# Put "List" Option

people.csv

serialization.rb

require 'csv'
require 'date'

class Person
  # Look at the above CSV file
  # What attributes should a Person object have?
  attr_reader :id , :first_name , :last_name , :email , :phone , :created_at

  def initialize(id, first_name, last_name, email, phone, created_at)
    @id = id 
    @first_name = first_name
    @last_name = last_name
    @email = email
    @phone = phone
    @created_at = created_at
  end

  def to_s
    puts "#{id}. #{first_name} #{last_name} #{email} #{phone} #{created_at}"
  end
end

class PersonParser
  attr_reader :file
  
  def initialize(file)
    @file = file
    @people = []
  end
  
  def people
    # If we've already parsed the CSV file, don't parse it again.
    # Remember: @people is +nil+ by default.
    return @people unless @people.empty?  # Return @people-> default nill ... since is not empty it return the right1
    
    # We've never called people before, now parse the CSV file
    # and return an Array of Person objects here.  Save the
    # Array in the @people instance variable.
    CSV.foreach(@file) {|row|
      @people << Person.new(row[0], row[1], row[2], row[3], row[4], row[5])
    }

    return @people
  end

  def add_people
    row = []
    row[0] = (people.size+1)

    print "First name : "
    row[1] = gets.chomp

    print "Last name : "
    row[2] =  gets.chomp

    print "Email : "
    row[3] =  gets.chomp

    print "Phone : "
    row[4] =  gets.chomp

    row[5] =  DateTime.parse(Time.now.to_s)  # Created_at(Date)

    @people << Person.new(row[0],row[1],row[2],row[3],row[4],row[5])  # store into the @people array

  end

  def save
    CSV.open(@file, 'wb'){|csv|
      @people.each {|person|
        csv << [person.id, person.first_name, person.last_name, person.email, person.phone, person.created_at]
      }
    } 
  end
  
  def list 
    @people.each_with_index { |person, index|
      puts "#{person.id}. #{person.first_name}   #{person.last_name}   #{person.email}  #{person.phone}  #{person.created_at}"
    }
    puts
  end
end

parser = PersonParser.new('people.csv')

parser.people
parser.add_people
parser.save

#parser.list
puts "There are #{parser.people.size} people in the file '#{parser.file}'."