add db

ChatBot/.gitea/workflows/build.yml

@@ -0,0 +1,89 @@
+name: ChatBot CI/CD
+on:
+  push:
+    branches:
+      - master
+      - main
+  pull_request:
+    types: [opened, synchronize, reopened]
+jobs:
+  build:
+    name: Build and Test
+    runs-on: windows-latest
+    services:
+      postgres:
+        image: postgres:15
+        env:
+          POSTGRES_PASSWORD: postgres
+          POSTGRES_USER: postgres
+          POSTGRES_DB: chatbot_test
+        options: >-
+          --health-cmd pg_isready
+          --health-interval 10s
+          --health-timeout 5s
+          --health-retries 5
+        ports:
+          - 5432:5432
+    steps:
+      - name: Set up JDK 17 (for SonarQube)
+        uses: actions/setup-java@v4
+        with:
+          java-version: 17
+          distribution: 'zulu'
+      
+      - name: Checkout code
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+      
+      - name: Setup .NET
+        uses: actions/setup-dotnet@v4
+        with:
+          dotnet-version: '9.0.x'
+      
+      - name: Cache SonarQube Cloud packages
+        uses: actions/cache@v4
+        with:
+          path: ~\sonar\cache
+          key: ${{ runner.os }}-sonar
+          restore-keys: ${{ runner.os }}-sonar
+      
+      - name: Cache SonarQube Cloud scanner
+        id: cache-sonar-scanner
+        uses: actions/cache@v4
+        with:
+          path: ${{ runner.temp }}\scanner
+          key: ${{ runner.os }}-sonar-scanner
+          restore-keys: ${{ runner.os }}-sonar-scanner
+      
+      - name: Install SonarQube Cloud scanner
+        if: steps.cache-sonar-scanner.outputs.cache-hit != 'true'
+        shell: powershell
+        run: |
+          New-Item -Path ${{ runner.temp }}\scanner -ItemType Directory
+          dotnet tool update dotnet-sonarscanner --tool-path ${{ runner.temp }}\scanner
+      
+      - name: Restore dependencies
+        run: dotnet restore
+      
+      - name: Build project
+        run: dotnet build --no-restore --configuration Release
+      
+      - name: Run tests
+        run: dotnet test --no-build --configuration Release --verbosity normal
+        env:
+          ConnectionStrings__DefaultConnection: "Host=localhost;Port=5432;Database=chatbot_test;Username=postgres;Password=postgres"
+      
+      - name: Run database migrations
+        run: dotnet ef database update --context ChatBotDbContext --no-build
+        env:
+          ConnectionStrings__DefaultConnection: "Host=localhost;Port=5432;Database=chatbot_test;Username=postgres;Password=postgres"
+      
+      - name: Code analysis with SonarQube
+        env:
+          SONAR_TOKEN: ${{ secrets.SONAR_TOKEN }}
+        shell: powershell
+        run: |
+          ${{ runner.temp }}\scanner\dotnet-sonarscanner begin /k:"mrleo1nid_chatbot" /o:"mrleo1nid" /d:sonar.token="${{ secrets.SONAR_TOKEN }}" /d:sonar.cs.opencover.reportsPaths="**/coverage.opencover.xml"
+          dotnet build --configuration Release
+          ${{ runner.temp }}\scanner\dotnet-sonarscanner end /d:sonar.token="${{ secrets.SONAR_TOKEN }}"

ChatBot/ChatBot.csproj

@@ -18,6 +18,12 @@
     <PackageReference Include="Serilog.Sinks.File" Version="7.0.0" />
     <PackageReference Include="Serilog.Settings.Configuration" Version="9.0.0" />
     <PackageReference Include="Microsoft.Extensions.Diagnostics.HealthChecks" Version="9.0.0" />
+    <PackageReference Include="Microsoft.EntityFrameworkCore" Version="9.0.0" />
+    <PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="9.0.0" />
+    <PackageReference Include="Npgsql.EntityFrameworkCore.PostgreSQL" Version="9.0.0" />
+    <PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="9.0.0" />
+    <PackageReference Include="FluentValidation" Version="11.9.0" />
+    <PackageReference Include="FluentValidation.DependencyInjectionExtensions" Version="11.9.0" />
   </ItemGroup>
   <ItemGroup>
     <None Update="Prompts\system-prompt.txt">

ChatBot/Data/ChatBotDbContext.cs

@@ -0,0 +1,78 @@
+using ChatBot.Models.Entities;
+using Microsoft.EntityFrameworkCore;
+
+namespace ChatBot.Data
+{
+    /// <summary>
+    /// DbContext for ChatBot application
+    /// </summary>
+    public class ChatBotDbContext : DbContext
+    {
+        public ChatBotDbContext(DbContextOptions<ChatBotDbContext> options)
+            : base(options) { }
+
+        /// <summary>
+        /// Chat sessions table
+        /// </summary>
+        public DbSet<ChatSessionEntity> ChatSessions { get; set; }
+
+        /// <summary>
+        /// Chat messages table
+        /// </summary>
+        public DbSet<ChatMessageEntity> ChatMessages { get; set; }
+
+        protected override void OnModelCreating(ModelBuilder modelBuilder)
+        {
+            base.OnModelCreating(modelBuilder);
+
+            // Configure ChatSessionEntity
+            modelBuilder.Entity<ChatSessionEntity>(entity =>
+            {
+                entity.HasKey(e => e.Id);
+                entity.Property(e => e.SessionId).IsRequired().HasMaxLength(50);
+                entity.Property(e => e.ChatId).IsRequired();
+                entity.Property(e => e.ChatType).IsRequired().HasMaxLength(20);
+                entity.Property(e => e.ChatTitle).HasMaxLength(200);
+                entity.Property(e => e.Model).HasMaxLength(100);
+                entity.Property(e => e.CreatedAt).IsRequired();
+                entity.Property(e => e.LastUpdatedAt).IsRequired();
+
+                // Unique constraint on SessionId
+                entity.HasIndex(e => e.SessionId).IsUnique();
+
+                // Index on ChatId for fast lookups
+                entity.HasIndex(e => e.ChatId);
+
+                // One-to-many relationship with messages
+                entity
+                    .HasMany(e => e.Messages)
+                    .WithOne(e => e.Session)
+                    .HasForeignKey(e => e.SessionId)
+                    .OnDelete(DeleteBehavior.Cascade);
+            });
+
+            // Configure ChatMessageEntity
+            modelBuilder.Entity<ChatMessageEntity>(entity =>
+            {
+                entity.HasKey(e => e.Id);
+                entity.Property(e => e.SessionId).IsRequired();
+                entity.Property(e => e.Content).IsRequired().HasMaxLength(10000);
+                entity.Property(e => e.Role).IsRequired().HasMaxLength(20);
+                entity.Property(e => e.CreatedAt).IsRequired();
+
+                // Index on SessionId for fast lookups
+                entity.HasIndex(e => e.SessionId);
+
+                // Index on CreatedAt for ordering
+                entity.HasIndex(e => e.CreatedAt);
+
+                // Composite index for efficient querying by session and order
+                entity.HasIndex(e => new { e.SessionId, e.MessageOrder });
+            });
+
+            // Configure table names to use snake_case
+            modelBuilder.Entity<ChatSessionEntity>().ToTable("chat_sessions");
+            modelBuilder.Entity<ChatMessageEntity>().ToTable("chat_messages");
+        }
+    }
+}

