# Copyright (c) 2010-2011 Chortos-2 <chortos@inbox.lv>

# TODO: copy the ansfile if not options.erase even if no validator is used

from __future__ import division, with_statement

from compat import *
import files, problem, config
from __main__ import options

import glob, re, sys, tempfile, time
from subprocess import Popen, PIPE, STDOUT

import os
devnull = open(os.path.devnull, 'w+')

if options.autotime:
	# This is really a dirty hack that assumes that sleep() does not spend
	# the CPU time of the current process and that if clock() measures
	# wall-clock time, then it is more precise than time() is. Both these
	# assumptions are true on all platforms I have tested this on so far,
	# but I am not aware of any guarantee that they will both be true
	# on every other platform.
	c = time.clock()
	time.sleep(1)
	c = time.clock() - c
	if int(c + .5) == 1:
		clock = time.clock
	else:
		clock = time.time

class DummySignalIgnorer(object):
	def __enter__(self): pass
	def __exit__(self, exc_type, exc_value, traceback): pass
signal_ignorer = DummySignalIgnorer()

try:
	from win32 import *
except Exception:
	from unix import *

__all__ = ('TestCase', 'load_problem', 'TestCaseNotPassed',
           'TimeLimitExceeded', 'CanceledByUser', 'WrongAnswer',
           'NonZeroExitCode', 'CannotStartTestee',
           'CannotStartValidator', 'CannotReadOutputFile',
           'CannotReadInputFile', 'CannotReadAnswerFile',
           'MemoryLimitExceeded', 'CPUTimeLimitExceeded',
           'WallTimeLimitExceeded')



# Exceptions

class TestCaseNotPassed(Exception): __slots__ = ()
class TestCaseSkipped(TestCaseNotPassed): __slots__ = ()
class TimeLimitExceeded(TestCaseNotPassed): __slots__ = ()
class CPUTimeLimitExceeded(TimeLimitExceeded): __slots__ = ()
class WallTimeLimitExceeded(TimeLimitExceeded): __slots__ = ()
class MemoryLimitExceeded(TestCaseNotPassed): __slots__ = ()
class CanceledByUser(TestCaseNotPassed): __slots__ = ()

class WrongAnswer(TestCaseNotPassed):
	__slots__ = 'comment'
	def __init__(self, comment=''):
		self.comment = comment

class NonZeroExitCode(TestCaseNotPassed):
	__slots__ = 'exitcode'
	def __init__(self, exitcode):
		self.exitcode = exitcode

class ExceptionWrapper(TestCaseNotPassed):
	__slots__ = 'upstream'
	def __init__(self, upstream):
		self.upstream = upstream

class CannotStartTestee(ExceptionWrapper): __slots__ = ()
class CannotStartValidator(ExceptionWrapper): __slots__ = ()
class CannotReadOutputFile(ExceptionWrapper): __slots__ = ()
class CannotReadInputFile(ExceptionWrapper): __slots__ = ()
class CannotReadAnswerFile(ExceptionWrapper): __slots__ = ()



# Helper context managers

class CopyDeleting(object):
	__slots__ = 'case', 'file', 'name'
	
	def __init__(self, case, file, name):
		self.case = case
		self.file = file
		self.name = name
	
	def __enter__(self):
		if self.name:
			try:
				self.file.copy(self.name)
			except:
				try:
					self.__exit__(None, None, None)
				except:
					pass
				raise
	
	def __exit__(self, exc_type, exc_val, exc_tb):
		if self.name:
			self.case.files_to_delete.append(self.name)


class Copying(object):
	__slots__ = 'file', 'name'
	
	def __init__(self, file, name):
		self.file = file
		self.name = name
	
	def __enter__(self):
		if self.name:
			self.file.copy(self.name)
	
