albums.rb

class Album
  attr_accessor :band, :title, :year, :tracks
  
  def initialize(title, band, year)
    @title  = title
    @band   = band
    @year   = year
    @tracks = []
  end

  def add_track(track)
    @tracks << track
  end

  def total_duration
    @tracks.map(&:duration).reduce(:+)
  end

  def print_booklet
    puts "title: #{title}"
    puts "band: #{band}"
    puts "year: #{year}"
    puts "total play time: #{total_duration}"
    puts "track list"
    puts "\n"

    @tracks.each do |track|
      puts "#{track.title} #{track.duration}"
    end
    puts "------------------------------"
  end
end

class Track
  attr_accessor :title, :duration

  def initialize(title, duration)
    @title    = title
    @duration = duration
  end
end

album = Album.new('La sottile linea grossa', 'Nemesi', '2014')
album.add_track(Track.new('Fenice', 270))
album.add_track(Track.new('Cara Barbara', 300))


album2 = Album.new('Solo Franco', 'Franco Califano', '1972')
album2.add_track(Track.new('Tutto il resto è noia', 270))
album2.add_track(Track.new('Solo gatti', 123))

album.print_booklet
album2.print_booklet