import sys

import signal

import unittest

from django.conf import settings

from django.db.models import get_app, get_apps

from django.test import _doctest as doctest

from django.test.utils import setup_test_environment, teardown_test_environment

from django.test.testcases import OutputChecker, DocTestRunner, TestCase

# The module name for tests outside models.py

TEST_MODULE = 'tests'

doctestOutputChecker = OutputChecker()

class DjangoTestRunner(unittest.TextTestRunner):

    def __init__(self, verbosity=0, failfast=False, **kwargs):

        super(DjangoTestRunner, self).__init__(verbosity=verbosity, **kwargs)

        self.failfast = failfast

        self._keyboard_interrupt_intercepted = False

    def run(self, *args, **kwargs):

        """

        Runs the test suite after registering a custom signal handler

        that triggers a graceful exit when Ctrl-C is pressed.

        """

        self._default_keyboard_interrupt_handler = signal.signal(signal.SIGINT,

            self._keyboard_interrupt_handler)

        try:

            result = super(DjangoTestRunner, self).run(*args, **kwargs)

        finally:

            signal.signal(signal.SIGINT, self._default_keyboard_interrupt_handler)

        return result

    def _keyboard_interrupt_handler(self, signal_number, stack_frame):

        """

        Handles Ctrl-C by setting a flag that will stop the test run when

        the currently running test completes.

        """

        self._keyboard_interrupt_intercepted = True

        sys.stderr.write(" <Test run halted by Ctrl-C> ")

        # Set the interrupt handler back to the default handler, so that

        # another Ctrl-C press will trigger immediate exit.

        signal.signal(signal.SIGINT, self._default_keyboard_interrupt_handler)

    def _makeResult(self):

        result = super(DjangoTestRunner, self)._makeResult()

        failfast = self.failfast

        def stoptest_override(func):

            def stoptest(test):

                # If we were set to failfast and the unit test failed,

                # or if the user has typed Ctrl-C, report and quit

                if (failfast and not result.wasSuccessful()) or \

                    self._keyboard_interrupt_intercepted:

                    result.stop()

                func(test)

            return stoptest

        setattr(result, 'stopTest', stoptest_override(result.stopTest))

        return result

def get_tests(app_module):

    try:

        app_path = app_module.__name__.split('.')[:-1]

        test_module = __import__('.'.join(app_path + [TEST_MODULE]), {}, {}, TEST_MODULE)

    except ImportError, e:

        # Couldn't import tests.py. Was it due to a missing file, or

        # due to an import error in a tests.py that actually exists?

        import os.path

        from imp import find_module

        try:

            mod = find_module(TEST_MODULE, [os.path.dirname(app_module.__file__)])

        except ImportError:

            # 'tests' module doesn't exist. Move on.

            test_module = None

        else:

            # The module exists, so there must be an import error in the

            # test module itself. We don't need the module; so if the

            # module was a single file module (i.e., tests.py), close the file

            # handle returned by find_module. Otherwise, the test module

            # is a directory, and there is nothing to close.

            if mod[0]:

                mod[0].close()

            raise

    return test_module

def build_suite(app_module):

    "Create a complete Django test suite for the provided application module"

    suite = unittest.TestSuite()

    # Load unit and doctests in the models.py module. If module has

    # a suite() method, use it. Otherwise build the test suite ourselves.

    if hasattr(app_module, 'suite'):

        suite.addTest(app_module.suite())

    else:

        suite.addTest(unittest.defaultTestLoader.loadTestsFromModule(app_module))

        try:

            suite.addTest(doctest.DocTestSuite(app_module,

                                               checker=doctestOutputChecker,

                                               runner=DocTestRunner))

        except ValueError:

            # No doc tests in models.py

            pass

    # Check to see if a separate 'tests' module exists parallel to the

    # models module

    test_module = get_tests(app_module)

    if test_module:

        # Load unit and doctests in the tests.py module. If module has

        # a suite() method, use it. Otherwise build the test suite ourselves.

        if hasattr(test_module, 'suite'):

            suite.addTest(test_module.suite())

        else:

            suite.addTest(unittest.defaultTestLoader.loadTestsFromModule(test_module))

            try:

                suite.addTest(doctest.DocTestSuite(test_module,

                                                   checker=doctestOutputChecker,

                                                   runner=DocTestRunner))

            except ValueError:

                # No doc tests in tests.py

                pass

    return suite

def build_test(label):

    """Construct a test case with the specified label. Label should be of the

    form model.TestClass or model.TestClass.test_method. Returns an

    instantiated test or test suite corresponding to the label provided.

    """

    parts = label.split('.')

    if len(parts) < 2 or len(parts) > 3:

        raise ValueError("Test label '%s' should be of the form app.TestCase or app.TestCase.test_method" % label)

    #

    # First, look for TestCase instances with a name that matches

    #

    app_module = get_app(parts[0])

    test_module = get_tests(app_module)

    TestClass = getattr(app_module, parts[1], None)

    # Couldn't find the test class in models.py; look in tests.py

    if TestClass is None:

        if test_module:

            TestClass = getattr(test_module, parts[1], None)

    try:

        if issubclass(TestClass, unittest.TestCase):

            if len(parts) == 2: # label is app.TestClass

                try:

                    return unittest.TestLoader().loadTestsFromTestCase(TestClass)

                except TypeError:

                    raise ValueError("Test label '%s' does not refer to a test class" % label)

            else: # label is app.TestClass.test_method

                return TestClass(parts[2])

    except TypeError:

