Merge pull request 'feat(#14): attendance statistics page' (#45) from issue-14-attendance-stats into main

feat(#14): attendance statistics page

.gitea/workflows/pr-checks.yml

@@ -0,0 +1,33 @@
+name: PR Checks
+
+on:
+  pull_request:
+    branches:
+      - main
+
+jobs:
+  test-and-build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Setup .NET
+        uses: actions/setup-dotnet@v4
+        with:
+          dotnet-version: '10.0.x'
+
+      - name: Restore dependencies
+        run: dotnet restore
+
+      - name: Build Shared
+        run: dotnet build src/GmRelay.Shared/GmRelay.Shared.csproj --no-restore
+
+      - name: Build Bot (compile check)
+        run: dotnet build src/GmRelay.Bot/GmRelay.Bot.csproj --no-restore
+
+      - name: Build Web (compile check)
+        run: dotnet build src/GmRelay.Web/GmRelay.Web.csproj --no-restore
+
+      - name: Run tests
+        run: dotnet test tests/GmRelay.Bot.Tests/GmRelay.Bot.Tests.csproj --verbosity normal

Directory.Build.props

@@ -1,6 +1,6 @@
 <Project>
   <PropertyGroup>
-    <Version>1.10.0</Version>
+    <Version>1.10.1</Version>
     <TargetFramework>net10.0</TargetFramework>
     <LangVersion>preview</LangVersion>
     <Nullable>enable</Nullable>

src/GmRelay.Bot/Features/Sessions/ExportCalendar/ExportCalendarHandler.cs

@@ -1,9 +1,11 @@
 using System.Text;
 using Dapper;
 using GmRelay.Shared.Domain;
+using Microsoft.Extensions.Configuration;
 using Npgsql;
 using Telegram.Bot;
 using Telegram.Bot.Types;
+using Telegram.Bot.Types.ReplyMarkups;
 
 namespace GmRelay.Bot.Features.Sessions.ExportCalendar;
 
@@ -11,20 +13,21 @@ internal sealed record CalendarSessionDto(Guid Id, string Title, DateTime Schedu
 
 public sealed class ExportCalendarHandler(
     NpgsqlDataSource dataSource,
-    ITelegramBotClient botClient)
+    ITelegramBotClient botClient,
+    IConfiguration configuration)
 {
     public async Task HandleAsync(Message message, CancellationToken cancellationToken)
     {
         await using var connection = await dataSource.OpenConnectionAsync(cancellationToken);
 
         var sessions = await connection.QueryAsync<CalendarSessionDto>(
-            @"SELECT s.id as Id, s.title as Title, s.scheduled_at as ScheduledAt
+            @"SELECT s.id as Id, s.title as Title, s.scheduled_at as ScheduledAt"
-              FROM sessions s
+            + " FROM sessions s"
-              JOIN game_groups g ON s.group_id = g.id
+            + " JOIN game_groups g ON s.group_id = g.id"
-              WHERE g.telegram_chat_id = @ChatId 
+            + " WHERE g.telegram_chat_id = @ChatId"
-                AND s.status = @Planned
+            + " AND s.status = @Planned"
-                AND s.scheduled_at > NOW()
+            + " AND s.scheduled_at > NOW()"
-              ORDER BY s.scheduled_at ASC",
+            + " ORDER BY s.scheduled_at ASC",
             new { ChatId = message.Chat.Id, Planned = SessionStatus.Planned });
 
         var sessionsList = sessions.ToList();
@@ -54,8 +57,6 @@ public sealed class ExportCalendarHandler(
             sb.AppendLine($"DTSTART:{dtStart}");
             sb.AppendLine($"DTEND:{dtEnd}");
             sb.AppendLine($"SUMMARY:{s.Title}");
-            // Escape special chars according to iCal standards (RFC 5545) -- simple escaping for summary
-            // In a fuller implementation we'd escape \r\n, commas, etc. But titles are mostly plain text.
             sb.AppendLine("END:VEVENT");
         }
 
@@ -66,11 +67,45 @@ public sealed class ExportCalendarHandler(
 
         var inputFile = InputFile.FromStream(stream, "schedule.ics");
 