	def __exit__(self, exc_type, exc_val, exc_tb):
		pass



# Test case types

class TestCase(object):
	__slots__ = ('problem', 'id', 'isdummy', 'infile', 'outfile', 'points',
	             'process', 'time_started', 'time_stopped',
	             'realinname', 'realoutname', 'maxcputime', 'maxwalltime',
	             'maxmemory', 'has_called_back', 'files_to_delete',
	             'cpu_time_limit_string', 'wall_time_limit_string',
	             'time_limit_string')
	has_ansfile = has_iofiles = False
	needs_realinname = True
	
	if ABCMeta:
		__metaclass__ = ABCMeta
	
	def __init__(case, prob, id, isdummy, points):
		case.problem = prob
		case.id = id
		case.isdummy = isdummy
		case.points = points
		case.maxcputime = case.problem.config.maxcputime
		case.maxwalltime = case.problem.config.maxwalltime
		case.maxmemory = case.problem.config.maxmemory
		if case.maxcputime:
			case.cpu_time_limit_string = '/%.3f' % case.maxcputime
		else:
			case.cpu_time_limit_string = ''
		if case.maxwalltime:
			case.wall_time_limit_string = '/%.3f' % case.maxwalltime
		else:
			case.wall_time_limit_string = ''
		if not isdummy:
			if case.needs_realinname:
				case.realinname = case.problem.config.testcaseinname
			case.realoutname = case.problem.config.testcaseoutname
		else:
			if case.needs_realinname:
				case.realinname = case.problem.config.dummyinname
			case.realoutname = case.problem.config.dummyoutname
	
	@abstractmethod
	def test(case):
		raise NotImplementedError
	
	def __call__(case, callback):
		case.has_called_back = False
		case.files_to_delete = []
		case.time_limit_string = case.wall_time_limit_string
		try:
			return case.test(callback)
		finally:
			now = clock()
			if getattr(case, 'time_started', None) is None:
				case.time_started = case.time_stopped = now
			elif getattr(case, 'time_stopped', None) is None:
				case.time_stopped = now
			if not case.has_called_back:
				callback()
			case.cleanup()
	
	def cleanup(case):
		#if getattr(case, 'infile', None):
		#	case.infile.close()
		#if getattr(case, 'outfile', None):
		#	case.outfile.close()
		if getattr(case, 'process', None) and case.process.returncode is None:
			# Try KILLing after three unsuccessful TERM attempts in a row
			for i in range(3):
				try:
					terminate(case.process)
				except Exception:
					time.sleep(0)
				else:
					wait(case.process)
					break
			else:
				# If killing the process is unsuccessful three times in a row,
				# just silently stop trying
				for i in range(3):
					try:
						kill(case.process)
					except Exception:
						time.sleep(0)
					else:
						wait(case.process)
						break
		if case.files_to_delete:
			for name in case.files_to_delete:
				try:
					os.remove(name)
				except Exception:
					# It can't be helped
					pass
	
	def open_infile(case):
		try:
			case.infile = files.File('/'.join((case.problem.name, case.realinname.replace('$', case.id))))
		except IOError:
			e = sys.exc_info()[1]
			raise CannotReadInputFile(e)
	
	def open_outfile(case):
		try:
			case.outfile = files.File('/'.join((case.problem.name, case.realoutname.replace('$', case.id))))
		except IOError:
			e = sys.exc_info()[1]
			raise CannotReadAnswerFile(e)


class SkippedTestCase(TestCase):
	__slots__ = ()
	
	def test(case, callback):
		raise TestCaseSkipped


class ValidatedTestCase(TestCase):
	__slots__ = 'validator'
	
	def __init__(case, *args):
		TestCase.__init__(case, *args)
		if not case.problem.config.tester:
			case.validator = None
		else:
			case.validator = case.problem.config.tester
	
