feat: add periodic server stats reporting and logging

- Introduced ServerStatsReport and ServerStatsCollector for tracking server activity.
- Implemented ServerStatsReportService to generate and persist stats reports periodically.
- Added configuration options for stats reporting in appsettings and .env.example.
- Enhanced logging in ChannelsController and ModerationController to include stats-related actions.
- Updated database context and migrations to support new ServerStatsReport entity.
- Adjusted logging levels in IrcGatewayService and ChatService for better performance.

.env.example

@@ -75,3 +75,19 @@ Irc__Enabled=false
 
 # ── Logging ──────────────────────────────────────────────────────────
 # Serilog__MinimumLevel__Default=Information
+
+# ── Server logs room ─────────────────────────────────────────────────
+# Read-only system channel that live-streams Serilog events to Mod+ users.
+# ServerLogs__Enabled=true
+# ServerLogs__RoomName=server-logs
+# ServerLogs__MinRole=Mod
+# ServerLogs__MinLevel=Information
+# ServerLogs__BacklogLines=100
+# ServerLogs__LogDirectory=logs
+# ServerLogs__LogFilePattern=echohub-server-*.log
+
+# ── Periodic stats report ────────────────────────────────────────────
+# Aggregate activity snapshot logged as JSON and persisted to the DB.
+# Stats__Enabled=true
+# Stats__IntervalHours=6
+# Stats__RetentionDays=90

src/EchoHub.Core/Models/ServerStatsReport.cs

@@ -0,0 +1,62 @@
+namespace EchoHub.Core.Models;
+
+/// <summary>
+/// A snapshot of server activity over one reporting window, produced periodically by the
+/// stats-report background job. Each report is logged as pretty-printed JSON and persisted
+/// for historical trend analysis. The window is "since the previous report" (or since startup
+/// for the first report of a run).
+/// </summary>
+public class ServerStatsReport
+{
+    public Guid Id { get; set; }
+
+    /// <summary>When this report was generated (equals <see cref="PeriodEnd"/>).</summary>
+    public DateTimeOffset GeneratedAt { get; set; } = DateTimeOffset.UtcNow;
+
+    /// <summary>Start of the reporting window.</summary>
+    public DateTimeOffset PeriodStart { get; set; }
+
+    /// <summary>End of the reporting window.</summary>
+    public DateTimeOffset PeriodEnd { get; set; }
+
+    /// <summary>Length of the reporting window in hours.</summary>
+    public double WindowHours { get; set; }
+
+    // ── Activity during the window ──────────────────────────────────────────
+    /// <summary>Messages sent during the window.</summary>
+    public int MessagesSent { get; set; }
+
+    /// <summary>Attachments (files/images/audio) uploaded during the window.</summary>
+    public int FilesUploaded { get; set; }
+
+    /// <summary>Total bytes across all attachments uploaded during the window.</summary>
+    public long BytesUploaded { get; set; }
+
+    /// <summary>Accounts registered during the window ("new members joined").</summary>
+    public int NewMembers { get; set; }
+
+    /// <summary>Distinct users who sent at least one message during the window.</summary>
+    public int ActiveMembers { get; set; }
+
+    /// <summary>Session connects during the window (per-connection, across SignalR + IRC).</summary>
+    public int Connections { get; set; }
+
+    /// <summary>Session disconnects during the window ("members left" sessions).</summary>
+    public int Disconnections { get; set; }
+
+    /// <summary>Users kicked during the window.</summary>
+    public int Kicks { get; set; }
+
+    /// <summary>Users banned during the window.</summary>
+    public int Bans { get; set; }
+
+    // ── Point-in-time totals at window end ──────────────────────────────────
+    /// <summary>Total registered (unique) members at window end.</summary>
+    public int TotalMembers { get; set; }
+
+    /// <summary>Distinct users online at window end.</summary>
+    public int OnlineNow { get; set; }
+
+    /// <summary>Peak distinct users online observed during the window.</summary>
+    public int PeakOnline { get; set; }
+}

src/EchoHub.Server.Irc/IrcGatewayService.cs

@@ -113,7 +113,7 @@ public sealed class IrcGatewayService : BackgroundService
         var connection = new IrcClientConnection(tcpClient, stream);
         _connections[connection.ConnectionId] = connection;
 
-        _logger.LogInformation("IRC client connected: {Id}", connection.ConnectionId);
+        _logger.LogDebug("IRC client connected: {Id}", connection.ConnectionId);
 
         IChatService? chatService = null;
 