+        // Create calendar subscription
+        string? subscriptionUrl = null;
+        var baseUrl = configuration["Web:BaseUrl"];
+        var senderId = message.From?.Id;
+        if (!string.IsNullOrWhiteSpace(baseUrl) && senderId.HasValue)
+        {
+            try
+            {
+                var token = Guid.NewGuid().ToString("N");
+                var groupId = await connection.QueryFirstOrDefaultAsync<Guid?>(
+                    @"SELECT id FROM game_groups WHERE telegram_chat_id = @ChatId",
+                    new { ChatId = message.Chat.Id });
+
+                await connection.ExecuteAsync(
+                    @"INSERT INTO calendar_subscriptions (id, token, user_telegram_id, group_id, filter_type, created_at, expires_at)
+                      VALUES (gen_random_uuid(), @token, @userTelegramId, @groupId, @filterType, now(), NULL)",
+                    new { token, userTelegramId = senderId.Value, groupId, filterType = (int)CalendarSubscriptionFilter.SpecificGroup });
+
+                subscriptionUrl = $"{baseUrl.TrimEnd('/')}/calendar/{token}.ics";
+            }
+            catch
+            {
+                // Non-critical: if subscription creation fails, still send the file
+            }
+        }
+
+        var replyMarkup = subscriptionUrl is not null
+            ? new InlineKeyboardMarkup(new[]
+            {
+                new[] { InlineKeyboardButton.WithUrl("🔗 Подписаться на календарь", subscriptionUrl) }
+            })
+            : null;
+
         await botClient.SendDocument(
              chatId: message.Chat.Id,
              document: inputFile,
              caption: "📅 <b>Ваш календарь игр!</b>\nОткройте файл на устройстве, чтобы добавить события в свой календарь.",
              parseMode: Telegram.Bot.Types.Enums.ParseMode.Html,
+             replyMarkup: replyMarkup,
              messageThreadId: message.MessageThreadId,
              cancellationToken: cancellationToken);
     }

src/GmRelay.Bot/Migrations/V011__add_calendar_subscriptions.sql

@@ -0,0 +1,11 @@
+CREATE TABLE calendar_subscriptions (
+    id                  UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    token               TEXT UNIQUE NOT NULL,
+    user_telegram_id    BIGINT NOT NULL,
+    group_id            UUID REFERENCES game_groups(id) ON DELETE CASCADE,
+    filter_type         SMALLINT NOT NULL DEFAULT 0,
+    created_at          TIMESTAMPTZ NOT NULL DEFAULT now(),
+    expires_at          TIMESTAMPTZ
+);
+
+CREATE INDEX ix_calendar_subscriptions_user_telegram_id ON calendar_subscriptions (user_telegram_id);

src/GmRelay.Bot/Migrations/V012__add_attendance_stats.sql

@@ -0,0 +1,66 @@
+-- =============================================================
+-- Attendance statistics view for GM analytics
+-- Returns per-player aggregated metrics for a given game group.
+-- NOTE: waitlist count reflects CURRENT registration_status only.
+--       Full historical waitlist tracking will come with #15.
+-- =============================================================
+
+CREATE OR REPLACE FUNCTION get_group_attendance_stats(p_group_id UUID)
+RETURNS TABLE (
+    player_id           UUID,
+    display_name        VARCHAR,
+    telegram_username   VARCHAR,
+    total_sessions      BIGINT,
+    confirmed_count     BIGINT,
+    declined_count      BIGINT,
+    no_response_count   BIGINT,
+    waitlisted_count    BIGINT,
+    cancellation_affected_count BIGINT,
+    attendance_rate     NUMERIC
+) AS $$
+BEGIN
+    RETURN QUERY
+    WITH player_sessions AS (
+        SELECT
+            sp.player_id,
+            s.id                AS session_id,
+            sp.rsvp_status,
+            sp.registration_status,
+            s.status            AS session_status,
+            s.scheduled_at
+        FROM session_participants sp
+        JOIN sessions s ON s.id = sp.session_id
+        WHERE s.group_id = p_group_id
+    ),
+    player_totals AS (
+        SELECT
+            ps.player_id,
+            COUNT(*) FILTER (WHERE ps.session_status <> 'Cancelled')                      AS total_sessions,
+            COUNT(*) FILTER (WHERE ps.rsvp_status = 'Confirmed' AND ps.session_status <> 'Cancelled') AS confirmed_count,
+            COUNT(*) FILTER (WHERE ps.rsvp_status = 'Declined' AND ps.session_status <> 'Cancelled')  AS declined_count,
+            COUNT(*) FILTER (WHERE ps.rsvp_status = 'Pending' AND ps.scheduled_at < NOW() AND ps.session_status <> 'Cancelled') AS no_response_count,
+            COUNT(*) FILTER (WHERE ps.registration_status = 'Waitlisted' AND ps.session_status <> 'Cancelled') AS waitlisted_count,
+            COUNT(*) FILTER (WHERE ps.session_status = 'Cancelled')                        AS cancellation_affected_count
+        FROM player_sessions ps
+        GROUP BY ps.player_id
+    )
+    SELECT
+        pt.player_id,
+        p.display_name,
+        p.telegram_username,
+        pt.total_sessions,
+        pt.confirmed_count,
+        pt.declined_count,
+        pt.no_response_count,
+        pt.waitlisted_count,
+        pt.cancellation_affected_count,
+        ROUND(
+            100.0 * pt.confirmed_count
+            / NULLIF(pt.total_sessions, 0),
+            1
+        ) AS attendance_rate
+    FROM player_totals pt
+    JOIN players p ON p.id = pt.player_id
+    ORDER BY pt.confirmed_count DESC, pt.total_sessions DESC;
+END;
+$$ LANGUAGE plpgsql STABLE;

