using System;

namespace AcDream.App.UI.Layout;

/// <summary>
/// Behavioral root widget for the vitals windows — retail's <c>gmVitalsUI</c>
/// family (<c>gmVitalsUI</c> 0x10000009, <c>gmFloatyVitalsUI</c> 0x1000004D =
/// the stacked window LayoutDesc 0x2100006C, <c>gmFloatySideVitalsUI</c>
/// 0x10000056 = the side-by-side window LayoutDesc 0x21000075; registrations
/// @0x004BFE10 / @0x004CED90 / @0x004D0490).
///
/// <para>
/// <b>The click toggle</b> (<c>gmVitalsUI::ListenToElementMessage @0x004BFC00</c>,
/// inherited verbatim by both floaty subclasses): on <c>Element_mouse_press</c>
/// (0x1C) with dwParam1 7 (left) or 0xA (right) the root flips
/// <c>SetState(m_state == HideDetail ? ShowDetail : HideDetail)</c>.
/// State semantics from the authored data + <c>UIElement::OnSetAttribute</c>
/// case 8 (0x3B = invisible, <c>SetVisible(value == 0)</c> @0x00462DAE):
/// </para>
/// <list type="bullet">
/// <item><description><b>Undef</b> (login default; DefaultState is authored
/// Undef and nothing calls SetState at init): numbers visible, no icons —
/// visually identical to HideDetail.</description></item>
/// <item><description><b>HideDetail</b> (0x10000006): the numeric mode — the
/// cur/max labels author {0x3B:false} (visible); the icon overlays author
/// File=0 (nothing).</description></item>
/// <item><description><b>ShowDetail</b> (0x10000007): the graphical mode —
/// labels author {0x3B:true} (hidden); each bar shows its authored icon pair
/// (dim back + bright fill-clipped front: heart / sword / scepter).</description></item>
/// </list>
///
/// <para>
/// The first press from Undef lands on HideDetail (retail's exact expression:
/// <c>ecx = (m_state == 0x10000006); SetState(ecx + 0x10000006)</c> — any
/// state that is not HideDetail, including the initial Undef, goes to
/// HideDetail first), so the first click appears to do nothing and the second
/// enters icon mode. NOT persisted anywhere: <c>gmGamePlayUI::SaveScreenLayout
/// @0x004EAD50</c> writes only window rects, and no PlayerModule option is
/// touched — the mode resets to Undef every session, per window.
/// </para>
///
/// <para>
/// <b>Press routing:</b> retail broadcasts the press to the pressed element
/// and forwards up the parent chain (<c>UIElement::ListenToElementMessage
/// @0x00462340</c> → ForwardElementMessage), but <c>UIElement_Dragbar</c>
/// (@0x0046C850) and <c>UIElement_Resizebar</c> (@0x0046B930) both return 2
/// (consumed) unconditionally — a press that starts a window move or resize
/// never reaches the vitals root. Mirrored here: presses whose hit target is a
/// move handle or resize grip are ignored. The handler returns false so the
/// event keeps bubbling, matching retail's fall-through to the base handler.
/// </para>
/// </summary>
public sealed class UiVitalsRoot : UiDatElement
{
    /// <summary>gmVitalsUI registered element class (@0x004BFE1A).</summary>
    public const uint GmVitalsClassId = 0x10000009u;
    /// <summary>gmFloatyVitalsUI registered element class (@0x004CED9A) — the stacked window root.</summary>
    public const uint GmFloatyVitalsClassId = 0x1000004Du;
    /// <summary>gmFloatySideVitalsUI registered element class (@0x004D049A) — the side-by-side window root.</summary>
    public const uint GmFloatySideVitalsClassId = 0x10000056u;

    public UiVitalsRoot(ElementInfo info, Func<uint, (uint tex, int w, int h)> resolve)
        : base(info, resolve)
    {
    }

    public override bool OnEvent(in UiEvent e)
    {
        if (e.Type is UiEventType.MouseDown or UiEventType.RightDown
            && !PressConsumedByChrome(e.Target))
        {
            // gmVitalsUI::ListenToElementMessage @0x004BFC04:
            //   this->SetState(m_state == HideDetail ? ShowDetail : HideDetail)
            // then falls through to the base handler (keep bubbling).
            TrySetRetailState(
                ActiveRetailStateId == RetailUiStateIds.HideDetail
                    ? RetailUiStateIds.ShowDetail
                    : RetailUiStateIds.HideDetail);
        }
        return base.OnEvent(in e);
    }

    /// <summary>
    /// True when the pressed element is (or sits inside) a window-move handle
    /// or resize grip — the two retail element classes that consume the press
    /// before it can bubble to the vitals root.
    /// </summary>
    private bool PressConsumedByChrome(UiElement? target)
    {
        for (UiElement? w = target; w is not null && w != this; w = w.Parent)
            if (w.WindowMoveHandle || w is UiResizeGrip)
                return true;
        return false;
    }
}