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

namespace AcDream.App.UI;

/// <summary>
/// The three column kinds a plugin markup <c>&lt;list&gt;&lt;column&gt;</c> can
/// declare (Campaign VT slice 1 Part B, VVS <c>HudList</c> parity —
/// <c>docs/research/vtank-kb/08-ui-views.md</c> §2-3). Mirrors VVS's
/// <c>TextColumn</c>/<c>CheckColumn</c>/<c>IconColumn</c> progids.
/// </summary>
public enum UiMarkupListColumnKind
{
    Text,
    Check,
    Icon,
}

/// <summary>
/// One column of a multi-column <see cref="UiMarkupList"/>. Built once by
/// <see cref="MarkupDocument"/> from a <c>&lt;column&gt;</c> element and then
/// only read by the widget — the plugin binding remains the sole owner of
/// every row's data, exactly like the single-column list's own
/// <see cref="UiMarkupList.ItemsSource"/>.
///
/// <para>
/// <see cref="Width"/> is the column's DECLARED width in px, meaningful only
/// when <see cref="IsAutoWidth"/> is false. The LAST column in a list always
/// ignores its own declared width/auto-ness at layout time — it always
/// absorbs whatever room remains after every earlier column. Any OTHER
/// column marked <see cref="IsAutoWidth"/> (fix round item 2, <c>width="*"</c>
/// — VVS's own "0-width column auto-sizes" convention) shares that same
/// remaining room equally with every other auto column, the last column
/// absorbing the rounding slack — see <see cref="UiMarkupList"/>'s
/// column-layout helper, which recomputes this dynamically off the list's
/// live <c>Width</c> rather than baking it in at Build.
/// </para>
///
/// <para>
/// Fix round item 8: every settable member is <c>internal init</c> — this
/// type is constructible only through its <see cref="Text"/>/
/// <see cref="Check"/>/<see cref="Icon"/> factories. A plugin (an external
/// assembly with no <c>InternalsVisibleTo</c> grant) can never assemble an
/// inconsistent instance (e.g. <see cref="Kind"/> Text with
/// <see cref="CheckChanged"/> set) via object-initializer syntax; only the
/// three factories, which each set exactly the fields their own kind uses,
/// can construct one.
/// </para>
/// </summary>
public sealed class UiMarkupListColumn
{
    // Fix round item 8: `required` cannot pair with a setter less visible
    // than the type itself (CS9032) — since Kind/Width are now internal
    // init, every factory sets both unconditionally instead (compiler
    // enforcement moves from "required" to "the only three call sites all
    // do it").
    public UiMarkupListColumnKind Kind { get; internal init; }
    public float Width { get; internal init; }
    /// <summary>
    /// Fix round item 2: <c>width="*"</c> — this column shares the list's
    /// remaining width equally with every other auto column (the last
    /// column in the list is ALWAYS treated as auto regardless of this flag
    /// or its own declared <see cref="Width"/> — see the class doc above).
    /// </summary>
    public bool IsAutoWidth { get; internal init; }

    // ── text ──────────────────────────────────────────────────────────────
    /// <summary><c>&lt;column type="text" items="{IReadOnlyList&lt;string&gt;}"&gt;</c>.</summary>
    public Func<IReadOnlyList<string>>? TextSource { get; internal init; }
    /// <summary>
    /// Optional per-row text color override, mirroring the single-column
    /// list's own <c>colors</c> attribute. Null (the default, when the
    /// column has no <c>colors</c> attribute at all) means every row in this
    /// column draws with the list's <see cref="UiMarkupList.TextColor"/>.
    /// </summary>
    public Func<IReadOnlyList<uint>>? ColorsSource { get; internal init; }
    /// <summary>
    /// Fix round finding 1: optional <c>onclick="{Action&lt;int&gt;}"</c> on a
    /// text column. Fired with the ROW INDEX on a click anywhere in the cell
    /// INSTEAD of selecting the row, when present. Null (the default — no
    /// <c>onclick</c> attribute at all) keeps today's original behavior: a
    /// click in this cell selects the row and fires the list's own
    /// <c>onchange</c>, exactly as before this fix. None of VTank's eight
    /// lists actually uses row selection — every real text cell is an action
    /// target — but the select-on-click default stays for any acdream markup
    /// that already relies on it.
    /// </summary>
    public Action<int>? TextClicked { get; internal init; }