@@ -148,7 +148,7 @@ public sealed class IrcGatewayService : BackgroundService
 
             _connections.TryRemove(connection.ConnectionId, out _);
             await connection.DisposeAsync();
-            _logger.LogInformation("IRC client {Id} ({Nick}) disconnected",
+            _logger.LogDebug("IRC client {Id} ({Nick}) disconnected",
                 connection.ConnectionId, connection.Nickname ?? "unregistered");
         }
     }

src/EchoHub.Server/Config/StatsOptions.cs

@@ -0,0 +1,21 @@
+namespace EchoHub.Server.Config;
+
+/// <summary>
+/// Periodic server-stats report settings, bound from the "Stats" config section (env override:
+/// <c>Stats__Enabled</c> etc.). When enabled, a background job periodically snapshots server
+/// activity, logs it as pretty-printed JSON, and persists it to the database.
+/// </summary>
+public sealed class StatsOptions
+{
+    /// <summary>Master switch for the periodic stats report job.</summary>
+    public bool Enabled { get; set; } = true;
+
+    /// <summary>How often a report is generated, in hours. Default: every 6 hours.</summary>
+    public double IntervalHours { get; set; } = 6;
+
+    /// <summary>
+    /// How long persisted reports are kept before being pruned, in days. Set to 0 to keep
+    /// reports indefinitely. Default: 90 days.
+    /// </summary>
+    public int RetentionDays { get; set; } = 90;
+}

src/EchoHub.Server/Controllers/ChannelsController.cs

@@ -29,6 +29,7 @@ public class ChannelsController : ControllerBase
     private readonly IChatService _chatService;
     private readonly IMessageEncryptionService _encryption;
     private readonly UploadLimits _uploadLimits;
+    private readonly ILogger<ChannelsController> _logger;
 
     public ChannelsController(
         IChannelService channelService,
@@ -38,7 +39,8 @@ public class ChannelsController : ControllerBase
         IHttpClientFactory httpClientFactory,
         IChatService chatService,
         IMessageEncryptionService encryption,
-        UploadLimits uploadLimits)
+        UploadLimits uploadLimits,
+        ILogger<ChannelsController> logger)
     {
         _channelService = channelService;
         _db = db;
@@ -48,6 +50,7 @@ public class ChannelsController : ControllerBase
         _chatService = chatService;
         _encryption = encryption;
         _uploadLimits = uploadLimits;
+        _logger = logger;
     }
 
     [HttpGet]
@@ -289,6 +292,12 @@ public class ChannelsController : ControllerBase
             });
             attachmentDtos.Add(new AttachmentDto(kind, url, file.FileName, file.Length,
                 _encryption.EncryptNullable(previewPlain)));
+
+            // Filename is client-encrypted ciphertext in E2E rooms — never log it there.
+            var loggedName = channelDto.IsEncrypted ? "[encrypted]" : file.FileName;
+            _logger.LogInformation(
+                "{User} uploaded {Kind} '{FileName}' ({Size} bytes) to '{Channel}': {Url}",
+                usernameClaim, kind, loggedName, file.Length, channelName, url);
         }
 
         var dbContent = _encryption.EncryptDatabaseEnabled ? _encryption.Encrypt(content) : content;
@@ -446,6 +455,10 @@ public class ChannelsController : ControllerBase
         _db.Messages.Add(message);
         await _db.SaveChangesAsync();
 
+        _logger.LogInformation(
+            "{User} uploaded Image '{FileName}' ({Size} bytes) from URL to '{Channel}': {Url} (source: {Source})",
+            usernameClaim, fileName, imageBytes.Length, channelName, attachmentUrl, request.Url);
+
         var messageDto = new MessageDto(
             message.Id,
             _encryption.Encrypt(string.Empty),

src/EchoHub.Server/Controllers/ModerationController.cs

@@ -4,6 +4,7 @@ using EchoHub.Core.DTOs;
 using EchoHub.Core.Models;
 using EchoHub.Server.Data;
 using EchoHub.Server.Services;
+using EchoHub.Server.Services.Stats;
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.AspNetCore.RateLimiting;
@@ -22,19 +23,25 @@ public class ModerationController : ControllerBase
     private readonly PresenceTracker _presenceTracker;
     private readonly FileStorageService _fileStorage;
     private readonly IEnumerable<IChatBroadcaster> _broadcasters;
+    private readonly ServerStatsCollector _statsCollector;
+    private readonly ILogger<ModerationController> _logger;
 
     public ModerationController(
         EchoHubDbContext db,
         IChatService chatService,
         PresenceTracker presenceTracker,
         FileStorageService fileStorage,
-        IEnumerable<IChatBroadcaster> broadcasters)
+        IEnumerable<IChatBroadcaster> broadcasters,
+        ServerStatsCollector statsCollector,
+        ILogger<ModerationController> logger)
     {
         _db = db;
         _chatService = chatService;
         _presenceTracker = presenceTracker;
         _fileStorage = fileStorage;
         _broadcasters = broadcasters;
+        _statsCollector = statsCollector;
+        _logger = logger;
     }
 
     [HttpPost("role")]
@@ -56,9 +63,14 @@ public class ModerationController : ControllerBase
         if (request.Role >= caller!.Role)
             return BadRequest(new ErrorResponse("Cannot assign a role equal to or above your own."));
 
+        var previousRole = target.Role;
         target.Role = request.Role;
         await _db.SaveChangesAsync();
 
+        _logger.LogInformation(
+            "Role change: {Actor} set {Target} from {OldRole} to {NewRole}",
+            caller!.Username, target.Username, previousRole, request.Role);
+
         return Ok(new { Message = $"{target.Username} is now {request.Role}." });
     }
 
@@ -86,6 +98,11 @@ public class ModerationController : ControllerBase
         var reason = request?.Reason ?? "You have been kicked from the server.";
         await ForceDisconnectAndCleanupAsync(target.Username, reason);
 
