#!/usr/bin/ruby

problem_home = ENV['PROBLEM_HOME']

def execute(command, error_message="")
  if not system(command)
    puts "ERROR: #{error_message}"
    exit(127)
  end
end

# ARGV[0] --- language
# ARGV[1] --- program source file
# ARGV[2] --- test result directory
# ARGV[3] --- sandbox directory

if ARGV.length < 2 || ARGV.length > 4
  puts "Usage: judge <language> <program-source> [<test-result-directory>] [<sandbox-directory>]"
  puts "  <sandbox-directory> is defaulted to ./sandbox"
  puts "  <test-result-directory> is defaulted to ./test-result"
  puts "WARNING: The judge script will forcefully create the (implicitly and explicitly) specified directories and remove anything inside it."
  exit(127)
end

language = ARGV[0]
if language != "c" && language != "c++" && language != "pascal"
  puts "You specified a language that is not supported."
  exit(127)
end

source_file = ARGV[1]
if File.exist?(source_file) == false
  puts "The source file does not exist."
  exit(127)
end

puts "Making test result and sandbox directories..."

current_dir = `pwd`
current_dir.strip!

if ARGV.length >= 3
  test_result_dir = ARGV[2]
else
  test_result_dir = "#{current_dir}/test-result"
end
puts "Test result directory: #{test_result_dir}"
system("rm -Rf #{test_result_dir}")
execute("mkdir #{test_result_dir}", "Cannot make directory #{test_result_dir}.")

if ARGV.length >= 4
  sandbox_dir = ARGV[3]
else
  sandbox_dir = "#{current_dir}/sandbox"
end
puts "Sandbox directory: #{sandbox_dir}"
system("rm -Rf #{sandbox_dir}")
execute("mkdir #{sandbox_dir}", "Cannot make directory #{sandbox_dir}")

# Compile
puts
puts "Compiling..."
execute("cp #{source_file} #{sandbox_dir}", "Cannot copy the source file to #{sandbox_dir}")
begin 
  Dir.chdir sandbox_dir
rescue
  puts "ERROR: Cannot change directory to #{sandbox_dir}."
  exit(127)
end
execute("#{problem_home}/script/compile #{language} #{source_file}", "Compilation error!")
compile_message = `cat compiler_message`
compile_message.strip!
execute("mv compiler_message #{test_result_dir}", "Cannot move the compiler message to #{test_result_dir}.")
if !FileTest.exist?("a.out")
  puts "Cannot compile the source code. See message in #{test_result_dir}/compile_message"
  exit(127)
else
  execute("mv a.out #{test_result_dir}", "Cannot move the compiled program to #{test_result_dir}")
  system("rm -Rf #{sandbox_dir}/*")
end

require "#{problem_home}/script/test_dsl.rb"
load "#{problem_home}/test_cases/all_tests.cfg"
problem = Problem.get_instance

if problem.well_formed? == false
  puts "The problem specification is not well formed."
  exit(127)
end

# Doing the testing.
(1..(problem.num_tests)).each do |test_num|
  puts
  execute("cp #{test_result_dir}/a.out #{sandbox_dir}", "Cannot copy the compiled program into #{sandbox_dir}")
  execute("#{problem_home}/script/run #{language} #{test_num}", "Error occured during execution of the run script")
  execute("mkdir #{test_result_dir}/#{test_num}", "Cannot create directory #{test_result_dir}/#{test_num}")
  execute("mv #{sandbox_dir}/result #{test_result_dir}/#{test_num}", "Cannot copy the result file into #{test_result_dir}/#{test_num}")
  execute("mv #{sandbox_dir}/comment #{test_result_dir}/#{test_num}", "Cannot copy the comment file into #{test_result_dir}/#{test_num}")
  execute("rm -Rf #{sandbox_dir}/*", "Cannot clear #{sandbox_dir}")
end

# Grade
puts
puts "Grading..."
begin
  Dir.chdir test_result_dir
rescue
  puts "ERROR: Cannot change directory to #{test_result_dir}."
  exit(127)
end
execute("#{problem_home}/script/grade", "An error occured during grading!")

puts
puts "All done!"