For this challenge, we'll be building out Netflix! A Viewer has many Movies through QueueItems. A Movie can appear on many Viewers' queues. A Viewer can rate a Movie, marking their rating on the QueueItem.

As always, make sure to sketch out your domain and think about the single source of truth for your data.

• Classes vs Instances
• Variable Scope ( Class, Instance, Local )
• Object Relationships
• Arrays and Array Methods
• Class Methods

Your goal is to build out all of the methods listed in the deliverables. Do your best to follow Ruby best practices. For example, use higher-level array methods such as map, select, and find when appropriate in place of each.

We've provided you with a console that you can use to test your code. To enter a console session, run ruby tools/console.rb. You must run this from this assignment's root directory, not from inside the tools directory. You'll be able to test out the methods that you write here. Take a look at that file to see how you can pre-define variables and create object instances, rather than manually doing it in every single console session.

Implement all of the methods described below

• Viewer.all
  • returns all of the viewers
• Viewer#queue_items
  • this method should return an array of QueueItem instances associated with this instance of Viewer.
• Viewer#queue_movies
  • this method should return an array of Movie instances in the Viewer's queue.
• Viewer#add_movie_to_queue(movie)
  • this method should receive a Movie instance as its only argument and add it to the Viewer's queue
• Viewer#rate_movie(movie, rating)
  • given a movie and a rating (a number between 1 and 5), this method should assign the rating to the viewer's QueueItem for that movie. If the movie is not already in the viewer's queue, this method should add a new QueueItem with the viewer, movie, and rating. If the movie is already in the queue, this method should not create a new QueueItem.

A QueueItem object represents that an individual user has added a particular movie to their queue, and possibly rated it. It is not the full queue, but a single item in the queue.

• QueueItem.all
  • returns an array of all QueueItems
• QueueItem#viewer
  • returns the viewer associated with this QueueItem
• QueueItem#movie
  • returns the movie associated with this QueueItem
• QueueItem#rating
  • returns the rating for this QueueItem. If the viewer has not yet rated the movie, QueueItem#rating should be nil

• Movie.all
  • returns an array of all Movie
• Movie#queue_items
  • returns an array of all the QueueItem instances that contain this movie
• Movie#viewers
  • returns an array of all of the Viewers with this Movie instance in their queue
• Movie#average_rating
  • returns the average of all ratings for this instance of Movie
• Movie.highest_rated
  • returns the instance of Movie with the highest average rating