using Avalonia.Controls.Presenters;
using Avalonia.Layout;
using Avalonia.UnitTests;
using Xunit;

namespace Avalonia.Controls.UnitTests.Presenters
{
    public class ContentPresenterTests_Layout : ScopedTestBase
    {
        [Theory]
        [InlineData(HorizontalAlignment.Stretch, VerticalAlignment.Stretch, 0, 0, 100, 100)]
        [InlineData(HorizontalAlignment.Left, VerticalAlignment.Stretch, 0, 0, 16, 100)]
        [InlineData(HorizontalAlignment.Right, VerticalAlignment.Stretch, 84, 0, 16, 100)]
        [InlineData(HorizontalAlignment.Center, VerticalAlignment.Stretch, 42, 0, 16, 100)]
        [InlineData(HorizontalAlignment.Stretch, VerticalAlignment.Top, 0, 0, 100, 16)]
        [InlineData(HorizontalAlignment.Stretch, VerticalAlignment.Bottom, 0, 84, 100, 16)]
        [InlineData(HorizontalAlignment.Stretch, VerticalAlignment.Center, 0, 42, 100, 16)]
        public void Content_Alignment_Is_Applied_To_Child_Bounds(
            HorizontalAlignment h,
            VerticalAlignment v,
            double expectedX,
            double expectedY,
            double expectedWidth,
            double expectedHeight)
        {
            Border content;
            var target = new ContentPresenter
            {
                HorizontalContentAlignment = h,
                VerticalContentAlignment = v,
                Content = content = new Border
                {
                    MinWidth = 16,
                    MinHeight = 16,
                },
            };

            target.UpdateChild();
            target.Measure(new Size(100, 100));
            target.Arrange(new Rect(0, 0, 100, 100));

            Assert.Equal(new Rect(expectedX, expectedY, expectedWidth, expectedHeight), content.Bounds);
        }

        [Theory]
        [InlineData(HorizontalAlignment.Stretch, VerticalAlignment.Stretch, 10, 10, 80, 80)]
        [InlineData(HorizontalAlignment.Left, VerticalAlignment.Stretch, 10, 10, 16, 80)]
        [InlineData(HorizontalAlignment.Right, VerticalAlignment.Stretch, 74, 10, 16, 80)]
        [InlineData(HorizontalAlignment.Center, VerticalAlignment.Stretch, 42, 10, 16, 80)]
        [InlineData(HorizontalAlignment.Stretch, VerticalAlignment.Top, 10, 10, 80, 16)]
        [InlineData(HorizontalAlignment.Stretch, VerticalAlignment.Bottom, 10, 74, 80, 16)]
        [InlineData(HorizontalAlignment.Stretch, VerticalAlignment.Center, 10, 42, 80, 16)]
        public void Content_Alignment_And_Padding_Are_Applied_To_Child_Bounds(
            HorizontalAlignment h,
            VerticalAlignment v,
            double expectedX,
            double expectedY,
            double expectedWidth,
            double expectedHeight)
        {
            Border content;
            var target = new ContentPresenter
            {
                HorizontalContentAlignment = h,
                VerticalContentAlignment = v,
                Padding = new Thickness(10),
                Content = content = new Border
                {
                    MinWidth = 16,
                    MinHeight = 16,
                },
            };

            target.UpdateChild();
            target.Measure(new Size(100, 100));
            target.Arrange(new Rect(0, 0, 100, 100));

            Assert.Equal(new Rect(expectedX, expectedY, expectedWidth, expectedHeight), content.Bounds);
        }

        [Fact]
        public void Should_Correctly_Align_Child_With_Fixed_Size()
        {
            Border content;
            var target = new ContentPresenter
            {
                HorizontalContentAlignment = HorizontalAlignment.Stretch,
                VerticalContentAlignment = VerticalAlignment.Stretch,
                Content = content = new Border
                {
                    HorizontalAlignment = HorizontalAlignment.Left,
                    VerticalAlignment = VerticalAlignment.Bottom,
                    Width = 16,
                    Height = 16,
                },
            };

            target.UpdateChild();
            target.Measure(new Size(100, 100));
            target.Arrange(new Rect(0, 0, 100, 100));

            // Check correct result for Issue #1447.
            Assert.Equal(new Rect(0, 84, 16, 16), content.Bounds);
        }

        [Fact]
        public void Content_Can_Be_Stretched()
        {
            Border content;
            var target = new ContentPresenter
            {
                Content = content = new Border
                {
                    MinWidth = 16,
                    MinHeight = 16,
                },
            };

            target.UpdateChild();
            target.Measure(new Size(100, 100));
            target.Arrange(new Rect(0, 0, 100, 100));

