feat: implement notification system with repository, service, and controller layers

Distribution/Features/Notifications/INotificationRepository.cs

@@ -0,0 +1,29 @@
+namespace Distribution.Features.Notifications;
+
+public interface INotificationRepository
+{
+    // ── Inbox ────────────────────────────────────────────────────────────
+    Task AddAsync(Models.Notification notification);
+    /// <summary>Stops tracking a notification (and its recipients) whose save failed.</summary>
+    void Discard(Models.Notification notification);
+
+    Task<int> GetInboxCountAsync(Guid userId, bool unreadOnly);
+    Task<List<Models.NotificationRecipient>> GetInboxAsync(Guid userId, bool unreadOnly, int page, int pageSize);
+    Task<int> GetUnreadCountAsync(Guid userId);
+    Task<Models.NotificationRecipient?> GetRecipientAsync(Guid userId, Guid recipientId);
+    Task<List<Models.NotificationRecipient>> GetUnreadRecipientsAsync(Guid userId);
+    void RemoveRecipient(Models.NotificationRecipient recipient);
+
+    // ── Recipient resolution ─────────────────────────────────────────────
+    Task<List<Guid>> FilterActiveUserIdsAsync(IEnumerable<Guid> userIds);
+    Task<List<Guid>> GetUserIdsByPermissionAsync(string permissionCode);
+    Task<List<Guid>> GetUserIdsByScopeAsync(ScopeKind kind, Guid id);
+    Task<Guid?> GetReportsToUserIdAsync(Guid userId);
+    Task<Guid?> GetRouteOwnerUserIdAsync(ScopeKind kind, Guid id);
+
+    // ── Retention ────────────────────────────────────────────────────────
+    Task<List<Models.NotificationRecipient>> GetExpiredReadRecipientsAsync(DateTime cutoff, int take);
+    Task<List<Models.Notification>> GetOrphanNotificationsAsync(int take);
+    void RemoveRecipients(IEnumerable<Models.NotificationRecipient> recipients);
+    void RemoveNotifications(IEnumerable<Models.Notification> notifications);
+}

Distribution/Features/Notifications/NotificationCleanupJob.cs

@@ -0,0 +1,63 @@
+using Distribution.Infra.UoW;
+
+namespace Distribution.Features.Notifications;
+
+/// <summary>
+/// Daily retention purge: deletes read inbox rows older than <c>Notifications:RetentionDays</c>
+/// (default 90), then any notification left with no recipients.
+/// </summary>
+public class NotificationCleanupJob(
+    IServiceScopeFactory scopes,
+    IConfiguration config,
+    ILogger<NotificationCleanupJob> logger) : BackgroundService
+{
+    private const int BatchSize = 500;
+
+    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
+    {
+        // Let the app finish starting before the first run.
+        await Task.Delay(TimeSpan.FromMinutes(1), stoppingToken);
+
+        while (!stoppingToken.IsCancellationRequested)
+        {
+            try { await RunOnceAsync(stoppingToken); }
+            catch (OperationCanceledException) { break; }
+            catch (Exception ex) { logger.LogError(ex, "Notification cleanup failed."); }
+
+            await Task.Delay(TimeSpan.FromHours(24), stoppingToken);
+        }
+    }
+
+    private async Task RunOnceAsync(CancellationToken ct)
+    {
+        var retentionDays = config.GetValue("Notifications:RetentionDays", 90);
+        var cutoff = DateTime.Now.AddDays(-retentionDays);
+
+        using var scope = scopes.CreateScope();
+        var repo = scope.ServiceProvider.GetRequiredService<INotificationRepository>();
+        var uow = scope.ServiceProvider.GetRequiredService<IUnitOfWork>();
+
+        var removed = 0;
+        while (true)
+        {
+            var expired = await repo.GetExpiredReadRecipientsAsync(cutoff, BatchSize);
+            if (expired.Count == 0) break;
+
+            repo.RemoveRecipients(expired);
+            await uow.CommitAsync(ct);
+            removed += expired.Count;
+        }
+
+        while (true)
+        {
+            var orphans = await repo.GetOrphanNotificationsAsync(BatchSize);
+            if (orphans.Count == 0) break;
+
+            repo.RemoveNotifications(orphans);
+            await uow.CommitAsync(ct);
+        }
+
+        if (removed > 0)
+            logger.LogInformation("Notification cleanup removed {Count} read inbox rows older than {Days} days.", removed, retentionDays);
+    }
+}

