using System.Collections.Generic;
using System.Linq;
using AcDream.App.UI;
using AcDream.App.UI.Layout;

namespace AcDream.App.Tests.UI.Layout;

/// <summary>
/// #409 (client-wide retail tooltip system) fixture coverage for
/// <see cref="RetailTooltipPresenter"/> and its <see cref="UiRoot"/> hover-
/// timer wiring. Builds synthetic popup layouts in-memory (no dats) via
/// <see cref="LayoutImporter.BuildFromInfos"/> — see
/// <see cref="TooltipLiveDatTests"/> for the installed-DAT structural pins.
/// </summary>
public sealed class RetailTooltipPresenterTests
{
    /// <summary>Minimal concrete hover target — plain <see cref="UiElement"/>
    /// with default (false) ClickThrough, so it is hit-testable.</summary>
    private sealed class HoverTarget : UiElement;

    private const uint PopupRootId = 0x900u;
    private const uint TextChildId = 0x901u;
    private const uint PopupLayoutDid = 0x21000041u;

    /// <summary>Builds a fresh 30x30/26x26 popup — the exact live-DAT-probed
    /// shape (four-piece bevel frame around one Type-12 text child) — every
    /// call, mirroring retail's own fresh-instance-per-show behaviour.</summary>
    private static ImportedLayout BuildPopup()
    {
        var rootInfo = new ElementInfo
        {
            Id = PopupRootId, Type = 3, X = 0, Y = 0, Width = 30, Height = 30,
            TooltipTextChildElementId = TextChildId,
        };
        var textInfo = new ElementInfo
        {
            Id = TextChildId, Type = 12, X = 2, Y = 2, Width = 26, Height = 26,
        };
        return LayoutImporter.BuildFromInfos(
            rootInfo, [textInfo], _ => (0u, 0, 0), null);
    }

    private static (UiRoot Root, RetailTooltipPresenter Presenter, List<(uint, uint)> Requests)
        CreateHarness()
    {
        var root = new UiRoot { Width = 800f, Height = 600f };
        var requests = new List<(uint LayoutDid, uint RootElementId)>();
        var presenter = new RetailTooltipPresenter(root, (layoutDid, rootElementId) =>
        {
            requests.Add((layoutDid, rootElementId));
            return BuildPopup();
        });
        return (root, presenter, requests);
    }

    private static HoverTarget AddFullyAuthoredTarget(UiRoot root, string text = "Rotate left.")
    {
        var target = new HoverTarget
        {
            Left = 100, Top = 100, Width = 40, Height = 20,
            AuthoredTooltipEnabled = true,
            AuthoredTooltipText = text,
            AuthoredTooltipRootElementId = PopupRootId,
            AuthoredTooltipLayoutDid = PopupLayoutDid,
        };
        root.AddChild(target);
        return target;
    }

    [Fact]
    public void NoTooltipShows_WhenPropertiesAbsent()
    {
        // Regression pin: an element that authors NONE of the five tooltip
        // properties must never produce a popup, even after the dwell delay
        // and the mouse resting on it.
        var (root, _, requests) = CreateHarness();
        var target = new HoverTarget { Left = 100, Top = 100, Width = 40, Height = 20 };
        root.AddChild(target);
        int childrenBefore = root.Children.Count;

        root.OnMouseMove(110, 110);
        root.Tick(0.016, 0);
        root.Tick(0.016, root.TooltipDelayMs + 50);

        Assert.Empty(requests);
        Assert.Equal(childrenBefore, root.Children.Count);
    }

    [Fact]
    public void DelayThenShow_MountsPopupOnlyAfterTheDwellDelay()
    {
        var (root, _, requests) = CreateHarness();
        AddFullyAuthoredTarget(root);
        int childrenBefore = root.Children.Count;

        root.OnMouseMove(110, 110);
        root.Tick(0.016, 0);
        Assert.Equal(childrenBefore, root.Children.Count); // not yet — dwell hasn't elapsed

        root.Tick(0.016, root.TooltipDelayMs - 1);
        Assert.Equal(childrenBefore, root.Children.Count); // still one ms short

        root.Tick(0.016, root.TooltipDelayMs);
        Assert.Equal(childrenBefore + 1, root.Children.Count); // popup mounted
        Assert.Single(requests, r => r == (PopupLayoutDid, PopupRootId));
    }

    [Fact]
    public void GlobalEnableGateOff_SuppressesPresentation_ButTheDwellTimerStillFires()
    {
        // Retail gates the POPUP at UIElement::MouseHover, not the dwell
        // timer itself (UIElementManager::CheckTooltip has no m_tooltipEnable
        // check) — the C# TooltipShow event must still fire; only the
        // presenter's own decision to build something is suppressed.
        var (root, presenter, requests) = CreateHarness();
        presenter.Enabled = false;
        AddFullyAuthoredTarget(root);
        int childrenBefore = root.Children.Count;
        bool eventFired = false;
        root.TooltipShow += _ => eventFired = true;

        root.OnMouseMove(110, 110);
        root.Tick(0.016, 0);
        root.Tick(0.016, root.TooltipDelayMs);

        Assert.True(eventFired);
        Assert.Empty(requests);
        Assert.Equal(childrenBefore, root.Children.Count);
    }