ChatBot/Data/Interfaces/IChatSessionRepository.cs

@@ -0,0 +1,74 @@
+using ChatBot.Models.Entities;
+
+namespace ChatBot.Data.Interfaces
+{
+    /// <summary>
+    /// Repository interface for chat session operations
+    /// </summary>
+    public interface IChatSessionRepository
+    {
+        /// <summary>
+        /// Get or create a chat session by chat ID
+        /// </summary>
+        Task<ChatSessionEntity> GetOrCreateAsync(
+            long chatId,
+            string chatType = "private",
+            string chatTitle = ""
+        );
+
+        /// <summary>
+        /// Get a chat session by chat ID
+        /// </summary>
+        Task<ChatSessionEntity?> GetByChatIdAsync(long chatId);
+
+        /// <summary>
+        /// Get a chat session by session ID
+        /// </summary>
+        Task<ChatSessionEntity?> GetBySessionIdAsync(string sessionId);
+
+        /// <summary>
+        /// Update a chat session
+        /// </summary>
+        Task<ChatSessionEntity> UpdateAsync(ChatSessionEntity session);
+
+        /// <summary>
+        /// Delete a chat session
+        /// </summary>
+        Task<bool> DeleteAsync(long chatId);
+
+        /// <summary>
+        /// Get all messages for a session
+        /// </summary>
+        Task<List<ChatMessageEntity>> GetMessagesAsync(int sessionId);
+
+        /// <summary>
+        /// Add a message to a session
+        /// </summary>
+        Task<ChatMessageEntity> AddMessageAsync(
+            int sessionId,
+            string content,
+            string role,
+            int messageOrder
+        );
+
+        /// <summary>
+        /// Clear all messages for a session
+        /// </summary>
+        Task ClearMessagesAsync(int sessionId);
+
+        /// <summary>
+        /// Get count of active sessions
+        /// </summary>
+        Task<int> GetActiveSessionsCountAsync();
+
+        /// <summary>
+        /// Clean up old sessions
+        /// </summary>
+        Task<int> CleanupOldSessionsAsync(int hoursOld = 24);
+
+        /// <summary>
+        /// Get sessions that need cleanup
+        /// </summary>
+        Task<List<ChatSessionEntity>> GetSessionsForCleanupAsync(int hoursOld = 24);
+    }
+}

ChatBot/Data/Repositories/ChatSessionRepository.cs

@@ -0,0 +1,171 @@
+using ChatBot.Data.Interfaces;
+using ChatBot.Models.Entities;
+using Microsoft.EntityFrameworkCore;
+
+namespace ChatBot.Data.Repositories
+{
+    /// <summary>
+    /// Repository implementation for chat session operations
+    /// </summary>
+    public class ChatSessionRepository : IChatSessionRepository
+    {
+        private readonly ChatBotDbContext _context;
+        private readonly ILogger<ChatSessionRepository> _logger;
+
+        public ChatSessionRepository(
+            ChatBotDbContext context,
+            ILogger<ChatSessionRepository> logger
+        )
+        {
+            _context = context;
+            _logger = logger;
+        }
+
+        public async Task<ChatSessionEntity> GetOrCreateAsync(
+            long chatId,
+            string chatType = "private",
+            string chatTitle = ""
+        )
+        {
+            var session = await GetByChatIdAsync(chatId);
+
+            if (session == null)
+            {
+                session = new ChatSessionEntity
+                {
+                    SessionId = Guid.NewGuid().ToString(),
+                    ChatId = chatId,
+                    ChatType = chatType,
+                    ChatTitle = chatTitle,
+                    Model = string.Empty, // Will be set by ModelService
+                    CreatedAt = DateTime.UtcNow,
+                    LastUpdatedAt = DateTime.UtcNow,
+                    MaxHistoryLength = 30,
+                };
+
+                _context.ChatSessions.Add(session);
+                await _context.SaveChangesAsync();
+
+                _logger.LogInformation(
+                    "Created new chat session for chat {ChatId}, type: {ChatType}, title: {ChatTitle}",
+                    chatId,
+                    chatType,
+                    chatTitle
+                );
+            }
+
+            return session;
+        }
+
+        public async Task<ChatSessionEntity?> GetByChatIdAsync(long chatId)
+        {
+            return await _context
+                .ChatSessions.Include(s => s.Messages.OrderBy(m => m.MessageOrder))
+                .FirstOrDefaultAsync(s => s.ChatId == chatId);
+        }
+
+        public async Task<ChatSessionEntity?> GetBySessionIdAsync(string sessionId)
+        {
+            return await _context
+                .ChatSessions.Include(s => s.Messages.OrderBy(m => m.MessageOrder))
+                .FirstOrDefaultAsync(s => s.SessionId == sessionId);
+        }
+
+        public async Task<ChatSessionEntity> UpdateAsync(ChatSessionEntity session)
+        {
+            session.LastUpdatedAt = DateTime.UtcNow;
+            _context.ChatSessions.Update(session);
+            await _context.SaveChangesAsync();
+            return session;
+        }
+
+        public async Task<bool> DeleteAsync(long chatId)
+        {
+            var session = await _context.ChatSessions.FirstOrDefaultAsync(s => s.ChatId == chatId);
+            if (session == null)
+                return false;
+
+            _context.ChatSessions.Remove(session);
+            await _context.SaveChangesAsync();
+
+            _logger.LogInformation("Deleted session for chat {ChatId}", chatId);
+            return true;
+        }
+
+        public async Task<List<ChatMessageEntity>> GetMessagesAsync(int sessionId)
+        {
+            return await _context
+                .ChatMessages.Where(m => m.SessionId == sessionId)
+                .OrderBy(m => m.MessageOrder)
+                .ToListAsync();
+        }
+
+        public async Task<ChatMessageEntity> AddMessageAsync(
+            int sessionId,
+            string content,
+            string role,
+            int messageOrder
+        )
+        {
+            var message = new ChatMessageEntity
+            {
+                SessionId = sessionId,
+                Content = content,
+                Role = role,
+                MessageOrder = messageOrder,
+                CreatedAt = DateTime.UtcNow,
+            };
+
+            _context.ChatMessages.Add(message);
+            await _context.SaveChangesAsync();
+            return message;
+        }
+
+        public async Task ClearMessagesAsync(int sessionId)
+        {
+            var messages = await _context
+                .ChatMessages.Where(m => m.SessionId == sessionId)
+                .ToListAsync();
+
+            _context.ChatMessages.RemoveRange(messages);
+            await _context.SaveChangesAsync();
+
+            _logger.LogInformation(
+                "Cleared {Count} messages for session {SessionId}",
+                messages.Count,
+                sessionId
+            );
+        }
+
+        public async Task<int> GetActiveSessionsCountAsync()
+        {
+            return await _context.ChatSessions.CountAsync();
+        }
+
+        public async Task<int> CleanupOldSessionsAsync(int hoursOld = 24)
+        {
+            var cutoffTime = DateTime.UtcNow.AddHours(-hoursOld);
+            var sessionsToRemove = await _context
+                .ChatSessions.Where(s => s.LastUpdatedAt < cutoffTime)
+                .ToListAsync();
+
+            if (sessionsToRemove.Any())
+            {
+                _context.ChatSessions.RemoveRange(sessionsToRemove);
+                await _context.SaveChangesAsync();
+
+                _logger.LogInformation("Cleaned up {Count} old sessions", sessionsToRemove.Count);
+            }
+
+            return sessionsToRemove.Count;
+        }
+
+        public async Task<List<ChatSessionEntity>> GetSessionsForCleanupAsync(int hoursOld = 24)
+        {
+            var cutoffTime = DateTime.UtcNow.AddHours(-hoursOld);
+            return await _context
+                .ChatSessions.Where(s => s.LastUpdatedAt < cutoffTime)
+                .ToListAsync();
+        }
+    }
+}

