// 2026년 포트폴리오용 재구성 코드. 실제 업무 당시 소스가 아닙니다.
// 2026 portfolio reconstruction. Not original production source or a transport protocol.
using System;
using System.Collections.Generic;
namespace PortfolioExamples
{
    public static class SessionRoleSelector
    {
        // Deterministic demonstration using one complete participant list.
        // Not consensus: inconsistent peer lists can produce split-brain results.
        public static int SelectCoordinator(IEnumerable<int> participantIds)
        {
            if (participantIds == null) throw new ArgumentNullException(nameof(participantIds));
            int smallest=int.MaxValue; bool any=false;
            foreach(int id in participantIds) { if(id<0)throw new ArgumentException("IDs must be nonnegative."); smallest=Math.Min(smallest,id); any=true; }
            if(!any)throw new ArgumentException("No participants."); return smallest;
        }
    }
}