	def validate(case, output):
		if not case.validator:
			# Compare the output with the reference output
			case.open_outfile()
			with case.outfile.open() as refoutput:
				for line, refline in zip_longest(output, refoutput):
					if refline is not None and not isinstance(refline, basestring):
						line = bytes(line, sys.getdefaultencoding())
					if line != refline:
						raise WrongAnswer
			return 1
		elif callable(case.validator):
			return case.validator(output)
		else:                 
			# Call the validator program
			output.close()
			if case.problem.config.ansname:
				case.open_outfile()
				case.outfile.copy(case.problem.config.ansname)
			try:
				case.process = Popen(case.validator, stdin=devnull, stdout=PIPE, stderr=STDOUT, universal_newlines=True, bufsize=-1)
			except OSError:
				raise CannotStartValidator(sys.exc_info()[1])
			with signal_ignorer:
				comment = case.process.communicate()[0].strip()
			match = re.match(r'(?i)(ok|(?:correct|wrong)(?:(?:\s|_)*answer)?)(?:$|\s+|[.,!:]+\s*)', comment)
			if match:
				comment = comment[match.end():]
			if not case.problem.config.maxexitcode:
				if case.process.returncode:
					raise WrongAnswer(comment)
				else:
					return 1, comment
			else:
				return case.process.returncode / case.problem.config.maxexitcode, comment


class BatchTestCase(ValidatedTestCase):
	__slots__ = ()
	
	@property
	def has_iofiles(case):
		return (not case.problem.config.stdio or
		        case.validator and not callable(case.validator))
	
	@property
	def has_ansfile(case):
		return case.validator and not callable(case.validator)
	
	def test(case, callback):
		case.open_infile()
		if case.problem.config.stdio:
			if options.erase and not case.validator or not case.problem.config.inname:
				# TODO: re-use the same file name if possible
				# FIXME: 2.5 lacks the delete parameter
				with tempfile.NamedTemporaryFile(delete=False) as f:
					inputdatafname = f.name
				contextmgr = CopyDeleting(case, case.infile, inputdatafname)
			else:
				inputdatafname = case.problem.config.inname
				contextmgr = Copying(case.infile, inputdatafname)
			with contextmgr:
				with open(inputdatafname) as infile:
					with tempfile.TemporaryFile('w+') if options.erase and (not case.validator or callable(case.validator)) else open(case.problem.config.outname, 'w+') as outfile:
						call(case.problem.config.path, case=case, stdin=infile, stdout=outfile, stderr=devnull)
						if config.globalconf.force_zero_exitcode and case.process.returncode or case.process.returncode < 0:
							raise NonZeroExitCode(case.process.returncode)
						case.has_called_back = True
						callback()
						outfile.seek(0)
						return case.validate(outfile)
		else:
			case.infile.copy(case.problem.config.inname)
			call(case.problem.config.path, case=case, stdin=devnull, stdout=devnull, stderr=STDOUT)
			if config.globalconf.force_zero_exitcode and case.process.returncode or case.process.returncode < 0:
				raise NonZeroExitCode(case.process.returncode)
			case.has_called_back = True
			callback()
			try:
				output = open(case.problem.config.outname, 'rU')
			except IOError:
				raise CannotReadOutputFile(sys.exc_info()[1])
			with output as output:
				return case.validate(output)


# This is the only test case type not executing any programs to be tested
class OutputOnlyTestCase(ValidatedTestCase):
	__slots__ = ()
	needs_realinname = False
	
	def cleanup(case):
		pass
	
	def test(case, callback):
		case.time_stopped = case.time_started = 0
		case.has_called_back = True
		callback()
		try:
			output = open(case.problem.config.outname.replace('$', case.id), 'rU')
		except IOError:
			raise CannotReadOutputFile(sys.exc_info()[1])
		with output as output:
			return case.validate(output)


class BestOutputTestCase(ValidatedTestCase):
	__slots__ = ()


# This is the only test case type executing two programs simultaneously
class ReactiveTestCase(TestCase):
	__slots__ = ()
	# The basic idea is to launch the program to be tested and the grader
	# and to pipe their standard I/O from and to each other,
	# and then to capture the grader's exit code and use it
	# like the exit code of an output validator is used.