ChatBot/HISTORY_COMPRESSION.md

@@ -1,86 +0,0 @@
-# Система постепенного сжатия истории сообщений
-
-## Обзор
-
-Реализована система постепенного сжатия истории сообщений для оптимизации использования памяти и улучшения производительности чат-бота. Система автоматически сжимает старые сообщения, сохраняя при этом важную информацию.
-
-## Основные возможности
-
-### 1. Автоматическое сжатие
-- Сжатие активируется при превышении порогового количества сообщений
-- Старые сообщения группируются и сжимаются в краткие резюме
-- Системные сообщения всегда сохраняются
-- Последние сообщения остаются без изменений
-
-### 2. Умная суммаризация
-- Использование ИИ для создания кратких резюме старых сообщений
-- Раздельная обработка сообщений пользователя и ассистента
-- Сохранение ключевой информации при сжатии
-
-### 3. Настраиваемые параметры
-- `EnableHistoryCompression` - включение/отключение сжатия
-- `CompressionThreshold` - порог активации сжатия (по умолчанию 20 сообщений)
-- `CompressionTarget` - целевое количество сообщений после сжатия (по умолчанию 10)
-- `MinMessageLengthForSummarization` - минимальная длина сообщения для суммаризации (50 символов)
-- `MaxSummarizedMessageLength` - максимальная длина сжатого сообщения (200 символов)
-
-## Архитектура
-
-### Новые компоненты
-
-1. **IHistoryCompressionService** - интерфейс для сжатия истории
-2. **HistoryCompressionService** - реализация сервиса сжатия
-3. **Обновленный ChatSession** - поддержка асинхронного сжатия
-4. **Обновленный AIService** - интеграция сжатия в генерацию ответов
-5. **Обновленный ChatService** - использование сжатия при обработке сообщений
-
-### Алгоритм сжатия
-
-1. **Проверка необходимости сжатия** - сравнение количества сообщений с порогом
-2. **Разделение сообщений** - отделение системных, старых и новых сообщений
-3. **Группировка по ролям** - отдельная обработка сообщений пользователя и ассистента
-4. **Суммаризация** - создание кратких резюме с помощью ИИ
-5. **Объединение** - формирование финального списка сообщений
-
-## Конфигурация
-
-### appsettings.json
-```json
-{
-  "AI": {
-    "EnableHistoryCompression": true,
-    "CompressionThreshold": 20,
-    "CompressionTarget": 10,
-    "MinMessageLengthForSummarization": 50,
-    "MaxSummarizedMessageLength": 200
-  }
-}
-```
-
-## Использование
-
-### Автоматическое сжатие
-Сжатие происходит автоматически при добавлении новых сообщений, если включено в настройках.
-
-### Мониторинг
-Команда `/settings` показывает текущее состояние сжатия и параметры.
-
-## Преимущества
-
-1. **Экономия памяти** - значительное сокращение использования RAM
-2. **Улучшенная производительность** - быстрее обработка длинных диалогов
-3. **Сохранение контекста** - важная информация не теряется
-4. **Гибкость настройки** - возможность адаптации под различные сценарии
-5. **Обратная совместимость** - можно отключить без изменения кода
-
-## Обработка ошибок
-
-- При ошибках сжатия система автоматически переключается на простое обрезание истории
-- Логирование всех операций сжатия для мониторинга
-- Graceful degradation - бот продолжает работать даже при проблемах со сжатием
-
-## Производительность
-
-- Сжатие выполняется асинхронно, не блокируя основной поток
-- Использование кэширования для оптимизации повторных операций
-- Минимальное влияние на время отклика бота

ChatBot/Migrations/20251016214154_InitialCreate.Designer.cs

@@ -0,0 +1,149 @@
+// <auto-generated />
+using System;
+using ChatBot.Data;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+using Npgsql.EntityFrameworkCore.PostgreSQL.Metadata;
+
+#nullable disable
+
+namespace ChatBot.Migrations
+{
+    [DbContext(typeof(ChatBotDbContext))]
+    [Migration("20251016214154_InitialCreate")]
+    partial class InitialCreate
+    {
+        /// <inheritdoc />
+        protected override void BuildTargetModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder
+                .HasAnnotation("ProductVersion", "9.0.0")
+                .HasAnnotation("Relational:MaxIdentifierLength", 63);
+
+            NpgsqlModelBuilderExtensions.UseIdentityByDefaultColumns(modelBuilder);
+
+            modelBuilder.Entity("ChatBot.Models.Entities.ChatMessageEntity", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("integer")
+                        .HasColumnName("id");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<int>("Id"));
+
+                    b.Property<string>("Content")
+                        .IsRequired()
+                        .HasMaxLength(10000)
+                        .HasColumnType("character varying(10000)")
+                        .HasColumnName("content");
+
+                    b.Property<DateTime>("CreatedAt")
+                        .HasColumnType("timestamp with time zone")
+                        .HasColumnName("created_at");
+
+                    b.Property<int>("MessageOrder")
+                        .HasColumnType("integer")
+                        .HasColumnName("message_order");
+
+                    b.Property<string>("Role")
+                        .IsRequired()
+                        .HasMaxLength(20)
+                        .HasColumnType("character varying(20)")
+                        .HasColumnName("role");
+
+                    b.Property<int>("SessionId")
+                        .HasColumnType("integer")
+                        .HasColumnName("session_id");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("CreatedAt");
+
+                    b.HasIndex("SessionId");
+
+                    b.HasIndex("SessionId", "MessageOrder");
+
+                    b.ToTable("chat_messages", (string)null);
+                });
+
+            modelBuilder.Entity("ChatBot.Models.Entities.ChatSessionEntity", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("integer")
+                        .HasColumnName("id");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<int>("Id"));
+
+                    b.Property<long>("ChatId")
+                        .HasColumnType("bigint")
+                        .HasColumnName("chat_id");
+
+                    b.Property<string>("ChatTitle")
+                        .IsRequired()
+                        .HasMaxLength(200)
+                        .HasColumnType("character varying(200)")
+                        .HasColumnName("chat_title");
+
+                    b.Property<string>("ChatType")
+                        .IsRequired()
+                        .HasMaxLength(20)
+                        .HasColumnType("character varying(20)")
+                        .HasColumnName("chat_type");
+
+                    b.Property<DateTime>("CreatedAt")
+                        .HasColumnType("timestamp with time zone")
+                        .HasColumnName("created_at");
+
+                    b.Property<DateTime>("LastUpdatedAt")
+                        .HasColumnType("timestamp with time zone")
+                        .HasColumnName("last_updated_at");
+
+                    b.Property<int>("MaxHistoryLength")
+                        .HasColumnType("integer")
+                        .HasColumnName("max_history_length");
+
+                    b.Property<string>("Model")
+                        .IsRequired()
+                        .HasMaxLength(100)
+                        .HasColumnType("character varying(100)")
+                        .HasColumnName("model");
+
+                    b.Property<string>("SessionId")
+                        .IsRequired()
+                        .HasMaxLength(50)
+                        .HasColumnType("character varying(50)")
+                        .HasColumnName("session_id");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("ChatId");
+
+                    b.HasIndex("SessionId")
+                        .IsUnique();
+
+                    b.ToTable("chat_sessions", (string)null);
+                });
+
+            modelBuilder.Entity("ChatBot.Models.Entities.ChatMessageEntity", b =>
+                {
+                    b.HasOne("ChatBot.Models.Entities.ChatSessionEntity", "Session")
+                        .WithMany("Messages")
+                        .HasForeignKey("SessionId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Session");
+                });
+
+            modelBuilder.Entity("ChatBot.Models.Entities.ChatSessionEntity", b =>
+                {
+                    b.Navigation("Messages");
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}

