#------------------------------------------------------------------------------
# Copyright (c) 2005-2013, Enthought, Inc.
# All rights reserved.
#
# This software is provided without warranty under the terms of the BSD
# license included in /LICENSE.txt and may be redistributed only
# under the conditions described in the aforementioned license.  The license
# is also available online at http://www.enthought.com/licenses/BSD.txt
# Thanks for using Enthought open source!
#------------------------------------------------------------------------------
import threading
import time
import sys

from traits import _py2to3

from traits.testing.unittest_tools import unittest
from traits.api import (Bool, Event, Float, HasTraits, Int, List,
                        on_trait_change)
from traits.testing.api import UnittestTools


class TestObject(HasTraits):

    number = Float(2.0)
    list_of_numbers = List(Float)
    flag = Bool

    @on_trait_change('number')
    def _add_number_to_list(self, value):
        self.list_of_numbers.append(value)

    def add_to_number(self, value):
        self.number += value


class UnittestToolsTestCase(unittest.TestCase, UnittestTools):

    def setUp(self):
        self.test_object = TestObject()

    def test_when_using_with(self):
        """ Check normal use cases as a context manager.
        """
        test_object = self.test_object

        # Change event should NOT BE detected
        with self.assertTraitDoesNotChange(test_object, 'number') as result:
            test_object.flag = True
            test_object.number = 2.0

        msg = 'The assertion result is not None: {0}'.format(result.event)
        self.assertIsNone(result.event, msg=msg)

        # Change event should BE detected
        with self.assertTraitChanges(test_object, 'number') as result:
            test_object.flag = False
            test_object.number = 5.0

        expected = (test_object, 'number', 2.0, 5.0)
        self.assertSequenceEqual(expected, result.event)

        # Change event should BE detected exactly 2 times
        with self.assertTraitChanges(test_object, 'number', count=2) as result:
            test_object.flag = False
            test_object.number = 4.0
            test_object.number = 3.0

        expected = [(test_object, 'number', 5.0, 4.0),
                    (test_object, 'number', 4.0, 3.0)]
        self.assertSequenceEqual(expected, result.events)
        self.assertSequenceEqual(expected[-1], result.event)

        # Change event should BE detected
        with self.assertTraitChanges(test_object, 'number') as result:
            test_object.flag = True
            test_object.add_to_number(10.0)

        expected = (test_object, 'number', 3.0, 13.0)
        self.assertSequenceEqual(expected, result.event)

        # Change event should BE detected exactly 3 times
        with self.assertTraitChanges(test_object, 'number', count=3) as result:
            test_object.flag = True
            test_object.add_to_number(10.0)
            test_object.add_to_number(10.0)
            test_object.add_to_number(10.0)

        expected = [(test_object, 'number', 13.0, 23.0),
                    (test_object, 'number', 23.0, 33.0),
                    (test_object, 'number', 33.0, 43.0)]
        self.assertSequenceEqual(expected, result.events)
        self.assertSequenceEqual(expected[-1], result.event)

    def test_assert_multi_changes(self):
        test_object = self.test_object

        # Change event should NOT BE detected
        with self.assertMultiTraitChanges([test_object], [],
                ['flag', 'number', 'list_of_numbers[]']) as results:
            test_object.number = 2.0

        events = filter(bool, (result.event for result in results))
        msg = 'The assertion result is not None: {0}'.format(", ".join(events))
        self.assertFalse(events, msg=msg)

        # Change event should BE detected
        with self.assertMultiTraitChanges(
                [test_object], ['number', 'list_of_numbers[]'],
                ['flag']) as results:
            test_object.number = 5.0

        events = filter(bool, (result.event for result in results))
        msg = 'The assertion result is None'
        self.assertTrue(events, msg=msg)

    def test_when_using_functions(self):
        test_object = self.test_object

        # Change event should BE detected
        self.assertTraitChanges(test_object, 'number', 1,
                                test_object.add_to_number, 13.0)

        # Change event should NOT BE detected
        self.assertTraitDoesNotChange(test_object, 'flag',
                                      test_object.add_to_number, 13.0)

    def test_indirect_events(self):
        """ Check catching indirect change events.
        """
        test_object = self.test_object

        # Change event should BE detected
        with self.assertTraitChanges(test_object, 'list_of_numbers[]') as \
                result:
            test_object.flag = True
            test_object.number = -3.0

        expected = (test_object, 'list_of_numbers_items', [], [-3.0])
        self.assertSequenceEqual(expected, result.event)

    def test_exception_inside_context(self):
        """ Check that exception inside the context statement block are
        propagated.

