feat(discord): add /listsessions slash command and handler

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

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

@@ -0,0 +1,38 @@
+using NetCord.Rest;
+using NetCord.Services.ApplicationCommands;
+
+namespace GmRelay.DiscordBot.Features.Sessions;
+
+[SlashCommand("listsessions", "Show upcoming game sessions in this server")]
+public class DiscordListSessionsCommand : ApplicationCommandModule<SlashCommandContext>
+{
+    private readonly DiscordListSessionsHandler _handler;
+
+    public DiscordListSessionsCommand(DiscordListSessionsHandler handler)
+    {
+        _handler = handler;
+    }
+
+    public async Task ExecuteAsync()
+    {
+        var guildId = Context.Guild?.Id.ToString()
+            ?? throw new InvalidOperationException("This command can only be used in a guild.");
+        var channelId = Context.Channel.Id.ToString();
+
+        var view = await _handler.BuildScheduleAsync(guildId, channelId, CancellationToken.None);
+
+        if (view is null)
+        {
+            await Context.Interaction.SendResponseAsync(
+                InteractionCallback.Message("📭 В этом сервере нет предстоящих игр."));
+            return;
+        }
+
+        var (embeds, actionRows) = Rendering.DiscordSessionBatchRenderer.Render(view);
+
+        await Context.Interaction.SendResponseAsync(
+            InteractionCallback.Message(new InteractionMessageProperties()
+                .WithEmbeds(embeds)
+                .WithComponents(actionRows)));
+    }
+}

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

@@ -0,0 +1,65 @@
+using Dapper;
+using GmRelay.Shared.Domain;
+using GmRelay.Shared.Rendering;
+using Npgsql;
+
+namespace GmRelay.DiscordBot.Features.Sessions;
+
+internal sealed record DiscordSessionListItemDto(
+    Guid Id, string Title, DateTime ScheduledAt, string Status, int? MaxPlayers,
+    int PlayerCount, int WaitlistCount);
+
+public sealed class DiscordListSessionsHandler(NpgsqlDataSource dataSource)
+{
+    public async Task<SessionBatchViewModel?> BuildScheduleAsync(
+        string guildId,
+        string channelId,
+        CancellationToken cancellationToken)
+    {
+        await using var connection = await dataSource.OpenConnectionAsync(cancellationToken);
+
+        var sessions = await connection.QueryAsync<DiscordSessionListItemDto>(
+            @"SELECT s.id as Id, s.title as Title, s.scheduled_at as ScheduledAt, s.status as Status,
+                     s.max_players as MaxPlayers,
+                     COUNT(sp.id) FILTER (WHERE sp.is_gm = false AND sp.registration_status = @Active) as PlayerCount,
+                     COUNT(sp.id) FILTER (WHERE sp.is_gm = false AND sp.registration_status = @Waitlisted) as WaitlistCount
+              FROM sessions s
+              JOIN game_groups g ON s.group_id = g.id
+              LEFT JOIN session_participants sp ON s.id = sp.session_id
+              WHERE g.platform = 'Discord'
+                AND g.external_group_id = @GuildId
+                AND s.status != @Cancelled
+                AND s.scheduled_at > NOW()
+              GROUP BY s.id, s.title, s.scheduled_at, s.status, s.max_players
+              ORDER BY s.scheduled_at ASC",
+            new
+            {
+                GuildId = guildId,
+                Cancelled = SessionStatus.Cancelled,
+                Active = ParticipantRegistrationStatus.Active,
+                Waitlisted = ParticipantRegistrationStatus.Waitlisted
+            });
+
+        var sessionList = sessions.ToList();
+        if (sessionList.Count == 0)
+            return null;
+
+        var sessionIds = sessionList.Select(s => s.Id).ToList();
+        var participants = await connection.QueryAsync<ParticipantBatchDto>(
+            @"SELECT sp.session_id as SessionId,
+                     p.display_name as DisplayName,
+                     COALESCE(p.external_username, p.telegram_username) as TelegramUsername,
+                     sp.registration_status as RegistrationStatus
+              FROM session_participants sp
+              JOIN players p ON p.id = sp.player_id
+              WHERE sp.session_id = ANY(@SessionIds) AND sp.is_gm = false
+              ORDER BY sp.registration_status ASC, sp.created_at ASC",
+            new { SessionIds = sessionIds });
+
+        var firstTitle = sessionList.First().Title;
+        var batchDtos = sessionList.Select(s => new SessionBatchDto(
+            s.Id, s.ScheduledAt, s.Status, s.MaxPlayers, "")).ToList();
+
+        return SessionBatchViewBuilder.Build(firstTitle, batchDtos, participants.ToList());
+    }
+}

src/GmRelay.DiscordBot/GmRelay.DiscordBot.csproj

@@ -10,9 +10,11 @@
 
   <ItemGroup>
     <PackageReference Include="Aspire.Npgsql" Version="13.2.2" />
+    <PackageReference Include="Dapper" Version="2.1.72" />
     <PackageReference Include="Microsoft.Extensions.Hosting" Version="10.0.5" />
     <PackageReference Include="NetCord.Hosting" Version="1.0.0-alpha.489" />
     <PackageReference Include="NetCord.Hosting.Services" Version="1.0.0-alpha.489" />
+    <PackageReference Include="NetCord.Services" Version="1.0.0-alpha.489" />
     <PackageReference Include="Npgsql" Version="10.0.2" />
   </ItemGroup>