acdream/src/AcDream.App/UI/UiPanel.cs

using System;
using System.Numerics;

namespace AcDream.App.UI;

/// <summary>
/// Rectangular container with an optional translucent background and
/// border. Used as the base of every retail panel (attributes, chat,
/// inventory, login, etc.).
///
/// Retail has panel background art stored as 9-slice sprite assets in
/// the <c>0x06xxxxxx</c> RenderSurface range, and composed via
/// <c>LayoutDesc</c> (<c>0x21xxxxxx</c>) trees. Until our
/// <c>AcFont</c>/<c>UiSpriteBatch</c> consumes those directly, we draw a
/// simple translucent rectangle so panels are visible during development.
/// </summary>
internal class UiPanel : UiElement
{
    /// <summary>Background fill color. Set <see cref="Vector4.Zero"/> to skip.</summary>
    public Vector4 BackgroundColor { get; set; } = new(0f, 0f, 0f, 0.55f);

    /// <summary>Border color. Set <see cref="Vector4.Zero"/> to skip.</summary>
    public Vector4 BorderColor     { get; set; } = new(0.15f, 0.15f, 0.2f, 0.8f);

    public float BorderThickness   { get; set; } = 1f;

    /// <summary>Optional dat RenderSurface id for the panel background sprite, drawn
    /// in place of (or alongside) <see cref="BackgroundColor"/>. 0 = none.
    /// When set, the sprite is stretched to fill the panel rect.
    /// Used by the attribute-list selected-row highlight (sprite 0x06001397 = Button state 6).</summary>
    public uint BackgroundSprite { get; set; }

    /// <summary>Resolves a dat RenderSurface id to (GL tex handle, pixel width, pixel height).
    /// Required when <see cref="BackgroundSprite"/> is non-zero.</summary>
    public Func<uint, (GpuTextureSlot tex, int w, int h)>? SpriteResolve { get; set; }

    protected override void OnDraw(UiRenderContext ctx)
    {
        if (BackgroundSprite != 0 && SpriteResolve is { } sr)
        {
            var (tex, tw, th) = sr(BackgroundSprite);
            if (tex.IsAssigned && tw != 0 && th != 0)
                ctx.DrawSprite(tex, 0, 0, Width, Height, 0, 0, Width / tw, Height / th, Vector4.One);
        }
        else if (BackgroundColor.W > 0f)
        {
            // Panel fills are backgrounds. Draw them through the sprite/fill
            // bucket so children that render as sprites/dat-font glyphs stay on
            // top in painter order; DrawRect flushes after sprites and would
            // cover text/icons.
            ctx.DrawFill(0, 0, Width, Height, BackgroundColor);
        }

        if (BorderColor.W > 0f && BorderThickness > 0f)
            ctx.DrawRectOutline(0, 0, Width, Height, BorderColor, BorderThickness);
    }
}

/// <summary>
/// Static text label. Draws a single line of text using the context's
/// default font (or an override). Does not consume input.
///
/// Equivalent retail primitive: wide-string appended to a CString via
/// <c>FUN_0040b8f0</c> then drawn by the widget's draw method through
/// <c>FUN_00698330</c>.
/// </summary>
internal class UiLabel : UiElement
{
    public string Text       { get; set; } = string.Empty;
    public Vector4 TextColor { get; set; } = new(1f, 1f, 1f, 1f);

    public UiLabel() { ClickThrough = true; }

    protected override void OnDraw(UiRenderContext ctx)
        => ctx.DrawString(Text, 0, 0, TextColor);
}

/// <summary>
/// Simple clickable button: panel background + centered label + click
/// callback. Retail equivalent is Keystone's button widget, driven by
/// a <c>StateDesc</c> per <c>UIStateId</c> (normal / hot / pressed /
/// disabled) from the panel layout.
/// Note: the dat-widget button (Type 1 / UIElement_Button) is <see cref="AcDream.App.UI.UiButton"/>
/// in <c>UiButton.cs</c> — that is the production widget used by D.2b panels.
/// This class is the earlier dev-scaffold button (plain rect + text; no dat sprites).
/// </summary>
internal class UiSimpleButton : UiPanel
{
    public string Text       { get; set; } = string.Empty;
    public Vector4 TextColor { get; set; } = new(1f, 1f, 1f, 1f);
    public event System.Action? Click;

    public UiSimpleButton()
    {
        BackgroundColor = new Vector4(0.1f, 0.1f, 0.15f, 0.8f);
        BorderColor     = new Vector4(0.45f, 0.45f, 0.55f, 1f);
    }

    public override bool OnEvent(in UiEvent e)
    {
        if (e.Type == UiEventType.Click && Enabled)
        {
            Click?.Invoke();
            return true;
        }
        return false;
    }

    protected override void OnDraw(UiRenderContext ctx)
    {
        base.OnDraw(ctx);
        if (Text.Length == 0 || ctx.DefaultFont is null) return;

        float textW = ctx.DefaultFont.MeasureWidth(Text);
        float tx = (Width  - textW) * 0.5f;
        float ty = (Height - ctx.DefaultFont.LineHeight) * 0.5f;
        ctx.DrawString(Text, tx, ty, TextColor);
    }
}