            Assert.Equal(new Rect(0, 0, 100, 100), content.Bounds);
        }

        [Fact]
        public void Content_Can_Be_Right_Aligned()
        {
            Border content;
            var target = new ContentPresenter
            {
                Content = content = new Border
                {
                    MinWidth = 16,
                    MinHeight = 16,
                    HorizontalAlignment = HorizontalAlignment.Right
                },
            };

            target.UpdateChild();
            target.Measure(new Size(100, 100));
            target.Arrange(new Rect(0, 0, 100, 100));

            Assert.Equal(new Rect(84, 0, 16, 100), content.Bounds);
        }

        [Fact]
        public void Content_Can_Be_Bottom_Aligned()
        {
            Border content;
            var target = new ContentPresenter
            {
                Content = content = new Border
                {
                    MinWidth = 16,
                    MinHeight = 16,
                    VerticalAlignment = VerticalAlignment.Bottom,
                },
            };

            target.UpdateChild();
            target.Measure(new Size(100, 100));
            target.Arrange(new Rect(0, 0, 100, 100));

            Assert.Equal(new Rect(0, 84, 100, 16), content.Bounds);
        }

        [Fact]
        public void Content_Can_Be_TopLeft_Aligned()
        {
            Border content;
            var target = new ContentPresenter
            {
                Content = content = new Border
                {
                    MinWidth = 16,
                    MinHeight = 16,
                    HorizontalAlignment = HorizontalAlignment.Right,
                    VerticalAlignment = VerticalAlignment.Top,
                },
            };

            target.UpdateChild();
            target.Measure(new Size(100, 100));
            target.Arrange(new Rect(0, 0, 100, 100));

            Assert.Equal(new Rect(84, 0, 16, 16), content.Bounds);
        }

        [Fact]
        public void Content_Can_Be_TopRight_Aligned()
        {
            Border content;
            var target = new ContentPresenter
            {
                Content = content = new Border
                {
                    MinWidth = 16,
                    MinHeight = 16,
                    HorizontalAlignment = HorizontalAlignment.Right,
                    VerticalAlignment = VerticalAlignment.Top,
                },
            };

            target.UpdateChild();
            target.Measure(new Size(100, 100));
            target.Arrange(new Rect(0, 0, 100, 100));

            Assert.Equal(new Rect(84, 0, 16, 16), content.Bounds);
        }

        [Fact]
        public void Child_Arrange_With_Zero_Height_When_Padding_Height_Greater_Than_Child_Height()
        {
            Border content;
            var target = new ContentPresenter
            {
                Padding = new Thickness(32),
                MaxHeight = 32,
                MaxWidth = 32,
                HorizontalContentAlignment = HorizontalAlignment.Center,
                VerticalContentAlignment = VerticalAlignment.Center,
                Content = content = new Border
                {
                    Height = 0,
                    Width = 0,
                },
            };

            target.UpdateChild();

            target.Arrange(new Rect(0, 0, 100, 100));

            Assert.Equal(new Rect(32, 32, 0, 0), content.Bounds);
        }

        public class UseLayoutRounding : ScopedTestBase
        {
            [Fact]
            public void Measure_Rounds_Padding()
            {
                var target = new ContentPresenter
                {
                    Padding = new Thickness(1),
                    Content = new Canvas
                    {
                        Width = 101,
                        Height = 101,
                    }
                };

                var root = CreatedRoot(1.5, target);

                root.LayoutManager.ExecuteInitialLayoutPass();

                // - 1 pixel padding is rounded up to 1.3333; for both sides it is 2.6666
                // - Size of 101 gets rounded up to 101.3333
                // - Desired size = 101.3333 + 2.6666 = 104
                Assert.Equal(new Size(104, 104), target.DesiredSize);
            }

            [Fact]
            public void Measure_Rounds_BorderThickness()
            {
                var target = new ContentPresenter
                {
                    BorderThickness = new Thickness(1),
                    Content = new Canvas
                    {
                        Width = 101,
                        Height = 101,
                    }
                };

                var root = CreatedRoot(1.5, target);

                root.LayoutManager.ExecuteInitialLayoutPass();

                // - 1 pixel border thickness is rounded up to 1.3333; for both sides it is 2.6666
                // - Size of 101 gets rounded up to 101.3333
                // - Desired size = 101.3333 + 2.6666 = 104
                Assert.Equal(new Size(104, 104), target.DesiredSize);
            }

            private static TestRoot CreatedRoot(
                double scaling,
                Control child,
                Size? constraint = null)
            {
                return new TestRoot
                {
                    LayoutScaling = scaling,
                    UseLayoutRounding = true,
                    Child = child,
                    ClientSize = constraint ?? new Size(1000, 1000),
                };
            }
        }
    }
}