+        _statsCollector.RecordKick();
+        _logger.LogInformation(
+            "Kick: {Actor} kicked {Target} (reason: {Reason})",
+            caller!.Username, target.Username, request?.Reason ?? "none");
+
         return Ok(new { Message = $"{target.Username} has been kicked." });
     }
 
@@ -111,13 +128,18 @@ public class ModerationController : ControllerBase
         var reason = request?.Reason ?? "You have been banned from this server.";
         await ForceDisconnectAndCleanupAsync(target.Username, reason);
 
+        _statsCollector.RecordBan();
+        _logger.LogWarning(
+            "Ban: {Actor} banned {Target} (reason: {Reason})",
+            caller!.Username, target.Username, request?.Reason ?? "none");
+
         return Ok(new { Message = $"{target.Username} has been banned." });
     }
 
     [HttpPost("unban/{username}")]
     public async Task<IActionResult> UnbanUser(string username)
     {
-        var (_, error) = await GetCallerAsync(ServerRole.Admin);
+        var (caller, error) = await GetCallerAsync(ServerRole.Admin);
         if (error is not null) return error;
 
         var target = await _db.Users.FirstOrDefaultAsync(u => u.Username == username.ToLowerInvariant());
@@ -127,6 +149,8 @@ public class ModerationController : ControllerBase
         target.IsBanned = false;
         await _db.SaveChangesAsync();
 
+        _logger.LogInformation("Unban: {Actor} unbanned {Target}", caller!.Username, target.Username);
+
         return Ok(new { Message = $"{target.Username} has been unbanned." });
     }
 
@@ -149,6 +173,12 @@ public class ModerationController : ControllerBase
             : null;
         await _db.SaveChangesAsync();
 
+        _logger.LogInformation(
+            "Mute: {Actor} muted {Target} ({Duration}, reason: {Reason})",
+            caller!.Username, target.Username,
+            request?.DurationMinutes is > 0 ? $"{request.DurationMinutes}m" : "indefinite",
+            request?.Reason ?? "none");
+
         var durationText = request?.DurationMinutes is > 0 ? $" for {request.DurationMinutes} minutes" : "";
         return Ok(new { Message = $"{target.Username} has been muted{durationText}." });
     }
@@ -156,7 +186,7 @@ public class ModerationController : ControllerBase
     [HttpPost("unmute/{username}")]
     public async Task<IActionResult> UnmuteUser(string username)
     {
-        var (_, error) = await GetCallerAsync(ServerRole.Mod);
+        var (caller, error) = await GetCallerAsync(ServerRole.Mod);
         if (error is not null) return error;
 
         var target = await _db.Users.FirstOrDefaultAsync(u => u.Username == username.ToLowerInvariant());
@@ -167,6 +197,8 @@ public class ModerationController : ControllerBase
         target.MutedUntil = null;
         await _db.SaveChangesAsync();
 
+        _logger.LogInformation("Unmute: {Actor} unmuted {Target}", caller!.Username, target.Username);
+
         return Ok(new { Message = $"{target.Username} has been unmuted." });
     }
 
@@ -219,13 +251,19 @@ public class ModerationController : ControllerBase
 
         await BroadcastToAllAsync(b => b.SendMessageDeletedAsync(channelName, messageId));
 
+        // Only moderator removals of another user's message are noteworthy; self-deletes are routine.
+        if (!isOwnMessage)
+            _logger.LogInformation(
+                "Message removed: {Actor} deleted {Author}'s message {MessageId} in '{Channel}'",
+                caller.Username, message.SenderUsername, messageId, channelName);
+
         return Ok(new { Message = "Message deleted." });
     }
 
     [HttpDelete("channels/{channel}/nuke")]
     public async Task<IActionResult> NukeChannel(string channel)
     {
-        var (_, error) = await GetCallerAsync(ServerRole.Mod);
+        var (caller, error) = await GetCallerAsync(ServerRole.Mod);
         if (error is not null) return error;
 
         var channelName = channel.ToLowerInvariant().Trim();
@@ -251,6 +289,10 @@ public class ModerationController : ControllerBase
 
         await BroadcastToAllAsync(b => b.SendChannelNukedAsync(channelName));
 
+        _logger.LogWarning(
+            "Channel nuked: {Actor} cleared {Count} messages from '{Channel}'",
+            caller!.Username, messages.Count, channelName);
+
         return Ok(new { Message = $"All messages in #{channelName} have been cleared." });
     }
 

src/EchoHub.Server/Data/EchoHubDbContext.cs

@@ -14,6 +14,7 @@ public class EchoHubDbContext : DbContext
     public DbSet<RefreshToken> RefreshTokens => Set<RefreshToken>();
     public DbSet<ChannelMembership> ChannelMemberships => Set<ChannelMembership>();
     public DbSet<InviteCode> InviteCodes => Set<InviteCode>();
+    public DbSet<ServerStatsReport> ServerStatsReports => Set<ServerStatsReport>();
 
     protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
     {
@@ -107,6 +108,12 @@ public class EchoHubDbContext : DbContext
             entity.Property(i => i.CreatedByUsername).IsRequired().HasMaxLength(50);
         });
 
