Структура

backend/src/Contracts/Messaging/Application/Abstractions/IChatAccessProvider.cs

@@ -0,0 +1,11 @@
+using System;
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Knot.Contracts.Messaging.Application.Abstractions;
+
+public interface IChatAccessProvider 
+{ 
+    Task<List<Guid>> GetValidChatIdsForUserAsync(Guid userId, CancellationToken ct); 
+}

backend/src/Contracts/Messaging/Application/Abstractions/IMessageNotifier.cs

@@ -0,0 +1,6 @@
+namespace Knot.Contracts.Messaging.Application.Abstractions;
+
+public interface IMessageNotifier 
+{ 
+    Task NotifyNewMessageAsync(Guid chatId, object messagePayload, CancellationToken cancellationToken); 
+}

backend/src/Contracts/Messaging/Application/Abstractions/IMessageRepository.cs

@@ -0,0 +1,21 @@
+using Knot.Contracts.Messaging.Domain;
+
+namespace Knot.Contracts.Messaging.Application.Abstractions;
+
+public interface IMessageRepository
+{
+    void Add(Message message);
+    Task<Message?> GetByIdAsync(Guid id, CancellationToken cancellationToken);
+    Task<List<Message>> GetChatMessagesAsync(Guid chatId, int limit, int offset, CancellationToken cancellationToken);
+    Task<Message?> GetLatestChatMessageAsync(Guid chatId, CancellationToken cancellationToken);
+    Task<List<Message>> SearchMessagesAsync(string query, Guid? chatId, Guid requestingUserId, CancellationToken cancellationToken);
+
+    Task<List<Message>> GetChatMessagesCursorAsync(Guid chatId, DateTime? cursor, int limit, CancellationToken cancellationToken);
+    Task<Message?> GetLastStoryMessageAsync(Guid chatId, Guid storyId, CancellationToken cancellationToken);
+
+    Task UpdateAsync(Message message, CancellationToken cancellationToken);
+    Task<List<Message>> GetAllMessagesAsync(CancellationToken cancellationToken);
+    Task DeleteChatMessagesAsync(Guid chatId, CancellationToken cancellationToken);
+    Task DeleteUserMessagesAsync(Guid userId, CancellationToken cancellationToken);
+    Task RemoveAsync(Guid id, CancellationToken cancellationToken);
+}

backend/src/Contracts/Messaging/Application/Abstractions/IUserStatsService.cs

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+using System;
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Knot.Contracts.Messaging.Application.Abstractions;
+
+public record UserStats(int MessageCount, long StorageSize);
+
+public interface IUserStatsService
+{
+    Task<Dictionary<Guid, UserStats>> GetStatsForUsersAsync(IEnumerable<Guid> userIds, CancellationToken ct = default);
+    Task<long> GetTotalStorageSizeAsync(CancellationToken ct = default);
+    Task<int> GetCountOrphanedMessagesAsync(HashSet<Guid> activeChatIds, CancellationToken ct = default);
+    Task<long> GetOrphanedMediaSizeAsync(HashSet<string> validFileIds, CancellationToken ct = default);
+}