using UnitTestSharp;

namespace Glass.UnitTests
{
    public class RadioButtonTests : TestFixture
    {
        public class CheckedTests : TestFixture
        {
            public void SettingTrueSelectsThisButtonInItsGroup()
            {
                var group = new RadioGroup();
                var button = new RadioButton { Group = group };

                button.Checked = true;

                CheckEqual(button, group.Selected);
            }

            public void SettingTrueUnchecksThePreviouslySelectedSibling()
            {
                var group = new RadioGroup();
                var first = new RadioButton { Group = group };
                var second = new RadioButton { Group = group };
                first.Checked = true;

                second.Checked = true;

                CheckFalse(first.Checked);
                CheckEqual(second, group.Selected);
            }

            public void SwitchingBackAndForthBetweenTwoGroupedButtonsSettles()
            {
                var group = new RadioGroup();
                var first = new RadioButton { Group = group };
                var second = new RadioButton { Group = group };

                first.Checked = true;
                second.Checked = true;
                first.Checked = true;

                Check(first.Checked);
                CheckFalse(second.Checked);
                CheckEqual(first, group.Selected);
            }

            public void SettingFalseOnTheSelectedButtonClearsTheGroup()
            {
                var group = new RadioGroup();
                var button = new RadioButton { Group = group, Checked = true };

                button.Checked = false;

                CheckNull(group.Selected);
            }

            public void SettingFalseOnAnUnselectedButtonDoesNotDisturbTheGroup()
            {
                var group = new RadioGroup();
                var first = new RadioButton { Group = group };
                var second = new RadioButton { Group = group };
                first.Checked = true;

                second.Checked = false;

                CheckEqual(first, group.Selected);
            }

            public void WithNoGroupBehavesLikeAPlainCheckbox()
            {
                var button = new RadioButton();

                button.Checked = true;

                Check(button.Checked);
            }
        }

        public class ToggleTests : TestFixture
        {
            public void OnAnUncheckedButtonChecksIt()
            {
                var button = new RadioButton();
                button.Toggle();
                Check(button.Checked);
            }

            public void OnACheckedButtonDoesNothing()
            {
                var button = new RadioButton { Checked = true };
                button.Toggle();
                Check(button.Checked);
            }

            public void OnACheckedButtonRaisesNothing()
            {
                var button = new RadioButton { Checked = true };
                bool raised = false;
                button.OnCheckedChanged +=_ => raised = true;

                button.Toggle();

                CheckFalse(raised);
            }
        }

        public class ClickTests : TestFixture
        {
            public void OnTheActiveButtonLeavesItChecked()
            {
                var button = new RadioButton { Checked = true };
                button.Click(new MouseState(), MouseButtonFlags.Left);
                Check(button.Checked);
            }

            public void SwitchingUnchecksTheOldSelection()
            {
                var group = new RadioGroup();
                var first = new RadioButton { Group = group, Checked = true };
                var second = new RadioButton { Group = group };

                second.Click(new MouseState(), MouseButtonFlags.Left);

                CheckFalse(first.Checked);
                Check(second.Checked);
            }

            public void OnClickStillFires()
            {
                var button = new RadioButton();
                bool clicked = false;
                button.OnClick += (in MouseState _, MouseButtonFlags __) => clicked = true;

                button.Click(new MouseState(), MouseButtonFlags.Left);

                Check(clicked);
            }

            public void DisabledDoesNothing()
            {
                var button = new RadioButton { Enabled = false };
                button.Click(new MouseState(), MouseButtonFlags.Left);
                CheckFalse(button.Checked);
            }
        }

        public class GroupAssignmentTests : TestFixture
        {
            public void AssigningAGroupWhileCheckedSelectsThisButton()
            {
                var button = new RadioButton { Checked = true };
                var group = new RadioGroup();

                button.Group = group;

                CheckEqual(button, group.Selected);
            }

            public void AssigningAGroupWhileUncheckedDoesNotSelectAnything()
            {
                var button = new RadioButton();
                var group = new RadioGroup();

                button.Group = group;

                CheckNull(group.Selected);
            }

            public void LastOfSeveralPreCheckedButtonsAssignedWins()
            {
                var group = new RadioGroup();
                var first = new RadioButton { Checked = true };
                var second = new RadioButton { Checked = true };

                first.Group = group;
                second.Group = group;

                CheckEqual(second, group.Selected);
                CheckFalse(first.Checked);
            }

            public void ReassigningToANullGroupClearsTheOldGroupsSelected()
            {
                var group = new RadioGroup();
                var button = new RadioButton { Group = group, Checked = true };

                button.Group = null;

                CheckNull(group.Selected);
            }

            public void ReassigningToANullGroupLeavesTheButtonChecked()
            {
                var group = new RadioGroup();
                var button = new RadioButton { Group = group, Checked = true };

                button.Group = null;

                Check(button.Checked);
            }

            public void ReassigningToADifferentGroupMovesTheSelectionThereAndStaysChecked()
            {
                var oldGroup = new RadioGroup();
                var newGroup = new RadioGroup();
                var button = new RadioButton { Group = oldGroup, Checked = true };

                button.Group = newGroup;

                CheckNull(oldGroup.Selected);
                CheckEqual(button, newGroup.Selected);
                Check(button.Checked);
            }

            public void ReassigningAnUncheckedButtonDoesNotDisturbTheOldGroupsSelection()
            {
                var group = new RadioGroup();
                var selected = new RadioButton { Group = group, Checked = true };
                var spare = new RadioButton { Group = group };

                spare.Group = null;

                CheckEqual(selected, group.Selected);
            }

            public void ReassigningToTheSameGroupIsANoOp()
            {
                var group = new RadioGroup();
                var button = new RadioButton { Group = group, Checked = true };
                int raiseCount = 0;
                group.OnSelectionChanged += _ => ++raiseCount;

                button.Group = group;

                CheckEqual(0, raiseCount);
            }
        }
    }
}