+        modelBuilder.Entity<ServerStatsReport>(entity =>
+        {
+            entity.HasKey(r => r.Id);
+            entity.HasIndex(r => r.GeneratedAt);
+        });
+
         modelBuilder.Entity<RefreshToken>(entity =>
         {
             entity.HasKey(r => r.Id);

src/EchoHub.Server/Data/Migrations/20260717200332_AddServerStatsReports.Designer.cs

@@ -0,0 +1,437 @@
+// <auto-generated />
+using System;
+using EchoHub.Server.Data;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+
+#nullable disable
+
+namespace EchoHub.Server.Data.Migrations
+{
+    [DbContext(typeof(EchoHubDbContext))]
+    [Migration("20260717200332_AddServerStatsReports")]
+    partial class AddServerStatsReports
+    {
+        /// <inheritdoc />
+        protected override void BuildTargetModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder.HasAnnotation("ProductVersion", "10.0.3");
+
+            modelBuilder.Entity("EchoHub.Core.Models.Attachment", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("AsciiPreview")
+                        .HasMaxLength(64000)
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("FileName")
+                        .IsRequired()
+                        .HasMaxLength(255)
+                        .HasColumnType("TEXT");
+
+                    b.Property<long>("FileSize")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("Kind")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<Guid>("MessageId")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Url")
+                        .IsRequired()
+                        .HasMaxLength(500)
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("MessageId");
+
+                    b.ToTable("Attachments");
+                });
+
+            modelBuilder.Entity("EchoHub.Core.Models.Channel", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("TEXT");
+
+                    b.Property<long>("CreatedAt")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<Guid>("CreatedByUserId")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("EncryptionSalt")
+                        .HasMaxLength(64)
+                        .HasColumnType("TEXT");
+
+                    b.Property<bool>("IsPublic")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<bool>("IsSystem")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("Name")
+                        .IsRequired()
+                        .HasMaxLength(100)
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("PasswordHash")
+                        .HasMaxLength(100)
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Topic")
+                        .HasMaxLength(500)
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("WrappedRoomKey")
+                        .HasMaxLength(200)
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("Name")
+                        .IsUnique();
+
+                    b.ToTable("Channels");
+                });
+
+            modelBuilder.Entity("EchoHub.Core.Models.ChannelMembership", b =>
+                {
+                    b.Property<Guid>("UserId")
+                        .HasColumnType("TEXT");
+
+                    b.Property<Guid>("ChannelId")
+                        .HasColumnType("TEXT");
+
+                    b.Property<long>("JoinedAt")
+                        .HasColumnType("INTEGER");
+
+                    b.HasKey("UserId", "ChannelId");
+
+                    b.HasIndex("ChannelId");
+
+                    b.HasIndex("UserId");
+
+                    b.ToTable("ChannelMemberships");
+                });
+
+            modelBuilder.Entity("EchoHub.Core.Models.InviteCode", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Code")
+                        .IsRequired()
+                        .HasMaxLength(32)
+                        .HasColumnType("TEXT");
+
+                    b.Property<long>("CreatedAt")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<Guid>("CreatedByUserId")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("CreatedByUsername")
+                        .IsRequired()
+                        .HasMaxLength(50)
+                        .HasColumnType("TEXT");
+
+                    b.Property<long?>("ExpiresAt")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("MaxUses")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("UseCount")
+                        .HasColumnType("INTEGER");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("Code")
+                        .IsUnique();
+
+                    b.ToTable("InviteCodes");
+                });
+
+            modelBuilder.Entity("EchoHub.Core.Models.Message", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("AttachmentFileName")
+                        .HasMaxLength(255)
+                        .HasColumnType("TEXT");
+
+                    b.Property<long?>("AttachmentFileSize")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("AttachmentUrl")
+                        .HasMaxLength(500)
+                        .HasColumnType("TEXT");
+
+                    b.Property<Guid>("ChannelId")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Content")
+                        .IsRequired()
+                        .HasMaxLength(16000)
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("EmbedJson")
+                        .HasMaxLength(32000)
+                        .HasColumnType("TEXT");
+
+                    b.Property<Guid?>("ReplyToMessageId")
+                        .HasColumnType("TEXT");
+
+                    b.Property<Guid>("SenderUserId")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("SenderUsername")
+                        .IsRequired()
+                        .HasMaxLength(50)
+                        .HasColumnType("TEXT");
+
+                    b.Property<long>("SentAt")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("Type")
+                        .HasColumnType("INTEGER");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("ChannelId");
+
+                    b.HasIndex("SentAt");
+
+                    b.ToTable("Messages");
+                });
+
+            modelBuilder.Entity("EchoHub.Core.Models.RefreshToken", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("TEXT");
+
+                    b.Property<long>("CreatedAt")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<long>("ExpiresAt")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<long?>("RevokedAt")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("TokenHash")
+                        .IsRequired()
+                        .HasMaxLength(128)
+                        .HasColumnType("TEXT");
+
+                    b.Property<Guid>("UserId")
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("TokenHash");
+
+                    b.HasIndex("UserId");
+
+                    b.ToTable("RefreshTokens");
+                });
+
+            modelBuilder.Entity("EchoHub.Core.Models.ServerStatsReport", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("TEXT");
+
+                    b.Property<int>("ActiveMembers")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("Bans")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<long>("BytesUploaded")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("Connections")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("Disconnections")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("FilesUploaded")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<long>("GeneratedAt")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("Kicks")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("MessagesSent")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("NewMembers")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("OnlineNow")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("PeakOnline")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<long>("PeriodEnd")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<long>("PeriodStart")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("TotalMembers")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<double>("WindowHours")
+                        .HasColumnType("REAL");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("GeneratedAt");
+
+                    b.ToTable("ServerStatsReports");
+                });
+
+            modelBuilder.Entity("EchoHub.Core.Models.User", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("AvatarAscii")
+                        .HasMaxLength(10000)
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Bio")
+                        .HasMaxLength(500)
+                        .HasColumnType("TEXT");
+
+                    b.Property<long>("CreatedAt")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("DisplayName")
+                        .HasMaxLength(100)
+                        .HasColumnType("TEXT");
+
+                    b.Property<bool>("IsBanned")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<bool>("IsMuted")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<long>("LastSeenAt")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<long?>("MutedUntil")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("NicknameColor")
+                        .HasMaxLength(7)
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("PasswordHash")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<int>("Role")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("Status")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("StatusMessage")
+                        .HasMaxLength(100)
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Username")
+                        .IsRequired()
+                        .HasMaxLength(50)
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("Username")
+                        .IsUnique();
+
+                    b.ToTable("Users");
+                });
+
+            modelBuilder.Entity("EchoHub.Core.Models.Attachment", b =>
+                {
+                    b.HasOne("EchoHub.Core.Models.Message", "Message")
+                        .WithMany("Attachments")
+                        .HasForeignKey("MessageId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Message");
+                });
+
+            modelBuilder.Entity("EchoHub.Core.Models.ChannelMembership", b =>
+                {
+                    b.HasOne("EchoHub.Core.Models.Channel", null)
+                        .WithMany()
+                        .HasForeignKey("ChannelId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("EchoHub.Core.Models.User", null)
+                        .WithMany()
+                        .HasForeignKey("UserId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("EchoHub.Core.Models.Message", b =>
+                {
+                    b.HasOne("EchoHub.Core.Models.Channel", "Channel")
+                        .WithMany("Messages")
+                        .HasForeignKey("ChannelId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Channel");
+                });
+
+            modelBuilder.Entity("EchoHub.Core.Models.RefreshToken", b =>
+                {
+                    b.HasOne("EchoHub.Core.Models.User", "User")
+                        .WithMany()
+                        .HasForeignKey("UserId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("User");
+                });
+
+            modelBuilder.Entity("EchoHub.Core.Models.Channel", b =>
+                {
+                    b.Navigation("Messages");
+                });
+
+            modelBuilder.Entity("EchoHub.Core.Models.Message", b =>
+                {
+                    b.Navigation("Attachments");
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}