Distribution/Features/Notifications/NotificationController.cs

@@ -0,0 +1,57 @@
+using Distribution.Infra.Authorization;
+using Microsoft.AspNetCore.Mvc;
+
+namespace Distribution.Features.Notifications;
+
+/// <summary>Every endpoint acts on the signed-in user's own notifications only.</summary>
+[ApiController]
+[Route("api/notifications")]
+public class NotificationController(NotificationService service, ICurrentUserService currentUser) : ControllerBase
+{
+    [HttpGet]
+    public async Task<IActionResult> GetInbox(
+        [FromQuery] bool unreadOnly = false, [FromQuery] int page = 1, [FromQuery] int pageSize = 20)
+    {
+        if (currentUser.UserId is not { } userId) return Unauthorized();
+        return Ok(await service.GetInboxAsync(userId, unreadOnly, page, pageSize));
+    }
+
+    [HttpGet("unread-count")]
+    public async Task<IActionResult> GetUnreadCount()
+    {
+        if (currentUser.UserId is not { } userId) return Unauthorized();
+        return Ok(await service.GetUnreadCountAsync(userId));
+    }
+
+    [HttpPatch("{id:guid}/read")]
+    public async Task<IActionResult> MarkRead(Guid id, CancellationToken ct)
+    {
+        if (currentUser.UserId is not { } userId) return Unauthorized();
+        try
+        {
+            await service.MarkReadAsync(userId, id, ct);
+            return NoContent();
+        }
+        catch (KeyNotFoundException ex) { return NotFound(new { error = ex.Message }); }
+    }
+
+    [HttpPatch("read-all")]
+    public async Task<IActionResult> MarkAllRead(CancellationToken ct)
+    {
+        if (currentUser.UserId is not { } userId) return Unauthorized();
+        await service.MarkAllReadAsync(userId, ct);
+        return NoContent();
+    }
+
+    [HttpDelete("{id:guid}")]
+    public async Task<IActionResult> Delete(Guid id, CancellationToken ct)
+    {
+        if (currentUser.UserId is not { } userId) return Unauthorized();
+        try
+        {
+            await service.DeleteAsync(userId, id, ct);
+            return NoContent();
+        }
+        catch (KeyNotFoundException ex) { return NotFound(new { error = ex.Message }); }
+    }
+}

Distribution/Features/Notifications/NotificationDTOs.cs

@@ -0,0 +1,28 @@
+using Distribution.Models;
+
+namespace Distribution.Features.Notifications;
+
+/// <param name="Values">Object whose public properties fill the {Token} placeholders in the type's templates.</param>
+/// <param name="CreatedByUserId">The acting user; excluded from the recipients.</param>
+public record NotificationArgs(
+    object? Values,
+    string EntityType,
+    Guid EntityId,
+    string Link,
+    Guid? CreatedByUserId = null);
+
+/// <param name="Id">The caller's own recipient row id — use it for read / delete.</param>
+public record NotificationResponse(
+    Guid Id,
+    string Type,
+    NotificationSeverity Severity,
+    string Title,
+    string Message,
+    string EntityType,
+    Guid EntityId,
+    string Link,
+    DateTime CreatedAt,
+    bool IsRead,
+    DateTime? ReadAt);
+
+public record UnreadCountResponse(int Count);

Distribution/Features/Notifications/NotificationHub.cs

@@ -0,0 +1,22 @@
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.SignalR;
+
+namespace Distribution.Features.Notifications;
+
+/// <summary>
+/// Server → client only. The server pushes a "notification" event to each recipient; clients never
+/// invoke hub methods. Users are addressed by their id (see <see cref="NotificationUserIdProvider"/>).
+/// </summary>
+[Authorize]
+public class NotificationHub : Hub
+{
+    public const string Path = "/hubs/notifications";
+    public const string ClientEvent = "notification";
+}
+
+/// <summary>Maps a SignalR connection to the "UserId" claim that <c>AuthMiddleware</c> puts on the principal.</summary>
+public class NotificationUserIdProvider : IUserIdProvider
+{
+    public string? GetUserId(HubConnectionContext connection) =>
+        connection.User?.FindFirst("UserId")?.Value;
+}

