class CephalopodMath
  attr_reader :worksheet
  def initialize(worksheet)
    @worksheet = worksheet
  end

  def self.for(input)
    new input
  end

  def wide_problem_answers
    problems.map do |problem|
      problem[..-2].map(&:to_i).reduce(&(problem[-1].strip.to_sym))
    end
  end

  def narrow_problem_answers
    problems.map do |problem|
      operator = problem[-1].strip.to_sym
      numbers = problem[..-2].map { |line| line.split("") }.transpose.map { |line| line.join("").to_i }.reject(&:zero?)
      numbers.reduce operator
    end
  end

  def problem_widths
    @problem_widths ||= operator_line.split("+").map { |c| c.split "*" }.flatten.map(&:length)[1..]
  end

  def problems
    @problems ||= lines.map(&:clone).map do |line|
      problem_widths.reduce([]) do |chunks, problem_width|
        slice = line.slice!(0, problem_width + 1)
        chunks << slice
      end
    end.transpose
  end

  def operator_line
    lines.last
  end

  def lines
    worksheet.split("\n")
  end
end