#nullable enable
using UnitTests;
using Xunit.Abstractions;

namespace ViewsTests;

/// <summary>
/// Pure unit tests for <see cref="Label"/> that don't require Application.Driver or Application context.
/// These tests can run in parallel without interference.
/// </summary>
public class LabelTests (ITestOutputHelper output) : FakeDriverBase
{
    [Fact]
    public void Text_Mirrors_Title ()
    {
        var label = new Label ();
        label.Title = "Hello";
        Assert.Equal ("Hello", label.Title);
        Assert.Equal ("Hello", label.TitleTextFormatter.Text);

        Assert.Equal ("Hello", label.Text);
        Assert.Equal ("Hello", label.TextFormatter.Text);
    }

    [Fact]
    public void Title_Mirrors_Text ()
    {
        var label = new Label ();
        label.Text = "Hello";
        Assert.Equal ("Hello", label.Text);
        Assert.Equal ("Hello", label.TextFormatter.Text);

        Assert.Equal ("Hello", label.Title);
        Assert.Equal ("Hello", label.TitleTextFormatter.Text);
    }

    [Theory]
    [CombinatorialData]
    public void HotKey_Command_SetsFocus_OnNextSubView (bool hasHotKey)
    {
        var superView = new View { CanFocus = true };
        var label = new Label ();
        label.HotKey = hasHotKey ? Key.A.WithAlt : Key.Empty;
        var nextSubView = new View { CanFocus = true };
        superView.Add (label, nextSubView);
        superView.BeginInit ();
        superView.EndInit ();

        Assert.False (label.HasFocus);
        Assert.False (nextSubView.HasFocus);

        label.InvokeCommand (Command.HotKey);
        Assert.False (label.HasFocus);
        Assert.Equal (hasHotKey, nextSubView.HasFocus);
    }

    [Theory]
    [CombinatorialData]
    public void MouseClick_SetsFocus_OnNextSubView (bool hasHotKey)
    {
        var superView = new View { CanFocus = true, Height = 1, Width = 15 };
        var focusedView = new View { CanFocus = true, Width = 1, Height = 1 };
        var label = new Label { X = 2 };
        label.HotKey = hasHotKey ? Key.X.WithAlt : Key.Empty;

        var nextSubView = new View { CanFocus = true, X = 4, Width = 4, Height = 1 };
        superView.Add (focusedView, label, nextSubView);
        superView.BeginInit ();
        superView.EndInit ();

        Assert.False (focusedView.HasFocus);
        Assert.False (label.HasFocus);
        Assert.False (nextSubView.HasFocus);

        label.NewMouseEvent (new () { Position = new (0, 0), Flags = MouseFlags.Button1Clicked });
        Assert.False (label.HasFocus);
        Assert.Equal (hasHotKey, nextSubView.HasFocus);
    }

    [Fact]
    public void HotKey_Command_Does_Not_Accept ()
    {
        var label = new Label ();
        var accepted = false;

        label.Accepting += LabelOnAccept;
        label.InvokeCommand (Command.HotKey);

        Assert.False (accepted);

        return;

        void LabelOnAccept (object? sender, CommandEventArgs e) { accepted = true; }
    }

    [Fact]
    public void Constructors_Defaults ()
    {
        var label = new Label ();
        Assert.Equal (string.Empty, label.Text);
        Assert.Equal (Alignment.Start, label.TextAlignment);
        Assert.False (label.CanFocus);
        Assert.Equal (new (0, 0, 0, 0), label.Frame);
        Assert.Equal (KeyCode.Null, label.HotKey);
    }

    [Fact]
    public void Label_HotKeyChanged_EventFires ()
    {
        var label = new Label ();
        var fired = false;
        Key oldKey = Key.Empty;
        Key newKey = Key.Empty;

        label.HotKeyChanged += (s, e) =>
        {
            fired = true;
            oldKey = e.OldKey;
            newKey = e.NewKey;
        };

        label.HotKey = Key.A.WithAlt;

        Assert.True (fired);
        Assert.Equal (Key.Empty, oldKey);
        Assert.Equal (Key.A.WithAlt, newKey);
    }

    [Fact]
    public void Label_HotKeyChanged_EventFires_WithNone ()
    {
        var label = new Label { HotKey = Key.A.WithAlt };
        var fired = false;
        Key oldKey = Key.Empty;
        Key newKey = Key.Empty;

        label.HotKeyChanged += (s, e) =>
        {
            fired = true;
            oldKey = e.OldKey;
            newKey = e.NewKey;
        };

        label.HotKey = Key.Empty;

        Assert.True (fired);
        Assert.Equal (Key.A.WithAlt, oldKey);
        Assert.Equal (Key.Empty, newKey);
    }

    [Fact]
    public void TestAssignTextToLabel ()
    {
        var label = new Label ();
        label.Text = "Test";
        Assert.Equal ("Test", label.Text);
    }


    [Fact]
    public void CanFocus_False_HotKey_SetsFocus_Next ()
    {
        View otherView = new ()
        {
            Text = "otherView",
            CanFocus = true
        };

        Label label = new ()
        {
            Text = "_label"
        };

        View nextView = new ()
        {
            Text = "nextView",
            CanFocus = true
        };

