using UnitTestSharp;

namespace Glass.UnitTests
{
    public class RadioGroupTests : TestFixture
    {
        public class SelectTests : TestFixture
        {
            public void FirstSelectionSetsSelected()
            {
                var group = new RadioGroup();
                var button = new RadioButton();

                group.Select(button);

                CheckEqual(button, group.Selected);
            }

            public void SwitchingUnchecksThePreviousAndFiresItsOnCheckedChanged()
            {
                var group = new RadioGroup();
                var first = new RadioButton { Group = group };
                first.Checked = true;
                var second = new RadioButton();
                bool? raisedWith = null;
                first.OnCheckedChanged +=value => raisedWith = value;

                group.Select(second);

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

            public void SelectingTheAlreadySelectedButtonIsANoOp()
            {
                var group = new RadioGroup();
                var button = new RadioButton();
                group.Select(button);
                int raiseCount = 0;
                group.OnSelectionChanged +=_ => ++raiseCount;

                group.Select(button);

                CheckEqual(0, raiseCount);
            }

            public void RaisesOnSelectionChangedWithTheNewlySelectedButton()
            {
                var group = new RadioGroup();
                var button = new RadioButton();
                RadioButton raisedWith = null;
                group.OnSelectionChanged +=selected => raisedWith = selected;

                group.Select(button);

                CheckEqual(button, raisedWith);
            }

            public void SelectingNullRaisesOnSelectionChangedWithNull()
            {
                var group = new RadioGroup();
                var button = new RadioButton();
                group.Select(button);
                RadioButton raisedWith = button;
                group.OnSelectionChanged +=selected => raisedWith = selected;

                group.Select(null);

                CheckNull(raisedWith);
                CheckNull(group.Selected);
            }
        }

        public class ForgetTests : TestFixture
        {
            public void ForgettingTheSelectedButtonClearsSelected()
            {
                var group = new RadioGroup();
                var button = new RadioButton();
                group.Select(button);

                group.Forget(button);

                CheckNull(group.Selected);
            }

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

                group.Forget(button);

                Check(button.Checked);
            }

            public void RaisesOnSelectionChangedWithNull()
            {
                var group = new RadioGroup();
                var button = new RadioButton();
                group.Select(button);
                RadioButton raisedWith = button;
                group.OnSelectionChanged +=selected => raisedWith = selected;

                group.Forget(button);

                CheckNull(raisedWith);
            }

            public void ForgettingADifferentButtonIsANoOp()
            {
                var group = new RadioGroup();
                var selected = new RadioButton();
                var other = new RadioButton();
                group.Select(selected);

                group.Forget(other);

                CheckEqual(selected, group.Selected);
            }

            public void ForgettingWithNothingSelectedIsANoOp()
            {
                var group = new RadioGroup();
                var button = new RadioButton();
                bool raised = false;
                group.OnSelectionChanged +=_ => raised = true;

                group.Forget(button);

                CheckFalse(raised);
            }
        }

        public class ClearTests : TestFixture
        {
            public void ReturnsToNoSelection()
            {
                var group = new RadioGroup();
                var button = new RadioButton { Group = group };
                button.Checked = true;

                group.Clear();

                CheckNull(group.Selected);
            }

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

                group.Clear();

                CheckFalse(button.Checked);
            }

            public void WithNothingSelectedIsANoOp()
            {
                var group = new RadioGroup();
                bool raised = false;
                group.OnSelectionChanged +=_ => raised = true;

                group.Clear();

                CheckFalse(raised);
            }
        }

        public class FromChildrenOfTests : TestFixture
        {
            public void PointsEveryDirectRadioButtonChildAtAFreshGroup()
            {
                var parent = new Panel();
                var first = new RadioButton();
                var second = new RadioButton();
                parent.CanvasChildren.Add(first);
                parent.CanvasChildren.Add(second);

                RadioGroup group = RadioGroup.FromChildrenOf(parent);

                CheckEqual(group, first.Group);
                CheckEqual(group, second.Group);
            }

            public void SkipsPlainCheckboxAndButtonChildren()
            {
                var parent = new Panel();
                var checkbox = new Checkbox();
                var button = new Button();
                var radioButton = new RadioButton();
                parent.CanvasChildren.Add(checkbox);
                parent.CanvasChildren.Add(button);
                parent.CanvasChildren.Add(radioButton);

                RadioGroup group = RadioGroup.FromChildrenOf(parent);

                CheckEqual(group, radioButton.Group);
            }

            public void DoesNotDescendIntoGrandchildren()
            {
                var parent = new Panel();
                var child = new Panel();
                var grandchild = new RadioButton();
                child.CanvasChildren.Add(grandchild);
                parent.CanvasChildren.Add(child);

                RadioGroup.FromChildrenOf(parent);

                CheckNull(grandchild.Group);
            }

            public void HonorsAPreCheckedChild()
            {
                var parent = new Panel();
                var button = new RadioButton { Checked = true };
                parent.CanvasChildren.Add(button);

                RadioGroup group = RadioGroup.FromChildrenOf(parent);

                CheckEqual(button, group.Selected);
            }

            public void LastPreCheckedChildWins()
            {
                var parent = new Panel();
                var first = new RadioButton { Checked = true };
                var second = new RadioButton { Checked = true };
                parent.CanvasChildren.Add(first);
                parent.CanvasChildren.Add(second);

                RadioGroup group = RadioGroup.FromChildrenOf(parent);

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