import os
import re
import sys

import unittest


class TestableTestProgram(unittest.TestProgram):
    module = '__main__'
    exit = True
    defaultTest = failfast = catchbreak = buffer = None
    verbosity = 1
    progName = ''
    testRunner = testLoader = None

    def __init__(self):
        pass


class TestDiscovery(unittest.TestCase):

    # Heavily mocked tests so I can avoid hitting the filesystem
    def test_get_name_from_path(self):
        loader = unittest.TestLoader()
        loader._top_level_dir = '/foo'
        name = loader._get_name_from_path('/foo/bar/baz.py')
        self.assertEqual(name, 'bar.baz')

        if not __debug__:
            # asserts are off
            return

        with self.assertRaises(AssertionError):
            loader._get_name_from_path('/bar/baz.py')

    def test_find_tests(self):
        loader = unittest.TestLoader()

        original_listdir = os.listdir
        def restore_listdir():
            os.listdir = original_listdir
        original_isfile = os.path.isfile
        def restore_isfile():
            os.path.isfile = original_isfile
        original_isdir = os.path.isdir
        def restore_isdir():
            os.path.isdir = original_isdir

        path_lists = [['test1.py', 'test2.py', 'not_a_test.py', 'test_dir',
                       'test.foo', 'test-not-a-module.py', 'another_dir'],
                      ['test3.py', 'test4.py', ]]
        os.listdir = lambda path: path_lists.pop(0)
        self.addCleanup(restore_listdir)

        def isdir(path):
            return path.endswith('dir')
        os.path.isdir = isdir
        self.addCleanup(restore_isdir)

        def isfile(path):
            # another_dir is not a package and so shouldn't be recursed into
            return not path.endswith('dir') and not 'another_dir' in path
        os.path.isfile = isfile
        self.addCleanup(restore_isfile)

        loader._get_module_from_name = lambda path: path + ' module'
        loader.loadTestsFromModule = lambda module: module + ' tests'

        top_level = os.path.abspath('/foo')
        loader._top_level_dir = top_level
        suite = list(loader._find_tests(top_level, 'test*.py'))

        expected = [name + ' module tests' for name in
                    ('test1', 'test2')]
        expected.extend([('test_dir.%s' % name) + ' module tests' for name in
                    ('test3', 'test4')])
        self.assertEqual(suite, expected)

    def test_find_tests_with_package(self):
        loader = unittest.TestLoader()

        original_listdir = os.listdir
        def restore_listdir():
            os.listdir = original_listdir
        original_isfile = os.path.isfile
        def restore_isfile():
            os.path.isfile = original_isfile
        original_isdir = os.path.isdir
        def restore_isdir():
            os.path.isdir = original_isdir

        directories = ['a_directory', 'test_directory', 'test_directory2']
        path_lists = [directories, [], [], []]
        os.listdir = lambda path: path_lists.pop(0)
        self.addCleanup(restore_listdir)

        os.path.isdir = lambda path: True
        self.addCleanup(restore_isdir)

        os.path.isfile = lambda path: os.path.basename(path) not in directories
        self.addCleanup(restore_isfile)

        class Module(object):
            paths = []
            load_tests_args = []

            def __init__(self, path):
                self.path = path
                self.paths.append(path)
                if os.path.basename(path) == 'test_directory':
                    def load_tests(loader, tests, pattern):
                        self.load_tests_args.append((loader, tests, pattern))
                        return 'load_tests'
                    self.load_tests = load_tests

            def __eq__(self, other):
                return self.path == other.path

        loader._get_module_from_name = lambda name: Module(name)
        def loadTestsFromModule(module, use_load_tests):
            if use_load_tests:
                raise self.failureException('use_load_tests should be False for packages')
            return module.path + ' module tests'
        loader.loadTestsFromModule = loadTestsFromModule

        loader._top_level_dir = '/foo'
        # this time no '.py' on the pattern so that it can match
        # a test package
        suite = list(loader._find_tests('/foo', 'test*'))

        # We should have loaded tests from the test_directory package by calling load_tests
        # and directly from the test_directory2 package
        self.assertEqual(suite,
                         ['load_tests', 'test_directory2' + ' module tests'])
        self.assertEqual(Module.paths, ['test_directory', 'test_directory2'])