        IApplication app = Application.Create ();
        Runnable<bool> runnable = new ();
        app.Begin (runnable);
        runnable.Add (otherView, label, nextView);
        otherView.SetFocus ();

        // runnable.SetFocus ();
        Assert.True (otherView.HasFocus);

        Assert.True (app.Keyboard.RaiseKeyDownEvent (label.HotKey));
        Assert.False (otherView.HasFocus);
        Assert.False (label.HasFocus);
        Assert.True (nextView.HasFocus);
    }

    [Fact]
    public void CanFocus_False_MouseClick_SetsFocus_Next ()
    {
        View otherView = new () { X = 0, Y = 0, Width = 1, Height = 1, Id = "otherView", CanFocus = true };
        Label label = new () { X = 0, Y = 1, Text = "_label" };
        View nextView = new ()
        {
            X = Pos.Right (label), Y = Pos.Top (label), Width = 1, Height = 1, Id = "nextView", CanFocus = true
        };

        IApplication app = Application.Create ();
        Runnable<bool> runnable = new ();
        app.Begin (runnable);
        runnable.Add (otherView, label, nextView);
        otherView.SetFocus ();

        // click on label
        app.Mouse.RaiseMouseEvent (new () { ScreenPosition = label.Frame.Location, Flags = MouseFlags.Button1Clicked });
        Assert.False (label.HasFocus);
        Assert.True (nextView.HasFocus);
    }


    [Fact]
    public void CanFocus_True_HotKey_SetsFocus ()
    {
        Label label = new ()
        {
            Text = "_label",
            CanFocus = true
        };

        View view = new ()
        {
            Text = "view",
            CanFocus = true
        };

        IApplication app = Application.Create ();
        Runnable<bool> runnable = new ();
        app.Begin (runnable);
        runnable.Add (label, view);

        view.SetFocus ();
        Assert.True (label.CanFocus);
        Assert.False (label.HasFocus);
        Assert.True (view.CanFocus);
        Assert.True (view.HasFocus);

        // No focused view accepts Tab, and there's no other view to focus, so OnKeyDown returns false
        Assert.True (app.Keyboard.RaiseKeyDownEvent (label.HotKey));
        Assert.True (label.HasFocus);
        Assert.False (view.HasFocus);
    }



    [Fact]
    public void CanFocus_True_MouseClick_Focuses ()
    {
        Label label = new ()
        {
            Text = "label",
            X = 0,
            Y = 0,
            CanFocus = true
        };

        View otherView = new ()
        {
            Text = "view",
            X = 0,
            Y = 1,
            Width = 4,
            Height = 1,
            CanFocus = true
        };

        IApplication app = Application.Create ();
        Runnable<bool> runnable = new ()
        {
            Width = 10,
            Height = 10
        }; ;
        app.Begin (runnable);
        runnable.Add (label, otherView);
        label.SetFocus ();

        Assert.True (label.CanFocus);
        Assert.True (label.HasFocus);
        Assert.True (otherView.CanFocus);
        Assert.False (otherView.HasFocus);

        otherView.SetFocus ();
        Assert.True (otherView.HasFocus);

        // label can focus, so clicking on it set focus
        app.Mouse.RaiseMouseEvent (new () { ScreenPosition = new (0, 0), Flags = MouseFlags.Button1Clicked });
        Assert.True (label.HasFocus);
        Assert.False (otherView.HasFocus);

        // click on view
        app.Mouse.RaiseMouseEvent (new () { ScreenPosition = new (0, 1), Flags = MouseFlags.Button1Clicked });
        Assert.False (label.HasFocus);
        Assert.True (otherView.HasFocus);
    }


    [Fact]
    public void With_Top_Margin_Without_Top_Border ()
    {
        IApplication app = Application.Create ();
        app.Init ("Fake");
        Runnable<bool> runnable = new ()
        {
            Width = 10,
            Height = 10
        }; ;
        app.Begin (runnable);

        var label = new Label { Text = "Test", /*Width = 6, Height = 3,*/ BorderStyle = LineStyle.Single };
        label.Margin!.Thickness = new (0, 1, 0, 0);
        label.Border!.Thickness = new (1, 0, 1, 1);
        runnable.Add (label);
        app.LayoutAndDraw ();

        Assert.Equal (new (0, 0, 6, 3), label.Frame);
        Assert.Equal (new (0, 0, 4, 1), label.Viewport);
        DriverAssert.AssertDriverContentsWithFrameAre (
                                                       @"
│Test│
└────┘",
                                                       output,
                                                       app.Driver
                                                      );
    }

    [Fact]
    public void Without_Top_Border ()
    {
        IApplication app = Application.Create ();
        app.Init ("Fake");
        Runnable<bool> runnable = new ()
        {
            Width = 10,
            Height = 10
        }; ;
        app.Begin (runnable);

        var label = new Label { Text = "Test", /* Width = 6, Height = 3, */BorderStyle = LineStyle.Single };
        label.Border!.Thickness = new (1, 0, 1, 1);
        runnable.Add (label);
        app.LayoutAndDraw ();

        Assert.Equal (new (0, 0, 6, 2), label.Frame);
        Assert.Equal (new (0, 0, 4, 1), label.Viewport);

        DriverAssert.AssertDriverContentsWithFrameAre (
                                                       @"
│Test│
└────┘",
                                                       output,
                                                       app.Driver
                                                      );
    }

}