For this challenge, we'll be working with a Movie Review domain, like Netflix.

We have three models: Viewer, Movie, and Review.

A Movie has many Reviews. A Viewer has many Reviews. A Review belongs to a Viewer and belongs to a Movie.

Viewer - Movie is a many to many relationship.

Note: You should draw your domain on paper or on a whiteboard before you start coding. Remember to identify a single source of truth for your data.

• Classes and Instances
• Class and Instance Methods
• Variable Scope
• Object Relationships
• Arrays and Array Methods

To get started, run bundle install while inside of this directory.

Build out all of the methods listed in the deliverables. The methods are listed in a suggested order, but you can feel free to tackle the ones you think are easiest. Be careful: some of the later methods rely on earlier ones.

Remember! This code challenge does not have tests. You cannot run rspec and you cannot run learn. You'll need to create your own sample instances so that you can try out your code on your own. Make sure your associations and methods work in the console before submitting.

We've provided you with a tool that you can use to test your code. To use it, run ruby tools/console.rb from the command line. This will start a pry session with your classes defined. You can test out the methods that you write here. You can add code to the tools/console.rb file to define variables and create sample instances of your objects.

Writing error-free code is more important than completing all of the deliverables listed - prioritize writing methods that work over writing more methods that don't work. You should test your code in the console as you write.

Similarly, messy code that works is better than clean code that doesn't. First, prioritize getting things working. Then, if there is time at the end, refactor your code to adhere to best practices. Examples of best practices might be to use higher-level array methods such as map, select, and find when appropriate in place of each, or, when you encounter duplicated logic, to extract it into a shared helper method.

Before you submit! Save and run your code to verify that it works as you expect. If you have any methods that are not working yet, feel free to leave comments describing your progress.

Write the following methods in the classes in the files provided. Feel free to build out any helper methods if needed.

Deliverables use the notation # for instance methods, and . for class methods.

Some of the methods listed are provided to you in the starter code. You should check that they work correctly, and that you understand them.

• Movie#initialize(title)
  • Movie is initialized with a title (string)
  • title can be changed after the Movie is initialized
• Movie#title
  • returns the Movie's title
• Movie.all
  • returns an array of all the Movie instances that have been initialized

• Viewer#initialize(username)
  • Viewer is initialized with a username (string)
  • username can be changed after the Viewer is initialized
• Viewer#username
  • returns the Viewer's username
• Viewer.all
  • returns an array of all the Viewer instances that have been initialized

• Review#initialize(viewer, movie, rating)
  • Review is initialized with a Viewer instance, a Movie instance, and a rating (number)
• Review#rating
  • returns the rating for the Review instance
• Review.all
  • returns an array of all initialized Review instances

• Review#viewer
  • returns the Viewer instance associated with the Review instance
• Review#movie
  • returns the Movie instance associated with the Review instance

• Viewer#reviews
  • returns an array of Review instances associated with the Viewer instance.
• Viewer#reviewed_movies
  • returns an array of Movie instances reviewed by the Viewer instance.

• Movie#reviews turns an array of all the Review instances for the Movie.
• Movie#reviewers
  • returns an array of all of the Viewer instances that reviewed the Movie.

• Viewer#reviewed_movie?(movie)
  • a Movie instance is the only argument
  • returns true if the Viewer has reviewed this Movie (if there is a Review instance that has this Viewer and Movie), returns false otherwise
• Viewer#rate_movie(movie, rating)
  • a Movie instance and a rating (number) are passed in as arguments
  • if the Viewer instance and the passed Movie instance are not already associated, this method should create a new Review instance
  • if this Viewer has already reviewed this Movie, assigns the new rating to the existing Review instance

• Movie#average_rating
  • returns the average of all ratings for the Movie instance
  • to average ratings, add all ratings together and divide by the total number of ratings.
• Movie.highest_rated
  • returns the Movie instance with the highest average rating.

You can find the rubric for this assessment here.