src/GmRelay.Bot/appsettings.json

@@ -9,5 +9,8 @@
   "Telegram": {
     "BotToken": "",
     "MiniAppUrl": ""
+  },
+  "Web": {
+    "BaseUrl": ""
   }
 }

src/GmRelay.Shared/Domain/CalendarSubscriptionFilter.cs

@@ -0,0 +1,7 @@
+namespace GmRelay.Shared.Domain;
+
+public enum CalendarSubscriptionFilter
+{
+    AllMyGroups = 0,
+    SpecificGroup = 1
+}

src/GmRelay.Shared/Rendering/SessionBatchViewBuilder.cs

@@ -57,3 +57,4 @@ public static class SessionBatchViewBuilder
         return $"✋ На {dateTitle}";
     }
 }
+// trigger pr

src/GmRelay.Web/Components/Layout/NavMenu.razor

@@ -2,10 +2,10 @@
 
 <div class="nav-header">
     <a class="nav-brand" href="">
-        <span class="nav-brand-icon">🎲</span>
+        <span class="nav-brand-icon">🐢</span>
         <span class="nav-brand-text">GM-Relay</span>
     </a>
-    <button class="nav-toggle" @onclick="ToggleMenu" aria-label="Навигационное меню">
+    <button class="nav-toggle" @onclick="ToggleMenu" aria-label="Переключить меню">
         <svg width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
             <line x1="3" y1="6" x2="21" y2="6"/>
             <line x1="3" y1="12" x2="21" y2="12"/>
@@ -23,7 +23,7 @@
                         <path d="M3 9l9-7 9 7v11a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2z"/>
                         <polyline points="9 22 9 12 15 12 15 22"/>
                     </svg>
-                    Панель управления
+                    Главная страница
                 </NavLink>
                 <NavLink class="nav-item" href="templates" @onclick="CloseMenu">
                     <svg class="nav-icon" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
@@ -52,11 +52,11 @@
                             <polyline points="16 17 21 12 16 7"/>
                             <line x1="21" y1="12" x2="9" y2="12"/>
                         </svg>
-                        Выйти
+                        Выход
                     </button>
                 </form>
 
-                <div class="nav-version">v1.9.9</div>
+                <div class="nav-version">v1.10.1</div>
             </div>
         </Authorized>
         <NotAuthorized>
@@ -67,7 +67,7 @@
                         <polyline points="10 17 15 12 10 7"/>
                         <line x1="15" y1="12" x2="3" y2="12"/>
                     </svg>
-                    Войти
+                    Вход
                 </NavLink>
             </div>
         </NotAuthorized>

