feat(discord): add reschedule vote button handler

src/GmRelay.Bot/Features/Sessions/RescheduleSession/HandleRescheduleVoteHandler.cs

@@ -14,13 +14,6 @@ public sealed record HandleRescheduleVoteCommand(
     long ChatId,
     int MessageId);
 
-internal sealed record VoteProposalDto(
-    Guid Id,
-    Guid SessionId,
-    DateTimeOffset VotingDeadlineAt,
-    string Title,
-    DateTime CurrentScheduledAt);
-
 public sealed class HandleRescheduleVoteHandler(
     NpgsqlDataSource dataSource,
     ITelegramBotClient bot,

src/GmRelay.DiscordBot/Features/Sessions/DiscordRescheduleHandler.cs

@@ -149,7 +149,8 @@ public sealed class DiscordRescheduleHandler(
         return new DiscordRescheduleResult(proposalId, optionDtos, deadline);
     }
 
-    private static (EmbedProperties Embed, ActionRowProperties ActionRow) BuildVoteMessage(
+    // internal for now — temporary duplication until DiscordRescheduleVotingRenderer is extracted in Task 6
+    internal static (EmbedProperties Embed, ActionRowProperties ActionRow) BuildVoteMessage(
         string title, DateTime currentTime, DateTimeOffset deadline,
         IReadOnlyList<RescheduleOptionDto> options, IReadOnlyList<VoteParticipantDto> participants, IReadOnlyList<RescheduleOptionVoteDto> votes)
     {

src/GmRelay.DiscordBot/Features/Sessions/DiscordRescheduleVoteHandler.cs

@@ -0,0 +1,130 @@
+namespace GmRelay.DiscordBot.Features.Sessions;
+
+using Dapper;
+using GmRelay.Shared.Domain;
+using GmRelay.Shared.Features.Sessions.RescheduleSession;
+using GmRelay.Shared.Platform;
+using Npgsql;
+using NetCord.Rest;
+
+public sealed record DiscordRescheduleVoteInput(
+    Guid OptionId, ulong UserId, string InteractionId,
+    string GuildId, string ChannelId, string MessageId);
+
+public sealed class DiscordRescheduleVoteHandler(
+    NpgsqlDataSource dataSource,
+    RestClient restClient,
+    ILogger<DiscordRescheduleVoteHandler> logger)
+{
+    public async Task<string> HandleAsync(DiscordRescheduleVoteInput input, CancellationToken ct)
+    {
+        await using var connection = await dataSource.OpenConnectionAsync(ct);
+        await using var transaction = await connection.BeginTransactionAsync(ct);
+
+        // 1. Load proposal + option
+        var proposal = await connection.QuerySingleOrDefaultAsync<VoteProposalDto>(
+            """
+            SELECT rp.id AS Id, rp.session_id AS SessionId, rp.voting_deadline_at AS VotingDeadlineAt,
+                   s.title AS Title, s.scheduled_at AS CurrentScheduledAt
+            FROM reschedule_options ro
+            JOIN reschedule_proposals rp ON rp.id = ro.proposal_id
+            JOIN sessions s ON s.id = rp.session_id
+            WHERE ro.id = @OptionId AND rp.status = 'Voting'
+            """,
+            new { input.OptionId },
+            transaction);
+
+        if (proposal is null)
+            return "Голосование уже завершено или не найдено.";
+
+        if (proposal.VotingDeadlineAt <= DateTimeOffset.UtcNow)
+            return "Дедлайн уже прошёл. Результаты скоро будут применены.";
+
+        // 2. Verify participant (Discord platform)
+        var playerId = await connection.ExecuteScalarAsync<Guid?>(
+            """
+            SELECT p.id
+            FROM session_participants sp
+            JOIN players p ON p.id = sp.player_id
+            WHERE sp.session_id = @SessionId
+              AND p.platform = 'Discord'
+              AND p.external_user_id = @UserId
+              AND sp.is_gm = false
+              AND sp.registration_status = @Active
+            """,
+            new { proposal.SessionId, UserId = input.UserId.ToString(), Active = ParticipantRegistrationStatus.Active },
+            transaction);
+
+        if (playerId is null)
+            return "Вы не являетесь участником этой сессии.";
+
+        // 3. Upsert vote
+        await connection.ExecuteAsync(
+            """
+            INSERT INTO reschedule_option_votes (proposal_id, player_id, option_id)
+            VALUES (@ProposalId, @PlayerId, @OptionId)
+            ON CONFLICT (proposal_id, player_id) DO UPDATE
+            SET option_id = EXCLUDED.option_id, voted_at = now()
+            """,
+            new { ProposalId = proposal.Id, PlayerId = playerId.Value, input.OptionId },
+            transaction);
+
+        // 4. Reload participants, options, votes for re-rendering
+        var participants = (await connection.QueryAsync<VoteParticipantDto>(
+            """
+            SELECT p.id AS PlayerId, p.display_name AS DisplayName, p.external_username AS TelegramUsername, 0 AS TelegramId
+            FROM session_participants sp
+            JOIN players p ON p.id = sp.player_id
+            WHERE sp.session_id = @SessionId AND sp.is_gm = false AND sp.registration_status = @Active
+            ORDER BY p.display_name
+            """,
+            new { proposal.SessionId, Active = ParticipantRegistrationStatus.Active },
+            transaction)).ToList();
+
+        var options = (await connection.QueryAsync<RescheduleOptionDto>(
+            """
+            SELECT id AS OptionId, display_order AS DisplayOrder, proposed_at AS ProposedAt
+            FROM reschedule_options
+            WHERE proposal_id = @ProposalId
+            ORDER BY display_order
+            """,
+            new { ProposalId = proposal.Id },
+            transaction)).ToList();
+
+        var votes = (await connection.QueryAsync<RescheduleOptionVoteDto>(
+            """
+            SELECT rov.option_id AS OptionId, p.id AS PlayerId, p.display_name AS DisplayName, p.external_username AS TelegramUsername
+            FROM reschedule_option_votes rov
+            JOIN players p ON p.id = rov.player_id
+            WHERE rov.proposal_id = @ProposalId
+            ORDER BY rov.voted_at, p.display_name
+            """,
+            new { ProposalId = proposal.Id },
+            transaction)).ToList();
+
+        await transaction.CommitAsync(ct);
+
+        // 5. Re-render and update Discord vote message
+        var (embed, actionRow) = DiscordRescheduleHandler.BuildVoteMessage(
+            proposal.Title, proposal.CurrentScheduledAt, proposal.VotingDeadlineAt,
+            options, participants, votes);
+
+        var channelIdUlong = ulong.Parse(input.ChannelId);
+        var messageIdUlong = ulong.Parse(input.MessageId);
+
+        try
+        {
+            await restClient.ModifyMessageAsync(channelIdUlong, messageIdUlong, options =>
+            {
+                options.Embeds = new[] { embed };
+                options.Components = new[] { actionRow };
+            });
+        }
+        catch (Exception ex)
+        {
+            logger.LogWarning(ex, "Failed to update Discord vote message for proposal {ProposalId}", proposal.Id);
+        }
+
+        return "Ваш голос учтён. До дедлайна его можно изменить.";
+    }
+}

