module Minitest
  def self.plugin_red_green_init options
    return if RedGreenPlugin.disabled
    reporters = self.reporter.reporters.grep Minitest::Reporter
    reporters.each do |reporter|
      reporter.io = RedGreenPlugin.new options[:io]
    end
  end

  class RedGreenPlugin
    singleton_class.send :attr_accessor, :disabled

    attr_accessor :sync

    ESC = "\e["

    def initialize io
      @io = io
    end

    def puts *strings
      if not strings.grep(%r{\d+\) (?:Failure|Error)}).empty?
        strings.map! &method(:red)
      end
      @io.puts *strings
    end

    def print str
      @io.print filter_test_output_chars str
    end

    def filter_test_output_chars str
      case str
      when '.' then green str
      when 'E', 'F' then red str
      when 'S' then yellow str
      else str
      end
    end

    def green str
      colorize str, 32
    end

    def red str
      colorize str, 31
    end

    def yellow str
      colorize str, 33
    end

    def colorize str, col_code
      "#{ESC}#{col_code}m#{str}#{ESC}0m"
    end
  end
end