Distribution/Features/Notifications/NotificationRecipientResolver.cs

@@ -0,0 +1,53 @@
+namespace Distribution.Features.Notifications;
+
+public class NotificationRecipientResolver(INotificationRepository repo)
+{
+    /// <summary>
+    /// Expands the rules into a de-duplicated list of active user ids, never including
+    /// <paramref name="actingUserId"/>.
+    /// </summary>
+    public async Task<List<Guid>> ResolveAsync(IEnumerable<RecipientRule> rules, Guid? actingUserId)
+    {
+        var ids = new HashSet<Guid>();
+
+        foreach (var rule in rules)
+            ids.UnionWith(await ResolveRuleAsync(rule));
+
+        if (actingUserId is { } actor)
+            ids.Remove(actor);
+
+        if (ids.Count == 0) return [];
+        return await repo.FilterActiveUserIdsAsync(ids);
+    }
+
+    private async Task<IEnumerable<Guid>> ResolveRuleAsync(RecipientRule rule)
+    {
+        switch (rule)
+        {
+            case UsersRule r:
+                return r.Ids;
+
+            case PermissionRule r:
+                return await repo.GetUserIdsByPermissionAsync(r.Code);
+
+            case ScopeRule r:
+                return await repo.GetUserIdsByScopeAsync(r.Kind, r.Id);
+
+            case PermissionInScopeRule r:
+                var withPermission = await repo.GetUserIdsByPermissionAsync(r.Code);
+                var inScope = await repo.GetUserIdsByScopeAsync(r.Kind, r.Id);
+                return withPermission.Intersect(inScope);
+
+            case ReportsToRule r:
+                var supervisor = await repo.GetReportsToUserIdAsync(r.UserId);
+                return supervisor is { } s ? [s] : [];
+
+            case RouteOwnerRule r:
+                var owner = await repo.GetRouteOwnerUserIdAsync(r.Kind, r.Id);
+                return owner is { } o ? [o] : [];
+
+            default:
+                throw new NotSupportedException($"Unknown recipient rule {rule.GetType().Name}.");
+        }
+    }
+}