ChatBot/Migrations/20251016214154_InitialCreate.cs

@@ -0,0 +1,95 @@
+using System;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Npgsql.EntityFrameworkCore.PostgreSQL.Metadata;
+
+#nullable disable
+
+namespace ChatBot.Migrations
+{
+    /// <inheritdoc />
+    public partial class InitialCreate : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.CreateTable(
+                name: "chat_sessions",
+                columns: table => new
+                {
+                    id = table.Column<int>(type: "integer", nullable: false)
+                        .Annotation("Npgsql:ValueGenerationStrategy", NpgsqlValueGenerationStrategy.IdentityByDefaultColumn),
+                    session_id = table.Column<string>(type: "character varying(50)", maxLength: 50, nullable: false),
+                    chat_id = table.Column<long>(type: "bigint", nullable: false),
+                    chat_type = table.Column<string>(type: "character varying(20)", maxLength: 20, nullable: false),
+                    chat_title = table.Column<string>(type: "character varying(200)", maxLength: 200, nullable: false),
+                    model = table.Column<string>(type: "character varying(100)", maxLength: 100, nullable: false),
+                    created_at = table.Column<DateTime>(type: "timestamp with time zone", nullable: false),
+                    last_updated_at = table.Column<DateTime>(type: "timestamp with time zone", nullable: false),
+                    max_history_length = table.Column<int>(type: "integer", nullable: false)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_chat_sessions", x => x.id);
+                });
+
+            migrationBuilder.CreateTable(
+                name: "chat_messages",
+                columns: table => new
+                {
+                    id = table.Column<int>(type: "integer", nullable: false)
+                        .Annotation("Npgsql:ValueGenerationStrategy", NpgsqlValueGenerationStrategy.IdentityByDefaultColumn),
+                    session_id = table.Column<int>(type: "integer", nullable: false),
+                    content = table.Column<string>(type: "character varying(10000)", maxLength: 10000, nullable: false),
+                    role = table.Column<string>(type: "character varying(20)", maxLength: 20, nullable: false),
+                    created_at = table.Column<DateTime>(type: "timestamp with time zone", nullable: false),
+                    message_order = table.Column<int>(type: "integer", nullable: false)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_chat_messages", x => x.id);
+                    table.ForeignKey(
+                        name: "FK_chat_messages_chat_sessions_session_id",
+                        column: x => x.session_id,
+                        principalTable: "chat_sessions",
+                        principalColumn: "id",
+                        onDelete: ReferentialAction.Cascade);
+                });
+
+            migrationBuilder.CreateIndex(
+                name: "IX_chat_messages_created_at",
+                table: "chat_messages",
+                column: "created_at");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_chat_messages_session_id",
+                table: "chat_messages",
+                column: "session_id");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_chat_messages_session_id_message_order",
+                table: "chat_messages",
+                columns: new[] { "session_id", "message_order" });
+
+            migrationBuilder.CreateIndex(
+                name: "IX_chat_sessions_chat_id",
+                table: "chat_sessions",
+                column: "chat_id");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_chat_sessions_session_id",
+                table: "chat_sessions",
+                column: "session_id",
+                unique: true);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropTable(
+                name: "chat_messages");
+
+            migrationBuilder.DropTable(
+                name: "chat_sessions");
+        }
+    }
+}

ChatBot/Migrations/ChatBotDbContextModelSnapshot.cs

@@ -0,0 +1,146 @@
+// <auto-generated />
+using System;
+using ChatBot.Data;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+using Npgsql.EntityFrameworkCore.PostgreSQL.Metadata;
+
+#nullable disable
+
+namespace ChatBot.Migrations
+{
+    [DbContext(typeof(ChatBotDbContext))]
+    partial class ChatBotDbContextModelSnapshot : ModelSnapshot
+    {
+        protected override void BuildModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder
+                .HasAnnotation("ProductVersion", "9.0.0")
+                .HasAnnotation("Relational:MaxIdentifierLength", 63);
+
+            NpgsqlModelBuilderExtensions.UseIdentityByDefaultColumns(modelBuilder);
+
+            modelBuilder.Entity("ChatBot.Models.Entities.ChatMessageEntity", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("integer")
+                        .HasColumnName("id");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<int>("Id"));
+
+                    b.Property<string>("Content")
+                        .IsRequired()
+                        .HasMaxLength(10000)
+                        .HasColumnType("character varying(10000)")
+                        .HasColumnName("content");
+
+                    b.Property<DateTime>("CreatedAt")
+                        .HasColumnType("timestamp with time zone")
+                        .HasColumnName("created_at");
+
+                    b.Property<int>("MessageOrder")
+                        .HasColumnType("integer")
+                        .HasColumnName("message_order");
+
+                    b.Property<string>("Role")
+                        .IsRequired()
+                        .HasMaxLength(20)
+                        .HasColumnType("character varying(20)")
+                        .HasColumnName("role");
+
+                    b.Property<int>("SessionId")
+                        .HasColumnType("integer")
+                        .HasColumnName("session_id");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("CreatedAt");
+
+                    b.HasIndex("SessionId");
+
+                    b.HasIndex("SessionId", "MessageOrder");
+
+                    b.ToTable("chat_messages", (string)null);
+                });
+
+            modelBuilder.Entity("ChatBot.Models.Entities.ChatSessionEntity", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("integer")
+                        .HasColumnName("id");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<int>("Id"));
+
+                    b.Property<long>("ChatId")
+                        .HasColumnType("bigint")
+                        .HasColumnName("chat_id");
+
+                    b.Property<string>("ChatTitle")
+                        .IsRequired()
+                        .HasMaxLength(200)
+                        .HasColumnType("character varying(200)")
+                        .HasColumnName("chat_title");
+
+                    b.Property<string>("ChatType")
+                        .IsRequired()
+                        .HasMaxLength(20)
+                        .HasColumnType("character varying(20)")
+                        .HasColumnName("chat_type");
+
+                    b.Property<DateTime>("CreatedAt")
+                        .HasColumnType("timestamp with time zone")
+                        .HasColumnName("created_at");
+
+                    b.Property<DateTime>("LastUpdatedAt")
+                        .HasColumnType("timestamp with time zone")
+                        .HasColumnName("last_updated_at");
+
+                    b.Property<int>("MaxHistoryLength")
+                        .HasColumnType("integer")
+                        .HasColumnName("max_history_length");
+
+                    b.Property<string>("Model")
+                        .IsRequired()
+                        .HasMaxLength(100)
+                        .HasColumnType("character varying(100)")
+                        .HasColumnName("model");
+
+                    b.Property<string>("SessionId")
+                        .IsRequired()
+                        .HasMaxLength(50)
+                        .HasColumnType("character varying(50)")
+                        .HasColumnName("session_id");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("ChatId");
+
+                    b.HasIndex("SessionId")
+                        .IsUnique();
+
+                    b.ToTable("chat_sessions", (string)null);
+                });
+
+            modelBuilder.Entity("ChatBot.Models.Entities.ChatMessageEntity", b =>
+                {
+                    b.HasOne("ChatBot.Models.Entities.ChatSessionEntity", "Session")
+                        .WithMany("Messages")
+                        .HasForeignKey("SessionId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Session");
+                });
+
+            modelBuilder.Entity("ChatBot.Models.Entities.ChatSessionEntity", b =>
+                {
+                    b.Navigation("Messages");
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}

