module YearGroupsHelper

# File app/helpers/year_groups_helper.rb, line 4
def format_year_group(year_group)
  if year_group == -4
    "Early (1st year)"
  elsif year_group == -3
    "Early (2nd year)"
  elsif year_group == -2
    "Nursery (1st year)"
  elsif year_group == -1
    "Nursery (2nd year)"
  elsif year_group.zero?
    "Reception"
  else
    "Year #{year_group}"
  end
end

# File app/helpers/year_groups_helper.rb, line 20
def format_year_groups(year_groups)
  if year_groups.empty?
    "No year groups"
  elsif year_groups.length == 1
    format_year_group(year_groups.first)
  else
    positive_values, negative_values = year_groups.sort.partition(&:positive?)

    word_items =
      negative_values.each_with_index.map do |value, index|
        string = format_year_group(value)
        index.zero? ? string : string.downcase_first
      end

    numeric_items =
      if positive_values.length == 1
        [format_year_group(positive_values.first)]
      elsif positive_values.length > 1
        # Check if there is a continuous sequence of 3 or more values.
        if positive_values.length > 2 &&
             positive_values.each_cons(2).all? { |a, b| b == a + 1 }
          ["Years #{positive_values.first} to #{positive_values.last}"]
        else
          ["Years #{positive_values.first}"] +
            positive_values[1..].map(&:to_s)
        end
      else
        []
      end

    if word_items.present? && numeric_items.present?
      "#{word_items.join(", ")} and #{numeric_items.to_sentence.downcase_first}"
    elsif word_items.present?
      word_items.to_sentence
    else
      numeric_items.to_sentence
    end
  end
end