def format_author(author)
  %i[name email company website].map do |key|
    author[key]
  end.compact.join(', ')
end

def format_estimate(cardinality, interval)
  case interval
  when :days
    "#{cardinality}d"
  when :weeks
    "#{cardinality}w"
  else
    cardinality.to_s
  end
end

def format_story(story, kind = :regular)
  story_attributes = []
  story_attributes << "##{story[:id]}" if story[:id]
  story_attributes << story[:status] if story[:status]
  story_attributes << format_estimate(*story[:estimate]) if story[:estimate]
  story_attributes << "i#{story[:iteration]}" if story[:iteration]

  prefix = kind == :nested ? '| ' : ''
  formatted = "#{prefix}#{story[:description]}"
  formatted << " - #{story_attributes.join(' ')}" unless story_attributes.empty?
  formatted << "\n"
  formatted << "#{prefix}  #{story[:notes]}\n" if story[:notes]
  if story[:stories]
    story[:stories].each do |nested|
      formatted << format_story(nested, :nested)
    end
  end
  formatted
end

def format_definition(definition)
  [definition[:title], definition[:definition]].join(': ')
end