Distribution/Features/Notifications/NotificationRepository.cs

@@ -0,0 +1,156 @@
+using Distribution.Data;
+using Microsoft.EntityFrameworkCore;
+
+namespace Distribution.Features.Notifications;
+
+public class NotificationRepository(AppDBContext context) : INotificationRepository
+{
+    // ── Inbox ────────────────────────────────────────────────────────────
+
+    public async Task AddAsync(Models.Notification notification) =>
+        await context.Notifications.AddAsync(notification);
+
+    public void Discard(Models.Notification notification)
+    {
+        foreach (var recipient in notification.Recipients)
+            context.Entry(recipient).State = EntityState.Detached;
+        context.Entry(notification).State = EntityState.Detached;
+    }
+
+    private IQueryable<Models.NotificationRecipient> InboxQuery(Guid userId, bool unreadOnly)
+    {
+        var query = context.NotificationRecipients.Where(r => r.FK_UserId == userId && r.IsActive);
+        return unreadOnly ? query.Where(r => !r.IsRead) : query;
+    }
+
+    public Task<int> GetInboxCountAsync(Guid userId, bool unreadOnly) =>
+        InboxQuery(userId, unreadOnly).CountAsync();
+
+    public Task<List<Models.NotificationRecipient>> GetInboxAsync(Guid userId, bool unreadOnly, int page, int pageSize) =>
+        InboxQuery(userId, unreadOnly)
+            .Include(r => r.Notification)
+            .OrderByDescending(r => r.Notification.CreatedAt)
+            .Skip((page - 1) * pageSize)
+            .Take(pageSize)
+            .AsNoTracking()
+            .ToListAsync();
+
+    public Task<int> GetUnreadCountAsync(Guid userId) =>
+        InboxQuery(userId, unreadOnly: true).CountAsync();
+
+    public Task<Models.NotificationRecipient?> GetRecipientAsync(Guid userId, Guid recipientId) =>
+        context.NotificationRecipients
+            .FirstOrDefaultAsync(r => r.Id == recipientId && r.FK_UserId == userId && r.IsActive);
+
+    public Task<List<Models.NotificationRecipient>> GetUnreadRecipientsAsync(Guid userId) =>
+        InboxQuery(userId, unreadOnly: true).ToListAsync();
+
+    public void RemoveRecipient(Models.NotificationRecipient recipient) =>
+        context.NotificationRecipients.Remove(recipient);
+
+    // ── Recipient resolution ─────────────────────────────────────────────
+
+    public Task<List<Guid>> FilterActiveUserIdsAsync(IEnumerable<Guid> userIds)
+    {
+        var ids = userIds.ToList();
+        return context.Users
+            .Where(u => u.IsActive && ids.Contains(u.Id))
+            .Select(u => u.Id)
+            .ToListAsync();
+    }
+
+    public Task<List<Guid>> GetUserIdsByPermissionAsync(string permissionCode) =>
+        context.Users
+            .Where(u => u.IsActive && context.RolePermissions.Any(rp =>
+                rp.FK_RoleId == u.FK_RoleId && rp.IsActive &&
+                rp.Permission.IsActive && rp.Permission.Code == permissionCode))
+            .Select(u => u.Id)
+            .ToListAsync();
+
+    public async Task<List<Guid>> GetUserIdsByScopeAsync(ScopeKind kind, Guid id)
+    {
+        Guid? regionId = null;
+        Guid? routeId = null;
+        Guid? storeId = null;
+
+        switch (kind)
+        {