ChatBot/Models/Configuration/DatabaseSettings.cs

@@ -0,0 +1,23 @@
+namespace ChatBot.Models.Configuration
+{
+    /// <summary>
+    /// Database configuration settings
+    /// </summary>
+    public class DatabaseSettings
+    {
+        /// <summary>
+        /// Connection string for the database
+        /// </summary>
+        public string ConnectionString { get; set; } = string.Empty;
+
+        /// <summary>
+        /// Enable sensitive data logging (for development only)
+        /// </summary>
+        public bool EnableSensitiveDataLogging { get; set; } = false;
+
+        /// <summary>
+        /// Command timeout in seconds
+        /// </summary>
+        public int CommandTimeout { get; set; } = 30;
+    }
+}

ChatBot/Models/Configuration/Validators/DatabaseSettingsValidator.cs

@@ -0,0 +1,40 @@
+using FluentValidation;
+using Microsoft.Extensions.Options;
+
+namespace ChatBot.Models.Configuration.Validators
+{
+    /// <summary>
+    /// Validator for DatabaseSettings
+    /// </summary>
+    public class DatabaseSettingsValidator
+        : AbstractValidator<DatabaseSettings>,
+            IValidateOptions<DatabaseSettings>
+    {
+        public DatabaseSettingsValidator()
+        {
+            RuleFor(x => x.ConnectionString)
+                .NotEmpty()
+                .WithMessage("Database connection string is required");
+
+            RuleFor(x => x.CommandTimeout)
+                .GreaterThan(0)
+                .WithMessage("Command timeout must be greater than 0");
+
+            RuleFor(x => x.CommandTimeout)
+                .LessThanOrEqualTo(300)
+                .WithMessage("Command timeout must be less than or equal to 300 seconds");
+        }
+
+        public ValidateOptionsResult Validate(string? name, DatabaseSettings options)
+        {
+            var result = Validate(options);
+            if (result.IsValid)
+            {
+                return ValidateOptionsResult.Success;
+            }
+
+            var errors = result.Errors.Select(e => e.ErrorMessage).ToArray();
+            return ValidateOptionsResult.Fail(errors);
+        }
+    }
+}

ChatBot/Models/Entities/ChatMessageEntity.cs

@@ -0,0 +1,61 @@
+using System.ComponentModel.DataAnnotations;
+using System.ComponentModel.DataAnnotations.Schema;
+
+namespace ChatBot.Models.Entities
+{
+    /// <summary>
+    /// Entity model for chat message stored in database
+    /// </summary>
+    [Table("chat_messages")]
+    public class ChatMessageEntity
+    {
+        /// <summary>
+        /// Primary key
+        /// </summary>
+        [Key]
+        [Column("id")]
+        public int Id { get; set; }
+
+        /// <summary>
+        /// Foreign key to chat session
+        /// </summary>
+        [Required]
+        [Column("session_id")]
+        public int SessionId { get; set; }
+
+        /// <summary>
+        /// The content of the message
+        /// </summary>
+        [Required]
+        [Column("content")]
+        [StringLength(10000)]
+        public string Content { get; set; } = string.Empty;
+
+        /// <summary>
+        /// The role of the message author (system, user, assistant)
+        /// </summary>
+        [Required]
+        [Column("role")]
+        [StringLength(20)]
+        public string Role { get; set; } = string.Empty;
+
+        /// <summary>
+        /// When the message was created
+        /// </summary>
+        [Required]
+        [Column("created_at")]
+        public DateTime CreatedAt { get; set; } = DateTime.UtcNow;
+
+        /// <summary>
+        /// Order of the message in the conversation
+        /// </summary>
+        [Column("message_order")]
+        public int MessageOrder { get; set; }
+
+        /// <summary>
+        /// Navigation property to chat session
+        /// </summary>
+        [ForeignKey("SessionId")]
+        public virtual ChatSessionEntity Session { get; set; } = null!;
+    }
+}

