using System;
using System.Collections.Generic;
using AcDream.UI.Abstractions.Input;
using Silk.NET.Input;

namespace AcDream.UI.Abstractions.Tests.Input;

/// <summary>
/// Hand-rolled in-memory <see cref="IMouseSource"/> for unit tests.
/// Tests drive button + cursor + wheel events; tests can also flip
/// <see cref="WantCaptureMouse"/> / <see cref="WantCaptureKeyboard"/>
/// to simulate ImGui-focus behavior.
/// </summary>
internal sealed class FakeMouseSource : IMouseSource
{
    public event Action<MouseButton, ModifierMask>? MouseDown;
    public event Action<MouseButton, ModifierMask>? MouseUp;
    public event Action<float, float>? MouseMove;
    public event Action<float>? Scroll;

    private readonly HashSet<MouseButton> _held = new();

    public bool IsHeld(MouseButton button) => _held.Contains(button);

    public bool WantCaptureMouse { get; set; }
    public bool WantCaptureKeyboard { get; set; }

    public void EmitMouseDown(MouseButton button, ModifierMask mods)
    {
        _held.Add(button);
        MouseDown?.Invoke(button, mods);
    }

    public void EmitMouseUp(MouseButton button, ModifierMask mods)
    {
        _held.Remove(button);
        MouseUp?.Invoke(button, mods);
    }

    public void EmitMouseMove(float dx, float dy) => MouseMove?.Invoke(dx, dy);
    public void EmitScroll(float delta) => Scroll?.Invoke(delta);
}