+            case ScopeKind.Region:
+                regionId = id;
+                break;
+            case ScopeKind.Route:
+                routeId = id;
+                regionId = await context.Routes.Where(r => r.Id == id)
+                    .Select(r => (Guid?)r.FK_RegionId).FirstOrDefaultAsync();
+                break;
+            case ScopeKind.Store:
+                storeId = id;
+                routeId = await context.Stores.Where(s => s.Id == id)
+                    .Select(s => (Guid?)s.FK_RouteId).FirstOrDefaultAsync();
+                if (routeId is { } rid)
+                    regionId = await context.Routes.Where(r => r.Id == rid)
+                        .Select(r => (Guid?)r.FK_RegionId).FirstOrDefaultAsync();
+                break;
+        }
+
+        var userIds = new HashSet<Guid>();
+
+        if (regionId is { } region)
+            userIds.UnionWith(await context.UserRegionScopes
+                .Where(s => s.IsActive && s.FK_RegionId == region)
+                .Select(s => s.FK_UserId).ToListAsync());
+
+        if (routeId is { } route)
+            userIds.UnionWith(await context.UserRouteScopes
+                .Where(s => s.IsActive && s.FK_RouteId == route)
+                .Select(s => s.FK_UserId).ToListAsync());
+
+        if (storeId is { } store)
+            userIds.UnionWith(await context.UserStoreScopes
+                .Where(s => s.IsActive && s.FK_StoreId == store)
+                .Select(s => s.FK_UserId).ToListAsync());
+
+        return userIds.ToList();
+    }
+
+    public Task<Guid?> GetReportsToUserIdAsync(Guid userId) =>
+        context.Users.Where(u => u.Id == userId)
+            .Select(u => u.FK_ReportsToUserId)
+            .FirstOrDefaultAsync();
+
+    public async Task<Guid?> GetRouteOwnerUserIdAsync(ScopeKind kind, Guid id)
+    {
+        Guid? routeId = kind switch
+        {
+            ScopeKind.Route => id,
+            ScopeKind.Store => await context.Stores.Where(s => s.Id == id)
+                .Select(s => (Guid?)s.FK_RouteId).FirstOrDefaultAsync(),
+            _ => null
+        };
+        if (routeId is not { } rid) return null;
+
+        return await context.Routes.Where(r => r.Id == rid && r.IsActive)
+            .Select(r => r.FK_OwnerUserId)
+            .FirstOrDefaultAsync();
+    }
+
+    // ── Retention ────────────────────────────────────────────────────────
+
+    public Task<List<Models.NotificationRecipient>> GetExpiredReadRecipientsAsync(DateTime cutoff, int take) =>
+        context.NotificationRecipients
+            .Where(r => r.IsRead && r.ReadAt != null && r.ReadAt < cutoff)
+            .Take(take)
+            .ToListAsync();
+
+    public Task<List<Models.Notification>> GetOrphanNotificationsAsync(int take) =>
+        context.Notifications
+            .Where(n => !n.Recipients.Any())
+            .Take(take)
+            .ToListAsync();
+
+    public void RemoveRecipients(IEnumerable<Models.NotificationRecipient> recipients) =>
+        context.NotificationRecipients.RemoveRange(recipients);
+
+    public void RemoveNotifications(IEnumerable<Models.Notification> notifications) =>
+        context.Notifications.RemoveRange(notifications);
+}