src/GmRelay.Web/Components/Pages/GroupStats.razor

@@ -0,0 +1,235 @@
+@page "/group/{GroupId:guid}/stats"
+@using GmRelay.Web.Services
+@using GmRelay.Shared.Domain
+@using Microsoft.AspNetCore.Authorization
+@using Microsoft.AspNetCore.Components.Authorization
+@using System.Security.Claims
+@attribute [Authorize]
+@inject ISessionStore SessionStore
+@inject AuthenticationStateProvider AuthStateProvider
+@inject NavigationManager Navigation
+
+<PageTitle>Статистика — GM-Relay</PageTitle>
+
+<div class="page-container">
+    <ul class="gm-breadcrumb animate-fade-in">
+        <li><a href="/">Главная</a></li>
+        <li><a href="/group/@GroupId">Сессии группы</a></li>
+        <li class="active">Статистика</li>
+    </ul>
+
+    <div class="page-header animate-fade-in">
+        <h2>📊 Статистика посещаемости</h2>
+        <p class="page-subtitle">Надёжность состава и качество расписания</p>
+    </div>
+
+    @if (!string.IsNullOrEmpty(errorMessage))
+    {
+        <div class="gm-alert gm-alert-danger" style="margin-bottom: 1rem;">
+            ⚠️ @errorMessage
+        </div>
+    }
+
+    @if (stats is null)
+    {
+        <div class="loading-spinner">⏳ Загружаем статистику…</div>
+    }
+    else if (stats.Count == 0)
+    {
+        <div class="empty-state">
+            <div class="empty-icon">📈</div>
+            <h3>Пока нет данных</h3>
+            <p>После первых сессий здесь появится аналитика.</p>
+        </div>
+    }
+    else
+    {
+        <div class="glass-card animate-slide-up" style="margin-bottom: 1rem;">
+            <div class="stats-summary" style="display: grid; grid-template-columns: repeat(auto-fit, minmax(120px, 1fr)); gap: 1rem; margin-bottom: 1.5rem;">
+                <div class="stat-card">
+                    <div class="stat-value">@stats.Count</div>
+                    <div class="stat-label">Игроков</div>
+                </div>
+                <div class="stat-card">
+                    <div class="stat-value">@TotalSessions</div>
+                    <div class="stat-label">Сессий</div>
+                </div>
+                <div class="stat-card">
+                    <div class="stat-value">@AvgAttendanceRate%</div>
+                    <div class="stat-label">Средняя посещаемость</div>
+                </div>
+                <div class="stat-card">
+                    <div class="stat-value">@topPlayer?.DisplayName</div>
+                    <div class="stat-label">Самый стабильный</div>
+                </div>
+            </div>
+
+            <div class="table-responsive">
+                <table class="gm-table" style="width: 100%;">
+                    <thead>
+                        <tr>
+                            <th @onclick="@(() => SortBy("player"))" style="cursor:pointer;" class="sortable">Игрок  @(sortColumn == "player" ? (sortDesc ? "▼" : "▲") : "")</th>
+                            <th @onclick="@(() => SortBy("total"))" style="cursor:pointer; text-align:center;" class="sortable">Всего  @(sortColumn == "total" ? (sortDesc ? "▼" : "▲") : "")</th>
+                            <th @onclick="@(() => SortBy("confirmed"))" style="cursor:pointer; text-align:center;" class="sortable">✅  @(sortColumn == "confirmed" ? (sortDesc ? "▼" : "▲") : "")</th>
+                            <th @onclick="@(() => SortBy("declined"))" style="cursor:pointer; text-align:center;" class="sortable">❌  @(sortColumn == "declined" ? (sortDesc ? "▼" : "▲") : "")</th>
+                            <th @onclick="@(() => SortBy("noresponse"))" style="cursor:pointer; text-align:center;" class="sortable">💤  @(sortColumn == "noresponse" ? (sortDesc ? "▼" : "▲") : "")</th>
+                            <th @onclick="@(() => SortBy("waitlist"))" style="cursor:pointer; text-align:center;" class="sortable">⏳  @(sortColumn == "waitlist" ? (sortDesc ? "▼" : "▲") : "")</th>
+                            <th @onclick="@(() => SortBy("rate"))" style="cursor:pointer; text-align:center;" class="sortable">%  @(sortColumn == "rate" ? (sortDesc ? "▼" : "▲") : "")</th>
+                            <th @onclick="@(() => SortBy("cancelled"))" style="cursor:pointer; text-align:center;" class="sortable">🚫  @(sortColumn == "cancelled" ? (sortDesc ? "▼" : "▲") : "")</th>
+                        </tr>
+                    </thead>
+                    <tbody>
+                        @foreach (var s in sortedStats)
+                        {
+                            <tr>
+                                <td>
+                                    <div class="player-info">
+                                        <span class="player-name">@s.DisplayName</span>
+                                        @if (!string.IsNullOrEmpty(s.TelegramUsername))
+                                        {
+                                            <span class="player-username">@@@s.TelegramUsername</span>
+                                        }
+                                    </div>
+                                </td>
+                                <td style="text-align:center;">@s.TotalSessions</td>
+                                <td style="text-align:center;">@s.ConfirmedCount</td>
+                                <td style="text-align:center;">@s.DeclinedCount</td>
+                                <td style="text-align:center;">@s.NoResponseCount</td>
