module PicturehouseUk
  # A film on the Picturehouse UK website
  class Film
    include Comparable

    # @return [String] the name of the film
    attr_reader :name
    # @return [String] the normalized slug derived from the film name
    attr_reader :slug

    # @param [String] name the film name
    # @return [PicturehouseUk::Film]
    def initialize(name)
      @name = name
      @slug = name.downcase.gsub(/[^0-9a-z ]/, '').gsub(/\s+/, '-')
    end

    # Films at a single cinema
    # @param [String] cinema_id the id of the cinema
    # @return [Array<PicturehouseUk::Film>]
    def self.at(cinema_id)
      cinema_page(cinema_id).film_html.map do |html|
        new(Internal::FilmWithScreeningsParser.new(html).film_name)
      end.uniq
    end

    # Allows sort on objects
    # @param [PicturehouseUk::Film] other another film object
    # @return [Integer] -1, 0 or 1
    def <=>(other)
      slug <=> other.slug
    end

    # Check an object is the same as another object.
    # @param [PicturehouseUk::Film] other another film
    # @return [Boolean] True if both objects are the same exact object, or if
    #   they are of the same type and share an equal slug
    # @note Guided by http://woss.name/2011/01/20/equality-comparison-and-ordering-in-ruby/
    def eql?(other)
      self.class == other.class && self == other
    end

    # Generates hash of slug in order to allow two records of the same type and
    # id to work with something like:
    #
    #   [ Film.new('AB'), Film.new('EF') ] & [ Film.new('EF'), Film.new('GH') ]
    #   #=> [ Film.new('EF') ]
    #
    # @return [Integer] hash of slug
    # @note Guided by http://woss.name/2011/01/20/equality-comparison-and-ordering-in-ruby/
    def hash
      slug.hash
    end

    private

    def self.cinema_page(cinema_id)
      @cinema_page ||= PicturehouseUk::Internal::CinemaPage.new(cinema_id)
    end
  end
end