    [Fact]
    public void WidgetOwnTooltipDisabled_SuppressesPresentation()
    {
        var (root, _, requests) = CreateHarness();
        var target = AddFullyAuthoredTarget(root);
        target.AuthoredTooltipEnabled = false;

        root.OnMouseMove(110, 110);
        root.Tick(0.016, 0);
        root.Tick(0.016, root.TooltipDelayMs);

        Assert.Empty(requests);
    }

    [Fact]
    public void MissingText_SuppressesPresentation()
    {
        var (root, _, requests) = CreateHarness();
        var target = AddFullyAuthoredTarget(root);
        target.AuthoredTooltipText = null;

        root.OnMouseMove(110, 110);
        root.Tick(0.016, 0);
        root.Tick(0.016, root.TooltipDelayMs);

        Assert.Empty(requests);
    }

    [Fact]
    public void DismissesOnHoverTargetChange()
    {
        var (root, _, _) = CreateHarness();
        AddFullyAuthoredTarget(root);
        var other = new HoverTarget { Left = 400, Top = 400, Width = 40, Height = 20 };
        root.AddChild(other);
        int childrenBeforeShow = root.Children.Count;

        root.OnMouseMove(110, 110);
        root.Tick(0.016, 0);
        root.Tick(0.016, root.TooltipDelayMs);
        Assert.Equal(childrenBeforeShow + 1, root.Children.Count);

        // Retail UIElementManager::SwitchMouseOver @0x0045B560: hovering a
        // DIFFERENT element tears down the active tooltip immediately.
        root.OnMouseMove(410, 410);
        Assert.Equal(childrenBeforeShow, root.Children.Count);
    }

    [Fact]
    public void DismissesWhenTheOwnerElementIsRemoved()
    {
        var (root, _, _) = CreateHarness();
        var target = AddFullyAuthoredTarget(root);
        int childrenBeforeShow = root.Children.Count;

        root.OnMouseMove(110, 110);
        root.Tick(0.016, 0);
        root.Tick(0.016, root.TooltipDelayMs);
        Assert.Equal(childrenBeforeShow + 1, root.Children.Count);

        // Retail UIElementManager::DeletingElement @0x0045E520: the tooltip's
        // owner going away tears the popup down too.
        root.RemoveChild(target);
        Assert.Equal(childrenBeforeShow - 1, root.Children.Count); // target removed, popup removed
    }

    [Fact]
    public void AutoHidesAfterTheDurationElapses()
    {
        var (root, _, _) = CreateHarness();
        AddFullyAuthoredTarget(root);
        int childrenBeforeShow = root.Children.Count;

        root.OnMouseMove(110, 110);
        root.Tick(0.016, 0);
        root.Tick(0.016, root.TooltipDelayMs);
        Assert.Equal(childrenBeforeShow + 1, root.Children.Count);

        root.Tick(0.016, root.TooltipDelayMs + root.TooltipDurationMs);
        Assert.Equal(childrenBeforeShow, root.Children.Count);
    }

    [Fact]
    public void PerElementDelayOverride_ReplacesTheGlobalDelay()
    {
        var (root, _, requests) = CreateHarness();
        var target = AddFullyAuthoredTarget(root);
        target.AuthoredTooltipDelaySeconds = 0f; // the live-DAT-probed override value

        root.OnMouseMove(110, 110);
        root.Tick(0.016, 0); // the very next tick after hover starts — no dwell wait
        Assert.Single(requests);
    }

    [Fact]
    public void PositionClampsToStayFullyOnTheDisplay()
    {
        var (root, _, _) = CreateHarness();
        // Small canvas + a hover point near the bottom-right corner, so the
        // 30x30 popup would overflow both edges without the clamp.
        root.Width = 40f;
        root.Height = 40f;
        var target = new HoverTarget
        {
            Left = 0, Top = 0, Width = 40, Height = 40,
            AuthoredTooltipEnabled = true,
            AuthoredTooltipText = "hi",
            AuthoredTooltipRootElementId = PopupRootId,
            AuthoredTooltipLayoutDid = PopupLayoutDid,
        };
        root.AddChild(target);

        root.OnMouseMove(38, 38);
        root.Tick(0.016, 0);
        root.Tick(0.016, root.TooltipDelayMs);

        UiElement popup = root.Children.Single(c => !ReferenceEquals(c, target));
        Assert.True(popup.Left + popup.Width <= 40f, $"popup right edge {popup.Left + popup.Width} exceeds canvas width 40");
        Assert.True(popup.Top + popup.Height <= 40f, $"popup bottom edge {popup.Top + popup.Height} exceeds canvas height 40");
        Assert.True(popup.Left >= 0f);
        Assert.True(popup.Top >= 0f);
    }

    [Fact]
    public void AutoResizesTheRootByTheMeasuredTextDelta()
    {
        var (root, _, _) = CreateHarness();
        var target = AddFullyAuthoredTarget(
            root, text: "This is a much longer tooltip than the authored placeholder.");

        root.OnMouseMove(110, 110);
        root.Tick(0.016, 0);
        root.Tick(0.016, root.TooltipDelayMs);

        UiElement popup = root.Children.Single(c => !ReferenceEquals(c, target));
        Assert.True(popup.Width > 30f, $"expected the popup to grow past its authored 30px width, got {popup.Width}");
    }
}