using JdeScoping.ConfigManager.Services;
using JdeScoping.ConfigManager.ViewModels.Dialogs;

namespace JdeScoping.ConfigManager.Tests.ViewModels.Dialogs;

public class DiffPreviewDialogViewModelTests
{
    [Fact]
    public void Constructor_WithEmptyDiff_InitializesCorrectly()
    {
        // Arrange
        var diff = new DiffResult
        {
            HasChanges = false,
            Lines = [],
            Insertions = 0,
            Deletions = 0
        };

        // Act
        var sut = new DiffPreviewDialogViewModel(diff);

        // Assert
        sut.Lines.Count.ShouldBe(0);
        sut.HasChanges.ShouldBeFalse();
        sut.Insertions.ShouldBe(0);
        sut.Deletions.ShouldBe(0);
        sut.Result.ShouldBeFalse();
    }

    [Fact]
    public void Constructor_WithChanges_PopulatesLines()
    {
        // Arrange
        var diff = new DiffResult
        {
            HasChanges = true,
            Lines =
            [
                new DiffLine { OldLineNumber = 1, NewLineNumber = 1, Text = "unchanged line", Type = DiffLineType.Unchanged },
                new DiffLine { OldLineNumber = 2, NewLineNumber = null, Text = "removed line", Type = DiffLineType.Removed },
                new DiffLine { OldLineNumber = null, NewLineNumber = 2, Text = "added line", Type = DiffLineType.Added }
            ],
            Insertions = 1,
            Deletions = 1
        };

        // Act
        var sut = new DiffPreviewDialogViewModel(diff);

        // Assert
        sut.Lines.Count.ShouldBe(3);
        sut.HasChanges.ShouldBeTrue();
        sut.Insertions.ShouldBe(1);
        sut.Deletions.ShouldBe(1);
    }

    [Fact]
    public void SaveCommand_SetsResultTrue_AndInvokesRequestClose()
    {
        // Arrange
        var diff = CreateEmptyDiff();
        var sut = new DiffPreviewDialogViewModel(diff);
        var closeInvoked = false;
        sut.RequestClose = () => closeInvoked = true;

        // Act
        sut.SaveCommand.Execute(null);

        // Assert
        sut.Result.ShouldBeTrue();
        closeInvoked.ShouldBeTrue();
    }

    [Fact]
    public void CancelCommand_SetsResultFalse_AndInvokesRequestClose()
    {
        // Arrange
        var diff = CreateEmptyDiff();
        var sut = new DiffPreviewDialogViewModel(diff);
        var closeInvoked = false;
        sut.RequestClose = () => closeInvoked = true;

        // Act
        sut.CancelCommand.Execute(null);

        // Assert
        sut.Result.ShouldBeFalse();
        closeInvoked.ShouldBeTrue();
    }

    [Fact]
    public void SaveCommand_DoesNotThrow_WhenRequestCloseIsNull()
    {
        // Arrange
        var diff = CreateEmptyDiff();
        var sut = new DiffPreviewDialogViewModel(diff);
        sut.RequestClose = null;

        // Act & Assert - Should not throw
        Should.NotThrow(() => sut.SaveCommand.Execute(null));
        sut.Result.ShouldBeTrue();
    }

    [Fact]
    public void CancelCommand_DoesNotThrow_WhenRequestCloseIsNull()
    {
        // Arrange
        var diff = CreateEmptyDiff();
        var sut = new DiffPreviewDialogViewModel(diff);
        sut.RequestClose = null;

        // Act & Assert - Should not throw
        Should.NotThrow(() => sut.CancelCommand.Execute(null));
        sut.Result.ShouldBeFalse();
    }

    [Fact]
    public void Constructor_ThrowsOnNullDiff()
    {
        // Act & Assert
        Should.Throw<ArgumentNullException>(() => new DiffPreviewDialogViewModel(null!));
    }

    [Fact]
    public void Result_InitialValue_IsFalse()
    {
        // Arrange
        var diff = CreateEmptyDiff();

        // Act
        var sut = new DiffPreviewDialogViewModel(diff);

        // Assert
        sut.Result.ShouldBeFalse();
    }

    private static DiffResult CreateEmptyDiff()
    {
        return new DiffResult
        {
            HasChanges = false,
            Lines = [],
            Insertions = 0,
            Deletions = 0
        };
    }
}

public class DiffLineViewModelTests
{
    [Fact]
    public void Constructor_UnchangedLine_SetsPropertiesCorrectly()
    {
        // Arrange
        var line = new DiffLine
        {
            OldLineNumber = 5,
            NewLineNumber = 5,
            Text = "unchanged content",
            Type = DiffLineType.Unchanged
        };

        // Act
        var sut = new DiffLineViewModel(line);

        // Assert
        sut.OldLineNumber.ShouldBe("5");
        sut.NewLineNumber.ShouldBe("5");
        sut.Text.ShouldBe("unchanged content");
        sut.Type.ShouldBe(DiffLineType.Unchanged);
        sut.Background.ShouldBe("Transparent");
        sut.BorderColor.ShouldBe("Transparent");
    }

    [Fact]
    public void Constructor_AddedLine_SetsGreenStyling()
    {
        // Arrange
        var line = new DiffLine
        {
            OldLineNumber = null,
            NewLineNumber = 10,
            Text = "new line",
            Type = DiffLineType.Added
        };

        // Act
        var sut = new DiffLineViewModel(line);

        // Assert
        sut.OldLineNumber.ShouldBe("");
        sut.NewLineNumber.ShouldBe("10");
        sut.Type.ShouldBe(DiffLineType.Added);
        sut.Background.ShouldBe("#1A3DD68C");
        sut.BorderColor.ShouldBe("#3DD68C");
    }

    [Fact]
    public void Constructor_RemovedLine_SetsRedStyling()
    {
        // Arrange
        var line = new DiffLine
        {
            OldLineNumber = 7,
            NewLineNumber = null,
            Text = "deleted line",
            Type = DiffLineType.Removed
        };

        // Act
        var sut = new DiffLineViewModel(line);

        // Assert
        sut.OldLineNumber.ShouldBe("7");
        sut.NewLineNumber.ShouldBe("");
        sut.Type.ShouldBe(DiffLineType.Removed);
        sut.Background.ShouldBe("#1AFF6B6B");
        sut.BorderColor.ShouldBe("#FF6B6B");
    }

    [Fact]
    public void Constructor_NullLineNumbers_ReturnsEmptyStrings()
    {
        // Arrange
        var line = new DiffLine
        {
            OldLineNumber = null,
            NewLineNumber = null,
            Text = "text",
            Type = DiffLineType.Unchanged
        };

        // Act
        var sut = new DiffLineViewModel(line);

        // Assert
        sut.OldLineNumber.ShouldBe("");
        sut.NewLineNumber.ShouldBe("");
    }
}