stgsharp/StgSharp.UserInterface/Generator/PanelStateIncrementalGenerator.StateCommandHandlers.cs

using System.Collections.Generic;
using System.Collections.Immutable;
using Microsoft.CodeAnalysis;

namespace StgSharp.UserInterface.Generator;

internal static class PanelStateIncrementalGeneratorStateCommandHandlers
{
    public static StateChangeCommandHandlerPartAnalysis Analyze(
                       PanelStateIncrementalGeneratorTypeTarget target,
                       PanelStateSymbolPartAnalysis stateSymbols,
                       StateChangeBindingPartAnalysis stateChangeBindings
    )
    {
        ImmutableArray<PanelStateIncrementalGeneratorMarkedMember> members = MergeMembers(
            stateChangeBindings.Members,
            stateSymbols.Members);

        return new StateChangeCommandHandlerPartAnalysis(
            target.TypeDisplayName,
            members);
    }

    private static ImmutableArray<PanelStateIncrementalGeneratorMarkedMember> MergeMembers(
                               ImmutableArray<PanelStateIncrementalGeneratorMarkedMember> primaryMembers,
                               ImmutableArray<PanelStateIncrementalGeneratorMarkedMember> secondaryMembers
    )
    {
        if (primaryMembers.IsDefaultOrEmpty && secondaryMembers.IsDefaultOrEmpty)
        {
            return ImmutableArray<PanelStateIncrementalGeneratorMarkedMember>.Empty;
        }

        HashSet<string> seen = new(StringComparer.Ordinal);
        ImmutableArray<PanelStateIncrementalGeneratorMarkedMember>.Builder builder =
            ImmutableArray.CreateBuilder<PanelStateIncrementalGeneratorMarkedMember>();

        AddMembers(builder, seen, primaryMembers);
        AddMembers(builder, seen, secondaryMembers);

        return builder.ToImmutable();
    }

    private static void AddMembers(
                        ImmutableArray<PanelStateIncrementalGeneratorMarkedMember>.Builder builder,
                        HashSet<string> seen,
                        ImmutableArray<PanelStateIncrementalGeneratorMarkedMember> members
    )
    {
        foreach (PanelStateIncrementalGeneratorMarkedMember member in members)
        {
            string key = member.Symbol.ToDisplayString(SymbolDisplayFormat.FullyQualifiedFormat);
            if (!seen.Add(key))
            {
                continue;
            }

            builder.Add(member);
        }
    }
}