Time flies! Keep on learnin'

class User < ActiveRecord::Base
    # via StackOverflow
    # In Rails 4, :order has been deprecated and needs to be
    # replaced with lambda scope block. Note that this scope
    # block needs to be passed before any other association
    # options such as dependent: :destroy etc.
    has_many :tweets, -> { order(created_at: :desc) }
    has_many :retweets

    # Self-Referential Association, via RailsCast 163
    has_many :follows
    has_many :followings, :through => :follows
    has_many :inverse_follows, :class_name => "Follow", :foreign_key => "following_id"
    has_many :followers, :through => :inverse_follows, :source => :user

    # Adds methods to set and authenticate against a BCrypt password. 
    # This mechanism requires you to have a password_digest attribute.
    # Validations for presence of password on create, confirmation
    # of password (using a password_confirmation attribute) are
    # automatically added
    has_secure_password
end

#reminder for password_digest in table
class CreateUsers < ActiveRecord::Migration
  def change
    create_table :users do |t|
        t.string :username
        t.string :email
        t.string :password_digest
        
      t.timestamps
    end
  end
end

class Follow < ActiveRecord::Base
    belongs_to :user
    belongs_to :following, :class_name => "User"
end

.top-nav {
    @include box-sizing;
    width: 100%;
    padding: 5px;
    border-bottom: 1px solid $background-dark-2;
    font-size: 20px;
    background-color: $off-white;
    display: inline-block;

    .right {
        float: right;
        display: inline-block;

        a {
            margin-left: 20px;
        }
    }
}

@mixin headers-and-tweets {
    background-color: $off-white;
    border-radius: 15px 0;
    border-bottom: 1px solid $background-dark-2;
    border-right: 1px solid $background-dark-2; 
}

@mixin new-session-and-user-form {
    @include headers-and-tweets;
    padding: 10px 0;
}

// Helpful BOX-SIZING explanation here:
// http://css-tricks.com/almanac/properties/b/box-sizing/
// Used to keep the nav bar within the page.
// Without box-sizing, the link furthest right spilt off the page
@mixin box-sizing {
  -webkit-box-sizing: border-box; /* Safari/Chrome, other WebKit */
  -moz-box-sizing: border-box;    /* Firefox, other Gecko */
  box-sizing: border-box;         /* Opera/IE 8+ */
}

class ApplicationController < ActionController::Base
  # Prevent CSRF attacks by raising an exception.
  # For APIs, you may want to use :null_session instead.
  protect_from_forgery with: :exception

  before_action :require_login

  helper_method :current_user, :logged_in?

  def current_user
    @current_user ||= User.find(session[:user_id]) if session[:user_id]
  end

  def logged_in?
    !current_user.nil?
  end

  private

  def require_login
    unless logged_in?
      flash[:error] = "You must log in first"
      redirect_to new_session_path
    end
  end
end

class SessionsController < ApplicationController
    skip_before_action :require_login, only: [:new, :create]

    def create
        # The line below works, and will return either false, or the User record
        # user = User.find_by(email: params[:email]).try(:authenticate, params[:password])

        # Here is a solution from RailsCasts using #authenticate, which is
        # an instance method provided by has_secure_password
        user = User.find_by(email: params[:email])
        if user && user.authenticate(params[:password])
            session[:user_id] = user.id
            redirect_to user, notice: "You've successfully logged in."
        else
            redirect_to root_path, notice: "Log in failed."
        end
    end

    def destroy
        session[:user_id] = nil
        redirect_to root_path, notice: "You've successfully logged out."
    end
end

# TweetsController
# User can not tweet from another user's page (or more specifically w/another user's ID)
def new
    @user = User.find(params[:user_id])
    if @user.id != current_user.id
        redirect_to user_path(current_user), notice: "Access forbidden"
    end
    @tweet = Tweet.new
end

def show
    # is this the correct way to eager load for a single record?
    @user = User.includes(:tweets).find(params[:id])
    # figure out good way to include :retweets as well!
end

<div class="new-tweet-form">
    <%= form_for [@user, @tweet] do |f| %>
        <%= f.text_area :body, value: @tweet.body, size: "30x10", required: true %>
        <%= f.submit "Tweet" %>
    <% end %>
</div>

<!-- LIST OF TWEETS -->
<div class="tweets-list">
    <% if @user.tweets.any? %>
        <h3>Tweets</h3>
        <% @user.tweets.each do |tweet| %>
            <a href="<%= user_tweet_path(tweet.user, tweet) %>">
                <div class="tweet">
                    <li class="timestamp"><%= tweet.created_at.strftime("%m/%d/%Y") %></li>
                    <li><%= tweet.body %></li>
                </div>
            </a>
        <% end %>
        </div>
    <% else %>
        <h3>No Tweets</h3>
    <% end %>
</div>