require 'rubygems'
require 'annals'
require 'formatador'

module Tach

  def self.meter(times = 1, &block)
    Tach::Meter.new(times, &block)
  end

  class Meter

    def initialize(times = 1, &block)
      @benchmarks = []
      @results = {}
      @times = times

      instance_eval(&block)

      Formatador.display_line
      longest = @benchmarks.map {|benchmark| benchmark[0]}.map {|name| name.length}.max
      for name, block in @benchmarks
        @results[name] = run_in_thread("#{name}#{' ' * (longest - name.length)}", @times, &block)
      end

      data = []
      for name, block in @benchmarks
        value = @results[name]
        total = value.inject(0) {|sum,item| sum + item}
        data << { :average => format("%8.6f", (total / value.length)), :tach => name, :total => format("%8.6f", total) }
      end

      Formatador.display_table(data, [:tach, :average, :total])
      Formatador.display_line
    end

    def tach(name, &block)
      @benchmarks << [name, block]
    end

    private

    def run_in_thread(name, count, &benchmark)
      if count.to_s.length > 3
        divisor = 1
        (count.to_s.length - 3).times do
          divisor *= 10
        end
      end
      thread = Thread.new {
        Thread.current[:results] ||= []
        Thread.current[:started_at] = Time.now
        Formatador.redisplay_progressbar(0, count, :label => name, :started_at => Thread.current[:started_at])
        for index in 1..count
          tach_start = Time.now
          instance_eval(&benchmark)
          Thread.current[:results] << Time.now.to_f - tach_start.to_f
          if !divisor || index % divisor == 0
            Formatador.redisplay_progressbar(index, count, :label => name, :started_at => Thread.current[:started_at])
          end
        end
        Formatador.display_line
      }
      thread.join
      thread[:results]
    end

  end

end

if __FILE__ == $0

  data = 'Content-Length: 100'
  Tach.meter(1_000_000) do

    tach('regex') do
      header = data.match(/(.*):\s(.*)/)
      [$1, $2]
    end

    tach('split') do
      header = data.split(': ')
    end

  end

end