easy-going-rails/lib/formatters/wrapper.rb

class Wrapper
  def self.wrap(text, prefix = ' > ', length = 80)
    text = carriage_return_filler(text.chomp(''), length)

    pure = ''
    ansi_code = {}
    while (md = text.match(/\e\[\d+;?\d*m/))
      pos = md.begin(0) + pure.length
      pure += md.pre_match
      text = md.post_match
      append_in_hash(ansi_code, pos, md.match(0))
    end
    pure += text

    offset = 0
    ansi_extra = {}
    rows = pure.length / length
    last_code = nil
    rows.times do |i|
      pos = (i + 1) * length
      last_code = last_ansi_by_range(ansi_code, last_code, offset, pos)
      if last_code
        append_in_hash(ansi_extra, pos, "\e[0m\n#{prefix}#{last_code}")
      elsif pos < pure.length
        append_in_hash(ansi_extra, pos, "\n#{prefix}")
      end
      offset = pos + 1
    end
    ansi_extra.each_pair do |k, v|
      append_in_hash(ansi_code, k, v.first)
    end

    ansi_code = ansi_code.sort

    final = pure
    offset = 0
    ansi_code.each do |k, v|
      insert_text = v.join
      final = final.insert(k + offset, insert_text)
      offset += insert_text.length
    end

    final
  end

  private

  def self.carriage_return_filler(text, length)
    lines = text.split("\n")
    return text if lines.count < 2

    last_ansi = nil
    final = lines.map do |line|
      fill_count = length - line.length
      current = line
      result = last_ansi ? "#{last_ansi}#{line}" : line
      last_ansi = nil if last_ansi == "\e[0m"
      while (md = current.match(/\e\[\d+;?\d*m/))
        last_ansi = md.to_s
        fill_count += last_ansi.length
        current = md.post_match
      end
      result = "#{result}\e[0m" if last_ansi
      next result if fill_count < 1

      "#{result}#{' ' * fill_count}"
    end.join
    last_ansi ? "#{final}\e[0m" : final
  end

  def self.last_ansi_by_range(ansi_code, last_code, offset, pos)
    pos.downto(offset) do |i|
      next unless ansi_code.has_key?(i)

      result = ansi_code[i].last
      result = nil if result == "\e[0m"
      return result
    end
    last_code
  end

  def self.append_in_hash(hash, key, value)
    if hash.has_key?(key)
      hash[key] << value
    else
      hash[key] = [value]
    end
  end
end