+                                <td style="text-align:center;">@s.WaitlistedCount</td>
+                                <td style="text-align:center;">
+                                    <span class="rate-badge @AttendanceBadgeClass(s.AttendanceRate)">
+                                        @s.AttendanceRate%
+                                    </span>
+                                </td>
+                                <td style="text-align:center;">@s.CancellationAffectedCount</td>
+                            </tr>
+                        }
+                    </tbody>
+                </table>
+            </div>
+        </div>
+    }
+</div>
+
+<style>
+    .stat-card {
+        background: var(--card-bg-secondary, rgba(255,255,255,0.05));
+        border-radius: 0.75rem;
+        padding: 1rem;
+        text-align: center;
+    }
+    .stat-value {
+        font-size: 1.5rem;
+        font-weight: 700;
+        color: var(--accent-color, #7cb97a);
+    }
+    .stat-label {
+        font-size: 0.8rem;
+        color: var(--text-muted, #94a3b8);
+        margin-top: 0.25rem;
+    }
+    .player-info {
+        display: flex;
+        flex-direction: column;
+    }
+    .player-name {
+        font-weight: 500;
+    }
+    .player-username {
+        font-size: 0.8rem;
+        color: var(--text-muted, #94a3b8);
+    }
+    .rate-badge {
+        display: inline-block;
+        padding: 0.25rem 0.5rem;
+        border-radius: 0.5rem;
+        font-weight: 600;
+        font-size: 0.875rem;
+    }
+    .rate-excellent { background: rgba(34,197,94,0.15); color: #22c55e; }
+    .rate-good      { background: rgba(234,179,8,0.15); color: #eab308; }
+    .rate-poor      { background: rgba(239,68,68,0.15); color: #ef4444; }
+</style>
+
+@code {
+    [Parameter] public Guid GroupId { get; set; }
+    private List<PlayerAttendanceStats>? stats;
+    private List<PlayerAttendanceStats> sortedStats = new();
+    private string? errorMessage;
+    private string sortColumn = "confirmed";
+    private bool sortDesc = true;
+    private int TotalSessions => stats?.Count > 0 ? (int)(stats.Max(s => s.TotalSessions)) : 0;
+    private int AvgAttendanceRate => stats?.Count > 0 ? (int)(stats.Average(s => s.AttendanceRate)) : 0;
+    private PlayerAttendanceStats? topPlayer => stats?.OrderByDescending(s => s.AttendanceRate).ThenByDescending(s => s.ConfirmedCount).FirstOrDefault();
+
+    protected override async Task OnInitializedAsync()
+    {
+        var authState = await AuthStateProvider.GetAuthenticationStateAsync();
+        var user = authState.User;
+        if (!user.Identity?.IsAuthenticated ?? true)
+        {
+            Navigation.NavigateTo("/login");
+            return;
+        }
+        var telegramIdClaim = user.FindFirst("telegram_id")?.Value
+            ?? user.FindFirst(ClaimTypes.NameIdentifier)?.Value;
+        if (!long.TryParse(telegramIdClaim, out var telegramId))
+        {
+            Navigation.NavigateTo("/login");
+            return;
+        }
+        try
+        {
+            if (!await SessionStore.IsGroupManagerAsync(GroupId, telegramId))
+            {
+                Navigation.NavigateTo("/access-denied");
+                return;
+            }
+            stats = await SessionStore.GetGroupAttendanceStatsAsync(GroupId) ?? new();
+            UpdateSortedStats();
+        }
+        catch (Exception ex)
+        {
+            errorMessage = $"Ошибка загрузки статистики: {ex.Message}";
+        }
+    }
+
+    private void SortBy(string column)
+    {
+        if (sortColumn == column)
+            sortDesc = !sortDesc;
+        else
+        {
+            sortColumn = column;
+            sortDesc = true;
+        }
+        UpdateSortedStats();
+    }
+
+    private void UpdateSortedStats()
+    {
+        if (stats is null) { sortedStats = new(); return; }
+        IOrderedEnumerable<PlayerAttendanceStats> ordered = sortColumn switch
+        {
+            "player" => sortDesc ? stats.OrderByDescending(s => s.DisplayName) : stats.OrderBy(s => s.DisplayName),
+            "total" => sortDesc ? stats.OrderByDescending(s => s.TotalSessions) : stats.OrderBy(s => s.TotalSessions),
+            "confirmed" => sortDesc ? stats.OrderByDescending(s => s.ConfirmedCount) : stats.OrderBy(s => s.ConfirmedCount),
+            "declined" => sortDesc ? stats.OrderByDescending(s => s.DeclinedCount) : stats.OrderBy(s => s.DeclinedCount),
+            "noresponse" => sortDesc ? stats.OrderByDescending(s => s.NoResponseCount) : stats.OrderBy(s => s.NoResponseCount),
+            "waitlist" => sortDesc ? stats.OrderByDescending(s => s.WaitlistedCount) : stats.OrderBy(s => s.WaitlistedCount),
+            "rate" => sortDesc ? stats.OrderByDescending(s => s.AttendanceRate) : stats.OrderBy(s => s.AttendanceRate),
+            "cancelled" => sortDesc ? stats.OrderByDescending(s => s.CancellationAffectedCount) : stats.OrderBy(s => s.CancellationAffectedCount),
+            _ => stats.OrderByDescending(s => s.ConfirmedCount)
+        };
+        sortedStats = ordered.ToList();
+    }
+
+    private string SortIndicator(string column) => sortColumn == column ? (sortDesc ? "▼" : "▲") : "";
+
+    private string AttendanceBadgeClass(decimal rate) => rate switch
+    {
+        >= 75m => "rate-excellent",
+        >= 50m => "rate-good",
+        _ => "rate-poor"
+    };
+}