src/EchoHub.Server/Data/Migrations/20260717200332_AddServerStatsReports.cs

@@ -0,0 +1,54 @@
+using System;
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace EchoHub.Server.Data.Migrations
+{
+    /// <inheritdoc />
+    public partial class AddServerStatsReports : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.CreateTable(
+                name: "ServerStatsReports",
+                columns: table => new
+                {
+                    Id = table.Column<Guid>(type: "TEXT", nullable: false),
+                    GeneratedAt = table.Column<long>(type: "INTEGER", nullable: false),
+                    PeriodStart = table.Column<long>(type: "INTEGER", nullable: false),
+                    PeriodEnd = table.Column<long>(type: "INTEGER", nullable: false),
+                    WindowHours = table.Column<double>(type: "REAL", nullable: false),
+                    MessagesSent = table.Column<int>(type: "INTEGER", nullable: false),
+                    FilesUploaded = table.Column<int>(type: "INTEGER", nullable: false),
+                    BytesUploaded = table.Column<long>(type: "INTEGER", nullable: false),
+                    NewMembers = table.Column<int>(type: "INTEGER", nullable: false),
+                    ActiveMembers = table.Column<int>(type: "INTEGER", nullable: false),
+                    Connections = table.Column<int>(type: "INTEGER", nullable: false),
+                    Disconnections = table.Column<int>(type: "INTEGER", nullable: false),
+                    Kicks = table.Column<int>(type: "INTEGER", nullable: false),
+                    Bans = table.Column<int>(type: "INTEGER", nullable: false),
+                    TotalMembers = table.Column<int>(type: "INTEGER", nullable: false),
+                    OnlineNow = table.Column<int>(type: "INTEGER", nullable: false),
+                    PeakOnline = table.Column<int>(type: "INTEGER", nullable: false)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_ServerStatsReports", x => x.Id);
+                });
+
+            migrationBuilder.CreateIndex(
+                name: "IX_ServerStatsReports_GeneratedAt",
+                table: "ServerStatsReports",
+                column: "GeneratedAt");
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropTable(
+                name: "ServerStatsReports");
+        }
+    }
+}

src/EchoHub.Server/Data/Migrations/EchoHubDbContextModelSnapshot.cs

@@ -246,6 +246,67 @@ namespace EchoHub.Server.Data.Migrations
                     b.ToTable("RefreshTokens");
                 });
 