Distribution/Features/Notifications/NotificationService.cs

@@ -0,0 +1,162 @@
+using System.Text.RegularExpressions;
+using Distribution.Features.Stock;
+using Distribution.Infra.UoW;
+using Microsoft.AspNetCore.SignalR;
+
+namespace Distribution.Features.Notifications;
+
+public interface INotificationService
+{
+    /// <summary>
+    /// Creates a notification for every resolved recipient and pushes it live. Best-effort: this method
+    /// never throws, so a notification problem can never fail the business action that triggered it.
+    /// Call it only AFTER the owning service's <c>uow.CommitAsync()</c> has succeeded.
+    /// </summary>
+    Task NotifyAsync(string type, IReadOnlyList<RecipientRule> recipients, NotificationArgs args, CancellationToken ct = default);
+}
+
+public class NotificationService(
+    INotificationRepository repo,
+    NotificationRecipientResolver resolver,
+    IHubContext<NotificationHub> hub,
+    IUnitOfWork uow,
+    ILogger<NotificationService> logger) : INotificationService
+{
+    private static readonly Regex TokenPattern = new(@"\{(\w+)\}", RegexOptions.Compiled);
+
+    // ── Trigger side ─────────────────────────────────────────────────────
+
+    public async Task NotifyAsync(string type, IReadOnlyList<RecipientRule> recipients, NotificationArgs args, CancellationToken ct = default)
+    {
+        try
+        {
+            if (!NotificationTypes.All.TryGetValue(type, out var definition))
+            {
+                logger.LogError("Notification type {Type} is not registered in NotificationTypes; skipped.", type);
+                return;
+            }
+
+            var userIds = await resolver.ResolveAsync(recipients, args.CreatedByUserId);
+            if (userIds.Count == 0) return;
+
+            var values = ToDictionary(args.Values);
+            var notification = new Models.Notification
+            {
+                Type = type,
+                Severity = definition.Severity,
+                Title = Truncate(Render(definition.TitleTemplate, values), 150),
+                Message = Truncate(Render(definition.MessageTemplate, values), 500),
+                EntityType = args.EntityType,
+                EntityId = args.EntityId,
+                Link = args.Link,
+                CreatedByUserId = args.CreatedByUserId,
+                CreatedAt = DateTime.Now,
+                Recipients = userIds.Select(id => new Models.NotificationRecipient { FK_UserId = id }).ToList()
+            };
+
+            await repo.AddAsync(notification);
+            try
+            {
+                await uow.CommitAsync(ct);
+            }
+            catch
+            {
+                repo.Discard(notification);
+                throw;
+            }
+
+            await PushAsync(notification);
+        }
+        catch (Exception ex)
+        {
+            logger.LogError(ex, "Failed to create {Type} notification for {EntityType} {EntityId}.",
+                type, args.EntityType, args.EntityId);
+        }
+    }
+
+    // Separate from persistence: a failed push still leaves the notification in the inbox.
+    private async Task PushAsync(Models.Notification notification)
+    {
+        foreach (var recipient in notification.Recipients)
+        {
+            try
+            {
+                await hub.Clients.User(recipient.FK_UserId.ToString())
+                    .SendAsync(NotificationHub.ClientEvent, ToResponse(notification, recipient));
+            }
+            catch (Exception ex)
+            {
+                logger.LogWarning(ex, "Failed to push notification {NotificationId} to user {UserId}.",
+                    notification.Id, recipient.FK_UserId);
+            }
+        }
+    }
+
+    // ── Inbox side ───────────────────────────────────────────────────────
+
+    public async Task<PagedResponse<NotificationResponse>> GetInboxAsync(Guid userId, bool unreadOnly, int page, int pageSize)
+    {
+        page = Math.Max(1, page);
+        pageSize = Math.Clamp(pageSize, 1, 100);
+
+        var total = await repo.GetInboxCountAsync(userId, unreadOnly);
+        var rows = await repo.GetInboxAsync(userId, unreadOnly, page, pageSize);
+        return new PagedResponse<NotificationResponse>(page, pageSize, total,
+            rows.Select(r => ToResponse(r.Notification, r)).ToList());
+    }
+
+    public async Task<UnreadCountResponse> GetUnreadCountAsync(Guid userId) =>
+        new(await repo.GetUnreadCountAsync(userId));
+
+    public async Task MarkReadAsync(Guid userId, Guid recipientId, CancellationToken ct = default)
+    {
+        var recipient = await repo.GetRecipientAsync(userId, recipientId)
+            ?? throw new KeyNotFoundException("Notification not found.");
+        if (recipient.IsRead) return;
+
+        recipient.IsRead = true;
+        recipient.ReadAt = DateTime.Now;
+        await uow.CommitAsync(ct);
+    }
+
+    public async Task MarkAllReadAsync(Guid userId, CancellationToken ct = default)
+    {
+        var unread = await repo.GetUnreadRecipientsAsync(userId);
+        if (unread.Count == 0) return;
+
+        var now = DateTime.Now;
+        foreach (var recipient in unread)
+        {
+            recipient.IsRead = true;
+            recipient.ReadAt = now;
+        }
+        await uow.CommitAsync(ct);
+    }
+
+    public async Task DeleteAsync(Guid userId, Guid recipientId, CancellationToken ct = default)
+    {
+        var recipient = await repo.GetRecipientAsync(userId, recipientId)
+            ?? throw new KeyNotFoundException("Notification not found.");
+
+        repo.RemoveRecipient(recipient);
+        await uow.CommitAsync(ct);
+    }
+
+    // ── Helpers ──────────────────────────────────────────────────────────
+
+    private static NotificationResponse ToResponse(Models.Notification n, Models.NotificationRecipient r) =>
+        new(r.Id, n.Type, n.Severity, n.Title, n.Message, n.EntityType, n.EntityId, n.Link,
+            n.CreatedAt, r.IsRead, r.ReadAt);
+
+    private static Dictionary<string, string> ToDictionary(object? values) =>
+        values is null
+            ? []
+            : values.GetType().GetProperties()
+                .ToDictionary(p => p.Name, p => p.GetValue(values)?.ToString() ?? string.Empty);
+
+    private static string Render(string template, Dictionary<string, string> values) =>
+        TokenPattern.Replace(template, m => values.TryGetValue(m.Groups[1].Value, out var v) ? v : string.Empty).Trim();
+
+    private static string Truncate(string value, int max) =>
+        value.Length <= max ? value : value[..(max - 1)] + "…";
+}