src/GmRelay.Web/Program.cs

@@ -23,6 +23,7 @@ builder.AddNpgsqlDataSource("gmrelaydb");
 builder.Services.AddSingleton<TelegramAuthService>();
 builder.Services.AddSingleton<ISessionStore, SessionService>();
 builder.Services.AddScoped<AuthorizedSessionService>();
+builder.Services.AddScoped<CalendarSubscriptionService>();
 
 // Add Bot Client
 builder.Services.AddSingleton<ITelegramBotClient>(sp =>
@@ -145,6 +146,24 @@ app.MapPost("/auth/logout", async (HttpContext context) =>
     return Results.Redirect("/");
 });
 
+// Public calendar subscription endpoint (no auth required)
+app.MapGet("/calendar/{token}.ics", async (
+    string token,
+    CalendarSubscriptionService service,
+    CancellationToken ct) =>
+{
+    try
+    {
+        var ics = await service.GetIcsAsync(token, ct);
+        var bytes = System.Text.Encoding.UTF8.GetBytes(ics);
+        return Results.File(bytes, "text/calendar", "schedule.ics");
+    }
+    catch (SubscriptionNotFoundException)
+    {
+        return Results.NotFound();
+    }
+});
+
 app.Run();
 
 static ClaimsPrincipal CreateTelegramPrincipal(long telegramId, string name)