+            modelBuilder.Entity("EchoHub.Core.Models.ServerStatsReport", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("TEXT");
+
+                    b.Property<int>("ActiveMembers")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("Bans")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<long>("BytesUploaded")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("Connections")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("Disconnections")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("FilesUploaded")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<long>("GeneratedAt")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("Kicks")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("MessagesSent")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("NewMembers")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("OnlineNow")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("PeakOnline")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<long>("PeriodEnd")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<long>("PeriodStart")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("TotalMembers")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<double>("WindowHours")
+                        .HasColumnType("REAL");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("GeneratedAt");
+
+                    b.ToTable("ServerStatsReports");
+                });
+
             modelBuilder.Entity("EchoHub.Core.Models.User", b =>
                 {
                     b.Property<Guid>("Id")

src/EchoHub.Server/Program.cs

@@ -11,6 +11,7 @@ using EchoHub.Server.Hubs;
 using EchoHub.Server.Irc;
 using EchoHub.Server.Services;
 using EchoHub.Server.Services.ServerLogs;
+using EchoHub.Server.Services.Stats;
 using EchoHub.Server.Setup;
 using Microsoft.AspNetCore.Authentication.JwtBearer;
 using Microsoft.AspNetCore.RateLimiting;
@@ -142,6 +143,13 @@ while (true)
         builder.Services.AddHostedService<FileCleanupService>();
         builder.Services.AddHostedService<MuteExpirationService>();
 
+        // ── Periodic stats report (admin-configurable via the "Stats" section) ─
+        var statsOptions = builder.Configuration.GetSection("Stats").Get<StatsOptions>() ?? new StatsOptions();
+        builder.Services.AddSingleton(statsOptions);
+        builder.Services.AddSingleton<ServerStatsCollector>();
+        if (statsOptions.Enabled)
+            builder.Services.AddHostedService<ServerStatsReportService>();
+
         // Live server-log streaming (only when the sink is active)
         if (serverLogsSink is not null)
             builder.Services.AddHostedService<ServerLogsStreamService>();

src/EchoHub.Server/Services/ChatService.cs

@@ -6,6 +6,7 @@ using EchoHub.Core.Models;
 using EchoHub.Core.Security;
 using EchoHub.Server.Data;
 using EchoHub.Server.Services.ServerLogs;
+using EchoHub.Server.Services.Stats;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
@@ -23,6 +24,7 @@ public class ChatService : IChatService
     private readonly FileStorageService _fileStorage;
     private readonly SpamGuard _spamGuard;
     private readonly ServerLogsService _serverLogs;
+    private readonly ServerStatsCollector _statsCollector;
     private readonly ILogger<ChatService> _logger;
 
     public ChatService(
@@ -35,6 +37,7 @@ public class ChatService : IChatService
         FileStorageService fileStorage,
         SpamGuard spamGuard,
         ServerLogsService serverLogs,
+        ServerStatsCollector statsCollector,
         ILogger<ChatService> logger)
     {
         _scopeFactory = scopeFactory;
@@ -46,12 +49,14 @@ public class ChatService : IChatService
         _fileStorage = fileStorage;
         _spamGuard = spamGuard;
         _serverLogs = serverLogs;
+        _statsCollector = statsCollector;
         _logger = logger;
     }
 
     public async Task UserConnectedAsync(string connectionId, Guid userId, string username)
     {
         _presenceTracker.UserConnected(connectionId, userId, username);
+        _statsCollector.RecordConnection(_presenceTracker.GetOnlineUserCount());
 
         using var scope = _scopeFactory.CreateScope();
         var db = scope.ServiceProvider.GetRequiredService<EchoHubDbContext>();
@@ -64,7 +69,9 @@ public class ChatService : IChatService
             await db.SaveChangesAsync();
         }
 
-        _logger.LogInformation("{User} connected (ConnectionId: {ConnectionId})", username, connectionId);
+        // Debug-level: connect/disconnect churn is high-volume on a busy server. Aggregate
+        // counts land in the periodic stats report instead.
+        _logger.LogDebug("{User} connected (ConnectionId: {ConnectionId})", username, connectionId);
     }
 
     public async Task<string?> UserDisconnectedAsync(string connectionId)
@@ -75,6 +82,7 @@ public class ChatService : IChatService
             : [];
 
         var username = _presenceTracker.UserDisconnected(connectionId);
+        _statsCollector.RecordDisconnection(_presenceTracker.GetOnlineUserCount());
 
         if (username is not null && !_presenceTracker.IsOnline(username))
         {
@@ -100,7 +108,7 @@ public class ChatService : IChatService
             }
         }
 
-        _logger.LogInformation("{User} disconnected (ConnectionId: {ConnectionId})", username ?? "Unknown", connectionId);
+        _logger.LogDebug("{User} disconnected (ConnectionId: {ConnectionId})", username ?? "Unknown", connectionId);
         return username;
     }
 
