class App
  def initialize
    @books  = []
    @people = []
  end

  def list_books
    puts 'No books available' if @books.empty?
    @books.each do |bk|
      puts "Title: #{bk.title}, Author: #{bk.author}"
    end
  end

  def list_people
    if @people.empty?
      puts 'No one has registered'
    else
      @people.each do |human|
        puts "[#{human.class}] ID: #{human.id}, Name: #{human.name}, Age: #{human.age}"
      end
    end
  end

  def create_person
    print 'Do you want to create a student (1) or a teacher (2)? [Input the number]: '
    choice = gets.chomp
    case choice
    when '1'
      create_student
    when '2'
      create_teacher
    else
      puts 'Invalid option'
    end
  end

  def create_student
    print 'Age: '
    age = gets.chomp.to_i
    print 'Name: '
    name = gets.chomp
    print 'Has parent permission? [Y/N]: '
    perm = gets.chomp.upcase
    parent_permission = perm == 'Y'
    stu = Student.new(age, nil, name, parent_permission: parent_permission)
    @people << stu
    puts 'Student created successfully'
  end

  def create_teacher
    print 'Age: '
    age = gets.chomp.to_i
    print 'Name: '
    name = gets.chomp
    print 'Specialization: '
    specialization = gets.chomp
    t = Teacher.new(age, specialization, name)
    @people << t
    puts 'Teacher created successfully'
  end

  def create_book
    print 'Title: '
    title = gets.chomp
    print 'Author: '
    author = gets.chomp
    @books << Book.new(title, author)
    puts 'Book created successfully'
  end

  def create_rental
    if @books.empty?
      puts 'No books available'
      return
    end
    if @people.empty?
      puts 'No people available'
      return
    end
    
    puts 'Select a book from the following list by number'
    @books.each_with_index { |b, i| puts "#{i}) Title: #{b.title}, Author: #{b.author}" }
    book_index = gets.chomp.to_i
    
    puts 'Select a person from the following list by number (not id)'
    @people.each_with_index { |p, i| puts "#{i}) [#{p.class}] Name: #{p.name}, ID: #{p.id}, Age: #{p.age}" }
    person_index = gets.chomp.to_i
    
    if valid_indices?(person_index, book_index)
      print 'Date: '
      date = gets.chomp
      Rental.new(date, @books[book_index], @people[person_index])
      puts 'Rental created successfully'
    else
      puts 'Invalid selection'
    end
  end

  def list_rentals
    print 'ID of person: '
    pid = gets.chomp.to_i
    person = @people.find { |p| p.id == pid }
    if person
      puts 'Rentals:'
      person.rentals.each { |r| puts "Date: #{r.date}, Book: #{r.book.title} by #{r.book.author}" }
    else
      puts 'Person not found'
    end
  end

  private

  def valid_indices?(p_i, b_i)
    p_i.between?(0, @people.length - 1) && b_i.between?(0, @books.length - 1)
  end
end

class Nameable
  def correct_name
    raise NotImplementedError
  end
end

class Decorator < Nameable
  def initialize(nameable)
    super()
    @nameable = nameable
  end

  def correct_name
    @nameable.correct_name
  end
end

class TrimmerDecorator < Decorator
  def correct_name
    @nameable.correct_name[0..9]
  end
end

class CapitalizeDecorator < Decorator
  def correct_name
    @nameable.correct_name.capitalize
  end
end

class Rental
  attr_accessor :date, :book, :person

  def initialize(date, book, person)
    @date = date
    @book = book
    @person = person
    
    book.rentals << self
    person.rentals << self
  end
end

class Book
  attr_accessor :title, :author, :rentals

  def initialize(title, author)
    @title = title
    @author = author
    @rentals = []
  end

  def add_rental(person, date)
    Rental.new(date, self, person)
  end
end

class Classroom
  attr_accessor :label, :students

  def initialize(label)
    @label = label
    @students = []
  end

  def add_student(student)
    students << student unless students.include?(student)
    student.classroom = self
  end
end

class Person < Nameable
  attr_accessor :name, :age, :rentals
  attr_reader :id

  def initialize(age, name = 'Unknown', parent_permission: true)
    super()
    @id = Random.rand(1..1000)
    @name = name
    @age = age
    @parent_permission = parent_permission
    @rentals = []
  end

  def can_use_services?
    of_age? || @parent_permission
  end

  def correct_name
    name
  end

  def add_rental(book, date)
    Rental.new(date, book, self)
  end

  private

  def of_age?
    @age >= 18
  end
end

class Student < Person
  attr_reader :classroom

  def initialize(age, classroom, name = 'Unknown', parent_permission: true)
    super(age, name, parent_permission: parent_permission)
    @classroom = classroom
    classroom&.add_student(self)
  end

  def play_hooky
    '╰(°▽°)╯'
  end

  def classroom=(room)
    @classroom = room
    room.students << self unless room.students.include?(self)
  end
end

class Teacher < Person
  attr_accessor :specialization

  def initialize(age, specialization, name = 'Unknown')
    super(age, name)
    @specialization = specialization
  end

  def can_use_services?
    true
  end
end