Distribution/Features/Notifications/NotificationTypes.cs

@@ -0,0 +1,49 @@
+using Distribution.Models;
+
+namespace Distribution.Features.Notifications;
+
+public record NotificationTypeDefinition(NotificationSeverity Severity, string TitleTemplate, string MessageTemplate);
+
+/// <summary>
+/// Registry of every notification type. Services must pass one of these constants to
+/// <see cref="INotificationService.NotifyAsync"/> — never a string literal. Templates use {Token}
+/// placeholders filled from <see cref="NotificationArgs.Values"/>.
+/// </summary>
+public static class NotificationTypes
+{
+    public const string RideCancelled = "RideCancelled";
+    public const string RideDriverAssigned = "RideDriverAssigned";
+    public const string DeliveryTaskFailed = "DeliveryTaskFailed";
+    public const string DeliveryTaskPartiallyDelivered = "DeliveryTaskPartiallyDelivered";
+    public const string SupplierClaimApproved = "SupplierClaimApproved";
+    public const string SupplierClaimRejected = "SupplierClaimRejected";
+    public const string ShopPOConfirmed = "ShopPOConfirmed";
+    public const string ShopPOCancelled = "ShopPOCancelled";
+    public const string StockLow = "StockLow";
+    public const string CreditLimitBreached = "CreditLimitBreached";
+
+    public static readonly IReadOnlyDictionary<string, NotificationTypeDefinition> All =
+        new Dictionary<string, NotificationTypeDefinition>
+        {
+            [RideCancelled] = new(NotificationSeverity.Critical,
+                "Ride cancelled", "A ride was cancelled ({CancelType}). {Reason}"),
+            [RideDriverAssigned] = new(NotificationSeverity.Info,
+                "Ride assigned", "You have been assigned to a ride."),
+            [DeliveryTaskFailed] = new(NotificationSeverity.Warning,
+                "Delivery failed", "Delivery to {StoreName} failed. {Note}"),
+            [DeliveryTaskPartiallyDelivered] = new(NotificationSeverity.Warning,
+                "Partial delivery", "Delivery to {StoreName} was only partly delivered."),
+            [SupplierClaimApproved] = new(NotificationSeverity.Success,
+                "Supplier claim approved", "Your supplier claim was approved."),
+            [SupplierClaimRejected] = new(NotificationSeverity.Warning,
+                "Supplier claim rejected", "Your supplier claim was rejected."),
+            [ShopPOConfirmed] = new(NotificationSeverity.Info,
+                "Shop order confirmed", "Shop order for {StoreName} was confirmed."),
+            [ShopPOCancelled] = new(NotificationSeverity.Warning,
+                "Shop order cancelled", "Shop order for {StoreName} was cancelled: {Reason}"),
+            [StockLow] = new(NotificationSeverity.Warning,
+                "Low stock", "{ItemName} is down to {Quantity} at {Location}."),
+            [CreditLimitBreached] = new(NotificationSeverity.Warning,
+                "Credit limit exceeded", "{StoreName} has exceeded its credit limit."),
+        };
+}

Distribution/Features/Notifications/RecipientRule.cs

@@ -0,0 +1,37 @@
+namespace Distribution.Features.Notifications;
+
+public enum ScopeKind { Region, Route, Store }
+
+/// <summary>
+/// Who a notification goes to. There is deliberately no "everyone" rule — every trigger must say who
+/// needs to know. Scope coverage follows Region → Route → Store: a region scope covers its routes
+/// and their stores, a route scope covers its stores.
+/// </summary>
+public abstract record RecipientRule
+{
+    /// <summary>These specific users (creator, driver, approver, route owner …).</summary>
+    public static RecipientRule Users(params Guid[] ids) => new UsersRule(ids);
+
+    /// <summary>Every active user whose role holds the permission code.</summary>
+    public static RecipientRule Permission(string code) => new PermissionRule(code);
+
+    /// <summary>Every active user whose scope covers the region / route / store.</summary>
+    public static RecipientRule Scope(ScopeKind kind, Guid id) => new ScopeRule(kind, id);
+
+    /// <summary>Users who hold the permission AND whose scope covers the region / route / store.</summary>
+    public static RecipientRule PermissionInScope(string code, ScopeKind kind, Guid id) =>
+        new PermissionInScopeRule(code, kind, id);
+
+    /// <summary>The user's supervisor (User.FK_ReportsToUserId).</summary>
+    public static RecipientRule ReportsTo(Guid userId) => new ReportsToRule(userId);
+
+    /// <summary>The owner of the route (<see cref="ScopeKind.Route"/>) or of the store's route (<see cref="ScopeKind.Store"/>).</summary>
+    public static RecipientRule RouteOwner(ScopeKind kind, Guid id) => new RouteOwnerRule(kind, id);
+}
+
+public sealed record UsersRule(IReadOnlyCollection<Guid> Ids) : RecipientRule;
+public sealed record PermissionRule(string Code) : RecipientRule;
+public sealed record ScopeRule(ScopeKind Kind, Guid Id) : RecipientRule;
+public sealed record PermissionInScopeRule(string Code, ScopeKind Kind, Guid Id) : RecipientRule;
+public sealed record ReportsToRule(Guid UserId) : RecipientRule;
+public sealed record RouteOwnerRule(ScopeKind Kind, Guid Id) : RecipientRule;