using System.Numerics;
using AcDream.App.UI;

namespace AcDream.App.Tests.UI;

public class UiRootInputTests
{
    [Fact]
    public void WantsMouse_TrueOverWidget_FalseOverEmptySpace()
    {
        var root = new UiRoot { Width = 800, Height = 600 };
        var panel = new UiPanel { Left = 10, Top = 10, Width = 100, Height = 50 };
        root.AddChild(panel);

        root.OnMouseMove(50, 30);    // inside the panel
        Assert.True(root.WantsMouse);

        root.OnMouseMove(500, 400);  // empty space
        Assert.False(root.WantsMouse);
    }

    [Fact]
    public void WindowDrag_RepositionsDraggablePanel_StopsOnRelease()
    {
        var root = new UiRoot { Width = 800, Height = 600 };
        var panel = new UiPanel { Left = 10, Top = 10, Width = 100, Height = 50, Draggable = true };
        root.AddChild(panel);

        root.OnMouseDown(UiMouseButton.Left, 20, 20); // grab at (10,10) into the panel
        root.OnMouseMove(120, 90);                     // drag
        Assert.Equal(110f, panel.Left);                // 120 - 10
        Assert.Equal(80f, panel.Top);                  // 90 - 10

        root.OnMouseUp(UiMouseButton.Left, 120, 90);
        root.OnMouseMove(300, 300);                    // released — must not move
        Assert.Equal(110f, panel.Left);
        Assert.Equal(80f, panel.Top);
    }

    [Fact]
    public void NonDraggablePanel_DoesNotMoveOnDrag()
    {
        var root = new UiRoot { Width = 800, Height = 600 };
        var panel = new UiPanel { Left = 10, Top = 10, Width = 100, Height = 50 }; // Draggable defaults false
        root.AddChild(panel);

        root.OnMouseDown(UiMouseButton.Left, 20, 20);
        root.OnMouseMove(120, 90);
        Assert.Equal(10f, panel.Left);
        Assert.Equal(10f, panel.Top);
    }

    [Fact]
    public void ResizeRect_RightBottom_GrowsSizeOnly()
    {
        var (x, y, w, h) = UiRoot.ResizeRect(10, 20, 100, 50,
            ResizeEdges.Right | ResizeEdges.Bottom, dx: 30, dy: 15, minW: 40, minH: 40);
        Assert.Equal(10f, x); Assert.Equal(20f, y);
        Assert.Equal(130f, w); Assert.Equal(65f, h);
    }

    [Fact]
    public void ResizeRect_LeftTop_MovesOriginAndClampsToMin()
    {
        // Drag left edge right by 80 on a 100-wide / min-40 window: width clamps to 40,
        // origin shifts so the RIGHT edge (110) stays put → x = 70.
        var (x, _, w, _) = UiRoot.ResizeRect(10, 20, 100, 50,
            ResizeEdges.Left, dx: 80, dy: 0, minW: 40, minH: 40);
        Assert.Equal(40f, w);
        Assert.Equal(70f, x);
    }

    [Fact]
    public void HitEdges_DetectsCornerAndInteriorNone()
    {
        var panel = new UiPanel { Left = 100, Top = 100, Width = 200, Height = 100 };
        // bottom-right corner (300,200)
        Assert.Equal(ResizeEdges.Right | ResizeEdges.Bottom, UiRoot.HitEdges(panel, 300, 200, 5));
        // deep interior → no edges
        Assert.Equal(ResizeEdges.None, UiRoot.HitEdges(panel, 200, 150, 5));
    }

    [Fact]
    public void EdgeDrag_ResizesPanel_InteriorDragMoves()
    {
        var root = new UiRoot { Width = 800, Height = 600 };
        var panel = new UiPanel { Left = 100, Top = 100, Width = 200, Height = 100,
            Draggable = true, Resizable = true, MinWidth = 40, MinHeight = 40 };
        root.AddChild(panel);

        // grab just inside the right edge (x=298, within ResizeGrip=5 of x=300) and drag right → wider, same origin
        root.OnMouseDown(UiMouseButton.Left, 298, 150);
        root.OnMouseMove(338, 150);
        Assert.Equal(240f, panel.Width);
        Assert.Equal(100f, panel.Left);
        root.OnMouseUp(UiMouseButton.Left, 338, 150);

        // grab the interior and drag → moves
        root.OnMouseDown(UiMouseButton.Left, 200, 150);
        root.OnMouseMove(220, 170);
        Assert.Equal(120f, panel.Left);
        Assert.Equal(120f, panel.Top);
        root.OnMouseUp(UiMouseButton.Left, 220, 170);
    }

    [Fact]
    public void HitEdges_RespectsResizeAxisLock()
    {
        var panel = new UiPanel { Left = 100, Top = 100, Width = 200, Height = 100, ResizeY = false };
        // right edge still detected (X allowed)
        Assert.True((UiRoot.HitEdges(panel, 300, 150, 5) & ResizeEdges.Right) != 0);
        // bottom edge masked out (Y locked)
        Assert.True((UiRoot.HitEdges(panel, 200, 200, 5) & ResizeEdges.Bottom) == 0);
    }
}