acdream/src/AcDream.App/UI/Layout/ChatOptionsDatDefaults.cs

using AcDream.Content;
using DatReaderWriter.DBObjs;
using DatReaderWriter.Types;

namespace AcDream.App.UI.Layout;

/// <summary>
/// Campaign OP slice OP5: reads the Chat tab's two opacity-slider defaults from the
/// installed DAT's <c>DBProperties</c> collection — retail
/// <c>UIOption::InqDefaultGameplayOptionProperty @0x004ef8d0</c>'s
/// <c>m_propName</c>-bound path, the ONE genuine consumer of that mechanism (the
/// Character tab's 49/50 checkboxes are <c>PlayerOption</c>-bound, not
/// <c>m_propName</c>-bound — see <see cref="CharacterOptionsPageController"/>'s own
/// U1 trace for why THAT tab does not use this seam).
///
/// <para>
/// Byte-verified recipe (<c>DBCache::GetDIDFromEnum @0x00413940</c>): the outer call
/// site is <c>GetDIDFromEnumStatic(&amp;ret, 0x16, 2)</c> — outer arg2 (<c>0x16</c>)
/// feeds the inner function's arg3 (the SUB-MAP lookup key), outer arg3 (<c>2</c>)
/// feeds arg4 (the MASTER-MAP lookup key FIRST). So:
/// <c>master.ClientEnumToID[2] → subMapDid; subMap.ClientEnumToID[0x16] → DID</c> —
/// i.e. <see cref="RetailDataIdResolver.Resolve"/>'s own <c>(enumValue, enumCategory)</c>
/// parameter order is <c>(0x16, 2)</c>, matching
/// <c>RetailUiRuntime.cs</c>'s existing <c>Resolve(dats, 2u, 5u)</c> convention
/// (enumCategory selects the master-map submap FIRST, enumValue indexes it SECOND).
/// Empirically confirmed against the installed DATs: resolves to DID
/// <c>0x78000001</c>, a 3-entry <c>DBProperties</c> —
/// <c>0x1000007F</c> (<c>Bitfield64</c>, the Chat filter blocks' shared
/// <c>m_propName</c> — NOT a per-window default; the five blocks' actual defaults are
/// the literal constants <c>gmChatOptionsUI::InitOptions</c> authors per window,
/// ported verbatim in <c>ChatWindowState</c>/<see cref="ChatOptionsPageController"/>),
/// <c>0x10000080</c> (<c>Float</c>, <c>0.5</c> — <c>Option_DefaultOpacity_Property</c>),
/// <c>0x10000081</c> (<c>Float</c>, <c>1.0</c> — <c>Option_ActiveOpacity_Property</c>).
/// </para>
/// </summary>
public static class ChatOptionsDatDefaults
{
    /// <summary>DAT enum-category key for the FIRST (master-map) lookup — see the
    /// class doc's byte-verified recipe.</summary>
    private const uint EnumCategory = 2u;

    /// <summary>DAT enum-value key for the SECOND (sub-map) lookup.</summary>
    private const uint EnumValue = 0x16u;

    /// <summary><c>Option_DefaultOpacity_Property</c> — the unfocused-window opacity
    /// slider's <c>m_propName</c>.</summary>
    public const uint DefaultOpacityPropertyId = 0x10000080u;

    /// <summary><c>Option_ActiveOpacity_Property</c> — the focused-window opacity
    /// slider's <c>m_propName</c>.</summary>
    public const uint ActiveOpacityPropertyId = 0x10000081u;

    /// <summary>Retail base-constructor fallback (<c>ChatInterface::ChatInterface
    /// @0x004F4550</c>) — used only when the DAT read fails (missing DAT entry,
    /// corrupt install); the live installed DAT resolves to these exact values today.</summary>
    public const float FallbackDefaultOpacity = 0.5f;

    public const float FallbackActiveOpacity = 1.0f;

    /// <summary>
    /// Resolves the two slider defaults from the live DAT. Returns
    /// <see langword="false"/> (with both out params set to the retail-constructor
    /// fallback) if the DID does not resolve, the <c>DBProperties</c> object is
    /// missing, or either property is absent/not a <c>Float</c> — matching this
    /// codebase's "degrade to a documented fallback, never invent a value" discipline.
    /// </summary>
    public static bool TryRead(
        IDatReaderWriter dats, out float defaultOpacity, out float activeOpacity)
    {
        defaultOpacity = FallbackDefaultOpacity;
        activeOpacity = FallbackActiveOpacity;

        uint did = RetailDataIdResolver.Resolve(dats, EnumValue, EnumCategory);
        if (did == 0u || !dats.Portal.TryGet<DBProperties>(did, out DBProperties? props) || props is null)
            return false;

        bool ok = true;
        if (props.Properties.TryGetValue(DefaultOpacityPropertyId, out BaseProperty? d)
            && d is FloatBaseProperty defaultProp)
            defaultOpacity = defaultProp.Value;
        else
            ok = false;

        if (props.Properties.TryGetValue(ActiveOpacityPropertyId, out BaseProperty? a)
            && a is FloatBaseProperty activeProp)
            activeOpacity = activeProp.Value;
        else
            ok = false;

        return ok;
    }
}