        # TestClass isn't a TestClass - it must be a method or normal class

        pass

    #

    # If there isn't a TestCase, look for a doctest that matches

    #

    tests = []

    for module in app_module, test_module:

        try:

            doctests = doctest.DocTestSuite(module,

                                            checker=doctestOutputChecker,

                                            runner=DocTestRunner)

            # Now iterate over the suite, looking for doctests whose name

            # matches the pattern that was given

            for test in doctests:

                if test._dt_test.name in (

                        '%s.%s' % (module.__name__, '.'.join(parts[1:])),

                        '%s.__test__.%s' % (module.__name__, '.'.join(parts[1:]))):

                    tests.append(test)

        except ValueError:

            # No doctests found.

            pass

    # If no tests were found, then we were given a bad test label.

    if not tests:

        raise ValueError("Test label '%s' does not refer to a test" % label)

    # Construct a suite out of the tests that matched.

    return unittest.TestSuite(tests)

def partition_suite(suite, classes, bins):

    """

    Partitions a test suite by test type.

    classes is a sequence of types

    bins is a sequence of TestSuites, one more than classes

    Tests of type classes[i] are added to bins[i],

    tests with no match found in classes are place in bins[-1]

    """

    for test in suite:

        if isinstance(test, unittest.TestSuite):

            partition_suite(test, classes, bins)

        else:

            for i in range(len(classes)):

                if isinstance(test, classes[i]):

                    bins[i].addTest(test)

                    break

            else:

                bins[-1].addTest(test)

def reorder_suite(suite, classes):

    """

    Reorders a test suite by test type.

    classes is a sequence of types

    All tests of type clases[0] are placed first, then tests of type classes[1], etc.

    Tests with no match in classes are placed last.

    """

    class_count = len(classes)

    bins = [unittest.TestSuite() for i in range(class_count+1)]

    partition_suite(suite, classes, bins)

    for i in range(class_count):

        bins[0].addTests(bins[i+1])

    return bins[0]

class DjangoTestSuiteRunner(object):

    def __init__(self, verbosity=1, interactive=True, failfast=True, **kwargs):

        self.verbosity = verbosity

        self.interactive = interactive

        self.failfast = failfast

    def setup_test_environment(self, **kwargs):

        setup_test_environment()

        settings.DEBUG = False

    def build_suite(self, test_labels, extra_tests=None, **kwargs):

        suite = unittest.TestSuite()

        if test_labels:

            for label in test_labels:

                if '.' in label:

                    suite.addTest(build_test(label))

                else:

                    app = get_app(label)

                    suite.addTest(build_suite(app))

        else:

            for app in get_apps():

                suite.addTest(build_suite(app))

        if extra_tests:

            for test in extra_tests:

                suite.addTest(test)

        return reorder_suite(suite, (TestCase,))

    def setup_databases(self, **kwargs):

        from django.db import connections

        old_names = []

        mirrors = []

        for alias in connections:

            connection = connections[alias]

            # If the database is a test mirror, redirect it's connection

            # instead of creating a test database.

            if connection.settings_dict['TEST_MIRROR']:

                mirrors.append((alias, connection))

                mirror_alias = connection.settings_dict['TEST_MIRROR']

                connections._connections[alias] = connections[mirror_alias]

            else:

                old_names.append((connection, connection.settings_dict['NAME']))

                connection.creation.create_test_db(self.verbosity, autoclobber=not self.interactive)

        return old_names, mirrors

    def run_suite(self, suite, **kwargs):

        return DjangoTestRunner(verbosity=self.verbosity, failfast=self.failfast).run(suite)

    def teardown_databases(self, old_config, **kwargs):

        from django.db import connections

        old_names, mirrors = old_config

        # Point all the mirrors back to the originals

        for alias, connection in mirrors:

            connections._connections[alias] = connection

        # Destroy all the non-mirror databases

        for connection, old_name in old_names:

            connection.creation.destroy_test_db(old_name, self.verbosity)

    def teardown_test_environment(self, **kwargs):

        teardown_test_environment()

    def suite_result(self, suite, result, **kwargs):

        return len(result.failures) + len(result.errors)

    def run_tests(self, test_labels, extra_tests=None, **kwargs):

        """

        Run the unit tests for all the test labels in the provided list.

        Labels must be of the form:

         - app.TestClass.test_method

            Run a single specific test method

         - app.TestClass

            Run all the test methods in a given class

         - app

            Search for doctests and unittests in the named application.

        When looking for tests, the test runner will look in the models and

        tests modules for the application.

        A list of 'extra' tests may also be provided; these tests

        will be added to the test suite.

        Returns the number of tests that failed.

        """

        self.setup_test_environment()

        suite = self.build_suite(test_labels, extra_tests)

        old_config = self.setup_databases()

        result = self.run_suite(suite)

        self.teardown_databases(old_config)

        self.teardown_test_environment()

        return self.suite_result(suite, result)

def run_tests(test_labels, verbosity=1, interactive=True, failfast=False, extra_tests=None):

    import warnings

    warnings.warn(

        'The run_tests() test runner has been deprecated in favor of DjangoTestSuiteRunner.',

        PendingDeprecationWarning

    )

    test_runner = DjangoTestSuiteRunner(verbosity=verbosity, interactive=interactive, failfast=failfast)

    return test_runner.run_tests(test_labels, extra_tests=extra_tests)