@@ -165,7 +173,7 @@ public class ChatService : IChatService
                 await BroadcastToAllAsync(b => b.SendUserJoinedAsync(channelName, username, presence, connectionId));
             }
 
-            _logger.LogInformation("{User} joined channel '{Channel}'", username, channelName);
+            _logger.LogDebug("{User} joined channel '{Channel}'", username, channelName);
         }
 
         var history = await GetChannelHistoryAsync(channelName, HubConstants.DefaultHistoryCount);
@@ -177,7 +185,7 @@ public class ChatService : IChatService
         channelName = channelName.ToLowerInvariant().Trim();
         _presenceTracker.LeaveChannel(username, channelName);
         await BroadcastToAllAsync(b => b.SendUserLeftAsync(channelName, username));
-        _logger.LogInformation("{User} left channel '{Channel}'", username, channelName);
+        _logger.LogDebug("{User} left channel '{Channel}'", username, channelName);
     }
 
     public async Task<string?> SendMessageAsync(Guid userId, string username, string channelName, string content, string? originConnectionId = null, Guid? replyToMessageId = null)

src/EchoHub.Server/Services/Stats/ServerStatsCollector.cs

@@ -0,0 +1,68 @@
+namespace EchoHub.Server.Services.Stats;
+
+/// <summary>
+/// Thread-safe, in-memory accumulator for server-activity counters that have no natural
+/// database timestamp to query after the fact — session connects/disconnects, moderation
+/// actions, and peak concurrency. The periodic stats-report job snapshots and resets these
+/// once per reporting window. Registered as a singleton; every increment is lock-free so it
+/// is safe to call from hot paths (connect/disconnect).
+/// </summary>
+public sealed class ServerStatsCollector
+{
+    private long _connections;
+    private long _disconnections;
+    private long _kicks;
+    private long _bans;
+    private int _peakOnline;
+
+    /// <summary>Record a session coming online, updating the running peak.</summary>
+    public void RecordConnection(int onlineNow)
+    {
+        Interlocked.Increment(ref _connections);
+        RecordOnline(onlineNow);
+    }
+
+    /// <summary>Record a session going offline, updating the running peak.</summary>
+    public void RecordDisconnection(int onlineNow)
+    {
+        Interlocked.Increment(ref _disconnections);
+        RecordOnline(onlineNow);
+    }
+
+    /// <summary>Record a kick action.</summary>
+    public void RecordKick() => Interlocked.Increment(ref _kicks);
+
+    /// <summary>Record a ban action.</summary>
+    public void RecordBan() => Interlocked.Increment(ref _bans);
+
+    /// <summary>Update the running maximum of concurrent online users (lock-free).</summary>
+    public void RecordOnline(int onlineNow)
+    {
+        int current;
+        while (onlineNow > (current = Volatile.Read(ref _peakOnline)))
+        {
+            if (Interlocked.CompareExchange(ref _peakOnline, onlineNow, current) == current)
+                break;
+        }
+    }
+
+    /// <summary>
+    /// Atomically read all counters and reset them for the next reporting window. The peak is
+    /// reset to <paramref name="onlineNow"/> so the next window's peak starts from the current
+    /// concurrency rather than zero.
+    /// </summary>
+    public StatsCounters SnapshotAndReset(int onlineNow) => new(
+        Connections: Interlocked.Exchange(ref _connections, 0),
+        Disconnections: Interlocked.Exchange(ref _disconnections, 0),
+        Kicks: Interlocked.Exchange(ref _kicks, 0),
+        Bans: Interlocked.Exchange(ref _bans, 0),
+        PeakOnline: Interlocked.Exchange(ref _peakOnline, onlineNow));
+}
+
+/// <summary>Immutable snapshot of the counters held by <see cref="ServerStatsCollector"/>.</summary>
+public readonly record struct StatsCounters(
+    long Connections,
+    long Disconnections,
+    long Kicks,
+    long Bans,
+    int PeakOnline);

