git a/spec/models/user_spec.rb b/spec/models/user_spec.rb
index 528cc38..f6bcc08 100644
--- a/spec/models/user_spec.rb
+++ b/spec/models/user_spec.rb
@@ -8,9 +8,9 @@
 
   describe "#posts_count" do
     before do
-      other_user = User.create!( :email => "ooxx@example.org", :password => "12345678")
-      m1 = Message.create!( :user => other_user )
-      Comment.create!( :user => other_user, :message => m1 )
+      @other_user = User.create!( :email => "ooxx@example.org", :password => "12345678")
+      m1 = Message.create!( :user => @other_user )
+      Comment.create!( :user => @other_user, :message => m1 )
 
       m2 = Message.create!( :user => @user )
       Comment.create!( :user => @user, :message => m2 )
@@ -19,17 +19,20 @@
 
     it "回傳該使用者的總 Mesasge 數量加 Comment 數量" do
       expect( @user.posts_count ).to eq(3)
+      expect( @other_user.posts_count ).to eq(2)
     end
   end
 
   describe "#words_count" do
     before do
       # TODO: 加 Message 和 Comment 測試資料
+      m1 = Message.create!( :user => @user, title: "foo sss", content: "bar xxx" )
+      c1 = Comment.create!( :user => @user, :message => m1, content:"foo bar" )
     end
 
     it "加總該使用者的所有 Mesasge 和 Comment 的總字數" do
       # TODO: 測試 words_count 方法
-
+      expect( @user.words_count ).to eq(6)
     end
   end