class ParallelTests::Test::Runner

def self.execute_command(cmd, process_number, options)
  cmd = "TEST_ENV_NUMBER=#{test_env_number(process_number)} ; export TEST_ENV_NUMBER; #{cmd}"
  f = open("|#{cmd}", 'r')
  output = fetch_output(f)
  f.close
  {:stdout => output, :exit_status => $?.exitstatus}
end

def self.fetch_output(process)
  all = ''
  while buffer = process.readpartial(1000000)
    all << buffer
    $stdout.print buffer
    $stdout.flush
  end rescue EOFError
  all
end

def self.files_in_folder(folder, options={})
  pattern = if options[:symlinks] == false # not nil or true
    "**/*"
  else
    # follow one symlink and direct children
    # http://stackoverflow.com/questions/357754/can-i-traverse-symlinked-directories-in-ruby-with-a-glob
    "**{,/*/**}/*"
  end
  Dir[File.join(folder, pattern)].uniq
end

def self.find_results(test_output)
  test_output.split("\n").map {|line|
    line = line.gsub(/\.|F|\*/,'').gsub(/\e\[\d+m/,'')
    next unless line_is_result?(line)
    line
  }.compact
end

def self.find_tests(tests, options = {})
  (tests || []).map do |file_or_folder|
    if File.directory?(file_or_folder)
      files = files_in_folder(file_or_folder, options)
      files.grep(/#{Regexp.escape test_suffix}$/).grep(options[:pattern]||//)
    else
      file_or_folder
    end
  end.flatten.uniq
end

def self.line_is_result?(line)
  line =~ /\d+ failure/
end

def self.run_tests(test_files, process_number, options)
  require_list = test_files.map { |filename| %{"#{File.expand_path filename}"} }.join(",")
  cmd = "ruby -Itest -e '[#{require_list}].each {|f| require f }' -- #{options[:test_options]}"
  execute_command(cmd, process_number, options)
end

def self.runtime_log
  'tmp/parallel_runtime_test.log'
end

def self.sum_up_results(results)
  results = results.join(' ').gsub(/s\b/,'') # combine and singularize results
  counts = results.scan(/(\d+) (\w+)/)
  sums = counts.inject(Hash.new(0)) do |sum, (number, word)|
    sum[word] += number.to_i
    sum
  end
  sums
end

def self.summarize_results(results)
  sums = sum_up_results(results)
  sums.sort.map{|word, number|  "#{number} #{word}#{'s' if number != 1}" }.join(', ')
end

def self.test_env_number(process_number)
  process_number == 0 ? '' : process_number + 1
end

def self.test_file_name
  "test"
end

def self.test_suffix
  "_test.rb"
end

def self.tests_in_groups(tests, num_groups, options={})
  tests = find_tests(tests, options)
  tests = if options[:group_by] == :found
    tests.map { |t| [t, 1] }
  else
    with_runtime_info(tests)
  end
  Grouper.in_even_groups_by_size(tests, num_groups, options)
end

def self.with_runtime_info(tests)
  lines = File.read(runtime_log).split("\n") rescue []
  # use recorded test runtime if we got enough data
  if lines.size * 1.5 > tests.size
    puts "Using recorded test runtime"
    times = Hash.new(1)
    lines.each do |line|
      test, time = line.split(":")
      next unless test and time
      times[File.expand_path(test)] = time.to_f
    end
    tests.sort.map{|test| [test, times[File.expand_path(test)]] }
  else # use file sizes
    tests.sort.map{|test| [test, File.stat(test).size] }
  end
end