# (C) Copyright 2005-2021 Enthought, Inc., Austin, TX
# 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 unittest

from traits.api import HasTraits, Str, Undefined, ReadOnly, Float


class Foo(HasTraits):
    name = Str()
    original_name = ReadOnly

    bar = Str
    baz = Float

    def _name_changed(self):
        if self.original_name is Undefined:
            self.original_name = self.name


class Bar(HasTraits):
    name = Str(Undefined)


class UndefinedTestCase(unittest.TestCase):
    def test_initial_value(self):
        b = Bar()
        self.assertEqual(b.name, Undefined)

    def test_name_change(self):
        b = Bar()
        b.name = "first"
        self.assertEqual(b.name, "first")

    def test_read_only_write_once(self):
        f = Foo()

        self.assertEqual(f.name, "")
        self.assertIs(f.original_name, Undefined)

        f.name = "first"
        self.assertEqual(f.name, "first")
        self.assertEqual(f.original_name, "first")

        f.name = "second"
        self.assertEqual(f.name, "second")
        self.assertEqual(f.original_name, "first")

    def test_read_only_write_once_from_constructor(self):
        f = Foo(name="first")

        f.name = "first"
        self.assertEqual(f.name, "first")
        self.assertEqual(f.original_name, "first")

        f.name = "second"
        self.assertEqual(f.name, "second")
        self.assertEqual(f.original_name, "first")