ChatBot/Models/Entities/ChatSessionEntity.cs

@@ -0,0 +1,82 @@
+using System.ComponentModel.DataAnnotations;
+using System.ComponentModel.DataAnnotations.Schema;
+
+namespace ChatBot.Models.Entities
+{
+    /// <summary>
+    /// Entity model for chat session stored in database
+    /// </summary>
+    [Table("chat_sessions")]
+    public class ChatSessionEntity
+    {
+        /// <summary>
+        /// Primary key
+        /// </summary>
+        [Key]
+        [Column("id")]
+        public int Id { get; set; }
+
+        /// <summary>
+        /// Unique identifier for the chat session
+        /// </summary>
+        [Required]
+        [Column("session_id")]
+        [StringLength(50)]
+        public string SessionId { get; set; } = string.Empty;
+
+        /// <summary>
+        /// Telegram chat ID (can be private chat or group chat)
+        /// </summary>
+        [Required]
+        [Column("chat_id")]
+        public long ChatId { get; set; }
+
+        /// <summary>
+        /// Chat type (private, group, supergroup, channel)
+        /// </summary>
+        [Required]
+        [Column("chat_type")]
+        [StringLength(20)]
+        public string ChatType { get; set; } = "private";
+
+        /// <summary>
+        /// Chat title (for groups)
+        /// </summary>
+        [Column("chat_title")]
+        [StringLength(200)]
+        public string ChatTitle { get; set; } = string.Empty;
+
+        /// <summary>
+        /// AI model to use for this session
+        /// </summary>
+        [Column("model")]
+        [StringLength(100)]
+        public string Model { get; set; } = string.Empty;
+
+        /// <summary>
+        /// When the session was created
+        /// </summary>
+        [Required]
+        [Column("created_at")]
+        public DateTime CreatedAt { get; set; } = DateTime.UtcNow;
+
+        /// <summary>
+        /// When the session was last updated
+        /// </summary>
+        [Required]
+        [Column("last_updated_at")]
+        public DateTime LastUpdatedAt { get; set; } = DateTime.UtcNow;
+
+        /// <summary>
+        /// Maximum number of messages to keep in history
+        /// </summary>
+        [Column("max_history_length")]
+        public int MaxHistoryLength { get; set; } = 30;
+
+        /// <summary>
+        /// Navigation property for messages
+        /// </summary>
+        public virtual ICollection<ChatMessageEntity> Messages { get; set; } =
+            new List<ChatMessageEntity>();
+    }
+}

ChatBot/Program.cs

@@ -1,3 +1,6 @@
+using ChatBot.Data;
+using ChatBot.Data.Interfaces;
+using ChatBot.Data.Repositories;
 using ChatBot.Models.Configuration;
 using ChatBot.Models.Configuration.Validators;
 using ChatBot.Services;
@@ -6,6 +9,7 @@ using ChatBot.Services.Interfaces;
 using ChatBot.Services.Telegram.Commands;
 using ChatBot.Services.Telegram.Interfaces;
 using ChatBot.Services.Telegram.Services;
+using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.Options;
 using Serilog;
 using Telegram.Bot;
@@ -35,10 +39,15 @@ try
         .Services.Configure<AISettings>(builder.Configuration.GetSection("AI"))
         .AddSingleton<IValidateOptions<AISettings>, AISettingsValidator>();
 
+    builder
+        .Services.Configure<DatabaseSettings>(builder.Configuration.GetSection("Database"))
+        .AddSingleton<IValidateOptions<DatabaseSettings>, DatabaseSettingsValidator>();
+
     // Валидируем конфигурацию при старте
     builder.Services.AddOptions<TelegramBotSettings>().ValidateOnStart();
     builder.Services.AddOptions<OllamaSettings>().ValidateOnStart();
     builder.Services.AddOptions<AISettings>().ValidateOnStart();
+    builder.Services.AddOptions<DatabaseSettings>().ValidateOnStart();
 
     // Регистрируем IOllamaClient
     builder.Services.AddSingleton<IOllamaClient>(sp =>
@@ -47,22 +56,49 @@ try
         return new OllamaClientAdapter(settings.Value.Url);
     });
 
+    // Регистрируем Entity Framework и базу данных
+    builder.Services.AddDbContext<ChatBotDbContext>(
+        (serviceProvider, options) =>
+        {
+            var dbSettings = serviceProvider.GetRequiredService<IOptions<DatabaseSettings>>().Value;
+            options.UseNpgsql(
+                dbSettings.ConnectionString,
+                npgsqlOptions =>
+                {
+                    npgsqlOptions.CommandTimeout(dbSettings.CommandTimeout);
+                }
+            );
+
+            if (dbSettings.EnableSensitiveDataLogging)
+            {
+                options.EnableSensitiveDataLogging();
+            }
+        }
+    );
+
+    // Регистрируем репозиторий
+    builder.Services.AddScoped<IChatSessionRepository, ChatSessionRepository>();
+
     // Регистрируем интерфейсы и сервисы
-    builder.Services.AddSingleton<ISessionStorage, InMemorySessionStorage>();
+    // Можно переключиться между InMemorySessionStorage и DatabaseSessionStorage
+    builder.Services.AddScoped<ISessionStorage, DatabaseSessionStorage>();
 
     // Регистрируем основные сервисы
     builder.Services.AddSingleton<ModelService>();
     builder.Services.AddSingleton<SystemPromptService>();
     builder.Services.AddSingleton<IHistoryCompressionService, HistoryCompressionService>();
     builder.Services.AddSingleton<IAIService, AIService>();
-    builder.Services.AddSingleton<ChatService>();
+    builder.Services.AddScoped<ChatService>();
+
+    // Регистрируем сервис инициализации базы данных
+    builder.Services.AddHostedService<DatabaseInitializationService>();
 
     // Регистрируем Telegram команды
-    builder.Services.AddSingleton<ITelegramCommand, StartCommand>();
+    builder.Services.AddScoped<ITelegramCommand, StartCommand>();
-    builder.Services.AddSingleton<ITelegramCommand, HelpCommand>();
+    builder.Services.AddScoped<ITelegramCommand, HelpCommand>();
-    builder.Services.AddSingleton<ITelegramCommand, ClearCommand>();
+    builder.Services.AddScoped<ITelegramCommand, ClearCommand>();
-    builder.Services.AddSingleton<ITelegramCommand, SettingsCommand>();
+    builder.Services.AddScoped<ITelegramCommand, SettingsCommand>();
-    builder.Services.AddSingleton<ITelegramCommand, StatusCommand>();
+    builder.Services.AddScoped<ITelegramCommand, StatusCommand>();
 
     // Регистрируем Telegram сервисы
     builder.Services.AddSingleton<ITelegramBotClient>(provider =>
@@ -72,17 +108,24 @@ try
     });
     builder.Services.AddSingleton<ITelegramMessageSender, TelegramMessageSender>();
     builder.Services.AddSingleton<ITelegramErrorHandler, TelegramErrorHandler>();
-    builder.Services.AddSingleton<CommandRegistry>();
+    builder.Services.AddScoped<CommandRegistry>();
     builder.Services.AddSingleton<BotInfoService>();
-    builder.Services.AddSingleton<ITelegramCommandProcessor, TelegramCommandProcessor>();
+    builder.Services.AddScoped<ITelegramCommandProcessor, TelegramCommandProcessor>();
-    builder.Services.AddSingleton<ITelegramMessageHandler, TelegramMessageHandler>();
+    builder.Services.AddScoped<ITelegramMessageHandler, TelegramMessageHandler>();
 
-    // Регистрируем TelegramBotService как singleton и используем один экземпляр для интерфейса и HostedService
+    // Регистрируем TelegramBotService как scoped и используем один экземпляр для интерфейса и HostedService
-    builder.Services.AddSingleton<TelegramBotService>();
+    builder.Services.AddScoped<TelegramBotService>();
-    builder.Services.AddSingleton<ITelegramBotService>(sp =>
+    builder.Services.AddScoped<ITelegramBotService>(sp =>
         sp.GetRequiredService<TelegramBotService>()
     );
-    builder.Services.AddHostedService(sp => sp.GetRequiredService<TelegramBotService>());
+
+    // Создаем обертку для HostedService, которая создает scope
+    builder.Services.AddSingleton<IHostedService>(sp =>
+    {
+        var serviceProvider = sp.GetRequiredService<IServiceProvider>();
+        var logger = sp.GetRequiredService<ILogger<TelegramBotHostedService>>();
+        return new TelegramBotHostedService(serviceProvider, logger);
+    });
 