    // ── check ─────────────────────────────────────────────────────────────
    /// <summary><c>&lt;column type="check" values="{IReadOnlyList&lt;bool&gt;}"&gt;</c>.</summary>
    public Func<IReadOnlyList<bool>>? CheckSource { get; internal init; }
    /// <summary>
    /// Fired with the ROW INDEX on a click anywhere in this cell — the
    /// plugin flips its own bool; the column never mutates
    /// <see cref="CheckSource"/>'s backing collection itself. Required (a
    /// check column with no <c>onchange</c> throws at Build).
    /// </summary>
    public Action<int>? CheckChanged { get; internal init; }

    // ── icon ──────────────────────────────────────────────────────────────
    /// <summary><c>&lt;column type="icon" values="{IReadOnlyList&lt;uint&gt;}"&gt;</c> — one icon id per row.</summary>
    public Func<IReadOnlyList<uint>>? IconValuesSource { get; internal init; }
    /// <summary>
    /// Resolves one <see cref="IconValuesSource"/> entry to a drawable icon,
    /// dispatched by the column's own <c>iconkind</c> — built by
    /// <see cref="MarkupDocument"/> from the shared
    /// <see cref="IMarkupIconResolver"/>. Null when no resolver is wired on
    /// the host (the column then draws no icons, matching every other
    /// Slice-B icon sink's "no resolver → draws nothing" rule).
    /// </summary>
    public Func<uint, (uint tex, int w, int h)>? IconResolve { get; internal init; }
    /// <summary>
    /// Fired with the ROW INDEX on a click anywhere in this cell. Required
    /// (an icon column with no <c>onclick</c> throws at Build).
    /// </summary>
    public Action<int>? IconClicked { get; internal init; }

    public static UiMarkupListColumn Text(
        float width,
        Func<IReadOnlyList<string>> textSource,
        Func<IReadOnlyList<uint>>? colorsSource,
        Action<int>? onClick = null,
        bool isAutoWidth = false) => new()
    {
        Kind = UiMarkupListColumnKind.Text,
        Width = width,
        IsAutoWidth = isAutoWidth,
        TextSource = textSource,
        ColorsSource = colorsSource,
        TextClicked = onClick,
    };

    public static UiMarkupListColumn Check(
        float width,
        Func<IReadOnlyList<bool>> checkSource,
        Action<int> onChange,
        bool isAutoWidth = false) => new()
    {
        Kind = UiMarkupListColumnKind.Check,
        Width = width,
        IsAutoWidth = isAutoWidth,
        CheckSource = checkSource,
        CheckChanged = onChange,
    };

    public static UiMarkupListColumn Icon(
        float width,
        Func<IReadOnlyList<uint>> valuesSource,
        Func<uint, (uint tex, int w, int h)>? resolve,
        Action<int> onClick,
        bool isAutoWidth = false) => new()
    {
        Kind = UiMarkupListColumnKind.Icon,
        Width = width,
        IsAutoWidth = isAutoWidth,
        IconValuesSource = valuesSource,
        IconResolve = resolve,
        IconClicked = onClick,
    };

    /// <summary>
    /// This column's own row count — the widget takes
    /// <c>Max</c> across every column in the list ("row count = the longest
    /// bound column" per the slice's contract).
    /// </summary>
    public int RowCount() => Kind switch
    {
        UiMarkupListColumnKind.Text => TextSource?.Invoke().Count ?? 0,
        UiMarkupListColumnKind.Check => CheckSource?.Invoke().Count ?? 0,
        UiMarkupListColumnKind.Icon => IconValuesSource?.Invoke().Count ?? 0,
        _ => 0,
    };
}