        """
        test_object = self.test_object

        with self.assertRaises(AttributeError):
            with self.assertTraitChanges(test_object, 'number'):
                test_object.i_do_exist

        with self.assertRaises(AttributeError):
            with self.assertTraitDoesNotChange(test_object, 'number'):
                test_object.i_do_exist

    def test_non_change_on_failure(self):
        """ Check behaviour when assertion should be raised for non trait
        change.

        """
        test_object = self.test_object
        traits = 'flag, number'
        with self.assertRaises(AssertionError):
            with self.assertTraitDoesNotChange(test_object, traits) as result:
                test_object.flag = True
                test_object.number = -3.0
        expected = [(test_object, 'flag', False, True),
                    (test_object, 'number', 2.0, -3.0)]
        self.assertEqual(result.events, expected)

    def test_change_on_failure(self):
        """ Check behaviour when assertion should be raised for trait change.
        """
        test_object = self.test_object
        with self.assertRaises(AssertionError):
            with self.assertTraitChanges(test_object, 'number') as result:
                test_object.flag = True
        self.assertEqual(result.events, [])

        # Change event will not be fired 3 times
        with self.assertRaises(AssertionError):
            with self.assertTraitChanges(test_object, 'number', count=3) as \
                    result:
                test_object.flag = True
                test_object.add_to_number(10.0)
                test_object.add_to_number(10.0)

        expected = [(test_object, 'number', 2.0, 12.0),
                    (test_object, 'number', 12.0, 22.0)]
        self.assertSequenceEqual(expected, result.events)

    def test_asserts_in_context_block(self):
        """ Make sure that the traits context manager does not stop
        regular assertions inside the managed code block from happening.
        """
        test_object = TestObject(number=16.0)

        with self.assertTraitDoesNotChange(test_object, 'number'):
            self.assertEqual(test_object.number, 16.0)

        with self.assertRaisesRegexp(AssertionError, '16\.0 != 12\.0'):
            with self.assertTraitDoesNotChange(test_object, 'number'):
                self.assertEqual(test_object.number, 12.0)

    def test_special_case_for_count(self):
        """ Count equal to 0 should be valid but it is discouraged.
        """
        test_object = TestObject(number=16.0)

        with self.assertTraitChanges(test_object, 'number', count=0):
            test_object.flag = True

    def test_assert_trait_changes_async(self):
        # Exercise assertTraitChangesAsync.
        thread_count = 10
        events_per_thread = 1000

        class A(HasTraits):
            event = Event

        a = A()

        def thread_target(obj, count):
            "Fire obj.event 'count' times."
            for _ in xrange(count):
                obj.event = True

        threads = [
            threading.Thread(target=thread_target, args=(a, events_per_thread))
            for _ in xrange(thread_count)
        ]

        expected_count = thread_count * events_per_thread
        with self.assertTraitChangesAsync(
            a, 'event', expected_count, timeout=60.0):
            for t in threads:
                t.start()

        for t in threads:
            t.join()

    def test_assert_trait_changes_async_events(self):
        # Check access to the events after the with
        # block completes.
        thread_count = 10
        events_per_thread = 100

        class A(HasTraits):
            event = Event(Int)

        a = A()

        def thread_target(obj, count):
            "Fire obj.event 'count' times."
            for n in xrange(count):
                time.sleep(0.001)
                obj.event = n

        threads = [
            threading.Thread(target=thread_target, args=(a, events_per_thread))
            for _ in xrange(thread_count)
        ]

        expected_count = thread_count * events_per_thread
        with self.assertTraitChangesAsync(
            a, 'event', expected_count, timeout=60.0) as event_collector:
            for t in threads:
                t.start()

        for t in threads:
            t.join()

        _py2to3.assertCountEqual(
            self,
            event_collector.events,
            range(events_per_thread) * thread_count,
        )

    def test_assert_trait_changes_async_failure(self):
        # Exercise assertTraitChangesAsync.
        thread_count = 10
        events_per_thread = 10000

        class A(HasTraits):
            event = Event

        a = A()

        def thread_target(obj, count):
            "Fire obj.event 'count' times."
            for _ in xrange(count):
                obj.event = True

        threads = [
            threading.Thread(target=thread_target, args=(a, events_per_thread))
            for _ in xrange(thread_count)
        ]

        expected_count = thread_count * events_per_thread
        with self.assertRaises(AssertionError):
            with self.assertTraitChangesAsync(a, 'event', expected_count + 1):
                for t in threads:
                    t.start()

        for t in threads:
            t.join()


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