tenant_name_normalizer

tenant_name_normalizer.rb

class Person < Struct.new(:name); end

@tenants = ('ah'..'ch').map { |l| Person.new(l) }
@tenant_names = @tenants.map(&:name)

class TenantNamesNormalizer
  def initialize(tenant_names, filter_by_letter:nil, sorted_in_reverse: false)
    @tenant_names      = tenant_names
    @filter_by_letter  = filter_by_letter
    @sorted_in_reverse = sorted_in_reverse
  end

  def filter_by_letter
    new_tenant_names = @filter_by_letter? @tenant_names.select{|n| n.start_with?(@filter_by_letter)} : @tenant_names
    new(new_tenant_names, filter_by_letter: @filter_by_letter, sorted_in_reverse: @sorted_in_reverse)
  end

  def sorted_in_reverse
    new_tenant_names = @sorted_in_reverse? @tenant_names.reverse : @tenant_names
    new(new_tenant_names, filter_by_letter: @filter_by_letter, sorted_in_reverse: @sorted_in_reverse)
  end

  def to_a
    @tenant_names
  end

  private

  def new(*args)
    self.class.new(*args)
  end
end


def tenant_names_on_page(tenant_names, page, num_per_page:5, sorted_in_reverse: false, filter_by_letter: nil)
  TenantNamesNormalizer.new(tenant_names, sorted_in_reverse:sorted_in_reverse, filter_by_letter: filter_by_letter)
    .filter_by_letter
    .sorted_in_reverse
    .to_a
    .each_slice(num_per_page).to_a[page-1]
end

puts tenant_names_on_page(@tenant_names, 1, sorted_in_reverse: false, filter_by_letter: 'c')