src/EchoHub.Server/Services/Stats/ServerStatsReportService.cs

@@ -0,0 +1,151 @@
+using System.Text.Json;
+using EchoHub.Core.Models;
+using EchoHub.Server.Config;
+using EchoHub.Server.Data;
+using EchoHub.Server.Services;
+using Microsoft.EntityFrameworkCore;
+
+namespace EchoHub.Server.Services.Stats;
+
+/// <summary>
+/// Background job that periodically snapshots server activity over a window, logs it as
+/// pretty-printed JSON (which also surfaces in the live server-logs room), and persists it to
+/// the database for historical trends. Interval and retention are configurable via the "Stats"
+/// section; the default cadence is every 6 hours.
+/// </summary>
+public sealed class ServerStatsReportService : BackgroundService
+{
+    private static readonly JsonSerializerOptions JsonOptions = new() { WriteIndented = true };
+
+    private readonly IServiceScopeFactory _scopeFactory;
+    private readonly PresenceTracker _presence;
+    private readonly ServerStatsCollector _collector;
+    private readonly StatsOptions _options;
+    private readonly ILogger<ServerStatsReportService> _logger;
+
+    // Start of the current reporting window. Advances to PeriodEnd after each report so that
+    // the DB-derived counts and the in-memory collector counters cover the same span.
+    private DateTimeOffset _periodStart;
+
+    public ServerStatsReportService(
+        IServiceScopeFactory scopeFactory,
+        PresenceTracker presence,
+        ServerStatsCollector collector,
+        StatsOptions options,
+        ILogger<ServerStatsReportService> logger)
+    {
+        _scopeFactory = scopeFactory;
+        _presence = presence;
+        _collector = collector;
+        _options = options;
+        _logger = logger;
+    }
+
+    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
+    {
+        if (!_options.Enabled)
+            return;
+
+        // A non-positive interval falls back to the 6h default; anything positive is honoured
+        // but floored at 1s so a mis-set tiny value can't spin the loop.
+        var interval = _options.IntervalHours > 0
+            ? TimeSpan.FromHours(_options.IntervalHours)
+            : TimeSpan.FromHours(6);
+        if (interval < TimeSpan.FromSeconds(1))
+            interval = TimeSpan.FromSeconds(1);
+        _periodStart = DateTimeOffset.UtcNow;
+
+        _logger.LogInformation(
+            "Server stats report job started — reporting every {Hours}h, retention {Days}d",
+            _options.IntervalHours, _options.RetentionDays);
+
+        while (!stoppingToken.IsCancellationRequested)
+        {
+            try
+            {
+                await Task.Delay(interval, stoppingToken);
+            }
+            catch (OperationCanceledException)
+            {
+                break;
+            }
+
+            try
+            {
+                await GenerateReportAsync(stoppingToken);
+            }
+            catch (Exception ex) when (ex is not OperationCanceledException)
+            {
+                _logger.LogError(ex, "Failed to generate periodic server stats report");
+            }
+        }
+    }
+
+    private async Task GenerateReportAsync(CancellationToken ct)
+    {
+        var periodStart = _periodStart;
+        var periodEnd = DateTimeOffset.UtcNow;
+        var onlineNow = _presence.GetOnlineUserCount();
+        var counters = _collector.SnapshotAndReset(onlineNow);
+
+        using var scope = _scopeFactory.CreateScope();
+        var db = scope.ServiceProvider.GetRequiredService<EchoHubDbContext>();
+
+        var messagesSent = await db.Messages.CountAsync(m => m.SentAt >= periodStart, ct);
+
+        var activeMembers = await db.Messages
+            .Where(m => m.SentAt >= periodStart)
+            .Select(m => m.SenderUserId)
+            .Distinct()
+            .CountAsync(ct);
+
+        var uploadQuery = db.Attachments
+            .Where(a => db.Messages.Any(m => m.Id == a.MessageId && m.SentAt >= periodStart));
+        var filesUploaded = await uploadQuery.CountAsync(ct);
+        var bytesUploaded = filesUploaded == 0 ? 0L : await uploadQuery.SumAsync(a => a.FileSize, ct);
+
+        var newMembers = await db.Users.CountAsync(u => u.CreatedAt >= periodStart, ct);
+        var totalMembers = await db.Users.CountAsync(ct);
+
+        var report = new ServerStatsReport
+        {
+            Id = Guid.NewGuid(),
+            GeneratedAt = periodEnd,
+            PeriodStart = periodStart,
+            PeriodEnd = periodEnd,
+            WindowHours = Math.Round((periodEnd - periodStart).TotalHours, 2),
+            MessagesSent = messagesSent,
+            FilesUploaded = filesUploaded,
+            BytesUploaded = bytesUploaded,
+            NewMembers = newMembers,
+            ActiveMembers = activeMembers,
+            Connections = (int)counters.Connections,
+            Disconnections = (int)counters.Disconnections,
+            Kicks = (int)counters.Kicks,
+            Bans = (int)counters.Bans,
+            TotalMembers = totalMembers,
+            OnlineNow = onlineNow,
+            PeakOnline = counters.PeakOnline,
+        };
+
+        db.ServerStatsReports.Add(report);
+
+        // Prune reports beyond the retention window (0 = keep forever).
+        if (_options.RetentionDays > 0)
+        {
+            var cutoff = periodEnd.AddDays(-_options.RetentionDays);
+            var stale = await db.ServerStatsReports
+                .Where(r => r.GeneratedAt < cutoff)
+                .ToListAsync(ct);
+            if (stale.Count > 0)
+                db.ServerStatsReports.RemoveRange(stale);
+        }
+
+        await db.SaveChangesAsync(ct);
+        _periodStart = periodEnd;
+
+        // Pretty-printed JSON so the report is readable both in the log files and the logs room.
+        var json = JsonSerializer.Serialize(report, JsonOptions);
+        _logger.LogInformation("Server stats report ({WindowHours}h window):\n{Report}", report.WindowHours, json);
+    }
+}

src/EchoHub.Server/appsettings.example.json

@@ -56,6 +56,11 @@
     "LogDirectory": "logs",
     "LogFilePattern": "echohub-server-*.log"
   },
+  "Stats": {
+    "Enabled": true,
+    "IntervalHours": 6,
+    "RetentionDays": 90
+  },
   "Irc": {
     "Enabled": false,
     "Port": 6667,