     // Регистрируем Health Checks
     builder

ChatBot/Services/ChatService.cs

@@ -83,6 +83,9 @@ namespace ChatBot.Services
                     session.AddUserMessage(message, username);
                 }
 
+                // Save session changes to database
+                await _sessionStorage.SaveSessionAsync(session);
+
                 _logger.LogInformation(
                     "Processing message from user {Username} in chat {ChatId} ({ChatType}): {Message}",
                     username,
@@ -130,6 +133,9 @@ namespace ChatBot.Services
                         session.AddAssistantMessage(response);
                     }
 
+                    // Save session changes to database
+                    await _sessionStorage.SaveSessionAsync(session);
+
                     _logger.LogDebug(
                         "AI response generated for chat {ChatId} (length: {Length})",
                         chatId,
@@ -149,7 +155,7 @@ namespace ChatBot.Services
         /// <summary>
         /// Update session parameters
         /// </summary>
-        public void UpdateSessionParameters(long chatId, string? model = null)
+        public async Task UpdateSessionParametersAsync(long chatId, string? model = null)
         {
             var session = _sessionStorage.Get(chatId);
             if (session != null)
@@ -158,6 +164,10 @@ namespace ChatBot.Services
                     session.Model = model;
 
                 session.LastUpdatedAt = DateTime.UtcNow;
+
+                // Save session changes to database
+                await _sessionStorage.SaveSessionAsync(session);
+
                 _logger.LogInformation("Updated session parameters for chat {ChatId}", chatId);
             }
         }
@@ -165,12 +175,16 @@ namespace ChatBot.Services
         /// <summary>
         /// Clear chat history for a session
         /// </summary>
-        public void ClearHistory(long chatId)
+        public async Task ClearHistoryAsync(long chatId)
         {
             var session = _sessionStorage.Get(chatId);
             if (session != null)
             {
                 session.ClearHistory();
+
+                // Save session changes to database
+                await _sessionStorage.SaveSessionAsync(session);
+
                 _logger.LogInformation("Cleared history for chat {ChatId}", chatId);
             }
         }

ChatBot/Services/DatabaseInitializationService.cs

@@ -0,0 +1,74 @@
+using ChatBot.Data;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Logging;
+
+namespace ChatBot.Services
+{
+    /// <summary>
+    /// Service for initializing database on application startup
+    /// </summary>
+    public class DatabaseInitializationService : IHostedService
+    {
+        private readonly IServiceProvider _serviceProvider;
+        private readonly ILogger<DatabaseInitializationService> _logger;
+
+        public DatabaseInitializationService(
+            IServiceProvider serviceProvider,
+            ILogger<DatabaseInitializationService> logger
+        )
+        {
+            _serviceProvider = serviceProvider;
+            _logger = logger;
+        }
+
+        public async Task StartAsync(CancellationToken cancellationToken)
+        {
+            _logger.LogInformation("Starting database initialization...");
+
+            using var scope = _serviceProvider.CreateScope();
+            var context = scope.ServiceProvider.GetRequiredService<ChatBotDbContext>();
+
+            try
+            {
+                // Check if database exists and is accessible
+                var canConnect = await context.Database.CanConnectAsync(cancellationToken);
+                if (!canConnect)
+                {
+                    _logger.LogInformation(
+                        "Database does not exist. Creating database and applying migrations..."
+                    );
+                }
+                else
+                {
+                    _logger.LogInformation("Database exists. Applying migrations...");
+                }
+
+                // Ensure database is created and migrations are applied
+                await context.Database.MigrateAsync(cancellationToken);
+
+                _logger.LogInformation("Database initialization completed successfully");
+            }
+            catch (Exception ex)
+                when (ex.Message.Contains("database") && ex.Message.Contains("does not exist"))
+            {
+                // This is expected when database doesn't exist - MigrateAsync will create it
+                _logger.LogInformation("Database does not exist, will be created during migration");
+                await context.Database.MigrateAsync(cancellationToken);
+                _logger.LogInformation("Database initialization completed successfully");
+            }
+            catch (Exception ex)
+            {
+                _logger.LogError(ex, "Failed to initialize database");
+                throw new InvalidOperationException("Database initialization failed", ex);
+            }
+        }
+
+        public Task StopAsync(CancellationToken cancellationToken)
+        {
+            _logger.LogInformation("Database initialization service stopped");
+            return Task.CompletedTask;
+        }
+    }
+}

