modular-avatar/Packages/nadena.dev.modular-avatar/Editor/Menu/ClonedMenuMappings.cs

using System.Collections.Generic;
using System.Collections.Immutable;
using VRC.SDK3.Avatars.ScriptableObjects;

namespace nadena.dev.modular_avatar.core.editor
{
    internal static class ClonedMenuMappings
    {
        /// <summary>
        /// Map to link the cloned menu from the clone source.
        /// If one menu is specified for multiple installers, they are replicated separately, so there is a one-to-many relationship.
        /// </summary>
        private static readonly Dictionary<VRCExpressionsMenu, ImmutableList<VRCExpressionsMenu>> ClonedMappings =
            new Dictionary<VRCExpressionsMenu, ImmutableList<VRCExpressionsMenu>>();

        /// <summary>
        /// Map to link the clone source from the cloned menu.
        /// Map is the opposite of ClonedMappings.
        /// </summary>
        private static readonly Dictionary<VRCExpressionsMenu, VRCExpressionsMenu> OriginalMapping =
            new Dictionary<VRCExpressionsMenu, VRCExpressionsMenu>();

        public static void Clear()
        {
            ClonedMappings.Clear();
            OriginalMapping.Clear();
        }

        public static void Add(VRCExpressionsMenu original, VRCExpressionsMenu clonedMenu)
        {
            if (!ClonedMappings.TryGetValue(original, out ImmutableList<VRCExpressionsMenu> clonedMenus))
            {
                clonedMenus = ImmutableList<VRCExpressionsMenu>.Empty;
            }

            ClonedMappings[original] = clonedMenus.Add(clonedMenu);
            OriginalMapping[clonedMenu] = original;
        }

        public static bool TryGetClonedMenus(VRCExpressionsMenu original,
            out ImmutableList<VRCExpressionsMenu> clonedMenus)
        {
            return ClonedMappings.TryGetValue(original, out clonedMenus);
        }

        public static VRCExpressionsMenu GetOriginal(VRCExpressionsMenu cloned)
        {
            return OriginalMapping.TryGetValue(cloned, out VRCExpressionsMenu original) ? original : null;
        }
    }
}