src/GmRelay.Web/Services/CalendarSubscriptionService.cs

@@ -0,0 +1,93 @@
+using System.Text;
+using Dapper;
+using GmRelay.Shared.Domain;
+using Npgsql;
+
+namespace GmRelay.Web.Services;
+
+public sealed class CalendarSubscriptionService(NpgsqlDataSource dataSource)
+{
+    private const string IcsProdId = "-//GM-Relay//TTRPG Schedule//EN";
+
+    public string GenerateToken() => Guid.NewGuid().ToString("N");
+
+    public async Task<string> CreateSubscriptionAsync(
+        long userTelegramId,
+        Guid? groupId,
+        CalendarSubscriptionFilter filter,
+        CancellationToken ct = default)
+    {
+        var token = GenerateToken();
+        await using var connection = await dataSource.OpenConnectionAsync(ct);
+        await connection.ExecuteAsync(
+            @"INSERT INTO calendar_subscriptions (id, token, user_telegram_id, group_id, filter_type, created_at, expires_at)
+              VALUES (gen_random_uuid(), @token, @userTelegramId, @groupId, @filterType, now(), NULL)",
+            new { token, userTelegramId, groupId, filterType = (int)filter });
+        return token;
+    }
+
+    public async Task<string> GetIcsAsync(string token, CancellationToken ct = default)
+    {
+        await using var connection = await dataSource.OpenConnectionAsync(ct);
+
+        var subscription = await connection.QueryFirstOrDefaultAsync<SubscriptionRecord>(
+            @"SELECT id, user_telegram_id as UserTelegramId, group_id as GroupId, filter_type as FilterType
+              FROM calendar_subscriptions
+              WHERE token = @token
+                AND (expires_at IS NULL OR expires_at > now())",
+            new { token });
+
+        if (subscription is null)
+            throw new SubscriptionNotFoundException();
+
+        var sessions = await connection.QueryAsync<CalendarSessionDto>(
+            subscription.FilterType == (int)CalendarSubscriptionFilter.SpecificGroup && subscription.GroupId.HasValue
+                ? @"SELECT s.id as Id, s.title as Title, s.scheduled_at as ScheduledAt
+                    FROM sessions s
+                    WHERE s.group_id = @GroupId
+                      AND s.status = @Planned
+                      AND s.scheduled_at > NOW()
+                    ORDER BY s.scheduled_at ASC"
+                : @"SELECT s.id as Id, s.title as Title, s.scheduled_at as ScheduledAt
+                    FROM sessions s
+                    WHERE s.status = @Planned
+                      AND s.scheduled_at > NOW()
+                    ORDER BY s.scheduled_at ASC",
+            new { subscription.GroupId, Planned = SessionStatus.Planned });
+
+        var sb = new StringBuilder();
+        sb.AppendLine("BEGIN:VCALENDAR");
+        sb.AppendLine("VERSION:2.0");
+        sb.AppendLine($"PRODID:{IcsProdId}");
+        sb.AppendLine("CALSCALE:GREGORIAN");
+        sb.AppendLine("METHOD:PUBLISH");
+
+        foreach (var s in sessions)
+        {
+            var dtStart = FormatIcsDate(s.ScheduledAt);
+            var dtEnd = FormatIcsDate(s.ScheduledAt.AddHours(4));
+            sb.AppendLine("BEGIN:VEVENT");
+            sb.AppendLine($"UID:{s.Id}@gmrelay");
+            sb.AppendLine($"DTSTAMP:{FormatIcsDate(DateTime.UtcNow)}");
+            sb.AppendLine($"DTSTART:{dtStart}");
+            sb.AppendLine($"DTEND:{dtEnd}");
+            sb.AppendLine($"SUMMARY:{EscapeIcsText(s.Title)}");
+            sb.AppendLine("END:VEVENT");
+        }
+
+        sb.AppendLine("END:VCALENDAR");
+        return sb.ToString();
+    }
+
+    private static string FormatIcsDate(DateTime dt) => dt.ToUniversalTime().ToString("yyyyMMddTHHmmssZ");
+
+    private static string EscapeIcsText(string text) => text
+        .Replace("\\", "\\\\")
+        .Replace(";", "\\;")
+        .Replace(",", "\\,")
+        .Replace("\n", "\\n")
+        .Replace("\r", "");
+
+    private sealed record SubscriptionRecord(Guid Id, long UserTelegramId, Guid? GroupId, int FilterType);
+    private sealed record CalendarSessionDto(Guid Id, string Title, DateTime ScheduledAt);
+}

src/GmRelay.Web/Services/ISessionStore.cs

@@ -2,6 +2,19 @@ using GmRelay.Shared.Domain;
 
 namespace GmRelay.Web.Services;
 
+public sealed record PlayerAttendanceStats(
+    Guid PlayerId,
+    string DisplayName,
+    string? TelegramUsername,
+    long TotalSessions,
+    long ConfirmedCount,
+    long DeclinedCount,
+    long NoResponseCount,
+    long WaitlistedCount,
+    long CancellationAffectedCount,
+    decimal AttendanceRate
+);
+
 public interface ISessionStore
 {
     Task<List<WebGameGroup>> GetGroupsForGmAsync(long gmId);
@@ -27,4 +40,5 @@ public interface ISessionStore
     Task RemoveGroupCoGmAsync(Guid groupId, long coGmTelegramId);
     Task<List<WebParticipant>> GetSessionParticipantsAsync(Guid sessionId);
     Task RemovePlayerFromSessionAsync(Guid sessionId, Guid groupId, Guid participantId);
+    Task<List<PlayerAttendanceStats>> GetGroupAttendanceStatsAsync(Guid groupId);
 }

src/GmRelay.Web/Services/SessionService.cs

@@ -169,6 +169,39 @@ public sealed class SessionService(
             new { GroupId = groupId, OwnerRole = GroupManagerRoleExtensions.OwnerValue })).ToList();
     }
 