ChatBot/Services/DatabaseSessionStorage.cs

@@ -0,0 +1,189 @@
+using ChatBot.Data.Interfaces;
+using ChatBot.Models;
+using ChatBot.Models.Dto;
+using ChatBot.Models.Entities;
+using ChatBot.Services.Interfaces;
+using OllamaSharp.Models.Chat;
+
+namespace ChatBot.Services
+{
+    /// <summary>
+    /// Database implementation of session storage
+    /// </summary>
+    public class DatabaseSessionStorage : ISessionStorage
+    {
+        private readonly IChatSessionRepository _repository;
+        private readonly ILogger<DatabaseSessionStorage> _logger;
+        private readonly IHistoryCompressionService? _compressionService;
+
+        public DatabaseSessionStorage(
+            IChatSessionRepository repository,
+            ILogger<DatabaseSessionStorage> logger,
+            IHistoryCompressionService? compressionService = null
+        )
+        {
+            _repository = repository;
+            _logger = logger;
+            _compressionService = compressionService;
+        }
+
+        public ChatSession GetOrCreate(
+            long chatId,
+            string chatType = "private",
+            string chatTitle = ""
+        )
+        {
+            try
+            {
+                var sessionEntity = _repository
+                    .GetOrCreateAsync(chatId, chatType, chatTitle)
+                    .GetAwaiter()
+                    .GetResult();
+                return ConvertToChatSession(sessionEntity);
+            }
+            catch (Exception ex)
+            {
+                _logger.LogError(ex, "Failed to get or create session for chat {ChatId}", chatId);
+                throw new InvalidOperationException(
+                    $"Failed to get or create session for chat {chatId}",
+                    ex
+                );
+            }
+        }
+
+        public ChatSession? Get(long chatId)
+        {
+            try
+            {
+                var sessionEntity = _repository.GetByChatIdAsync(chatId).GetAwaiter().GetResult();
+                return sessionEntity != null ? ConvertToChatSession(sessionEntity) : null;
+            }
+            catch (Exception ex)
+            {
+                _logger.LogError(ex, "Failed to get session for chat {ChatId}", chatId);
+                return null;
+            }
+        }
+
+        public bool Remove(long chatId)
+        {
+            try
+            {
+                return _repository.DeleteAsync(chatId).GetAwaiter().GetResult();
+            }
+            catch (Exception ex)
+            {
+                _logger.LogError(ex, "Failed to remove session for chat {ChatId}", chatId);
+                return false;
+            }
+        }
+
+        public int GetActiveSessionsCount()
+        {
+            try
+            {
+                return _repository.GetActiveSessionsCountAsync().GetAwaiter().GetResult();
+            }
+            catch (Exception ex)
+            {
+                _logger.LogError(ex, "Failed to get active sessions count");
+                return 0;
+            }
+        }
+
+        public int CleanupOldSessions(int hoursOld = 24)
+        {
+            try
+            {
+                return _repository.CleanupOldSessionsAsync(hoursOld).GetAwaiter().GetResult();
+            }
+            catch (Exception ex)
+            {
+                _logger.LogError(ex, "Failed to cleanup old sessions");
+                return 0;
+            }
+        }
+
+        /// <summary>
+        /// Save session changes to database
+        /// </summary>
+        public async Task SaveSessionAsync(ChatSession session)
+        {
+            try
+            {
+                var sessionEntity = await _repository.GetByChatIdAsync(session.ChatId);
+                if (sessionEntity == null)
+                {
+                    _logger.LogWarning(
+                        "Session not found for chat {ChatId} during save",
+                        session.ChatId
+                    );
+                    return;
+                }
+
+                // Update session properties
+                sessionEntity.Model = session.Model;
+                sessionEntity.MaxHistoryLength = session.MaxHistoryLength;
+                sessionEntity.LastUpdatedAt = DateTime.UtcNow;
+
+                // Clear existing messages and add new ones
+                await _repository.ClearMessagesAsync(sessionEntity.Id);
+
+                var messages = session.GetAllMessages();
+                for (int i = 0; i < messages.Count; i++)
+                {
+                    await _repository.AddMessageAsync(
+                        sessionEntity.Id,
+                        messages[i].Content,
+                        messages[i].Role.ToString(),
+                        i
+                    );
+                }
+
+                await _repository.UpdateAsync(sessionEntity);
+            }
+            catch (Exception ex)
+            {
+                _logger.LogError(ex, "Failed to save session for chat {ChatId}", session.ChatId);
+                throw new InvalidOperationException(
+                    $"Failed to save session for chat {session.ChatId}",
+                    ex
+                );
+            }
+        }
+
+        /// <summary>
+        /// Convert ChatSessionEntity to ChatSession
+        /// </summary>
+        private ChatSession ConvertToChatSession(ChatSessionEntity entity)
+        {
+            var session = new ChatSession
+            {
+                SessionId = entity.SessionId,
+                ChatId = entity.ChatId,
+                ChatType = entity.ChatType,
+                ChatTitle = entity.ChatTitle,
+                Model = entity.Model,
+                CreatedAt = entity.CreatedAt,
+                LastUpdatedAt = entity.LastUpdatedAt,
+                MaxHistoryLength = entity.MaxHistoryLength,
+            };
+
+            // Set compression service if available
+            if (_compressionService != null)
+            {
+                session.SetCompressionService(_compressionService);
+            }
+
+            // Add messages to session
+            foreach (var messageEntity in entity.Messages.OrderBy(m => m.MessageOrder))
+            {
+                var role = Enum.Parse<ChatRole>(messageEntity.Role);
+                var message = new ChatMessage { Content = messageEntity.Content, Role = role };
+                session.AddMessage(message);
+            }
+
+            return session;
+        }
+    }
+}

ChatBot/Services/InMemorySessionStorage.cs

@@ -98,5 +98,12 @@ namespace ChatBot.Services
 
             return sessionsToRemove.Count;
         }
+
+        public Task SaveSessionAsync(ChatSession session)
+        {
+            // For in-memory storage, no additional save is needed
+            // The session is already in memory and will be updated automatically
+            return Task.CompletedTask;
+        }
     }
 }

ChatBot/Services/Interfaces/ISessionStorage.cs

@@ -31,5 +31,10 @@ namespace ChatBot.Services.Interfaces
         /// Clean up old sessions
         /// </summary>
         int CleanupOldSessions(int hoursOld = 24);
+
+        /// <summary>
+        /// Save session changes to storage (for database implementations)
+        /// </summary>
+        Task SaveSessionAsync(ChatSession session);
     }
 }

ChatBot/Services/Telegram/Commands/ClearCommand.cs

@@ -12,13 +12,13 @@ namespace ChatBot.Services.Telegram.Commands
         public override string CommandName => "/clear";
         public override string Description => "Очистить историю чата";
 
-        public override Task<string> ExecuteAsync(
+        public override async Task<string> ExecuteAsync(
             TelegramCommandContext context,
             CancellationToken cancellationToken = default
         )
         {
-            _chatService.ClearHistory(context.ChatId);
+            await _chatService.ClearHistoryAsync(context.ChatId);
-            return Task.FromResult("История чата очищена. Начинаем новый разговор!");
+            return "История чата очищена. Начинаем новый разговор!";
         }
     }
 }

ChatBot/Services/TelegramBotHostedService.cs

@@ -0,0 +1,46 @@
+using ChatBot.Services.Telegram.Interfaces;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Logging;
+
+namespace ChatBot.Services
+{
+    /// <summary>
+    /// Hosted service wrapper for TelegramBotService to handle scoped dependencies
+    /// </summary>
+    public class TelegramBotHostedService : IHostedService
+    {
+        private readonly IServiceProvider _serviceProvider;
+        private readonly ILogger<TelegramBotHostedService> _logger;
+        private ITelegramBotService? _botService;
+
+        public TelegramBotHostedService(
+            IServiceProvider serviceProvider,
+            ILogger<TelegramBotHostedService> logger
+        )
+        {
+            _serviceProvider = serviceProvider;
+            _logger = logger;
+        }
+
+        public async Task StartAsync(CancellationToken cancellationToken)
+        {
+            _logger.LogInformation("Starting Telegram Bot Hosted Service...");
+
+            using var scope = _serviceProvider.CreateScope();
+            _botService = scope.ServiceProvider.GetRequiredService<ITelegramBotService>();
+
+            await _botService.StartAsync(cancellationToken);
+        }
+
+        public async Task StopAsync(CancellationToken cancellationToken)
+        {
+            _logger.LogInformation("Stopping Telegram Bot Hosted Service...");
+
+            if (_botService != null)
+            {
+                await _botService.StopAsync(cancellationToken);
+            }
+        }
+    }
+}

ChatBot/appsettings.json

@@ -5,6 +5,8 @@
       "Default": "Information",
       "Override": {
         "Microsoft": "Warning",
+        "Microsoft.EntityFrameworkCore.Database.Connection": "Information",
+        "Microsoft.EntityFrameworkCore.Database.Command": "Information",
         "System": "Warning",
         "Telegram.Bot": "Information"
       }
@@ -50,5 +52,10 @@
     "MaxRetryDelayMs": 30000,
     "CompressionTimeoutSeconds": 30,
     "StatusCheckTimeoutSeconds": 10
+  },
+  "Database": {
+    "ConnectionString": "Host=localhost;Port=5432;Database=chatbot;Username=postgres;Password=postgres",
+    "EnableSensitiveDataLogging": false,
+    "CommandTimeout": 30
   }
 }