/// <summary>
/// A <see cref="UiPanel"/> that fires an <see cref="OnClick"/> callback when the user
/// left-clicks it. Used for the attribute-list rows in the Character window — each row
/// is a transparent container that needs to respond to pointer hits while its children
/// (icon, name, value) are ClickThrough decorations.
///
/// <para>Retail analog: the <c>AttributeInfoRegion</c> row widget in <c>gmAttributeUI</c>
/// catches <c>UIEvent_LeftClick</c> (0x01) and calls <c>SetSelectedAttribute</c> on the
/// parent window. In acdream we wire the equivalent via this action callback instead of
/// the retail message bus.</para>
///
/// <para>When <see cref="UseSelectionBars"/> is true and <see cref="UiPanel.BackgroundSprite"/>
/// is non-zero, draws the sprite as a thin full-width bar at the TOP and BOTTOM edges of
/// the row (not stretched to fill). This matches retail's selection highlight which shows
/// a horizontal dark bar on both the top and bottom edge of the selected attribute row,
/// with NO left/right end-caps. Bar height is <see cref="SelectionBarHeight"/> pixels
/// (default 3px).</para>
/// </summary>
internal class UiClickablePanel : UiPanel
{
    /// <summary>Called when the user releases the left mouse button over this panel.</summary>
    public Action? OnClick { get; set; }

    /// <summary>When true and <see cref="UiPanel.BackgroundSprite"/> is non-zero, draws
    /// the sprite as a thin horizontal bar at the top AND bottom edges of the panel,
    /// NOT as a full-height stretched fill. Matches retail's selected-row highlight
    /// (sprite 0x06001397 — 300×32 px — shown as bars, not a block fill).
    /// Default false (preserves legacy full-stretch behavior).</summary>
    public bool UseSelectionBars { get; set; }

    /// <summary>Height in pixels of each selection bar (top and bottom). Default 3px.
    /// Ignored when <see cref="UseSelectionBars"/> is false.</summary>
    public float SelectionBarHeight { get; set; } = 3f;

    public UiClickablePanel()
    {
        // Rows must receive pointer events — override the UiPanel default (ClickThrough=false,
        // which is the UiElement base default).  Explicit for clarity.
        ClickThrough = false;
    }

    /// <summary>HandlesClick = true ensures this row receives its own Click even when
    /// it is nested inside a Draggable ancestor window frame (e.g. the future character
    /// window with a whole-window drag handle). Without this, the press would be consumed
    /// by the ancestor's drag logic and the Click would never fire.</summary>
    public override bool HandlesClick => true;

    public override bool OnEvent(in UiEvent e)
    {
        if (e.Type == UiEventType.Click && Enabled)
        {
            OnClick?.Invoke();
            return true;
        }
        return false;
    }

    protected override void OnDraw(UiRenderContext ctx)
    {
        if (UseSelectionBars && BackgroundSprite != 0 && SpriteResolve is { } sr)
        {
            // Draw the selection highlight as a thin bar at the TOP and BOTTOM of the row.
            // The sprite (0x06001397) is 300×32 px — we draw it as horizontal strips at
            // native height (SelectionBarHeight), stretched to full panel width (UV tile
            // horizontally). No left/right end-caps: u0=0, u1=Width/nativeW (UV repeat).
            var (tex, tw, th) = sr(BackgroundSprite);
            if (tex.IsAssigned && tw > 0 && th > 0)
            {
                float barH  = SelectionBarHeight;
                float uTile = tw > 0 ? Width / tw : 1f;
                // Top bar: shows the top barH px of the sprite (v = 0 → barH/th).
                float vBot  = th > 0 ? barH / th : 1f;
                ctx.DrawSprite(tex, 0f, 0f,           Width, barH, 0f, 0f,    uTile, vBot, Vector4.One);
                // Bottom bar: shows the bottom barH px of the sprite (v = 1−barH/th → 1).
                float vTop2 = th > 0 ? 1f - barH / th : 0f;
                ctx.DrawSprite(tex, 0f, Height - barH, Width, barH, 0f, vTop2, uTile, 1f,  Vector4.One);
            }
            // Selection-bar mode draws no border (rows have BorderColor=Zero by design).
        }
        else
        {
            // Default UiPanel draw: handles BackgroundSprite, BackgroundColor, AND border.
            base.OnDraw(ctx);
        }
    }
}