IPollRepo.cs

using System.Collections.Immutable;
using System.Threading.Tasks;
using TPP.Model;

namespace TPP.Persistence
{
    public record VoteFailure
    {
        private VoteFailure()
        {
        }

        public sealed record PollNotFound(string PollCode) : VoteFailure;
        public sealed record PollNotAlive : VoteFailure;
        public sealed record AlreadyVoted : VoteFailure;
        public sealed record CannotVoteForNone : VoteFailure;
        public sealed record NotMultipleChoice : VoteFailure;
        public sealed record InvalidOptions(IImmutableList<int> Options) : VoteFailure;
    }

    public interface IPollRepo
    {
        public Task<Poll?> FindPoll(string pollCode);
        public Task<IImmutableList<Poll>> FindPolls(bool onlyActive);
        public Task<Poll> CreatePoll(
            string pollCode, string pollName, bool multiChoice, bool allowChangeVote,
            IImmutableList<string> pollOptions);
        public Task<VoteFailure?> Vote(string id, string userId, IImmutableList<int> options);

        /// <summary>
        /// Sets whether a poll is alive.
        /// </summary>
        /// <param name="id">poll code</param>
        /// <param name="alive">alive bool</param>
        /// <returns>null if the poll was not found, else the previous alive value</returns>
        public Task<bool?> SetAlive(string id, bool alive);
    }
}