require 'atcoder_greedy'
require 'atcoder_greedy/command'
require 'diff/lcs'
require 'tempfile'
require 'benchmark'


module AtcoderGreedy
  class Command < Thor
    desc 'test PROBLEMNAME', 'test your solution'

    def test(problem_name)
      name = File.basename(problem_name, '.*')
      puts "Running a test for problem #{name}..."
      TestCase.new(name).validate
      puts "Test done."
    end
  end

  class TestCase
    def initialize(problem_name)
      @input_file = File.open("./input_#{problem_name}.txt", 'r')
      @exec_file = "./#{problem_name}.rb"
      get_in_out
    end

    def get_in_out
      i = 0
      @input = []
      @output = []
      now = nil
      while (t = @input_file.gets) != nil
        example_string = "-- Example #{i}"
        answer_string = "-- Answer #{i}"

        if t.chomp == example_string
          now.close(false) unless now.nil?
          now = Tempfile.new(['in', '.txt'], './')
          @input.push(now)
          now.open
        elsif t.chomp == answer_string
          now.close(false) unless now.nil?
          now = Tempfile.new(['out', '.txt'], './')
          @output.push(now)
          now.open
          i += 1
        else
          now.puts t
        end
      end
      @input[-1].close(false)
      @output[-1].close(false)
    end

    def validate
      @input.size.times do |j|
        myout_file = Tempfile.new(['myout', '.txt'], './')
        myout_file.open
        result = Benchmark.realtime do
          pid = Process.fork do
            exec "ruby #{@exec_file} < #{@input[j].path} > #{myout_file.path}"
            @input[j].close
            myout_file.close(false)
          end
          Process.waitpid pid
        end

        myout = myout_file.open.read
        myout_file.close
        correct = File.open("#{@output[j].path}").read
        diffs = Diff::LCS.diff(myout, correct)
        if diffs.size == 0
          puts "Testcase ##{j} ... PASSED! Time: #{result}s"
        else
          puts "Testcase ##{j} ... FAILED! Time: #{result}s"
          puts "Your Output:"
          puts "#{myout}\n"
          puts "Correct Answer:"
          puts "#{correct}\n"
        end
      end
    end
  end
end