+    public async Task<List<PlayerAttendanceStats>> GetGroupAttendanceStatsAsync(Guid groupId)
+    {
+        await using var conn = await dataSource.OpenConnectionAsync();
+        return (await conn.QueryAsync<PlayerAttendanceStats>(
+            """
+            SELECT
+                p.id AS PlayerId,
+                p.display_name AS DisplayName,
+                p.telegram_username AS TelegramUsername,
+                COUNT(DISTINCT s.id) AS TotalSessions,
+                COUNT(DISTINCT CASE WHEN sp.rsvp_status = 'Confirmed' THEN s.id END) AS ConfirmedCount,
+                COUNT(DISTINCT CASE WHEN sp.rsvp_status = 'Declined' THEN s.id END) AS DeclinedCount,
+                COUNT(DISTINCT CASE WHEN sp.rsvp_status = 'Pending' THEN s.id END) AS NoResponseCount,
+                COUNT(DISTINCT CASE WHEN sp.registration_status = 'Waitlisted' THEN s.id END) AS WaitlistedCount,
+                COUNT(DISTINCT CASE WHEN s.status = 'Cancelled' AND sp.rsvp_status IN ('Confirmed','Declined') THEN s.id END) AS CancellationAffectedCount,
+                CASE WHEN COUNT(DISTINCT s.id) > 0
+                    THEN ROUND(
+                        COUNT(DISTINCT CASE WHEN sp.rsvp_status = 'Confirmed' THEN s.id END)
+                        * 100.0 / COUNT(DISTINCT s.id), 2)
+                    ELSE 0
+                END AS AttendanceRate
+            FROM players p
+            JOIN session_participants sp ON sp.player_id = p.id
+            JOIN sessions s ON s.id = sp.session_id
+            WHERE s.group_id = @GroupId
+              AND s.scheduled_at <= now()
+              AND sp.is_gm = false
+            GROUP BY p.id, p.display_name, p.telegram_username
+            ORDER BY AttendanceRate DESC, ConfirmedCount DESC
+            """,
+            new { GroupId = groupId })).ToList();
+    }
+
     public async Task AddGroupCoGmAsync(
         Guid groupId,
         long ownerTelegramId,

src/GmRelay.Web/Services/SubscriptionNotFoundException.cs

@@ -0,0 +1,6 @@
+namespace GmRelay.Web.Services;
+
+public sealed class SubscriptionNotFoundException : Exception
+{
+    public SubscriptionNotFoundException() : base("Calendar subscription not found.") { }
+}

tests/GmRelay.Bot.Tests/Rendering/SessionBatchViewBuilderTests.cs

@@ -51,8 +51,8 @@ public sealed class SessionBatchViewBuilderTests
 
         Assert.Equal(2, session.ActivePlayerCount);
         Assert.Equal(4, session.MaxPlayers);
-        Assert.Equal(2, session.ActivePlayers.Count);
+        Assert.True(session.ActivePlayers.Count == 2);
-        Assert.Equal(1, session.WaitlistedPlayers.Count);
+        Assert.True(session.WaitlistedPlayers.Count == 1);
     }
 
     [Fact]
@@ -66,8 +66,8 @@ public sealed class SessionBatchViewBuilderTests
         var actions = result.Sessions[0].AvailableActions;
 
         Assert.Equal(2, actions.Count);
-        Assert.Equal("join_session", actions[0].ActionKey);
+        Assert.Equal("join_session", result.Sessions[0].AvailableActions[0].ActionKey);
-        Assert.Equal("leave_session", actions[1].ActionKey);
+        Assert.Equal("leave_session", result.Sessions[0].AvailableActions[1].ActionKey);
         Assert.Equal(sessionId, actions[0].SessionId);
         Assert.Equal(sessionId, actions[1].SessionId);
     }

tests/GmRelay.Bot.Tests/Rendering/TelegramSessionBatchRendererTests.cs

@@ -1,3 +1,4 @@
+using GmRelay.Bot.Infrastructure.Telegram;
 using GmRelay.Shared.Domain;
 using GmRelay.Shared.Rendering;
 using Telegram.Bot.Types.ReplyMarkups;

tests/GmRelay.Bot.Tests/Web/AuthorizedSessionServiceTests.cs

@@ -886,6 +886,9 @@ public sealed class AuthorizedSessionServiceTests
             return Task.CompletedTask;
         }
 
+        public Task<List<PlayerAttendanceStats>> GetGroupAttendanceStatsAsync(Guid groupId) =>
+            Task.FromResult(new List<PlayerAttendanceStats>());
+
         private bool IsManager(Guid groupId, long telegramId) =>
             IsOwner(groupId, telegramId) ||
             managers.Any(manager => manager.GroupId == groupId && manager.TelegramId == telegramId);