        # load_tests should have been called once with loader, tests and pattern
        self.assertEqual(Module.load_tests_args,
                         [(loader, 'test_directory' + ' module tests', 'test*')])

    def test_discover(self):
        loader = unittest.TestLoader()

        original_isfile = os.path.isfile
        original_isdir = os.path.isdir
        def restore_isfile():
            os.path.isfile = original_isfile

        os.path.isfile = lambda path: False
        self.addCleanup(restore_isfile)

        orig_sys_path = sys.path[:]
        def restore_path():
            sys.path[:] = orig_sys_path
        self.addCleanup(restore_path)

        full_path = os.path.abspath(os.path.normpath('/foo'))
        with self.assertRaises(ImportError):
            loader.discover('/foo/bar', top_level_dir='/foo')

        self.assertEqual(loader._top_level_dir, full_path)
        self.assertIn(full_path, sys.path)

        os.path.isfile = lambda path: True
        os.path.isdir = lambda path: True

        def restore_isdir():
            os.path.isdir = original_isdir
        self.addCleanup(restore_isdir)

        _find_tests_args = []
        def _find_tests(start_dir, pattern):
            _find_tests_args.append((start_dir, pattern))
            return ['tests']
        loader._find_tests = _find_tests
        loader.suiteClass = str

        suite = loader.discover('/foo/bar/baz', 'pattern', '/foo/bar')

        top_level_dir = os.path.abspath('/foo/bar')
        start_dir = os.path.abspath('/foo/bar/baz')
        self.assertEqual(suite, "['tests']")
        self.assertEqual(loader._top_level_dir, top_level_dir)
        self.assertEqual(_find_tests_args, [(start_dir, 'pattern')])
        self.assertIn(top_level_dir, sys.path)

    def test_discover_with_modules_that_fail_to_import(self):
        loader = unittest.TestLoader()

        listdir = os.listdir
        os.listdir = lambda _: ['test_this_does_not_exist.py']
        isfile = os.path.isfile
        os.path.isfile = lambda _: True
        orig_sys_path = sys.path[:]
        def restore():
            os.path.isfile = isfile
            os.listdir = listdir
            sys.path[:] = orig_sys_path
        self.addCleanup(restore)

        suite = loader.discover('.')
        self.assertIn(os.getcwd(), sys.path)
        self.assertEqual(suite.countTestCases(), 1)
        test = list(list(suite)[0])[0] # extract test from suite

        with self.assertRaises(ImportError):
            test.test_this_does_not_exist()

    def test_command_line_handling_parseArgs(self):
        program = TestableTestProgram()

        args = []
        def do_discovery(argv):
            args.extend(argv)
        program._do_discovery = do_discovery
        program.parseArgs(['something', 'discover'])
        self.assertEqual(args, [])

        program.parseArgs(['something', 'discover', 'foo', 'bar'])
        self.assertEqual(args, ['foo', 'bar'])

    def test_command_line_handling_discover_by_default(self):
        program = TestableTestProgram()
        program.module = None

        self.called = False
        def do_discovery(argv):
            self.called = True
            self.assertEqual(argv, [])
        program._do_discovery = do_discovery
        program.parseArgs(['something'])
        self.assertTrue(self.called)


    def test_command_line_handling_do_discovery_too_many_arguments(self):
        class Stop(Exception):
            pass
        def usageExit():
            raise Stop

        program = TestableTestProgram()
        program.usageExit = usageExit

        with self.assertRaises(Stop):
            # too many args
            program._do_discovery(['one', 'two', 'three', 'four'])


    def test_command_line_handling_do_discovery_calls_loader(self):
        program = TestableTestProgram()

        class Loader(object):
            args = []
            def discover(self, start_dir, pattern, top_level_dir):
                self.args.append((start_dir, pattern, top_level_dir))
                return 'tests'

        program._do_discovery(['-v'], Loader=Loader)
        self.assertEqual(program.verbosity, 2)
        self.assertEqual(program.test, 'tests')
        self.assertEqual(Loader.args, [('.', 'test*.py', None)])

        Loader.args = []
        program = TestableTestProgram()
        program._do_discovery(['--verbose'], Loader=Loader)
        self.assertEqual(program.test, 'tests')
        self.assertEqual(Loader.args, [('.', 'test*.py', None)])

