using CursorLang.Core.Interop;
using CursorLang.Tests.Shared;

namespace CursorLang.Core.Tests.Interop;

/// <summary>
/// Vetting the caret position. Some applications report it in their own
/// coordinate system, and such answers have to be sifted out by the bounds
/// of the input window.
/// </summary>
public sealed class CaretNativeTests
{
    private static readonly PopupWindowNative.Rect Window = new()
    {
        Left = 100,
        Top = 100,
        Right = 900,
        Bottom = 700,
    };

    [Fact]
    public void A_caret_inside_the_window_is_taken_as_is()
    {
        var caret = new PopupWindowNative.Rect { Left = 200, Top = 300, Right = 202, Bottom = 320 };

        Assert.Equal(caret, CaretNative.Validate(caret, Window, scale: 1.5));
    }

    // The application reported the coordinates without the screen scale: on
    // their own they sit above and to the left of the input window, and after
    // being brought to the scale they land inside it
    [Fact]
    public void An_unscaled_caret_is_brought_to_the_screen_scale()
    {
        var caret = new PopupWindowNative.Rect { Left = 80, Top = 80, Right = 81, Bottom = 90 };

        PopupWindowNative.Rect? validated = CaretNative.Validate(caret, Window, scale: 1.5);

        Assert.NotNull(validated);
        Assert.Equal(120, validated.Value.Left);
        Assert.Equal(120, validated.Value.Top);
        Assert.Equal(121, validated.Value.Right);
        Assert.Equal(135, validated.Value.Bottom);
    }

    [Fact]
    public void A_caret_far_from_the_window_is_discarded()
    {
        var caret = new PopupWindowNative.Rect { Left = 5000, Top = 5000, Right = 5002, Bottom = 5020 };

        Assert.Null(CaretNative.Validate(caret, Window, scale: 1.5));
    }

    // At the ordinary scale there is nothing to fix: wrong coordinates stay wrong
    [Fact]
    public void At_scale_one_a_caret_outside_the_window_is_discarded()
    {
        var caret = new PopupWindowNative.Rect { Left = 10, Top = 10, Right = 12, Bottom = 30 };

        Assert.Null(CaretNative.Validate(caret, Window, scale: 1.0));
    }

    [Theory]
    [InlineData(100, 100, 900, 700, true)]
    [InlineData(99, 100, 900, 700, false)]
    [InlineData(100, 99, 900, 700, false)]
    [InlineData(100, 100, 901, 700, false)]
    [InlineData(100, 100, 900, 701, false)]
    [InlineData(400, 400, 402, 420, true)]
    public void Inside_the_window_means_entirely_inside(
        int left, int top, int right, int bottom, bool expected)
    {
        var caret = new PopupWindowNative.Rect { Left = left, Top = top, Right = right, Bottom = bottom };

        Assert.Equal(expected, CaretNative.IsInside(caret, Window));
    }

    // When there is no caret, its rectangle comes back with zero height. Zero
    // coordinates, on the other hand, are the ordinary start of an empty field
    [Theory]
    [InlineData(0, 0, 0, 0, true)]
    [InlineData(0, 0, 2, 0, true)]
    [InlineData(0, 10, 2, 5, true)]
    [InlineData(0, 0, 0, 1, false)]
    [InlineData(0, 0, 0, 20, false)]
    public void A_caret_without_height_counts_as_empty(
        int left, int top, int right, int bottom, bool expected)
    {
        var rect = new PopupWindowNative.Rect { Left = left, Top = top, Right = right, Bottom = bottom };

        Assert.Equal(expected, CaretNative.IsEmpty(rect));
    }

    // The answer depends on what is on screen right now, but it has no right to
    // throw: the tooltip is shown whatever the answer
    [Fact]
    public void Asking_the_system_for_the_caret_goes_without_errors()
    {
        PopupWindowNative.Rect? caret = Pump.Run(CaretNative.TryGetCaretRect);

        if (caret is not null)
        {
            Assert.True(caret.Value.Bottom > caret.Value.Top);
        }
    }
}