class DummyTestContext(problem.TestGroup):
	__slots__ = ()
	def end(self):
		say('Sample total: %d/%d tests' % (self.ncorrect, self.ntotal))
		return 0, 0, self.log

def load_problem(prob, _types={'batch'   : BatchTestCase,
                               'outonly' : OutputOnlyTestCase,
                               'bestout' : BestOutputTestCase,
                               'reactive': ReactiveTestCase}):
	# We will need to iterate over these configuration variables twice
	try:
		len(prob.config.dummies)
	except Exception:
		prob.config.dummies = tuple(prob.config.dummies)
	try:
		len(prob.config.tests)
	except Exception:
		prob.config.tests = tuple(prob.config.tests)
	
	if options.legacy:
		prob.config.usegroups = False
		newtests = []
		for i, name in enumerate(prob.config.tests):
			# Same here; we'll need to iterate over them twice
			try:
				l = len(name)
			except Exception:
				try:
					name = tuple(name)
				except TypeError:
					name = (name,)
				l = len(name)
			if l > 1:
				prob.config.usegroups = True
			newtests.append(name)
		if prob.config.usegroups:
			prob.config.tests = newtests
		del newtests
	
	# Even if they have duplicate test identifiers, we must honour sequence pointmaps
	if isinstance(prob.config.pointmap, dict):
		def getpoints(i, j, k=None):
			try:
				return prob.config.pointmap[i]
			except KeyError:
				try:
					return prob.config.pointmap[None]
				except KeyError:
					return prob.config.maxexitcode or 1
	elif prob.config.usegroups:
		def getpoints(i, j, k):
			try:
				return prob.config.pointmap[k][j]
			except LookupError:
				return prob.config.maxexitcode or 1
	else:
		def getpoints(i, j):
			try:
				return prob.config.pointmap[j]
			except LookupError:
				return prob.config.maxexitcode or 1
	
	# First get prob.cache.padoutput right,
	# then yield the actual test cases
	for i in prob.config.dummies:
		s = 'sample ' + str(i).zfill(prob.config.paddummies)
		prob.cache.padoutput = max(prob.cache.padoutput, len(s))
	if prob.config.usegroups:
		if not isinstance(prob.config.groupweight, dict):
			prob.config.groupweight = dict(enumerate(prob.config.groupweight))
		for group in prob.config.tests:
			for i in group:
				s = str(i).zfill(prob.config.padtests)
				prob.cache.padoutput = max(prob.cache.padoutput, len(s))
		if prob.config.dummies:
			yield DummyTestContext()
			for i in prob.config.dummies:
				s = str(i).zfill(prob.config.paddummies)
				if (yield _types[prob.config.kind](prob, s, True, 0)):
					yield
			yield problem.test_context_end
		for k, group in enumerate(prob.config.tests):
			if not group:
				continue
			yield problem.TestGroup(prob.config.groupweight.get(k, prob.config.groupweight.get(None)))
			case_type = _types[prob.config.kind]
			for j, i in enumerate(group):
				s = str(i).zfill(prob.config.padtests)
				if not (yield case_type(prob, s, False, getpoints(i, j, k))):
					if options.skim:
						case_type = SkippedTestCase
				else:
					yield
			yield problem.test_context_end
	else:
		for i in prob.config.tests:
			s = str(i).zfill(prob.config.padtests)
			prob.cache.padoutput = max(prob.cache.padoutput, len(s))
		for i in prob.config.dummies:
			s = str(i).zfill(prob.config.paddummies)
			if (yield _types[prob.config.kind](prob, s, True, 0)):
				yield
		for j, i in enumerate(prob.config.tests):
			s = str(i).zfill(prob.config.padtests)
			if (yield _types[prob.config.kind](prob, s, False, getpoints(i, j))):
				yield