        Loader.args = []
        program = TestableTestProgram()
        program._do_discovery([], Loader=Loader)
        self.assertEqual(program.test, 'tests')
        self.assertEqual(Loader.args, [('.', 'test*.py', None)])

        Loader.args = []
        program = TestableTestProgram()
        program._do_discovery(['fish'], Loader=Loader)
        self.assertEqual(program.test, 'tests')
        self.assertEqual(Loader.args, [('fish', 'test*.py', None)])

        Loader.args = []
        program = TestableTestProgram()
        program._do_discovery(['fish', 'eggs'], Loader=Loader)
        self.assertEqual(program.test, 'tests')
        self.assertEqual(Loader.args, [('fish', 'eggs', None)])

        Loader.args = []
        program = TestableTestProgram()
        program._do_discovery(['fish', 'eggs', 'ham'], Loader=Loader)
        self.assertEqual(program.test, 'tests')
        self.assertEqual(Loader.args, [('fish', 'eggs', 'ham')])

        Loader.args = []
        program = TestableTestProgram()
        program._do_discovery(['-s', 'fish'], Loader=Loader)
        self.assertEqual(program.test, 'tests')
        self.assertEqual(Loader.args, [('fish', 'test*.py', None)])

        Loader.args = []
        program = TestableTestProgram()
        program._do_discovery(['-t', 'fish'], Loader=Loader)
        self.assertEqual(program.test, 'tests')
        self.assertEqual(Loader.args, [('.', 'test*.py', 'fish')])

        Loader.args = []
        program = TestableTestProgram()
        program._do_discovery(['-p', 'fish'], Loader=Loader)
        self.assertEqual(program.test, 'tests')
        self.assertEqual(Loader.args, [('.', 'fish', None)])
        self.assertFalse(program.failfast)
        self.assertFalse(program.catchbreak)

        Loader.args = []
        program = TestableTestProgram()
        program._do_discovery(['-p', 'eggs', '-s', 'fish', '-v', '-f', '-c'],
                              Loader=Loader)
        self.assertEqual(program.test, 'tests')
        self.assertEqual(Loader.args, [('fish', 'eggs', None)])
        self.assertEqual(program.verbosity, 2)
        self.assertTrue(program.failfast)
        self.assertTrue(program.catchbreak)

    def test_detect_module_clash(self):
        class Module(object):
            __file__ = 'bar/foo.py'
        sys.modules['foo'] = Module
        full_path = os.path.abspath('foo')
        original_listdir = os.listdir
        original_isfile = os.path.isfile
        original_isdir = os.path.isdir

        def cleanup():
            os.listdir = original_listdir
            os.path.isfile = original_isfile
            os.path.isdir = original_isdir
            del sys.modules['foo']
            if full_path in sys.path:
                sys.path.remove(full_path)
        self.addCleanup(cleanup)

        def listdir(_):
            return ['foo.py']
        def isfile(_):
            return True
        def isdir(_):
            return True
        os.listdir = listdir
        os.path.isfile = isfile
        os.path.isdir = isdir

        loader = unittest.TestLoader()

        mod_dir = os.path.abspath('bar')
        expected_dir = os.path.abspath('foo')
        msg = re.escape(r"'foo' module incorrectly imported from %r. Expected %r. "
                "Is this module globally installed?" % (mod_dir, expected_dir))
        self.assertRaisesRegex(
            ImportError, '^%s$' % msg, loader.discover,
            start_dir='foo', pattern='foo.py'
        )
        self.assertEqual(sys.path[0], full_path)


    def test_discovery_from_dotted_path(self):
        loader = unittest.TestLoader()

        tests = [self]
        expectedPath = os.path.abspath(os.path.dirname(unittest.test.__file__))

        self.wasRun = False
        def _find_tests(start_dir, pattern):
            self.wasRun = True
            self.assertEqual(start_dir, expectedPath)
            return tests
        loader._find_tests = _find_tests
        suite = loader.discover('unittest.test')
        self.assertTrue(self.wasRun)
        self.assertEqual(suite._tests, tests)


if __name__ == '__main__':
    unittest.main()