src/GmRelay.DiscordBot/Features/Sessions/DiscordSessionInteractionModule.cs

@@ -9,6 +9,7 @@ namespace GmRelay.DiscordBot.Features.Sessions;
 public sealed class DiscordSessionInteractionModule(
     JoinSessionHandler joinSessionHandler,
     LeaveSessionHandler leaveSessionHandler,
+    DiscordRescheduleVoteHandler voteHandler,
     DiscordInteractionReplyCache interactionReplies,
     ILogger<DiscordSessionInteractionModule> logger) : ComponentInteractionModule<ButtonInteractionContext>
 {
@@ -66,6 +67,41 @@ public sealed class DiscordSessionInteractionModule(
         await CompleteWithStoredReplyAsync(input.InteractionId);
     }
 
+    [ComponentInteraction("reschedule_vote")]
+    public async Task RescheduleVoteAsync(string optionId)
+    {
+        if (!Guid.TryParse(optionId, out var parsedOptionId))
+        {
+            await RespondAsync(CreateEphemeralReply("Vote button is outdated."));
+            return;
+        }
+
+        var input = CreateInput(Guid.Empty); // sessionId not needed for vote routing
+        var voteInput = new DiscordRescheduleVoteInput(
+            parsedOptionId,
+            Context.User.Id,
+            Context.Interaction.Id.ToString(System.Globalization.CultureInfo.InvariantCulture),
+            input.GuildId,
+            input.ChannelId,
+            input.MessageId);
+
+        await RespondAsync(InteractionCallback.DeferredMessage(MessageFlags.Ephemeral));
+
+        string replyText;
+        try
+        {
+            replyText = await voteHandler.HandleAsync(voteInput, CancellationToken.None);
+        }
+        catch (Exception ex)
+        {
+            logger.LogError(ex, "Failed to handle Discord reschedule vote for option {OptionId}", parsedOptionId);
+            await CompleteResponseAsync("Не удалось обработать голос.");
+            return;
+        }
+
+        await CompleteResponseAsync(replyText);
+    }
+
     private DiscordSessionInteractionInput CreateInput(Guid sessionId)
     {
         var guild = Context.Guild

src/GmRelay.DiscordBot/Program.cs

@@ -45,6 +45,7 @@ builder.Services.AddSingleton<DiscordPermissionChecker>();
 builder.Services.AddSingleton<DiscordListSessionsHandler>();
 builder.Services.AddSingleton<DiscordNewSessionHandler>();
 builder.Services.AddSingleton<DiscordRescheduleHandler>();
+builder.Services.AddSingleton<DiscordRescheduleVoteHandler>();
 builder.Services.AddSingleton<IScheduleMessageUpdateLock, ScheduleMessageUpdateLock>();
 builder.Services.AddSingleton<JoinSessionHandler>();
 builder.Services.AddSingleton<LeaveSessionHandler>();

src/GmRelay.Shared/Features/Sessions/RescheduleSession/RescheduleDtos.cs

@@ -5,6 +5,13 @@ public sealed record RescheduleOptionDto(
     int DisplayOrder,
     DateTimeOffset ProposedAt);
 
+public sealed record VoteProposalDto(
+    Guid Id,
+    Guid SessionId,
+    DateTimeOffset VotingDeadlineAt,
+    string Title,
+    DateTime CurrentScheduledAt);
+
 public sealed record RescheduleOptionVoteDto(
     Guid OptionId,
     Guid PlayerId,