feat(states): add UserStates table and repository for persistent states

Database/BaseDBMigration.cs

@@ -117,6 +117,22 @@ PRIMARY KEY (UserId, ContactId)
                 .WithColumn("TargetType").AsString(255).NotNullable()
                 .WithColumn("TargetValue").AsString(255).NotNullable();
         }
+
+        // UserStates
+        if (!Schema.Table("UserStates").Exists())
+        {
+            Execute.Sql(@"
+                CREATE TABLE IF NOT EXISTS UserStates (
+                    ChatId INTEGER PRIMARY KEY,
+                    StateName TEXT NOT NULL,
+                    StateDataJson TEXT NOT NULL DEFAULT '{}',
+                    CreatedAt TEXT NOT NULL DEFAULT (datetime('now')),
+                    ExpiresAt TEXT NOT NULL
+                )");
+
+            Execute.Sql(@"
+                CREATE INDEX IF NOT EXISTS IX_UserStates_ExpiresAt ON UserStates(ExpiresAt)");
+        }
     }
 
     protected abstract void CreateSpecificConstraints();

Database/DBInit.cs

@@ -101,6 +101,10 @@ public static WebApplicationBuilder CreateBuilderByDBType(string[] args)
             new SqliteGroupGetter(Config.sqlConnectionString!));
         builder.Services.AddSingleton<IGroupSetter>(_ =>
             new SqliteGroupSetter(Config.sqlConnectionString!));
+
+        builder.Services.AddSingleton<IUserStateRepository>(_ =>
+            new SqliteUserStateRepository(Config.sqlConnectionString!));
+
         return builder;
     }
 }

Database/Interfaces/IUserStateRepository.cs

@@ -0,0 +1,20 @@
+// Copyright (C) 2024-2025 ZenonEl
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published
+// by the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Эта программа является свободным программным обеспечением: вы можете распространять и/или изменять
+// её на условиях Стандартной общественной лицензии GNU Affero, опубликованной
+// Фондом свободного программного обеспечения, либо версии 3 лицензии, либо
+// (по вашему выбору) любой более поздней версии.
+
+namespace TelegramMediaRelayBot.Database.Interfaces;
+
+public interface IUserStateRepository
+{
+    Task SaveStateAsync(long chatId, string stateName, string stateDataJson, DateTime expiresAt);
+    Task<(string StateName, string StateDataJson)?> GetStateAsync(long chatId);
+    Task RemoveStateAsync(long chatId);
+    Task<int> CleanupExpiredAsync();
+}

Database/Repositories/SqLite/SQLiteDBMigration.cs

@@ -80,5 +80,8 @@ protected override void CreateSpecificConstraints()
         Create.Index("IX_PrivacySettings_UserId")
             .OnTable("PrivacySettings")
             .OnColumn("UserId");
+
+        // ========== Индексы для UserStates ==========
+        // IX_UserStates_ExpiresAt is created inline via Execute.Sql in BaseDBMigration
     }
 }

Database/Repositories/SqLite/UserStateRepository.cs

@@ -0,0 +1,81 @@
+// Copyright (C) 2024-2025 ZenonEl
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published
+// by the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Эта программа является свободным программным обеспечением: вы можете распространять и/или изменять
+// её на условиях Стандартной общественной лицензии GNU Affero, опубликованной
+// Фондом свободного программного обеспечения, либо версии 3 лицензии, либо
+// (по вашему выбору) любой более поздней версии.
+
+using Dapper;
+using Microsoft.Data.Sqlite;
+using TelegramMediaRelayBot.Database.Interfaces;
+
+namespace TelegramMediaRelayBot.Database.Repositories.Sqlite;
+
+public class SqliteUserStateRepository(string connectionString) : IUserStateRepository
+{
+    private readonly string _connectionString = connectionString;
+
+    public async Task SaveStateAsync(long chatId, string stateName, string stateDataJson, DateTime expiresAt)
+    {
+        const string query = @"
+            INSERT INTO UserStates (ChatId, StateName, StateDataJson, ExpiresAt)
+            VALUES (@chatId, @stateName, @stateDataJson, @expiresAt)
+            ON CONFLICT(ChatId) DO UPDATE SET
+                StateName = @stateName,
+                StateDataJson = @stateDataJson,
+                CreatedAt = datetime('now'),
+                ExpiresAt = @expiresAt";
+
+        using var connection = new SqliteConnection(_connectionString);
+        await connection.ExecuteAsync(query, new
+        {
+            chatId,
+            stateName,
+            stateDataJson,
+            expiresAt = expiresAt.ToString("yyyy-MM-dd HH:mm:ss")
+        });
+    }
+
+    public async Task<(string StateName, string StateDataJson)?> GetStateAsync(long chatId)
+    {
+        const string query = @"
+            SELECT StateName, StateDataJson
+            FROM UserStates
+            WHERE ChatId = @chatId
+            AND ExpiresAt > datetime('now')";
+
+        using var connection = new SqliteConnection(_connectionString);
+        var result = await connection.QueryFirstOrDefaultAsync<StateRow>(query, new { chatId });
+
+        if (result is null)
+            return null;
+
+        return (result.StateName, result.StateDataJson);
+    }
+
+    public async Task RemoveStateAsync(long chatId)
+    {
+        const string query = "DELETE FROM UserStates WHERE ChatId = @chatId";
+
+        using var connection = new SqliteConnection(_connectionString);
+        await connection.ExecuteAsync(query, new { chatId });
+    }
+
+    public async Task<int> CleanupExpiredAsync()
+    {
+        const string query = "DELETE FROM UserStates WHERE ExpiresAt <= datetime('now')";
+
+        using var connection = new SqliteConnection(_connectionString);
+        return await connection.ExecuteAsync(query);
+    }
+
+    private class StateRow
+    {
+        public string StateName { get; set; } = string.Empty;
+        public string StateDataJson { get; set; } = "{}";
+    }
+}